High efficiency path based power amplifier circuitry

[0001] This application claims the benefit of U.S. provisional patent application No. 61/611,694, filed Mar. 16, 2012.

[0002] The present application claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 13/656,997, filed Oct. 22, 2012, entitled “CASCADED CONVERGED POWER AMPLIFIER,” now U.S. Pat. No. 8,942,651, which claims priority to U.S. Provisional Patent Application No. 61/550,074 filed Oct. 21, 2011.

[0003] U.S. patent application Ser. No. 13/656,997 claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 13/090,663, filed Apr. 20, 2011, entitled “QUADRATURE POWER AMPLIFIER ARCHITECTURE,” now U.S. Pat. No. 8,538,355, which claims priority to U.S. Provisional Patent Application No. 61/325,859, filed Apr. 20, 2010; No. 61/359,487, filed Jun. 29, 2010; No. 61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010.

[0004] U.S. patent application Ser. No. 13/656,997 claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 13/172,371, filed Jun. 29, 2011, entitled “AUTOMATICALLY CONFIGURABLE 2-WIRE/3-WIRE SERIAL COMMUNICATIONS INTERFACE,” now U.S. Pat. No. 8,983,409, which claims priority to U.S. Provisional Patent Application No. 61/359,487, filed Jun. 29, 2010; No. 61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010. U.S. patent application Ser. No. 13/172,371 is a continuation-in-part of U.S. patent application Ser. No. 13/090,663, filed Apr. 20, 2011, which claims priority to U.S. Provisional Patent Applications No. 61/325,859, filed Apr. 20, 2010; No. 61/359,487, filed Jun. 29, 2010; No. 61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010.

[0005] U.S. patent application Ser. No. 13/656,997 claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 13/198,074, filed Aug. 4, 2011, entitled “FREQUENCY CORRECTION OF A PROGRAMMABLE FREQUENCY OSCILLATOR BY PROPAGATION DELAY COMPENSATION,” now U.S. Pat. No. 8,515,361, which claims priority to U.S. Provisional Patent Applications No. 61/370,554 filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010. U.S. patent application Ser. No. 13/198,074 is a continuation-in-part of U.S. patent application Ser. No. 13/090,663, filed Apr. 20, 2011, which claims priority to U.S. Provisional Patent Application No. 61/325,859, filed Apr. 20, 2010; No. 61/359,487, filed Jun. 29, 2010; No. 61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010. U.S. patent application Ser. No. 13/198,074 is also a continuation-in-part of U.S. patent application Ser. No. 13/172,371, filed Jun. 29, 2011, which claims priority to U.S. Provisional Patent Application No. 61/359,487, filed Jun. 29, 2010; No. 61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010.

[0006] U.S. patent application Ser. No. 13/656,997 claims priority to and is a continuation-in-part of U.S. patent application Ser. No. 13/226,831, filed Sep. 7, 2011, entitled “VOLTAGE COMPATIBLE CHARGE PUMP BUCK AND BUCK POWER SUPPLIES,” which claims priority to U.S. Provisional Patent Application No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010. U.S. patent application Ser. No. 13/226,831 is a continuation-in-part of U.S. patent application Ser. No. 13/090,663, filed Apr. 20, 2011, which claims priority to U.S. Provisional Patent Application No. 61/325,859, filed Apr. 20, 2010; No. 61/359,487, filed Jun. 29, 2010; No. 61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010. U.S. patent application Ser. No. 13/226,831 is also a continuation-in-part of U.S. patent application Ser. No. 13/172,371, filed Jun. 29, 2011, which claims priority to U.S. Provisional Patent Application No. 61/359,487, filed Jun. 29, 2010; No. 61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010. In addition, U.S. patent application Ser. No. 13/226,831 is a continuation-in-part of U.S. patent application Ser. No. 13/198,074, filed Aug. 4, 2011, which claims priority to U.S. Provisional Patent Application No. 61/370,554, filed Aug. 4, 2010; No. 61/380,522, filed Sep. 7, 2010; No. 61/410,071, filed Nov. 4, 2010; and No. 61/417,633, filed Nov. 29, 2010.

[0007] All of the applications listed above are hereby incorporated herein by reference in their entireties.

[0008] Embodiments of the present disclosure relate to radio frequency (RF) power amplifier (PA) circuitry, which may be used in RF communications systems.

[0009] As wireless communications technologies evolve, wireless communications systems become increasingly sophisticated. As such, wireless communications protocols continue to expand and change to take advantage of the technological evolution. As a result, to maximize flexibility, many wireless communications devices must be capable of supporting any number of wireless communications protocols, including protocols that operate using different communications modes, such as a half-duplex mode or a full-duplex mode, and including protocols that operate using different frequency bands. Further, the different communications modes may include different types of RF modulation modes, each of which may have certain performance requirements, such as specific out-of-band emissions requirements or symbol differentiation requirements. In this regard, certain requirements may mandate operation in a linear mode. Other requirements may be less stringent that may allow operation in a non-linear mode to increase efficiency. Wireless communications devices that support such wireless communications protocols may be referred to as multi-mode multi-band communications devices. The linear mode relates to RF signals that include amplitude modulation (AM). The non-linear mode relates to RF signals that do not include AM. Since non-linear mode RF signals do not include AM, devices that amplify such signals may be allowed to operate in saturation. Devices that amplify linear mode RF signals may operate with some level of saturation, but must be able to retain AM characteristics sufficient for proper operation.

[0010] A half-duplex mode is a two-way mode of operation, in which a first transceiver communicates with a second transceiver; however, only one transceiver transmits at a time. Therefore, the transmitter and receiver in such a transceiver do not operate simultaneously. For example, certain telemetry systems operate in a send-then-wait-for-reply manner. Many time division duplex (TDD) systems, such as certain Global System for Mobile communications (GSM) systems, operate using the half-duplex mode. A full-duplex mode is a simultaneous two-way mode of operation, in which a first transceiver communicates with a second transceiver, and both transceivers may transmit simultaneously. Therefore, the transmitter and receiver in such a transceiver must be capable of operating simultaneously. In a full-duplex transceiver, signals from the transmitter should not overly interfere with signals received by the receiver; therefore, transmitted signals are at transmit frequencies that are different from received signals, which are at receive frequencies. Many frequency division duplex (FDD) systems, such as certain wideband code division multiple access (WCDMA) systems or certain long term evolution (LTE) systems, operate using a full-duplex mode.

[0011] As a result of the differences between full-duplex operation and half-duplex operation, RF front-end circuitry may need specific circuitry for each mode. Additionally, support of multiple frequency bands may require specific circuitry for each frequency band or for certain groupings of frequency bands. FIG. 1 shows a traditional multi-mode multi-band communications device 10 according to the prior art. The traditional multi-mode multi-band communications device 10 includes a traditional multi-mode multi-band transceiver 12, traditional multi-mode multi-band PA circuitry 14, traditional multi-mode multi-band front-end aggregation circuitry 16, and an antenna 18. The traditional multi-mode multi-band PA circuitry 14 includes a first traditional PA 20, a second traditional PA 22, and up to and including an N^TH traditional PA 24.

[0012] The traditional multi-mode multi-band transceiver 12 may select one of multiple communications modes, which may include a half-duplex transmit mode, a half-duplex receive mode, a full-duplex mode, a linear mode, a non-linear mode, multiple RF modulation modes, or any combination thereof. Further, the traditional multi-mode multi-band transceiver 12 may select one of multiple frequency bands. The traditional multi-mode multi-band transceiver 12 provides an aggregation control signal ACS to the traditional multi-mode multi-band front-end aggregation circuitry 16 based on the selected mode and the selected frequency band. The traditional multi-mode multi-band front-end aggregation circuitry 16 may include various RF components, including RF switches; RF filters, such as bandpass filters, harmonic filters, and duplexers; RF amplifiers, such as low noise amplifiers (LNAs); impedance matching circuitry; the like; or any combination thereof. In this regard, routing of RF receive signals and RF transmit signals through the RF components may be based on the selected mode and the selected frequency band as directed by the aggregation control signal ACS.

[0013] The first traditional PA 20 may receive and amplify a first traditional RF transmit signal FTTX from the traditional multi-mode multi-band transceiver 12 to provide a first traditional amplified RF transmit signal FTATX to the antenna 18 via the traditional multi-mode multi-band front-end aggregation circuitry 16. The second traditional PA 22 may receive and amplify a second traditional RF transmit signal STTX from the traditional multi-mode multi-band transceiver 12 to provide a second traditional RF amplified transmit signal STATX to the antenna 18 via the traditional multi-mode multi-band front-end aggregation circuitry 16. The N^TH traditional PA 24 may receive an amplify an N^TH traditional RF transmit signal NTTX from the traditional multi-mode multi-band transceiver 12 to provide an N^TH traditional RF amplified transmit signal NTATX to the antenna 18 via the traditional multi-mode multi-band front-end aggregation circuitry 16.

[0014] The traditional multi-mode multi-band transceiver 12 may receive a first RF receive signal FRX, a second RF receive signal SRX, and up to and including an M^TH RF receive signal MRX from the antenna 18 via the traditional multi-mode multi-band front-end aggregation circuitry 16. Each of the RF receive signals FRX, SRX, MRX may be associated with at least one selected mode, at least one selected frequency band, or both. Similarly, each of the traditional RF transmit signals FTTX, STTX, NTTX and corresponding traditional amplified RF transmit signals FTATX, STATX, NTATX may be associated with at least one selected mode, at least one selected frequency band, or both.

[0015] Portable wireless communications devices are typically battery powered, need to be relatively small, and have low cost. As such, to minimize size, cost, and power consumption, multi-mode multi-band RF circuitry in such a device needs to be as simple, small, and efficient as is practical. Thus, there is a need for multi-mode multi-band RF circuitry in a multi-mode multi-band communications device that is low cost, small, simple, efficient, and meets performance requirements.

[0016] Those skilled in the art will appreciate the scope of the present disclosure and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures.

[0017] Embodiments of the present disclosure relate to a first transmit path, a second transmit path, and a third transmit path. The first transmit path includes a first radio frequency (RF) power amplifier (PA) and alpha switching circuitry, which is coupled to an output from the first RF PA. The second transmit path includes a second RF PA and beta switching circuitry, which is coupled to an output from the second RF PA. The third transmit path includes a third RF PA.

[0018] In one embodiment of the present disclosure, an RF PA module includes the first transmit path, the second transmit path, and the third transmit path. In one embodiment of the first transmit path and the second transmit path, the first RF PA is a multi-mode multi-band PA, the second RF PA is a multi-mode multi-band PA, the alpha switching circuitry is multi-mode multi-band switching circuitry, and the beta switching circuitry is multi-mode multi-band switching circuitry.

[0019] Since the alpha switching circuitry is coupled to the output from the first RF PA and since the beta switching circuitry is coupled to the output from the second RF PA, both the first transmit path and the second transmit path include switching circuitry downstream from their respective RF PAs. As such, insertion losses of the alpha switching circuitry and the beta switching circuitry are applied to relatively large output signals from the first RF PA and the second RF PA, respectively. Such insertion losses may noticeably degrade efficiency of the RF PA module. Conversely, in one embodiment of the third transmit path, the third transmit path includes no switching circuitry downstream from the third RF PA. As a result, using the third transmit path while transmitting from one or more dedicated communications bands may maximize efficiency by avoiding downstream circuitry from the third RF PA.

[0222] The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the disclosure and illustrate the best mode of practicing the disclosure. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.

[0223] FIG. 2 shows an RF communications system 26 according to one embodiment of the RF communications system 26. The RF communications system 26 includes RF modulation and control circuitry 28, RF PA circuitry 30, and a DC-DC converter 32. The RF modulation and control circuitry 28 provides an envelope control signal ECS to the DC-DC converter 32 and provides an RF input signal RFI to the RF PA circuitry 30. The DC-DC converter 32 provides a bias power supply signal BPS and an envelope power supply signal EPS to the RF PA circuitry 30. The envelope power supply signal EPS may be based on the envelope control signal ECS. As such, a magnitude of the envelope power supply signal EPS may be controlled by the RF modulation and control circuitry 28 via the envelope control signal ECS. The RF PA circuitry 30 may receive and amplify the RF input signal RFI to provide an RF output signal RFO. The envelope power supply signal EPS may provide power for amplification of the RF input signal RFI to the RF PA circuitry 30. The RF PA circuitry 30 may use the bias power supply signal BPS to provide biasing of amplifying elements in the RF PA circuitry 30.

[0224] In a first embodiment of the RF communications system 26, the RF communications system 26 is a multi-mode RF communications system 26. As such, the RF communications system 26 may operate using multiple communications modes. In this regard, the RF modulation and control circuitry 28 may be multi-mode RF modulation and control circuitry 28 and the RF PA circuitry 30 may be multi-mode RF PA circuitry 30. In a second embodiment of the RF communications system 26, the RF communications system 26 is a multi-band RF communications system 26. As such, the RF communications system 26 may operate using multiple RF communications bands. In this regard, the RF modulation and control circuitry 28 may be multi-band RF modulation and control circuitry 28 and the RF PA circuitry 30 may be multi-band RF PA circuitry 30. In a third embodiment of the RF communications system 26, the RF communications system 26 is a multi-mode multi-band RF communications system 26. As such, the RF communications system 26 may operate using multiple communications modes, multiple RF communications bands, or both. In this regard, the RF modulation and control circuitry 28 may be multi-mode multi-band RF modulation and control circuitry 28 and the RF PA circuitry 30 may be multi-mode multi-band RF PA circuitry 30.

[0225] The communications modes may be associated with any number of different communications protocols, such as Global System of Mobile communications (GSM), Gaussian Minimum Shift Keying (GMSK), IS-136, Enhanced Data rates for GSM Evolution (EDGE), Code Division Multiple Access (CDMA), Universal Mobile Telecommunications System (UMTS) protocols, such as Wideband CDMA (WCDMA), Worldwide Interoperability for Microwave Access (WIMAX), Long Term Evolution (LTE), or the like. The GSM, GMSK, and IS-136 protocols typically do not include amplitude modulation (AM). As such, the GSM, GMSK, and IS-136 protocols may be associated with a non-linear mode. Further, the GSM, GMSK, and IS-136 protocols may be associated with a saturated mode. The EDGE, CDMA, UMTS, WCDMA, WIMAX, and LTE protocols may include AM. As such, the EDGE, CDMA, UMTS, WCDMA, WIMAX, and LTE protocols may be associated with a linear mode.

[0226] In one embodiment of the RF communications system 26, the RF communications system 26 is a mobile communications terminal, such as a cell phone, smartphone, laptop computer, tablet computer, personal digital assistant (PDA), or the like. In an alternate embodiment of the RF communications system 26, the RF communications system 26 is a fixed communications terminal, such as a base station, a cellular base station, a wireless router, a hotspot distribution node, a wireless access point, or the like. The antenna 18 may include any apparatus for conveying RF transmit and RF receive signals to and from at least one other RF communications system. As such, in one embodiment of the antenna 18, the antenna 18 is a single antenna. In an alternate embodiment of the antenna 18, the antenna 18 is an antenna array having multiple radiating and receiving elements. In an additional embodiment of the antenna 18, the antenna 18 is a distribution system for transmitting and receiving RF signals.

[0227] FIG. 3 shows the RF communications system 26 according to an alternate embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 3 is similar to the RF communications system 26 illustrated in FIG. 2, except in the RF communications system 26 illustrated in FIG. 3, the RF modulation and control circuitry 28 provides a first RF input signal FRFI, a second RF input signal SRFI, and a PA configuration control signal PCC to the RF PA circuitry 30. The RF PA circuitry 30 may receive and amplify the first RF input signal FRFI to provide a first RF output signal FRFO. The envelope power supply signal EPS may provide power for amplification of the first RF input signal FRFI to the RF PA circuitry 30. The RF PA circuitry 30 may receive and amplify the second RF input signal SRFI to provide a second RF output signal SRFO. The envelope power supply signal EPS may provide power for amplification of the second RF output signal SRFO to the RF PA circuitry 30. Certain configurations of the RF PA circuitry 30 may be based on the PA configuration control signal PCC. As a result, the RF modulation and control circuitry 28 may control such configurations of the RF PA circuitry 30.

[0228] FIG. 4 shows the RF communications system 26 according to an additional embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 4 is similar to the RF communications system 26 illustrated in FIG. 3, except in the RF communications system 26 illustrated in FIG. 4, the RF PA circuitry 30 does not provide the first RF output signal FRFO and the second RF output signal SRFO. Instead, the RF PA circuitry 30 may provide one of a first alpha RF transmit signal FATX, a second alpha RF transmit signal SATX, and up to and including a P^TH alpha RF transmit signal PATX based on receiving and amplifying the first RF input signal FRFI. Similarly, the RF PA circuitry 30 may provide one of a first beta RF transmit signal FBTX, a second beta RF transmit signal SBTX, and up to and including a Q^TH beta RF transmit signal QBTX based on receiving and amplifying the second RF input signal SRFI. The one of the transmit signals FATX, SATX, PATX, FBTX, SBTX, QBTX that is selected may be based on the PA configuration control signal PCC. Additionally, the RF modulation and control circuitry 28 may provide a DC configuration control signal DCC to the DC-DC converter 32. Certain configurations of the DC-DC converter 32 may be based on the DC configuration control signal DCC.

[0229] FIG. 5 shows the RF communications system 26 according to another embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 5 shows details of the RF modulation and control circuitry 28 and the RF PA circuitry 30 illustrated in FIG. 4. Additionally, the RF communications system 26 illustrated in FIG. 5 further includes transceiver circuitry 34, front-end aggregation circuitry 36, and the antenna 18. The transceiver circuitry 34 includes down-conversion circuitry 38, baseband processing circuitry 40, and the RF modulation and control circuitry 28, which includes control circuitry 42 and RF modulation circuitry 44. The RF PA circuitry 30 includes a first transmit path 46 and a second transmit path 48. The first transmit path 46 includes a first RF PA 50 and alpha switching circuitry 52. The second transmit path 48 includes a second RF PA 54 and beta switching circuitry 56. The front-end aggregation circuitry 36 is coupled to the antenna 18. The control circuitry 42 provides the aggregation control signal ACS to the front-end aggregation circuitry 36. Configuration of the front-end aggregation circuitry 36 may be based on the aggregation control signal ACS. As such, configuration of the front-end aggregation circuitry 36 may be controlled by the control circuitry 42 via the aggregation control signal ACS.

[0230] The control circuitry 42 provides the envelope control signal ECS and the DC configuration control signal DCC to the DC-DC converter 32. Further, the control circuitry 42 provides the PA configuration control signal PCC to the RF PA circuitry 30. As such, the control circuitry 42 may control configuration of the RF PA circuitry 30 via the PA configuration control signal PCC and may control a magnitude of the envelope power supply signal EPS via the envelope control signal ECS. The control circuitry 42 may select one of multiple communications modes, which may include a first half-duplex transmit mode, a first half-duplex receive mode, a second half-duplex transmit mode, a second half-duplex receive mode, a first full-duplex mode, a second full-duplex mode, at least one linear mode, at least one non-linear mode, multiple RF modulation modes, or any combination thereof. Further, the control circuitry 42 may select one of multiple frequency bands. The control circuitry 42 may provide the aggregation control signal ACS to the front-end aggregation circuitry 36 based on the selected mode and the selected frequency band. The front-end aggregation circuitry 36 may include various RF components, including RF switches; RF filters, such as bandpass filters, harmonic filters, and duplexers; RF amplifiers, such as low noise amplifiers (LNAs); impedance matching circuitry; the like; or any combination thereof. In this regard, routing of RF receive signals and RF transmit signals through the RF components may be based on the selected mode and the selected frequency band as directed by the aggregation control signal ACS.

[0231] The down-conversion circuitry 38 may receive the first RF receive signal FRX, the second RF receive signal SRX, and up to and including the M^TH RF receive signal MRX from the antenna 18 via the front-end aggregation circuitry 36. Each of the RF receive signals FRX, SRX, MRX may be associated with at least one selected mode, at least one selected frequency band, or both. The down-conversion circuitry 38 may down-convert any of the RF receive signals FRX, SRX, MRX to baseband receive signals, which may be forwarded to the baseband processing circuitry 40 for processing. The baseband processing circuitry 40 may provide baseband transmit signals to the RF modulation circuitry 44, which may RF modulate the baseband transmit signals to provide the first RF input signal FRFI or the second RF input signal SRFI to the first RF PA 50 or the second RF PA 54, respectively, depending on the selected communications mode.

[0232] The first RF PA 50 may receive and amplify the first RF input signal FRFI to provide the first RF output signal FRFO to the alpha switching circuitry 52. Similarly, the second RF PA 54 may receive and amplify the second RF input signal SRFI to provide the second RF output signal SRFO to the beta switching circuitry 56. The first RF PA 50 and the second RF PA 54 may receive the envelope power supply signal EPS, which may provide power for amplification of the first RF input signal FRFI and the second RF input signal SRFI, respectively. The alpha switching circuitry 52 may forward the first RF output signal FRFO to provide one of the alpha transmit signals FATX, SATX, PATX to the antenna 18 via the front-end aggregation circuitry 36, depending on the selected communications mode based on the PA configuration control signal PCC. Similarly, the beta switching circuitry 56 may forward the second RF output signal SRFO to provide one of the beta transmit signals FBTX, SBTX, QBTX to the antenna 18 via the front-end aggregation circuitry 36, depending on the selected communications mode based on the PA configuration control signal PCC.

[0233] FIG. 6 shows the RF communications system 26 according to a further embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 6 is similar to the RF communications system 26 illustrated in FIG. 5, except in the RF communications system 26 illustrated in FIG. 6, the transceiver circuitry 34 includes a control circuitry digital communications interface (DCI) 58, the RF PA circuitry 30 includes a PA-DCI 60, the DC-DC converter 32 includes a DC-DC converter DCI 62, and the front-end aggregation circuitry 36 includes an aggregation circuitry DCI 64. The front-end aggregation circuitry 36 includes an antenna port AP, which is coupled to the antenna 18. In one embodiment of the RF communications system 26, the antenna port AP is directly coupled to the antenna 18. In one embodiment of the RF communications system 26, the front-end aggregation circuitry 36 is coupled between the alpha switching circuitry 52 and the antenna port AP. Further, the front-end aggregation circuitry 36 is coupled between the beta switching circuitry 56 and the antenna port AP. The alpha switching circuitry 52 may be multi-mode multi-band alpha switching circuitry and the beta switching circuitry 56 may be multi-mode multi-band beta switching circuitry.

[0234] The DCIs 58, 60, 62, 64 are coupled to one another using a digital communications bus 66. In the digital communications bus 66 illustrated in FIG. 6, the digital communications bus 66 is a uni-directional bus in which the control circuitry DCI 58 may communicate information to the PA-DCI 60, the DC-DC converter DCI 62, the aggregation circuitry DCI 64, or any combination thereof. As such, the control circuitry 42 may provide the envelope control signal ECS and the DC configuration control signal DCC via the control circuitry DCI 58 to the DC-DC converter 32 via the DC-DC converter DCI 62. Similarly, the control circuitry 42 may provide the aggregation control signal ACS via the control circuitry DCI 58 to the front-end aggregation circuitry 36 via the aggregation circuitry DCI 64. Additionally, the control circuitry 42 may provide the PA configuration control signal PCC via the control circuitry DCI 58 to the RF PA circuitry 30 via the PA-DCI 60.

[0235] FIG. 7 shows the RF communications system 26 according to one embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 7 is similar to the RF communications system 26 illustrated in FIG. 6, except in the RF communications system 26 illustrated in FIG. 7, the digital communications bus 66 is a bi-directional bus and each of the DCIs 58, 60, 62, 64 is capable of receiving or transmitting information. In alternate embodiments of the RF communications system 26, any or all of the DCIs 58, 60, 62, 64 may be uni-directional and any or all of the DCIs 58, 60, 62, 64 may be bi-directional.

[0236] FIG. 8 shows details of the RF PA circuitry 30 illustrated in FIG. 5 according to one embodiment of the RF PA circuitry 30. Specifically, FIG. 8 shows details of the alpha switching circuitry 52 and the beta switching circuitry 56 according to one embodiment of the alpha switching circuitry 52 and the beta switching circuitry 56. The alpha switching circuitry 52 includes an alpha RF switch 68 and a first alpha harmonic filter 70. The beta switching circuitry 56 includes a beta RF switch 72 and a first beta harmonic filter 74. Configuration of the alpha RF switch 68 and the beta RF switch 72 may be based on the PA configuration control signal PCC. In one communications mode, such as an alpha half-duplex transmit mode, an alpha saturated mode, or an alpha non-linear mode, the alpha RF switch 68 is configured to forward the first RF output signal FRFO to provide the first alpha RF transmit signal FATX via the first alpha harmonic filter 70. In another communications mode, such as an alpha full-duplex mode or an alpha linear mode, the alpha RF switch 68 is configured to forward the first RF output signal FRFO to provide any of the second alpha RF transmit signal SATX through the P^TH alpha RF transmit signal PATX. When a specific RF band is selected, the alpha RF switch 68 may be configured to provide a corresponding selected one of the second alpha RF transmit signal SATX through the P^TH alpha RF transmit signal PATX.

[0237] In one communications mode, such as a beta half-duplex transmit mode, a beta saturated mode, or a beta non-linear mode, the beta RF switch 72 is configured to forward the second RF output signal SRFO to provide the first beta RF transmit signal FBTX via the first beta harmonic filter 74. In another communications mode, such as a beta full-duplex mode or a beta linear mode, the beta RF switch 72 is configured to forward the second RF output signal SRFO to provide any of the second beta RF transmit signal SBTX through the Q^TH beta RF transmit signal QBTX. When a specific RF band is selected, beta RF switch 72 may be configured to provide a corresponding selected one of the second beta RF transmit signal SBTX through the Q^TH beta RF transmit signal QBTX. The first alpha harmonic filter 70 may be used to filter out harmonics of an RF carrier in the first RF output signal FRFO. The first beta harmonic filter 74 may be used to filter out harmonics of an RF carrier in the second RF output signal SRFO.

[0238] FIG. 9 shows details of the RF PA circuitry 30 illustrated in FIG. 5 according to an alternate embodiment of the RF PA circuitry 30. Specifically, FIG. 9 shows details of the alpha switching circuitry 52 and the beta switching circuitry 56 according to an alternate embodiment of the alpha switching circuitry 52 and the beta switching circuitry 56. The alpha switching circuitry 52 includes the alpha RF switch 68, the first alpha harmonic filter 70, and a second alpha harmonic filter 76. The beta switching circuitry 56 includes the beta RF switch 72, the first beta harmonic filter 74, and a second beta harmonic filter 78. Configuration of the alpha RF switch 68 and the beta RF switch 72 may be based on the PA configuration control signal PCC. In one communications mode, such as a first alpha half-duplex transmit mode, a first alpha saturated mode, or a first alpha non-linear mode, the alpha RF switch 68 is configured to forward the first RF output signal FRFO to provide the first alpha RF transmit signal FATX via the first alpha harmonic filter 70. In another communications mode, such as a second alpha half-duplex transmit mode, a second alpha saturated mode, or a second alpha non-linear mode, the alpha RF switch 68 is configured to forward the first RF output signal FRFO to provide the second alpha RF transmit signal SATX via the second alpha harmonic filter 76. In an alternate communications mode, such as an alpha full-duplex mode or an alpha linear mode, the alpha RF switch 68 is configured to forward the first RF output signal FRFO to provide any of a third alpha RF transmit signal TATX through the P^TH alpha RF transmit signal PATX. When a specific RF band is selected, the alpha RF switch 68 may be configured to provide a corresponding selected one of the third alpha RF transmit signal TATX through the P^TH alpha RF transmit signal PATX.

[0239] In one communications mode, such as a first beta half-duplex transmit mode, a first beta saturated mode, or a first beta non-linear mode, the beta RF switch 72 is configured to forward the second RF output signal SRFO to provide the first beta RF transmit signal FBTX via the first beta harmonic filter 74. In another communications mode, such as a second beta half-duplex transmit mode, a second beta saturated mode, or a second beta non-linear mode, the beta RF switch 72 is configured to forward the second RF output signal SRFO to provide the second beta RF transmit signal SBTX via the second beta harmonic filter 78. In an alternate communications mode, such as a beta full-duplex mode or a beta linear mode, the beta RF switch 72 is configured to forward the second RF output signal SRFO to provide any of a third beta RF transmit signal TBTX through the Q^TH beta RF transmit signal QBTX. When a specific RF band is selected, the beta RF switch 72 may be configured to provide a corresponding selected one of the third beta RF transmit signal TBTX through the Q^TH beta RF transmit signal QBTX. The first alpha harmonic filter 70 or the second alpha harmonic filter 76 may be used to filter out harmonics of an RF carrier in the first RF output signal FRFO. The first beta harmonic filter 74 or the second beta harmonic filter 78 may be used to filter out harmonics of an RF carrier in the second RF output signal SRFO.

[0240] FIG. 10 shows the RF communications system 26 according to one embodiment of the RF communications system 26. The RF communications system 26 shown in FIG. 10 is similar to the RF communications system 26 shown in FIG. 4, except the RF communications system 26 illustrated in FIG. 10 further includes a DC power supply 80 and the DC configuration control signal DCC is omitted. Additionally, details of the DC-DC converter 32 are shown according to one embodiment of the DC-DC converter 32. The DC-DC converter 32 includes first power filtering circuitry 82, a charge pump buck converter 84, a buck converter 86, second power filtering circuitry 88, a first inductive element L1, and a second inductive element L2. The DC power supply 80 provides a DC power supply signal DCPS to the charge pump buck converter 84, the buck converter 86, and the second power filtering circuitry 88. In one embodiment of the DC power supply 80, the DC power supply 80 is a battery.

[0241] The second power filtering circuitry 88 is coupled to the RF PA circuitry 30 and to the DC power supply 80. The charge pump buck converter 84 is coupled to the DC power supply 80. The first inductive element L1 is coupled between the charge pump buck converter 84 and the first power filtering circuitry 82. The buck converter 86 is coupled to the DC power supply 80. The second inductive element L2 is coupled between the buck converter 86 and the first power filtering circuitry 82. The first power filtering circuitry 82 is coupled to the RF PA circuitry 30. One end of the first inductive element L1 is coupled to one end of the second inductive element L2 at the first power filtering circuitry 82.

[0242] In one embodiment of the DC-DC converter 32, the DC-DC converter 32 operates in one of multiple converter operating modes, which include a first converter operating mode, a second converter operating mode, and a third converter operating mode. In an alternate embodiment of the DC-DC converter 32, the DC-DC converter 32 operates in one of the first converter operating mode and the second converter operating mode. In the first converter operating mode, the charge pump buck converter 84 is active, such that the envelope power supply signal EPS is based on the DC power supply signal DCPS via the charge pump buck converter 84, and the first inductive element L1. In the first converter operating mode, the buck converter 86 is inactive and does not contribute to the envelope power supply signal EPS. In the second converter operating mode, the buck converter 86 is active, such that the envelope power supply signal EPS is based on the DC power supply signal DCPS via the buck converter 86 and the second inductive element L2. In the second converter operating mode, the charge pump buck converter 84 is inactive, such that the charge pump buck converter 84 does not contribute to the envelope power supply signal EPS. In the third converter operating mode, the charge pump buck converter 84 and the buck converter 86 are active, such that either the charge pump buck converter 84; the buck converter 86; or both may contribute to the envelope power supply signal EPS. As such, in the third converter operating mode, the envelope power supply signal EPS is based on the DC power supply signal DCPS either via the charge pump buck converter 84, and the first inductive element L1; via the buck converter 86 and the second inductive element L2; or both.

[0243] The second power filtering circuitry 88 filters the DC power supply signal DCPS to provide the bias power supply signal BPS. The second power filtering circuitry 88 may function as a lowpass filter by removing ripple, noise, and the like from the DC power supply signal DCPS to provide the bias power supply signal BPS. As such, in one embodiment of the DC-DC converter 32, the bias power supply signal BPS is based on the DC power supply signal DCPS.

[0244] In the first converter operating mode or the third converter operating mode, the charge pump buck converter 84 may receive, charge pump, and buck convert the DC power supply signal DCPS to provide a first buck output signal FBO to the first inductive element L1. As such, in one embodiment of the charge pump buck converter 84, the first buck output signal FBO is based on the DC power supply signal DCPS. Further, the first inductive element L1 may function as a first energy transfer element of the charge pump buck converter 84 to transfer energy via the first buck output signal FBO to the first power filtering circuitry 82. In the first converter operating mode or the third converter operating mode, the first inductive element L1 and the first power filtering circuitry 82 may receive and filter the first buck output signal FBO to provide the envelope power supply signal EPS. The charge pump buck converter 84 may regulate the envelope power supply signal EPS by controlling the first buck output signal FBO based on a setpoint of the envelope power supply signal EPS provided by the envelope control signal ECS.

[0245] In the second converter operating mode or the third converter operating mode, the buck converter 86 may receive and buck convert the DC power supply signal DCPS to provide a second buck output signal SBO to the second inductive element L2. As such, in one embodiment of the buck converter 86, the second buck output signal SBO is based on the DC power supply signal DCPS. Further, the second inductive element L2 may function as a second energy transfer element of the buck converter 86 to transfer energy via the first power filtering circuitry 82 to the first power filtering circuitry 82. In the second converter operating mode or the third converter operating mode, the second inductive element L2 and the first power filtering circuitry 82 may receive and filter the second buck output signal SBO to provide the envelope power supply signal EPS. The buck converter 86 may regulate the envelope power supply signal EPS by controlling the second buck output signal SBO based on a setpoint of the envelope power supply signal EPS provided by the envelope control signal ECS.

[0246] In one embodiment of the charge pump buck converter 84, the charge pump buck converter 84 operates in one of multiple pump buck operating modes. During a pump buck pump-up operating mode of the charge pump buck converter 84, the charge pump buck converter 84 pumps-up the DC power supply signal DCPS to provide an internal signal (not shown), such that a voltage of the internal signal is greater than a voltage of the DC power supply signal DCPS. In an alternate embodiment of the charge pump buck converter 84, during the pump buck pump-up operating mode, a voltage of the envelope power supply signal EPS is greater than the voltage of the DC power supply signal DCPS. During a pump buck pump-down operating mode of the charge pump buck converter 84, the charge pump buck converter 84 pumps-down the DC power supply signal DCPS to provide the internal signal, such that a voltage of the internal signal is less than a voltage of the DC power supply signal DCPS. In an alternate embodiment of the charge pump buck converter 84, during the pump buck pump-down operating mode, the voltage of the envelope power supply signal EPS is less than the voltage of the DC power supply signal DCPS. During a pump buck pump-even operating mode of the charge pump buck converter 84, the charge pump buck converter 84 pumps the DC power supply signal DCPS to the internal signal, such that a voltage of the internal signal is about equal to a voltage of the DC power supply signal DCPS. One embodiment of the DC-DC converter 32 includes a pump buck bypass operating mode of the charge pump buck converter 84, such that during the pump buck bypass operating mode, the charge pump buck converter 84 by-passes charge pump circuitry (not shown) using by-pass circuitry (not shown) to forward the DC power supply signal DCPS to provide the internal signal, such that a voltage of the internal is about equal to a voltage of the DC power supply signal DCPS.

[0247] In one embodiment of the charge pump buck converter 84, the pump buck operating modes include the pump buck pump-up operating mode, the pump buck pump-down operating mode, the pump buck pump-even operating mode, and the pump buck bypass operating mode. In an alternate embodiment of the charge pump buck converter 84, the pump buck pump-even operating mode is omitted. In an additional embodiment of the charge pump buck converter 84, the pump buck bypass operating mode is omitted. In another embodiment of the charge pump buck converter 84, the pump buck pump-down operating mode is omitted. In a further embodiment of the charge pump buck converter 84, any or all of the pump buck pump-up operating mode, the pump buck pump-down operating mode, the pump buck pump-even operating mode, and the pump buck bypass operating mode are omitted. In a supplemental embodiment of the charge pump buck converter 84, the charge pump buck converter 84 operates in only the pump buck pump-up operating mode. In an additional embodiment of the charge pump buck converter 84, the charge pump buck converter 84 operates in one of the pump buck pump-up operating mode and at least one other pump buck operating mode of the charge pump buck converter 84. The at least one other pump buck operating mode of the charge pump buck converter 84 may include any or all of the pump buck pump-up operating mode, the pump buck pump-down operating mode, the pump buck pump-even operating mode, and the pump buck bypass operating mode.

[0248] FIG. 11 shows the RF communications system 26 according to an alternate embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 11 is similar to the RF communications system 26 illustrated in FIG. 10, except in the RF communications system 26 illustrated in FIG. 11, the DC-DC converter 32 further includes DC-DC control circuitry 90 and a charge pump 92, and omits the second inductive element L2. Instead of the second power filtering circuitry 88 being coupled to the DC power supply 80 as shown in FIG. 10, the charge pump 92 is coupled to the DC power supply 80, such that the charge pump 92 is coupled between the DC power supply 80 and the second power filtering circuitry 88. Additionally, the RF modulation and control circuitry 28 provides the DC configuration control signal DCC and the envelope control signal ECS to the DC-DC control circuitry 90.

[0249] The DC-DC control circuitry 90 provides a charge pump buck control signal CPBS to the charge pump buck converter 84, provides a buck control signal BCS to the buck converter 86, and provides a charge pump control signal CPS to the charge pump 92. The charge pump buck control signal CPBS, the buck control signal BCS, or both may indicate which converter operating mode is selected. Further, the charge pump buck control signal CPBS, the buck control signal BCS, or both may provide the setpoint of the envelope power supply signal EPS as provided by the envelope control signal ECS. The charge pump buck control signal CPBS may indicate which pump buck operating mode is selected.

[0250] In one embodiment of the DC-DC converter 32, selection of the converter operating mode is made by the DC-DC control circuitry 90. In an alternate embodiment of the DC-DC converter 32, selection of the converter operating mode is made by the RF modulation and control circuitry 28 and may be communicated to the DC-DC converter 32 via the DC configuration control signal DCC. In an additional embodiment of the DC-DC converter 32, selection of the converter operating mode is made by the control circuitry 42 (FIG. 5) and may be communicated to the DC-DC converter 32 via the DC configuration control signal DCC. In general, selection of the converter operating mode is made by control circuitry, which may be any of the DC-DC control circuitry 90, the RF modulation and control circuitry 28, and the control circuitry 42 (FIG. 5).

[0251] In one embodiment of the DC-DC converter 32, selection of the pump buck operating mode is made by the DC-DC control circuitry 90. In an alternate embodiment of the DC-DC converter 32, selection of the pump buck operating mode is made by the RF modulation and control circuitry 28 and communicated to the DC-DC converter 32 via the DC configuration control signal DCC. In an additional embodiment of the DC-DC converter 32, selection of the pump buck operating mode is made by the control circuitry 42 (FIG. 5) and communicated to the DC-DC converter 32 via the DC configuration control signal DCC. In general, selection of the pump buck operating mode is made by control circuitry, which may be any of the DC-DC control circuitry 90, the RF modulation and control circuitry 28, and the control circuitry 42 (FIG. 5). As such, the control circuitry may select one of the pump buck pump-up operating mode and at least one other pump buck operating mode of the charge pump buck converter 84. The at least one other pump buck operating mode of the charge pump buck converter 84 may include any or all of the pump buck pump-down operating mode, the pump buck pump-even operating mode, and the pump buck bypass operating mode.

[0252] The charge pump 92 may operate in one of multiple bias supply pump operating modes. During a bias supply pump-up operating mode of the charge pump 92, the charge pump 92 receives and pumps-up the DC power supply signal DCPS to provide the bias power supply signal BPS, such that a voltage of the bias power supply signal BPS is greater than a voltage of the DC power supply signal DCPS. During a bias supply pump-down operating mode of the charge pump 92, the charge pump 92 pumps-down the DC power supply signal DCPS to provide the bias power supply signal BPS, such that a voltage of the bias power supply signal BPS is less than a voltage of the DC power supply signal DCPS. During a bias supply pump-even operating mode of the charge pump 92, the charge pump 92 pumps the DC power supply signal DCPS to provide the bias power supply signal BPS, such that a voltage of the bias power supply signal BPS is about equal to a voltage of the DC power supply signal DCPS. One embodiment of the DC-DC converter 32 includes a bias supply bypass operating mode of the charge pump 92, such that during the bias supply bypass operating mode, the charge pump 92 by-passes charge pump circuitry (not shown) using by-pass circuitry (not shown) to forward the DC power supply signal DCPS to provide the bias power supply signal BPS, such that a voltage of the bias power supply signal BPS is about equal to a voltage of the DC power supply signal DCPS. The charge pump control signal CPS may indicate which bias supply pump operating mode is selected.

[0253] In one embodiment of the charge pump 92, the bias supply pump operating modes include the bias supply pump-up operating mode, the bias supply pump-down operating mode, the bias supply pump-even operating mode, and the bias supply bypass operating mode. In an alternate embodiment of the charge pump 92, the bias supply pump-even operating mode is omitted. In an additional embodiment of the charge pump 92, the bias supply bypass operating mode is omitted. In another embodiment of the charge pump 92, the bias supply pump-down operating mode is omitted. In a further embodiment of the charge pump 92, any or all of the bias supply pump-up operating mode, the bias supply pump-down operating mode, the bias supply pump-even operating mode, and the bias supply bypass operating mode are omitted. In a supplemental embodiment of the charge pump 92, the charge pump 92 operates in only the bias supply pump-up operating mode. In an additional embodiment of the charge pump 92, the charge pump 92 operates in the bias supply pump-up operating mode and at least one other operating mode of the charge pump 92, which may include any or all of the bias supply pump-down operating mode, the bias supply pump-even operating mode, and the bias supply bypass operating mode.

[0254] In one embodiment of the DC-DC converter 32, selection of the bias supply pump operating mode is made by the DC-DC control circuitry 90. In an alternate embodiment of the DC-DC converter 32, selection of the bias supply pump operating mode is made by the RF modulation and control circuitry 28 and communicated to the DC-DC converter 32 via the DC configuration control signal DCC. In an additional embodiment of the DC-DC converter 32, selection of the bias supply pump operating mode is made by the control circuitry 42 (FIG. 5) and communicated to the DC-DC converter 32 via the DC configuration control signal DCC. In general, selection of the bias supply pump operating mode is made by control circuitry, which may be any of the DC-DC control circuitry 90, the RF modulation and control circuitry 28, and the control circuitry 42 (FIG. 5). As such, the control circuitry may select one of the bias supply pump-up operating mode and at least one other bias supply operating mode. The at least one other bias supply operating mode may include any or all of the bias supply pump-down operating mode, the bias supply pump-even operating mode, and the bias supply bypass operating mode.

[0255] The second power filtering circuitry 88 filters the bias power supply signal BPS. The second power filtering circuitry 88 may function as a lowpass filter by removing ripple, noise, and the like to provide the bias power supply signal BPS. As such, in one embodiment of the DC-DC converter 32, the bias power supply signal BPS is based on the DC power supply signal DCPS.

[0256] Regarding omission of the second inductive element L2, instead of the second inductive element L2 coupled between the buck converter 86 and the first power filtering circuitry 82 as shown in FIG. 10, one end of the first inductive element L1 is coupled to both the charge pump buck converter 84 and the buck converter 86. As such, in the second converter operating mode or the third converter operating mode, the buck converter 86 may receive and buck convert the DC power supply signal DCPS to provide the second buck output signal SBO to the first inductive element L1. As such, in one embodiment of the charge pump buck converter 84, the second buck output signal SBO is based on the DC power supply signal DCPS. Further, the first inductive element L1 may function as a first energy transfer element of the buck converter 86 to transfer energy via the second buck output signal SBO to the first power filtering circuitry 82. In the first converter operating mode, the second converter operating mode, or the third converter operating mode, the first inductive element L1 and the first power filtering circuitry 82 receive and filter the first buck output signal FBO, the second buck output signal SBO, or both to provide the envelope power supply signal EPS.

[0257] FIG. 12 shows details of the DC-DC converter 32 illustrated in FIG. 11 according to an alternate embodiment of the DC-DC converter 32. The DC-DC converter 32 illustrated in FIG. 12 is similar to the DC-DC converter 32 illustrated in FIG. 10, except the DC-DC converter 32 illustrated in FIG. 12 shows details of the first power filtering circuitry 82 and the second power filtering circuitry 88. Further, the DC-DC converter 32 illustrated in FIG. 12 includes the DC-DC control circuitry 90 and the charge pump 92 as shown in FIG. 11.

[0258] The first power filtering circuitry 82 includes a first capacitive element C1, a second capacitive element C2, and a third inductive element L3. The first capacitive element C1 is coupled between one end of the third inductive element L3 and a ground. The second capacitive element C2 is coupled between an opposite end of the third inductive element L3 and ground. The one end of the third inductive element L3 is coupled to one end of the first inductive element L1. Further, the one end of the third inductive element L3 is coupled to one end of the second inductive element L2. In an additional embodiment of the DC-DC converter 32, the second inductive element L2 is omitted. The opposite end of the third inductive element L3 is coupled to the RF PA circuitry 30. As such, the opposite end of the third inductive element L3 and one end of the second capacitive element C2 provide the envelope power supply signal EPS. In an alternate embodiment of the first power filtering circuitry 82, the third inductive element L3, the second capacitive element C2, or both are omitted.

[0259] FIG. 13 shows details of the RF PA circuitry 30 illustrated in FIG. 5 according to one embodiment of the RF PA circuitry 30. The RF PA circuitry 30 illustrated in FIG. 13 is similar to the RF PA circuitry 30 illustrated in FIG. 5, except the RF PA circuitry 30 illustrated in FIG. 13 further includes PA control circuitry 94, PA bias circuitry 96, and switch driver circuitry 98. The PA bias circuitry 96 is coupled between the PA control circuitry 94 and the RF PAs 50, 54. The switch driver circuitry 98 is coupled between the PA control circuitry 94 and the switching circuitry 52, 56. The PA control circuitry 94 receives the PA configuration control signal PCC, provides a bias configuration control signal BCC to the PA bias circuitry 96 based on the PA configuration control signal PCC, and provides a switch configuration control signal SCC to the switch driver circuitry 98 based on the PA configuration control signal PCC. The switch driver circuitry 98 provides any needed drive signals to configure the alpha switching circuitry 52 and the beta switching circuitry 56.

[0260] The PA bias circuitry 96 receives the bias power supply signal BPS and the bias configuration control signal BCC. The PA bias circuitry 96 provides a first driver bias signal FDB and a first final bias signal FFB to the first RF PA 50 based on the bias power supply signal BPS and the bias configuration control signal BCC. The PA bias circuitry 96 provides a second driver bias signal SDB and a second final bias signal SFB to the second RF PA 54 based on the bias power supply signal BPS and the bias configuration control signal BCC. The bias power supply signal BPS provides the power necessary to generate the bias signals FDB, FFB, SDB, SFB. A selected magnitude of each of the bias signals FDB, FFB, SDB, SFB is provided by the PA bias circuitry 96. In one embodiment of the RF PA circuitry 30, the PA control circuitry 94 selects the magnitude of any or all of the bias signals FDB, FFB, SDB, SFB and communicates the magnitude selections to the PA bias circuitry 96 via the bias configuration control signal BCC. The magnitude selections by the PA control circuitry 94 may be based on the PA configuration control signal PCC. In an alternate embodiment of the RF PA circuitry 30, the control circuitry 42 (FIG. 5) selects the magnitude of any or all of the bias signals FDB, FFB, SDB, SFB and communicates the magnitude selections to the PA bias circuitry 96 via the PA control circuitry 94.

[0261] In one embodiment of the RF PA circuitry 30, the RF PA circuitry 30 operates in one of a first PA operating mode and a second PA operating mode. During the first PA operating mode, the first transmit path 46 is enabled and the second transmit path 48 is disabled. During the second PA operating mode, the first transmit path 46 is disabled and the second transmit path 48 is enabled. In one embodiment of the first RF PA 50 and the second RF PA 54, during the second PA operating mode, the first RF PA 50 is disabled, and during the first PA operating mode, the second RF PA 54 is disabled. In one embodiment of the alpha switching circuitry 52 and the beta switching circuitry 56, during the second PA operating mode, the alpha switching circuitry 52 is disabled, and during the first PA operating mode, the beta switching circuitry 56 is disabled.

[0262] In one embodiment of the first RF PA 50, during the second PA operating mode, the first RF PA 50 is disabled via the first driver bias signal FDB. In an alternate embodiment of the first RF PA 50, during the second PA operating mode, the first RF PA 50 is disabled via the first final bias signal FFB. In an additional embodiment of the first RF PA 50, during the second PA operating mode, the first RF PA 50 is disabled via both the first driver bias signal FDB and the first final bias signal FFB. In one embodiment of the second RF PA 54, during the first PA operating mode, the second RF PA 54 is disabled via the second driver bias signal SDB. In an alternate embodiment of the second RF PA 54, during the first PA operating mode, the second RF PA 54 is disabled via the second final bias signal SFB. In an additional embodiment of the second RF PA 54, during the first PA operating mode, the second RF PA 54 is disabled via both the second driver bias signal SDB and the second final bias signal SFB.

[0263] In one embodiment of the RF PA circuitry 30, the PA control circuitry 94 selects the one of the first PA operating mode and the second PA operating mode. As such, the PA control circuitry 94 may control any or all of the bias signals FDB, FFB, SDB, SFB via the bias configuration control signal BCC based on the PA operating mode selection. Further, the PA control circuitry 94 may control the switching circuitry 52, 56 via the switch configuration control signal SCC based on the PA operating mode selection. The PA operating mode selection may be based on the PA configuration control signal PCC. In an alternate embodiment of the RF PA circuitry 30, the control circuitry 42 (FIG. 5) selects the one of the first PA operating mode and the second PA operating mode. As such, the control circuitry 42 (FIG. 5) may indicate the operating mode selection to the PA control circuitry 94 via the PA configuration control signal PCC. In an additional embodiment of the RF PA circuitry 30, the RF modulation and control circuitry 28 (FIG. 5) selects the one of the first PA operating mode and the second PA operating mode. As such, the RF modulation and control circuitry 28 (FIG. 5) may indicate the operating mode selection to the PA control circuitry 94 via the PA configuration control signal PCC. In general, selection of the PA operating mode is made by control circuitry, which may be any of the PA control circuitry 94, the RF modulation and control circuitry 28 (FIG. 5), and the control circuitry 42 (FIG. 5).

[0264] FIG. 14 shows details of the RF PA circuitry 30 illustrated in FIG. 6 according to an alternate embodiment of the RF PA circuitry 30. The RF PA circuitry 30 illustrated in FIG. 14 is similar to the RF PA circuitry 30 illustrated in FIG. 13, except the RF PA circuitry 30 illustrated in FIG. 14 further includes the PA-DCI 60, which is coupled to the PA control circuitry 94 and to the digital communications bus 66. As such, the control circuitry 42 (FIG. 6) may provide the PA configuration control signal PCC via the control circuitry DCI 58 (FIG. 6) to the PA control circuitry 94 via the PA-DCI 60.

[0265] FIG. 15 shows details of the first RF PA 50 and the second RF PA 54 illustrated in FIG. 13 according one embodiment of the first RF PA 50 and the second RF PA 54. The first RF PA 50 includes a first non-quadrature PA path 100 and a first quadrature PA path 102. The second RF PA 54 includes a second non-quadrature PA path 104 and a second quadrature PA path 106. In one embodiment of the first RF PA 50, the first quadrature PA path 102 is coupled between the first non-quadrature PA path 100 and the antenna port AP (FIG. 6), which is coupled to the antenna 18 (FIG. 6). In an alternate embodiment of the first RF PA 50, the first non-quadrature PA path 100 is omitted, such that the first quadrature PA path 102 is coupled to the antenna port AP (FIG. 6). The first quadrature PA path 102 may be coupled to the antenna port AP (FIG. 6) via the alpha switching circuitry 52 (FIG. 6) and the front-end aggregation circuitry 36 (FIG. 6). The first non-quadrature PA path 100 may include any number of non-quadrature gain stages. The first quadrature PA path 102 may include any number of quadrature gain stages. In one embodiment of the second RF PA 54, the second quadrature PA path 106 is coupled between the second non-quadrature PA path 104 and the antenna port AP (FIG. 6). In an alternate embodiment of the second RF PA 54, the second non-quadrature PA path 104 is omitted, such that the second quadrature PA path 106 is coupled to the antenna port AP (FIG. 6). The second quadrature PA path 106 may be coupled to the antenna port AP (FIG. 6) via the beta switching circuitry 56 (FIG. 6) and the front-end aggregation circuitry 36 (FIG. 6). The second non-quadrature PA path 104 may include any number of non-quadrature gain stages. The second quadrature PA path 106 may include any number of quadrature gain stages.

[0266] In one embodiment of the RF communications system 26, the control circuitry 42 (FIG. 5) selects one of multiple communications modes, which include a first PA operating mode and a second PA operating mode. During the first PA operating mode, the first PA paths 100, 102 receive the envelope power supply signal EPS, which provides power for amplification. During the second PA operating mode, the second PA paths 104, 106 receive the envelope power supply signal EPS, which provides power for amplification. During the first PA operating mode, the first non-quadrature PA path 100 receives the first driver bias signal FDB, which provides biasing to the first non-quadrature PA path 100, and the first quadrature PA path 102 receives the first final bias signal FFB, which provides biasing to the first quadrature PA path 102. During the second PA operating mode, the second non-quadrature PA path 104 receives the second driver bias signal SDB, which provides biasing to the second non-quadrature PA path 104, and the second quadrature PA path 106 receives the second final bias signal SFB, which provides biasing to the second quadrature PA path 106.

[0267] The first non-quadrature PA path 100 has a first single-ended output FSO and the first quadrature PA path 102 has a first single-ended input FSI. The first single-ended output FSO may be coupled to the first single-ended input FSI. In one embodiment of the first RF PA 50, the first single-ended output FSO is directly coupled to the first single-ended input FSI. The second non-quadrature PA path 104 has a second single-ended output SSO and the second quadrature PA path 106 has a second single-ended input SSI. The second single-ended output SSO may be coupled to the second single-ended input SSI. In one embodiment of the second RF PA 54, the second single-ended output SSO is directly coupled to the second single-ended input SSI.

[0268] During the first PA operating mode, the first RF PA 50 receives and amplifies the first RF input signal FRFI to provide the first RF output signal FRFO, and the second RF PA 54 is disabled. During the second PA operating mode, the second RF PA 54 receives and amplifies the second RF input signal SRFI to provide the second RF output signal SRFO, and the first RF PA 50 is disabled. In one embodiment of the RF communications system 26, the first RF input signal FRFI is a highband RF input signal and the second RF input signal SRFI is a lowband RF input signal. In one exemplary embodiment of the RF communications system 26, a difference between a frequency of the highband RF input signal and a frequency of the lowband RF input signal is greater than about 500 megahertz, such that the frequency of the highband RF input signal is greater than the frequency of the lowband RF input signal. In an alternate exemplary embodiment of the RF communications system 26, a ratio of a frequency of the highband RF input signal divided by a frequency of the lowband RF input signal is greater than about 1.5.

[0269] In one embodiment of the first RF PA 50, during the first PA operating mode, the first non-quadrature PA path 100 receives and amplifies the first RF input signal FRFI to provide a first RF feeder output signal FFO to the first quadrature PA path 102 via the first single-ended output FSO. Further, during the first PA operating mode, the first quadrature PA path 102 receives and amplifies the first RF feeder output signal FFO via the first single-ended input FSI to provide the first RF output signal FRFO. In one embodiment of the second RF PA 54, during the second PA operating mode, the second non-quadrature PA path 104 receives and amplifies the second RF input signal SRFI to provide a second RF feeder output signal SFO to the second quadrature PA path 106 via the second single-ended output SSO. Further, during the second PA operating mode, the second quadrature PA path 106 receives and amplifies the second RF feeder output signal SFO via the second single-ended input SSI to provide the second RF output signal SRFO.

[0270] A summary of quadrature PA architecture is presented, followed by a detailed description of the quadrature PA architecture according to one embodiment of the present disclosure. One embodiment of the RF communications system 26 (FIG. 6) relates to a quadrature RF PA architecture that utilizes a single-ended interface to couple a non-quadrature PA path to a quadrature PA path, which may be coupled to the antenna port (FIG. 6). The quadrature nature of the quadrature PA path may provide tolerance for changes in antenna loading conditions. An RF splitter in the quadrature PA path may present a relatively stable input impedance, which may be predominantly resistive, to the non-quadrature PA path over a wide frequency range, thereby substantially isolating the non-quadrature PA path from changes in the antenna loading conditions. Further, the input impedance may substantially establish a load line slope of a feeder PA stage in the non-quadrature PA path, thereby simplifying the quadrature RF PA architecture. One embodiment of the quadrature RF PA architecture uses two separate PA paths, either of which may incorporate a combined non-quadrature and quadrature PA architecture.

[0271] Due to the relatively stable input impedance, RF power measurements taken at the single-ended interface may provide high directivity and accuracy. Further, by combining the non-quadrature PA path and the quadrature PA path, gain stages may be eliminated and circuit topology may be simplified. In one embodiment of the RF splitter, the RF splitter is a quadrature hybrid coupler, which may include a pair of tightly coupled inductors. The input impedance may be based on inductances of the pair of tightly coupled inductors and parasitic capacitance between the inductors. As such, construction of the pair of tightly coupled inductors may be varied to select a specific parasitic capacitance to provide a specific input impedance. Further, the RF splitter may be integrated onto one semiconductor die with amplifying elements of the non-quadrature PA path, with amplifying elements of the quadrature PA path, or both, thereby reducing size and cost. Additionally, the quadrature PA path may have only a single quadrature amplifier stage to further simplify the design. In certain embodiments, using only the single quadrature amplifier stage provides adequate tolerance for changes in antenna loading conditions.

[0272] FIG. 16 shows details of the first non-quadrature PA path 100 and the second non-quadrature PA path 104 illustrated in FIG. 15 according to one embodiment of the first non-quadrature PA path 100 and the second non-quadrature PA path 104. The first non-quadrature PA path 100 includes a first input PA impedance matching circuit 108, a first input PA stage 110, a first feeder PA impedance matching circuit 112, and a first feeder PA stage 114, which provides the first single-ended output FSO. The first input PA stage 110 is coupled between the first input PA impedance matching circuit 108 and the first feeder PA impedance matching circuit 112. The first feeder PA stage 114 is coupled between the first feeder PA impedance matching circuit 112 and the first quadrature PA path 102. The first input PA impedance matching circuit 108 may provide at least an approximate impedance match between the RF modulation circuitry 44 (FIG. 5) and the first input PA stage 110. The first feeder PA impedance matching circuit 112 may provide at least an approximate impedance match between the first input PA stage 110 and the first feeder PA stage 114. In alternate embodiments of the first non-quadrature PA path 100, any or all of the first input PA impedance matching circuit 108, the first input PA stage 110, and the first feeder PA impedance matching circuit 112, may be omitted.

[0273] During the first PA operating mode, the first input PA impedance matching circuit 108 receives and forwards the first RF input signal FRFI to the first input PA stage 110. During the first PA operating mode, the first input PA stage 110 receives and amplifies the forwarded first RF input signal FRFI to provide a first RF feeder input signal FFI to the first feeder PA stage 114 via the first feeder PA impedance matching circuit 112. During the first PA operating mode, the first feeder PA stage 114 receives and amplifies the first RF feeder input signal FFI to provide the first RF feeder output signal FFO via the first single-ended output FSO. The first feeder PA stage 114 may have a first output load line having a first load line slope. During the first PA operating mode, the envelope power supply signal EPS provides power for amplification to the first input PA stage 110 and to the first feeder PA stage 114. During the first PA operating mode, the first driver bias signal FDB provides biasing to the first input PA stage 110 and the first feeder PA stage 114.

[0274] The second non-quadrature PA path 104 includes a second input PA impedance matching circuit 116, a second input PA stage 118, a second feeder PA impedance matching circuit 120, and a second feeder PA stage 122, which provides the second single-ended output SSO. The second input PA stage 118 is coupled between the second input PA impedance matching circuit 116 and the second feeder PA impedance matching circuit 120. The second feeder PA stage 122 is coupled between the second feeder PA impedance matching circuit 120 and the second quadrature PA path 106. The second input PA impedance matching circuit 116 may provide at least an approximate impedance match between the RF modulation circuitry 44 (FIG. 5) and the second input PA stage 118. The second feeder PA impedance matching circuit 120 may provide at least an approximate impedance match between the second input PA stage 118 and the second feeder PA stage 122. In alternate embodiments of the second non-quadrature PA path 104, any or all of the second input PA impedance matching circuit 116, the second input PA stage 118, and the second feeder PA impedance matching circuit 120, may be omitted.

[0275] During the second PA operating mode, the second input PA impedance matching circuit 116 receives and forwards the second RF input signal SRFI to the second input PA stage 118. During the second PA operating mode, the second input PA stage 118 receives and amplifies the forwarded second RF input signal SRFI to provide a second RF feeder input signal SFI to the second feeder PA stage 122 via the second feeder PA impedance matching circuit 120. During the second PA operating mode, the second feeder PA stage 122 receives and amplifies the second RF feeder input signal SFI to provide the second RF feeder output signal SFO via the second single-ended output SSO. The second feeder PA stage 122 may have a second output load line having a second load line slope. During the second PA operating mode, the envelope power supply signal EPS provides power for amplification to the second input PA stage 118 and to the second feeder PA stage 122. During the second PA operating mode, the second driver bias signal SDB provides biasing to the second input PA stage 118 and the second feeder PA stage 122.

[0276] FIG. 17 shows details of the first quadrature PA path 102 and the second quadrature PA path 106 illustrated in FIG. 15 according to one embodiment of the first quadrature PA path 102 and the second quadrature PA path 106. The first quadrature PA path 102 includes a first quadrature RF splitter 124, a first in-phase amplification path 126, a first quadrature-phase amplification path 128, and a first quadrature RF combiner 130. The first quadrature RF splitter 124 has a first single-ended input FSI, a first in-phase output FIO, and a first quadrature-phase output FQO. The first quadrature RF combiner 130 has a first in-phase input FII, a first quadrature-phase input FQI, and a first quadrature combiner output FCO. The first single-ended output FSO is coupled to the first single-ended input FSI. In one embodiment of the first quadrature PA path 102, the first single-ended output FSO is directly coupled to the first single-ended input FSI. The first in-phase amplification path 126 is coupled between the first in-phase output FIO and the first in-phase input FII. The first quadrature-phase amplification path 128 is coupled between the first quadrature-phase output FQO and the first quadrature-phase input FQI. The first quadrature combiner output FCO is coupled to the antenna port AP (FIG. 6) via the alpha switching circuitry 52 (FIG. 6) and the front-end aggregation circuitry 36 (FIG. 6).

[0277] During the first PA operating mode, the first quadrature RF splitter 124 receives the first RF feeder output signal FFO via the first single-ended input FSI. Further, during the first PA operating mode, the first quadrature RF splitter 124 splits and phase-shifts the first RF feeder output signal FFO into a first in-phase RF input signal FIN and a first quadrature-phase RF input signal FQN, such that the first quadrature-phase RF input signal FQN is nominally phase-shifted from the first in-phase RF input signal FIN by about 90 degrees. The first quadrature RF splitter 124 has a first input impedance presented at the first single-ended input FSI. In one embodiment of the first quadrature RF splitter 124, the first input impedance establishes the first load line slope. During the first PA operating mode, the first in-phase amplification path 126 receives and amplifies the first in-phase RF input signal FIN to provide the first in-phase RF output signal FIT. The first quadrature-phase amplification path 128 receives and amplifies the first quadrature-phase RF input signal FQN to provide the first quadrature-phase RF output signal FQT.

[0278] During the first PA operating mode, the first quadrature RF combiner 130 receives the first in-phase RF output signal FIT via the first in-phase input FII, and receives the first quadrature-phase RF output signal FQT via the first quadrature-phase input FQI. Further, the first quadrature RF combiner 130 phase-shifts and combines the first in-phase RF output signal FIT and the first quadrature-phase RF output signal FQT to provide the first RF output signal FRFO via the first quadrature combiner output FCO, such that the phase-shifted first in-phase RF output signal FIT and first quadrature-phase RF output signal FQT are about phase-aligned with one another before combining. During the first PA operating mode, the envelope power supply signal EPS provides power for amplification to the first in-phase amplification path 126 and the first quadrature-phase amplification path 128. During the first PA operating mode, the first final bias signal FFB provides biasing to the first in-phase amplification path 126 and the first quadrature-phase amplification path 128.

[0279] The second quadrature PA path 106 includes a second quadrature RF splitter 132, a second in-phase amplification path 134, a second quadrature-phase amplification path 136, and a second quadrature RF combiner 138. The second quadrature RF splitter 132 has a second single-ended input SSI, a second in-phase output SIO, and a second quadrature-phase output SQO. The second quadrature RF combiner 138 has a second in-phase input SII, a second quadrature-phase input SQI, and a second quadrature combiner output SCO. The second single-ended output SSO is coupled to the second single-ended input SSI. In one embodiment of the second quadrature PA path 106, the second single-ended output SSO is directly coupled to the second single-ended input SSI. The second in-phase amplification path 134 is coupled between the second in-phase output SIO and the second in-phase input SII. The second quadrature-phase amplification path 136 is coupled between the second quadrature-phase output SQO and the second quadrature-phase input SQI. The second quadrature combiner output SCO is coupled to the antenna port AP (FIG. 6) via the alpha switching circuitry 52 (FIG. 6) and the front-end aggregation circuitry 36 (FIG. 6).

[0280] During the second PA operating mode, the second quadrature RF splitter 132 receives the second RF feeder output signal SFO via the second single-ended input SSI. Further, during the second PA operating mode, the second quadrature RF splitter 132 splits and phase-shifts the second RF feeder output signal SFO into a second in-phase RF input signal SIN and a second quadrature-phase RF input signal SQN, such that the second quadrature-phase RF input signal SQN is nominally phase-shifted from the second in-phase RF input signal SIN by about 90 degrees. The second quadrature RF splitter 132 has a second input impedance presented at the second single-ended input SSI. In one embodiment of the second quadrature RF splitter 132, the second input impedance establishes the second load line slope. During the second PA operating mode, the second in-phase amplification path 134 receives and amplifies the second in-phase RF input signal SIN to provide the second in-phase RF output signal SIT. The second quadrature-phase amplification path 136 receives and amplifies the second quadrature-phase RF input signal SQN to provide the second quadrature-phase RF output signal SQT.

[0281] During the second PA operating mode, the second quadrature RF combiner 138 receives the second in-phase RF output signal SIT via the second in-phase input SII, and receives the second quadrature-phase RF output signal SQT via the second quadrature-phase input SQI. Further, the second quadrature RF combiner 138 phase-shifts and combines the second in-phase RF output signal SIT and the second quadrature-phase RF output signal SQT to provide the second RF output signal SRFO via the second quadrature combiner output SCO, such that the phase-shifted second in-phase RF output signal SIT and second quadrature-phase RF output signal SQT are about phase-aligned with one another before combining. During the second PA operating mode, the envelope power supply signal EPS provides power for amplification to the second in-phase amplification path 134 and the second quadrature-phase amplification path 136. During the second PA operating mode, the second final bias signal SFB provides biasing to the second in-phase amplification path 134 and the second quadrature-phase amplification path 136.

[0282] In one embodiment of the RF PA circuitry 30 (FIG. 13), the second transmit path 48 (FIG. 13) is omitted. As such, the first feeder PA stage 114 (FIG. 16) is a feeder PA stage and the first single-ended output FSO (FIG. 16) is a single-ended output. The first RF feeder input signal FFI (FIG. 16) is an RF feeder input signal and the first RF feeder output signal FFO (FIG. 16) is an RF feeder output signal. The feeder PA stage receives and amplifies the RF feeder input signal to provide the RF feeder output signal via the single-ended output. The feeder PA stage has an output load line having a load line slope. The first quadrature RF splitter 124 is a quadrature RF splitter and the first single-ended input FSI is a single-ended input. As such, the quadrature RF splitter has the single-ended input. In one embodiment of the first RF PA 50, the single-ended output is directly coupled to the single-ended input.

[0283] In the embodiment in which the second transmit path 48 (FIG. 13) is omitted, the first in-phase RF input signal FIN is an in-phase RF input signal and the first quadrature-phase RF input signal FQN is a quadrature-phase RF input signal. The quadrature RF splitter receives the RF feeder output signal via the single-ended input. Further, the quadrature RF splitter splits and phase-shifts the RF feeder output signal into the in-phase RF input signal and the quadrature-phase RF input signal, such that the quadrature-phase RF input signal is nominally phase-shifted from the in-phase RF input signal by about 90 degrees. The quadrature RF splitter has an input impedance presented at the single-ended input. The input impedance substantially establishes the load line slope. The first in-phase amplification path 126 is an in-phase amplification path and the first quadrature-phase amplification path 128 is a quadrature-phase amplification path. The first in-phase RF output signal FIT is an in-phase RF output signal and the first quadrature-phase RF output signal FQT is a quadrature-phase RF output signal. As such, the in-phase amplification path receives and amplifies the in-phase RF input signal to provide the in-phase RF output signal. The quadrature-phase amplification path receives and amplifies the quadrature-phase RF input signal to provide the quadrature-phase RF output signal.

[0284] In the embodiment in which the second transmit path 48 (FIG. 13) is omitted, the first RF output signal FRFO is an RF output signal. As such, the quadrature RF combiner receives, phase-shifts, and combines the in-phase RF output signal and the quadrature-phase RF output signal to provide the RF output signal. In one embodiment of the quadrature RF splitter, the input impedance has resistance and reactance, such that the reactance is less than the resistance. In a first exemplary embodiment of the quadrature RF splitter, the resistance is greater than two times the reactance. In a second exemplary embodiment of the quadrature RF splitter, the resistance is greater than four times the reactance. In a third exemplary embodiment of the quadrature RF splitter, the resistance is greater than six times the reactance. In a fourth exemplary embodiment of the quadrature RF splitter, the resistance is greater than eight times the reactance. In a first exemplary embodiment of the quadrature RF splitter, the resistance is greater than ten times the reactance.

[0285] In alternate embodiments of the first quadrature PA path 102 and the second quadrature PA path 106, any or all of the first quadrature RF splitter 124, the first quadrature RF combiner 130, the second quadrature RF splitter 132, and the second quadrature RF combiner 138 may be any combination of quadrature RF couplers, quadrature hybrid RF couplers; Fisher couplers; lumped-element based RF couplers; transmission line based RF couplers; and combinations of phase-shifting circuitry and RF power couplers, such as phase-shifting circuitry and Wilkinson couplers; and the like. As such, any of the RF couplers listed above may be suitable to provide the first input impedance, the second input impedance, or both.

[0286] FIG. 18 shows details of the first in-phase amplification path 126, the first quadrature-phase amplification path 128, the second in-phase amplification path 134, and the second quadrature-phase amplification path 136 illustrated in FIG. 17 according to one embodiment of the first in-phase amplification path 126, the first quadrature-phase amplification path 128, the second in-phase amplification path 134, and the second quadrature-phase amplification path 136. The first in-phase amplification path 126 includes a first in-phase driver PA impedance matching circuit 140, a first in-phase driver PA stage 142, a first in-phase final PA impedance matching circuit 144, a first in-phase final PA stage 146, and a first in-phase combiner impedance matching circuit 148. The first in-phase driver PA impedance matching circuit 140 is coupled between the first in-phase output FIO and the first in-phase driver PA stage 142. The first in-phase final PA impedance matching circuit 144 is coupled between the first in-phase driver PA stage 142 and the first in-phase final PA stage 146. The first in-phase combiner impedance matching circuit 148 is coupled between the first in-phase final PA stage 146 and the first in-phase input FII.

[0287] The first in-phase driver PA impedance matching circuit 140 may provide at least an approximate impedance match between the first quadrature RF splitter 124 and the first in-phase driver PA stage 142. The first in-phase final PA impedance matching circuit 144 may provide at least an approximate impedance match between the first in-phase driver PA stage 142 and the first in-phase final PA stage 146. The first in-phase combiner impedance matching circuit 148 may provide at least an approximate impedance match between the first in-phase final PA stage 146 and the first quadrature RF combiner 130.

[0288] During the first PA operating mode, the first in-phase driver PA impedance matching circuit 140 receives and forwards the first in-phase RF input signal FIN to the first in-phase driver PA stage 142, which receives and amplifies the forwarded first in-phase RF input signal to provide an amplified first in-phase RF input signal to the first in-phase final PA stage 146 via the first in-phase final PA impedance matching circuit 144. The first in-phase final PA stage 146 receives and amplifies the amplified first in-phase RF input signal to provide the first in-phase RF output signal FIT via the first in-phase combiner impedance matching circuit 148. During the first PA operating mode, the envelope power supply signal EPS provides power for amplification to the first in-phase driver PA stage 142 and the first in-phase final PA stage 146. During the first PA operating mode, the first final bias signal FFB provides biasing to the first in-phase driver PA stage 142 and the first in-phase final PA stage 146.

[0289] The first quadrature-phase amplification path 128 includes a first quadrature-phase driver PA impedance matching circuit 150, a first quadrature-phase driver PA stage 152, a first quadrature-phase final PA impedance matching circuit 154, a first quadrature-phase final PA stage 156, and a first quadrature-phase combiner impedance matching circuit 158. The first quadrature-phase driver PA impedance matching circuit 150 is coupled between the first quadrature-phase output FQO and the first quadrature-phase driver PA stage 152. The first quadrature-phase final PA impedance matching circuit 154 is coupled between the first quadrature-phase driver PA stage 152 and the first quadrature-phase final PA stage 156. The first quadrature-phase combiner impedance matching circuit 158 is coupled between the first quadrature-phase final PA stage 156 and the first quadrature-phase input FQI.

[0290] The first quadrature-phase driver PA impedance matching circuit 150 may provide at least an approximate impedance match between the first quadrature RF splitter 124 and the first quadrature-phase driver PA stage 152. The first quadrature-phase final PA impedance matching circuit 154 may provide at least an approximate impedance match between the first quadrature-phase driver PA stage 152 and the first quadrature-phase final PA stage 156. The first quadrature-phase combiner impedance matching circuit 158 may provide at least an approximate impedance match between the first quadrature-phase final PA stage 156 and the first quadrature RF combiner 130.

[0291] During the first PA operating mode, the first quadrature-phase driver PA impedance matching circuit 150 receives and forwards the first quadrature-phase RF input signal FQN to the first quadrature-phase driver PA stage 152, which receives and amplifies the forwarded first quadrature-phase RF input signal to provide an amplified first quadrature-phase RF input signal to the first quadrature-phase final PA stage 156 via the first quadrature-phase final PA impedance matching circuit 154. The first quadrature-phase final PA stage 156 receives and amplifies the amplified first quadrature-phase RF input signal to provide the first quadrature-phase RF output signal FQT via the first quadrature-phase combiner impedance matching circuit 158. During the first PA operating mode, the envelope power supply signal EPS provides power for amplification to the first quadrature-phase driver PA stage 152 and the first quadrature-phase final PA stage 156. During the first PA operating mode, the first final bias signal FFB provides biasing to the first quadrature-phase driver PA stage 152 and the first quadrature-phase final PA stage 156.

[0292] The second in-phase amplification path 134 includes a second in-phase driver PA impedance matching circuit 160, a second in-phase driver PA stage 162, a second in-phase final PA impedance matching circuit 164, a second in-phase final PA stage 166, and a second in-phase combiner impedance matching circuit 168. The second in-phase driver PA impedance matching circuit 160 is coupled between the second in-phase output SIO and the second in-phase driver PA stage 162. The second in-phase final PA impedance matching circuit 164 is coupled between the second in-phase driver PA stage 162 and the second in-phase final PA stage 166. The second in-phase combiner impedance matching circuit 168 is coupled between the second in-phase final PA stage 166 and the second in-phase input SII.

[0293] The second in-phase driver PA impedance matching circuit 160 may provide at least an approximate impedance match between the second quadrature RF splitter 132 and the second in-phase driver PA stage 162. The second in-phase final PA impedance matching circuit 164 may provide at least an approximate impedance match between the second in-phase driver PA stage 162 and the second in-phase final PA stage 166. The second in-phase combiner impedance matching circuit 168 may provide at least an approximate impedance match between the second in-phase final PA stage 166 and the second quadrature RF combiner 138.

[0294] During the second PA operating mode, the second in-phase driver PA impedance matching circuit 160 receives and forwards the second in-phase RF input signal SIN to the second in-phase driver PA stage 162, which receives and amplifies the forwarded second in-phase RF input signal to provide an amplified second in-phase RF input signal to the second in-phase final PA stage 166 via the second in-phase final PA impedance matching circuit 164. The second in-phase final PA stage 166 receives and amplifies the amplified second in-phase RF input signal to provide the second in-phase RF output signal SIT via the second in-phase combiner impedance matching circuit 168. During the second PA operating mode, the envelope power supply signal EPS provides power for amplification to the second in-phase driver PA stage 162 and the second in-phase final PA stage 166. During the second PA operating mode, the second final bias signal SFB provides biasing to the second in-phase driver PA stage 162 and the second in-phase final PA stage 166.

[0295] The second quadrature-phase amplification path 136 includes a second quadrature-phase driver PA impedance matching circuit 170, a second quadrature-phase driver PA stage 172, a second quadrature-phase final PA impedance matching circuit 174, a second quadrature-phase final PA stage 176, and a second quadrature-phase combiner impedance matching circuit 178. The second quadrature-phase driver PA impedance matching circuit 170 is coupled between the second quadrature-phase output SQO and the second quadrature-phase driver PA stage 172. The second quadrature-phase final PA impedance matching circuit 174 is coupled between the second quadrature-phase driver PA stage 172 and the second quadrature-phase final PA stage 176. The second quadrature-phase combiner impedance matching circuit 178 is coupled between the second quadrature-phase final PA stage 176 and the second quadrature-phase input SQI.

[0296] The second quadrature-phase driver PA impedance matching circuit 170 may provide at least an approximate impedance match between the second quadrature RF splitter 132 and the second quadrature-phase driver PA stage 172. The second quadrature-phase final PA impedance matching circuit 174 may provide at least an approximate impedance match between the second quadrature-phase driver PA stage 172 and the second quadrature-phase final PA stage 176. The second quadrature-phase combiner impedance matching circuit 178 may provide at least an approximate impedance match between the second quadrature-phase final PA stage 176 and the second quadrature RF combiner 138.

[0297] During the second PA operating mode, the second quadrature-phase driver PA impedance matching circuit 170 receives and forwards the second quadrature-phase RF input signal SQN to the second quadrature-phase driver PA stage 172, which receives and amplifies the forwarded second quadrature-phase RF input signal to provide an amplified second quadrature-phase RF input signal to the second quadrature-phase final PA stage 176 via the second quadrature-phase final PA impedance matching circuit 174. The second quadrature-phase final PA stage 176 receives and amplifies the amplified second quadrature-phase RF input signal to provide the second quadrature-phase RF output signal SQT via the second quadrature-phase combiner impedance matching circuit 178. During the second PA operating mode, the envelope power supply signal EPS provides power for amplification to the second quadrature-phase driver PA stage 172 and the second quadrature-phase final PA stage 176. During the second PA operating mode, the second final bias signal SFB provides biasing to the second quadrature-phase driver PA stage 172 and the second quadrature-phase final PA stage 176.

[0298] In alternate embodiments of the first in-phase amplification path 126, any or all of the first in-phase driver PA impedance matching circuit 140, the first in-phase driver PA stage 142, the first in-phase final PA impedance matching circuit 144, and the first in-phase combiner impedance matching circuit 148 may be omitted. In alternate embodiments of the first quadrature-phase amplification path 128, any or all of the first quadrature-phase driver PA impedance matching circuit 150, the first quadrature-phase driver PA stage 152, the first quadrature-phase final PA impedance matching circuit 154, and the first quadrature-phase combiner impedance matching circuit 158 may be omitted. In alternate embodiments of the second in-phase amplification path 134, any or all of the second in-phase driver PA impedance matching circuit 160, the second in-phase driver PA stage 162, the second in-phase final PA impedance matching circuit 164, and the second in-phase combiner impedance matching circuit 168 may be omitted. In alternate embodiments of the second quadrature-phase amplification path 136, any or all of the second quadrature-phase driver PA impedance matching circuit 170, the second quadrature-phase driver PA stage 172, the second quadrature-phase final PA impedance matching circuit 174, and the second quadrature-phase combiner impedance matching circuit 178 may be omitted.

[0299] FIG. 19 shows details of the first quadrature PA path 102 and the second quadrature PA path 106 illustrated in FIG. 15 according to an alternate embodiment of the first quadrature PA path 102 and the second quadrature PA path 106. The first quadrature PA path 102 and the second quadrature PA path 106 illustrated in FIG. 19 are similar to the first quadrature PA path 102 and the second quadrature PA path 106 illustrated in FIG. 17, except in the first quadrature PA path 102 and the second quadrature PA path 106 illustrated in FIG. 19, during the first PA operating mode, the first driver bias signal FDB provides further biasing to the first in-phase amplification path 126 and the first quadrature-phase amplification path 128, and during the second PA operating mode, the second driver bias signal SDB provides further biasing to the second in-phase amplification path 134 and the second quadrature-phase amplification path 136.

[0300] FIG. 20 shows details of the first in-phase amplification path 126, the first quadrature-phase amplification path 128, the second in-phase amplification path 134, and the second quadrature-phase amplification path 136 illustrated in FIG. 19 according to an alternate embodiment of the first in-phase amplification path 126, the first quadrature-phase amplification path 128, the second in-phase amplification path 134, and the second quadrature-phase amplification path 136. The amplification paths 126, 128, 134, 136 illustrated in FIG. 20 are similar to the amplification paths 126, 128, 134, 136 illustrated in FIG. 18, except in the amplification paths 126, 128, 134, 136 illustrated in FIG. 20, during the first PA operating mode, the first driver bias signal FDB provides biasing to the first in-phase driver PA stage 142 and the first quadrature-phase driver PA stage 152 instead of the first final bias signal FFB, and during the second PA operating mode, the second driver bias signal SDB provides biasing to the second in-phase driver PA stage 162 and the second quadrature-phase driver PA stage 172 instead of the second final bias signal SFB.

[0301] FIG. 21 shows details of the first RF PA 50 and the second RF PA 54 illustrated in FIG. 14 according an alternate embodiment of the first RF PA 50 and the second RF PA 54. The first RF PA 50 shown in FIG. 21 is similar to the first RF PA 50 illustrated in FIG. 15. The second RF PA 54 shown in FIG. 21 is similar to the second RF PA 54 illustrated in FIG. 15, except in the second RF PA 54 illustrated in FIG. 21 the second quadrature PA path 106 is omitted. As such, during the second PA operating mode, the second RF input signal SRFI provides the second RF feeder output signal SFO to the second quadrature PA path 106. In this regard, during the second PA operating mode, the second quadrature PA path 106 receives and amplifies the second RF input signal SRFI to provide the second RF output signal SRFO. During the second PA operating mode, the second quadrature PA path 106 receives the envelope power supply signal EPS, which provides power for amplification. Further, during the second PA operating mode, the second quadrature PA path 106 receives the second driver bias signal SDB and the second final bias signal SFB, both of which provide biasing to the second quadrature PA path 106.

[0302] FIG. 22 shows details of the first non-quadrature PA path 100, the first quadrature PA path 102, and the second quadrature PA path 106 illustrated in FIG. 21 according to an additional embodiment of the first non-quadrature PA path 100, the first quadrature PA path 102, and the second quadrature PA path 106. The second quadrature PA path 106 illustrated in FIG. 22 is similar to the second quadrature PA path 106 illustrated in FIG. 20. The first quadrature PA path 102 illustrated in FIG. 22 is similar to the first quadrature PA path 102 illustrated in FIG. 20, except in the first quadrature PA path 102 illustrated in FIG. 22, the first in-phase driver PA impedance matching circuit 140, the first in-phase driver PA stage 142, the first quadrature-phase driver PA impedance matching circuit 150, and the first quadrature-phase driver PA stage 152 are omitted. In this regard, the first in-phase final PA impedance matching circuit 144 is coupled between the first in-phase output FIO and the first in-phase final PA stage 146. The first in-phase combiner impedance matching circuit 148 is coupled between the first in-phase final PA stage 146 and the first in-phase input FII. The first in-phase final PA impedance matching circuit 144 may provide at least an approximate impedance match between the first quadrature RF splitter 124 and the first in-phase final PA stage 146. The first in-phase combiner impedance matching circuit 148 may provide at least an approximate impedance match between the first in-phase final PA stage 146 and the first quadrature RF combiner 130.

[0303] During the first PA operating mode, the first in-phase final PA impedance matching circuit 144 receives and forwards the first in-phase RF input signal FIN to the first in-phase final PA stage 146, which receives and amplifies the forwarded first in-phase RF input signal to provide the first in-phase RF output signal FIT via the first in-phase combiner impedance matching circuit 148. During the first PA operating mode, the envelope power supply signal EPS provides power for amplification to the first in-phase final PA stage 146. During the first PA operating mode, the first final bias signal FFB provides biasing to the first in-phase final PA stage 146.

[0304] The first quadrature-phase final PA impedance matching circuit 154 is coupled between the first quadrature-phase output FQO and the first quadrature-phase final PA stage 156. The first quadrature-phase combiner impedance matching circuit 158 is coupled between the first quadrature-phase final PA stage 156 and the first quadrature-phase input FQI. The first quadrature-phase final PA impedance matching circuit 154 may provide at least an approximate impedance match between the first quadrature RF splitter 124 and the first quadrature-phase final PA stage 156. The first quadrature-phase combiner impedance matching circuit 158 may provide at least an approximate impedance match between the first quadrature-phase final PA stage 156 and the first quadrature RF combiner 130.

[0305] During the first PA operating mode, the first quadrature-phase final PA impedance matching circuit 154 receives and forwards the first quadrature-phase RF input signal FQN to the first quadrature-phase final PA stage 156, which receives and amplifies the forwarded first quadrature-phase RF input signal to provide the first quadrature-phase RF output signal FQT via the first quadrature-phase combiner impedance matching circuit 158. During the first PA operating mode, the envelope power supply signal EPS provides power for amplification to the first quadrature-phase final PA stage 156. During the first PA operating mode, the first final bias signal FFB provides biasing to the first quadrature-phase final PA stage 156.

[0306] The first non-quadrature PA path 100 illustrated in FIG. 22 is similar to the first non-quadrature PA path 100 illustrated in FIG. 16, except in the first non-quadrature PA path 100 illustrated in FIG. 22, the first input PA impedance matching circuit 108 and the first input PA stage 110 are omitted. As such, the first feeder PA stage 114 is coupled between the first feeder PA impedance matching circuit 112 and the first quadrature PA path 102. The first feeder PA impedance matching circuit 112 may provide at least an approximate impedance match between the RF modulation circuitry 44 (FIG. 5) and the first feeder PA stage 114. During the first PA operating mode, the first feeder PA impedance matching circuit 112 receives and forwards the first RF input signal FRFI to provide the first RF feeder input signal FFI to the first feeder PA stage 114. During the first PA operating mode, the first feeder PA stage 114 receives and amplifies the first RF feeder input signal FFI to provide the first RF feeder output signal FFO via the first single-ended output FSO. During the first PA operating mode, the envelope power supply signal EPS provides power for amplification to the first feeder PA stage 114. During the first PA operating mode, the first final bias signal FFB provides biasing to the first feeder PA stage 114.

[0307] In one embodiment of the first quadrature PA path 102, the first quadrature PA path 102 has only one in-phase PA stage, which is the first in-phase final PA stage 146, and only one quadrature-phase PA stage, which is the first quadrature-phase final PA stage 156. In one embodiment of the second quadrature PA path 106, the second in-phase driver PA impedance matching circuit 160, the second in-phase driver PA stage 162, the second quadrature-phase driver PA impedance matching circuit 170, and the second quadrature-phase driver PA stage 172 are omitted. As such, the second quadrature PA path 106 has only one in-phase PA stage, which is the second in-phase final PA stage 166, and only one quadrature-phase PA stage, which is the second quadrature-phase final PA stage 176.

[0308] FIG. 23 shows details of the first feeder PA stage 114 and the first quadrature RF splitter 124 illustrated in FIG. 16 and FIG. 17, respectively, according to one embodiment of the first feeder PA stage 114 and the first quadrature RF splitter 124. FIGS. 23 and 24 show only a portion of the first feeder PA stage 114 and the first quadrature RF splitter 124. The first feeder PA stage 114 includes a first output transistor element 180, an inverting output inductive element LIO, and the first single-ended output FSO. The first output transistor element 180 has a first transistor inverting output FTIO, a first transistor non-inverting output FTNO, and a first transistor input FTIN. The first transistor non-inverting output FTNO is coupled to a ground and the first transistor inverting output FTIO is coupled to the first single-ended output FSO and to one end of the inverting output inductive element LIO. An opposite end of the inverting output inductive element LIO receives the envelope power supply signal EPS.

[0309] The first quadrature RF splitter 124 has the first single-ended input FSI, such that the first input impedance is presented at the first single-ended input FSI. Since the first input impedance may be predominantly resistive, the first input impedance may be approximated as a first input resistive element RFI coupled between the first single-ended input FSI and the ground. The first single-ended output FSO is directly coupled to the first single-ended input FSI. Therefore, the first input resistive element RFI is presented to the first transistor inverting output FTIO.

[0310] FIG. 24 shows details of the first feeder PA stage 114 and the first quadrature RF splitter 124 illustrated in FIG. 16 and FIG. 17, respectively, according to an alternate embodiment of the first feeder PA stage 114 and the first quadrature RF splitter 124. The first output transistor element 180 is an NPN bipolar transistor element, such that an emitter of the NPN bipolar transistor element provides the first transistor non-inverting output FTNO (FIG. 23), a base of the NPN bipolar transistor element provides the first transistor input FTIN (FIG. 23), and a collector of the NPN bipolar transistor element provides the first transistor inverting output FTIO (FIG. 23). The inverting output inductive element LIO has an inverting output inductor current IDC, the collector of the NPN bipolar transistor element has a collector current IC, and the first input resistive element RFI has a first input current IFR. The NPN bipolar transistor element has a collector-emitter voltage VCE between the emitter and the collector of the NPN bipolar transistor element.

[0311] In general, the first feeder PA stage 114 is the feeder PA stage having the single-ended output and an output transistor element, which has an inverting output. In general, the first quadrature RF splitter 124 is the quadrature RF splitter having the single-ended input, such that the input impedance is presented at the single-ended input. The inverting output may provide the single-ended output and may be directly coupled to the single-ended input. The inverting output may be a collector of the output transistor element and the output transistor element has the output load line.

[0312] FIG. 25 is a graph illustrating output characteristics of the first output transistor element 180 illustrated in FIG. 24 according to one embodiment of the first output transistor element 180. The horizontal axis of the graph represents the collector-emitter voltage VCE of the NPN bipolar transistor element and the vertical axis represents the collector current IC of the NPN bipolar transistor element. Characteristic curves 182 of the NPN bipolar transistor element are shown relating the collector-emitter voltage VCE to the collector current IC at different base currents (not shown). The NPN bipolar transistor element has a first output load line 184 having a first load line slope 186. The first output load line 184 may be represented by an equation for a straight line having the form Y=mX+b, where X represents the horizontal axis, Y represents the vertical axis, b represents the Y-intercept, and m represents the first load line slope 186. As such, Y=IC, X=VCE, and b=ISAT, which is a saturation current ISAT of the NPN bipolar transistor element. Further, an X-intercept occurs at an off transistor voltage VCO. Substituting into the equation for a straight line provides EQ. 1, as shown below.
IC=m(VCE)+ISAT.  EQ. 1:

[0313] EQ. 2 illustrates Ohm's Law as applied to the first input resistive element RFI, as shown below.
VCE=(IFR)(RFI).  EQ. 2:

[0314] EQ. 3 illustrates Kirchhoff's Current Law applied to the circuit illustrated in FIG. 24 as shown below.
IDC=IC+IFR.  EQ. 3:

[0315] The inductive reactance of the inverting output inductive element LIO at frequencies of interest may be large compared to the resistance of the first input resistive element RFI. As such, for the purpose of analysis, the inverting output inductor current IDC may be treated as a constant DC current. Therefore, when VCE=0, the voltage across the first input resistive element RFI is zero, which makes IFR=0. From EQ. 3, if IFR=0, then IC=IDC. However, from EQ. 1, when VCE=0 and IC=IDC, then ISAT=IDC, which is a constant. Substituting into EQ. 1 provides EQ. 1A as shown below.
IC=m(VCE)+IDC.  EQ. 1A:

[0316] From FIG. 25, when IC=0, VCE=VCO. Substituting into EQ. 1A, EQ. 2, and EQ. 3 provides EQ. 1B, EQ. 2A, and EQ. 3A as shown below.
0=m(VCO)+IDC.  EQ. 1B:
VCO=(IFR)(RFI)  EQ. 2A
IDC=0+IFR.  EQ. 3A:

[0317] EQ. 3A may be substituted into EQ. 2A, which may be substituted into EQ. 1B to provide EQ. 10 as shown below.
0=m(VCO)+IDC=m(IDC)(RFI)+IDC.  EQ. 1C:

[0318] Therefore, m=−1/RFI. As a result, the first load line slope 186, which is represented by m is determined by the first input resistive element RFI, such that there is a negative inverse relationship between the first load line slope 186 and the first input resistive element RFI. In general, the first load line slope 186 is based on the first input impedance, such that the first input impedance substantially establishes the first load line slope 186. Further, there may be a negative inverse relationship between the first load line slope 186 and the first input impedance.

[0319] FIG. 26 illustrates a process for matching an input impedance, such as the first input impedance to the first quadrature RF splitter 124 (FIG. 16) to a target load line slope for a feeder PA stage, such as the first feeder PA stage 114 (FIG. 17). The first step of the process is to determine an operating power range of an RF PA, which has the feeder PA stage feeding a quadrature RF splitter (Step A10). The next step of the process is to determine the target load line slope for the feeder PA stage based on the operating power range (Step A12). A further step is to determine the input impedance to the quadrature RF splitter that substantially provides the target load line slope (Step A14). The final step of the process is to determine an operating frequency range of the RF PA, such that the target load line slope is further based on the operating frequency range (Step A16). In an alternate embodiment of the process for matching the input impedance to the target load line slope, the final step (Step A16) is omitted.

[0320] FIG. 27 shows details of the first RF PA 50 illustrated in FIG. 14 according an alternate embodiment of the first RF PA 50. The first RF PA 50 illustrated in FIG. 27 is similar to the first RF PA 50 illustrated in FIG. 15, except the first RF PA 50 illustrated in FIG. 27 further includes a first non-quadrature path power coupler 188. As previously mentioned, the first quadrature PA path 102 may present a first input impedance at the first single-ended input FSI that is predominantly resistive. Further, the first input impedance may be stable over a wide frequency range and over widely varying antenna loading conditions. As a result, coupling RF power from the first single-ended output FSO may be used for RF power detection or sampling with a high degree of accuracy and directivity. Since the first single-ended input FSI may be directly coupled to the first single-ended output FSO, coupling RF power from the first single-ended output FSO may be equivalent to coupling RF power from the first single-ended input FSI.

[0321] The first non-quadrature path power coupler 188 is coupled to the first single-ended output FSO and couples a portion of RF power flowing though the first single-ended output FSO to provide a first non-quadrature path power output signal FNPO. In an additional embodiment of the first RF PA 50, the first non-quadrature path power coupler 188 is coupled to the first single-ended input FSI and couples a portion of RF power flowing though the first single-ended input FSI to provide the first non-quadrature path power output signal FNPO.

[0322] FIG. 28 shows details of the second RF PA 54 illustrated in FIG. 14 according an alternate embodiment of the second RF PA 54. The second RF PA 54 illustrated in FIG. 28 is similar to the second RF PA 54 illustrated in FIG. 15, except the second RF PA 54 illustrated in FIG. 28 further includes a second non-quadrature path power coupler 190. As previously mentioned, the second quadrature PA path 106 may present a second input impedance at the second single-ended input SSI that is predominantly resistive. Further, the second input impedance may be stable over a wide frequency range and over widely varying antenna loading conditions. As a result, coupling RF power from the second single-ended output SSO may be used for RF power detection or sampling with a high degree of accuracy and directivity. Since the second single-ended input SSI may be directly coupled to the second single-ended output SSO, coupling RF power from the second single-ended output SSO may be equivalent to coupling RF power from the second single-ended input SSI.

[0323] The second non-quadrature path power coupler 190 is coupled to the second single-ended output SSO and couples a portion of RF power flowing though the second single-ended output SSO to provide a second non-quadrature path power output signal SNPO. In an additional embodiment of the second RF PA 54, the second non-quadrature path power coupler 190 is coupled to the second single-ended input SSI and couples a portion of RF power flowing though the second single-ended input SSI to provide the second non-quadrature path power output signal SNPO.

[0324] FIG. 29 shows details of the first in-phase amplification path 126, the first quadrature-phase amplification path 128, and the first quadrature RF combiner 130 illustrated in FIG. 22 according to one embodiment of the first in-phase amplification path 126, the first quadrature-phase amplification path 128, and the first quadrature RF combiner 130. The first in-phase combiner impedance matching circuit 148 and the first quadrature-phase combiner impedance matching circuit 158 have been omitted from the first in-phase amplification path 126 and the first quadrature-phase amplification path 128, respectively. The first quadrature RF combiner 130 includes first phase-shifting circuitry 192 and a first Wilkinson RF combiner 194. The first phase-shifting circuitry 192 has the first in-phase input FII and the first quadrature-phase input FQI. The first Wilkinson RF combiner 194 has the first quadrature combiner output FCO.

[0325] During the first PA operating mode, the first phase-shifting circuitry 192 receives and phase-aligns RF signals from the first in-phase final PA stage 146 and the first quadrature-phase final PA stage 156 via the first in-phase input FII and the first quadrature-phase input FQI, respectively, to provide phase-aligned RF signals to the first Wilkinson RF combiner 194. The first Wilkinson RF combiner 194 combines phase-aligned RF signals to provide the first RF output signal FRFO via the first quadrature combiner output FCO. The first phase-shifting circuitry 192 and the first Wilkinson RF combiner 194 may provide stable input impedances presented at the first in-phase input FII and the first quadrature-phase input FQI, respectively, which allows elimination of the first in-phase combiner impedance matching circuit 148 and the first quadrature-phase combiner impedance matching circuit 158.

[0326] FIG. 30 shows details of the first feeder PA stage 114, the first quadrature RF splitter 124, the first in-phase final PA impedance matching circuit 144, the first in-phase final PA stage 146, the first quadrature-phase final PA impedance matching circuit 154, and the first quadrature-phase final PA stage 156 illustrated in FIG. 29 according to one embodiment of the first feeder PA stage 114, the first quadrature RF splitter 124, the first in-phase final PA impedance matching circuit 144, the first in-phase final PA stage 146, the first quadrature-phase final PA impedance matching circuit 154, and the first quadrature-phase final PA stage 156. Further, FIG. 30 shows a portion of the first phase-shifting circuitry 192 illustrated in FIG. 29.

[0327] The first in-phase final PA stage 146 includes a first in-phase final transistor element 196, first in-phase biasing circuitry 198, and a first in-phase collector inductive element LCI. The first quadrature-phase final PA stage 156 includes a first quadrature-phase final transistor element 200, first quadrature-phase biasing circuitry 202, and a first quadrature-phase collector inductive element LCQ. The first in-phase final PA impedance matching circuit 144 includes a first in-phase series capacitive element CSI1, a second in-phase series capacitive element CSI2, and a first in-phase shunt inductive element LUI. The first quadrature-phase final PA impedance matching circuit 154 includes a first quadrature-phase series capacitive element CSQ1, a second quadrature-phase series capacitive element CSQ2, and a first quadrature-phase shunt inductive element LUQ.

[0328] The first quadrature RF splitter 124 includes a first pair 204 of tightly coupled inductors and a first isolation port resistive element RI1. The first pair 204 of tightly coupled inductors has first parasitic capacitance 206 between the first pair 204 of tightly coupled inductors. Additionally, the first quadrature RF splitter 124 has the first single-ended input FSI, the first in-phase output FIO, and the first quadrature-phase output FQO. The first feeder PA stage 114 includes the first output transistor element 180, first feeder biasing circuitry 208, a first DC blocking capacitive element CD1, a first base resistive element RB1, and a first collector inductive element LC1. Additionally, the first feeder PA stage 114 has the first single-ended output FSO.

[0329] The first output transistor element 180 shown is an NPN bipolar transistor element. Other embodiments of the first output transistor element 180 may use other types of transistor elements, such as field effect transistor elements (FET) elements. The first DC blocking capacitive element CD1 is coupled between the first feeder PA impedance matching circuit 112 (FIG. 22) and the first base resistive element RB. A base of the first output transistor element 180 and the first feeder biasing circuitry 208 are coupled to the first base resistive element RB1. In alternate embodiments of the first feeder PA stage 114, the first base resistive element RB1, the first DC blocking capacitive element CD1, or both may be omitted. The first feeder biasing circuitry 208 receives the first driver bias signal FDB. An emitter of the first output transistor element 180 is coupled to a ground. A collector of the first output transistor element 180 is coupled to the first single-ended output FSO. One end of the first collector inductive element LC1 is coupled to the first single-ended output FSO. An opposite end of the first collector inductive element LC1 receives the envelope power supply signal EPS. The first single-ended output FSO is coupled to the first single-ended input FSI.

[0330] During the first PA operating mode, the first output transistor element 180 receives and amplifies an RF signal from the first feeder PA impedance matching circuit 112 (FIG. 22) via the first DC blocking capacitive element CD1 and the first base resistive element RB1 to provide the first RF feeder output signal FFO (FIG. 29) to the first single-ended input FSI via the first single-ended output FSO. The envelope power supply signal EPS provides power for amplification via the first collector inductive element LC1. The first feeder biasing circuitry 208 biases the first output transistor element 180. The first driver bias signal FDB provides power for biasing the first output transistor element 180 to the first feeder biasing circuitry 208.

[0331] The first quadrature RF splitter 124 illustrated in FIG. 30 is a quadrature hybrid coupler. In this regard, the first pair 204 of tightly coupled inductors, the first parasitic capacitance 206, and the first isolation port resistive element RI1 provide quadrature hybrid coupler functionality. As such, the first single-ended input FSI functions as an input port to the quadrature hybrid coupler, the first in-phase output FIO functions as a zero degree output port from the quadrature hybrid coupler, and the first quadrature-phase output FQO functions as a 90 degree output port from the quadrature hybrid coupler. One of the first pair 204 of tightly coupled inductors is coupled between the first single-ended input FSI and the first in-phase output FIO. Another of the first pair 204 of tightly coupled inductors has a first end coupled to the first quadrature-phase output FQO and a second end coupled to the first isolation port resistive element RI1. As such, the second end functions as an isolation port of the quadrature hybrid coupler. In this regard, the first isolation port resistive element RI1 is coupled between the isolation port and the ground. The first in-phase output FIO is coupled to the first in-phase series capacitive element CSI1 and the first quadrature-phase output FQO is coupled to the first quadrature-phase series capacitive element CSQ1.

[0332] During the first PA operating mode, the first pair 204 of tightly coupled inductors receives, splits, and phase-shifts the first RF feeder output signal FFO (FIG. 29) from the first single-ended output FSO via the first single-ended input FSI to provide split, phase-shifted output signals to the first in-phase series capacitive element CSI1 and the first quadrature-phase series capacitive element CSQ1. As previously mentioned, the first input impedance is presented at the first single-ended input FSI. As such, the first input impedance is substantially based on the first parasitic capacitance 206 and inductances of the first pair 204 of tightly coupled inductors.

[0333] The first in-phase series capacitive element CSI1 and the second in-phase series capacitive element CSI2 are coupled in series between the first in-phase output FIO and a base of the first in-phase final transistor element 196. The first in-phase shunt inductive element LUI is coupled between the ground and a junction between the first in-phase series capacitive element CSI1 and the second in-phase series capacitive element CSI2. The first quadrature-phase series capacitive element CSQ1 and the second quadrature-phase series capacitive element CSQ2 are coupled in series between the first quadrature-phase output FQO and a base of the first quadrature-phase final transistor element 200. The first quadrature-phase shunt inductive element LUQ is coupled between the ground and a junction between the first quadrature-phase series capacitive element CSQ1 and the second quadrature-phase series capacitive element CSQ2.

[0334] The first in-phase series capacitive element CSI1, the second in-phase series capacitive element CSI2, and the first in-phase shunt inductive element LUI form a “T” network, which may provide at least an approximate impedance match between the first in-phase output FIO and the base of the first in-phase final transistor element 196. Similarly, the first quadrature-phase series capacitive element CSQ1, the second quadrature-phase series capacitive element CSQ2, and the first quadrature-phase shunt inductive element LUQ form a “T” network, which may provide at least an approximate impedance match between the first quadrature-phase output FQO and the base of the first quadrature-phase final transistor element 200.

[0335] During the first PA operating mode, the first in-phase final PA impedance matching circuit 144 receives and forwards an RF signal from the first in-phase output FIO to the base of the first in-phase final transistor element 196 via the first in-phase series capacitive element CSI1 and the second in-phase series capacitive element CSI2. During the first PA operating mode, the first quadrature-phase final PA impedance matching circuit 154 receives and forwards an RF signal from the first quadrature-phase output FQO to the base of the first quadrature-phase final transistor element 200 via the first quadrature-phase series capacitive element CSQ1 and the second quadrature-phase series capacitive element CSQ2.

[0336] The first in-phase final transistor element 196 shown is an NPN bipolar transistor element. Other embodiments of the first in-phase final transistor element 196 may use other types of transistor elements, such as FET elements. The base of the first in-phase final transistor element 196 and the first in-phase biasing circuitry 198 are coupled to the second in-phase series capacitive element CSI2. The first in-phase biasing circuitry 198 receives the first final bias signal FFB. An emitter of the first in-phase final transistor element 196 is coupled to the ground. A collector of the first in-phase final transistor element 196 is coupled to the first in-phase input FII. One end of the first in-phase collector inductive element LCI is coupled to the collector of the first in-phase final transistor element 196. An opposite end of the first in-phase collector inductive element LCI receives the envelope power supply signal EPS.

[0337] During the first PA operating mode, the first in-phase final transistor element 196 receives and amplifies an RF signal from the second in-phase series capacitive element CSI2 to provide an RF output signal to the first in-phase input FII. The envelope power supply signal EPS provides power for amplification via the first in-phase collector inductive element LCI. The first in-phase biasing circuitry 198 biases the first in-phase final transistor element 196. The first final bias signal FFB provides power for biasing the first in-phase final transistor element 196 to the first in-phase biasing circuitry 198.

[0338] The first quadrature-phase final transistor element 200 shown is an NPN bipolar transistor element. Other embodiments of the first quadrature-phase final transistor element 200 may use other types of transistor elements, such as FET elements. The base of the first quadrature-phase final transistor element 200 and the first quadrature-phase biasing circuitry 202 are coupled to the second quadrature-phase series capacitive element CSQ2. The first quadrature-phase biasing circuitry 202 receives the first final bias signal FFB. An emitter of the first quadrature-phase final transistor element 200 is coupled to the ground. A collector of the first quadrature-phase final transistor element 200 is coupled to the first quadrature-phase input FQI. One end of the first quadrature-phase collector inductive element LCQ is coupled to the collector of the first quadrature-phase final transistor element 200. An opposite end of the first quadrature-phase collector inductive element LCQ receives the envelope power supply signal EPS.

[0339] During the first PA operating mode, the first quadrature-phase final transistor element 200 receives and amplifies an RF signal from the second quadrature-phase series capacitive element CSQ2 to provide an RF output signal to the first quadrature-phase input FQI. The envelope power supply signal EPS provides power for amplification via the first quadrature-phase collector inductive element LCQ. The first quadrature-phase biasing circuitry 202 biases the first quadrature-phase final transistor element 200. The first final bias signal FFB provides power for biasing the first quadrature-phase final transistor element 200 to the first quadrature-phase biasing circuitry 202.

[0340] In one embodiment of the RF PA circuitry 30 (FIG. 5), the RF PA circuitry 30 includes a first PA semiconductor die 210. In one embodiment of the first PA semiconductor die 210, the first PA semiconductor die 210 includes the first output transistor element 180, the first in-phase final transistor element 196, the first in-phase biasing circuitry 198, the first quadrature-phase final transistor element 200, the first quadrature-phase biasing circuitry 202, the first pair 204 of tightly coupled inductors, the first feeder biasing circuitry 208, the first in-phase series capacitive element CSI1, the second in-phase series capacitive element CSI2, the first quadrature-phase series capacitive element CSQ1, the second quadrature-phase series capacitive element CSQ2, the first isolation port resistive element RI1, the first base resistive element RB1, and the first DC blocking capacitive element CD1.

[0341] In alternate embodiments of the first PA semiconductor die 210, the first PA semiconductor die 210 may not include any or all of the first output transistor element 180, the first in-phase final transistor element 196, the first in-phase biasing circuitry 198, the first quadrature-phase final transistor element 200, the first quadrature-phase biasing circuitry 202, the first pair 204 of tightly coupled inductors, the first feeder biasing circuitry 208, the first in-phase series capacitive element CSI1, the second in-phase series capacitive element CSI2, the first quadrature-phase series capacitive element CSQ1, the second quadrature-phase series capacitive element CSQ2, the first isolation port resistive element RI1, the first base resistive element RB1, and the first DC blocking capacitive element CD1.

[0342] FIG. 31 shows details of the first feeder PA stage 114, the first quadrature RF splitter 124, the first in-phase final PA impedance matching circuit 144, the first in-phase final PA stage 146, the first quadrature-phase final PA impedance matching circuit 154, and the first quadrature-phase final PA stage 156 illustrated in FIG. 29 according to an alternate embodiment of the first feeder PA stage 114, the first quadrature RF splitter 124, the first in-phase final PA impedance matching circuit 144, the first in-phase final PA stage 146, the first quadrature-phase final PA impedance matching circuit 154, and the first quadrature-phase final PA stage 156. Further, FIG. 31 shows a portion of the first phase-shifting circuitry 192 illustrated in FIG. 29.

[0343] The first feeder PA stage 114, the first in-phase final PA impedance matching circuit 144, the first in-phase final PA stage 146, the first quadrature-phase final PA impedance matching circuit 154, and the first quadrature-phase final PA stage 156 illustrated in FIG. 31 are similar to the first feeder PA stage 114, the first in-phase final PA impedance matching circuit 144, the first in-phase final PA stage 146, the first quadrature-phase final PA impedance matching circuit 154, and the first quadrature-phase final PA stage 156 illustrated in FIG. 30. The first quadrature RF splitter 124 illustrated in FIG. 31 is similar to the first quadrature RF splitter 124 illustrated in FIG. 30, except the first quadrature RF splitter 124 illustrated in FIG. 31 further includes a first coupler capacitive element CC1 coupled between the first pair 204 of tightly coupled inductors and a second coupler capacitive element CC2 coupled between the first pair 204 of tightly coupled inductors. Specifically, the first coupler capacitive element CC1 is coupled between the first in-phase output FIO and the first isolation port resistive element RI1. The second coupler capacitive element CC2 is coupled between the first single-ended input FSI and the first quadrature-phase output FQO.

[0344] The first input impedance is substantially based on the first parasitic capacitance 206, inductances of the first pair 204 of tightly coupled inductors, the first coupler capacitive element CC1, and the second coupler capacitive element CC2. In general, the first input impedance is based on the first parasitic capacitance 206 and inductances of the first pair 204 of tightly coupled inductors. The first input impedance is further based on at least one coupler capacitive element, such as the first coupler capacitive element CC1, the second coupler capacitive element CC2, or both, coupled between the first pair 204 of tightly coupled inductors. In an alternate embodiment of the first quadrature RF splitter 124, either the first coupler capacitive element CC1 or the second coupler capacitive element CC2 is omitted.

[0345] FIG. 32 shows details of the first phase-shifting circuitry 192 and the first Wilkinson RF combiner 194 illustrated in FIG. 29 according to one embodiment of the first phase-shifting circuitry 192 and the first Wilkinson RF combiner 194. The first phase-shifting circuitry 192 includes a first in-phase phase-shift capacitive element CPI1, a first quadrature-phase phase-shift capacitive element CPQ1, a first in-phase phase-shift inductive element LPI1, and a first quadrature-phase phase-shift inductive element LPQ1. The first Wilkinson RF combiner 194 includes a first Wilkinson resistive element RW1, a first Wilkinson capacitive element CW1, a first Wilkinson in-phase side capacitive element CWI1, a first Wilkinson quadrature-phase side capacitive element CWQ1, a first Wilkinson in-phase side inductive element LWI1, a first Wilkinson quadrature-phase side inductive element LWQ1, a second DC blocking capacitive element CD2, a third DC blocking capacitive element CD3, and a fourth DC blocking capacitive element CD4

[0346] The first in-phase phase-shift capacitive element CPI1 is coupled between the first in-phase input FII and a first internal node (not shown). The first in-phase phase-shift inductive element LPI1 is coupled between the first internal node and the ground. The first quadrature-phase phase-shift inductive element LPQ1 is coupled between the first quadrature-phase input FQI and a second internal node (not shown). The first quadrature-phase phase-shift capacitive element CPQ1 is coupled between the second internal node and the ground. The second DC blocking capacitive element CD2 and the first Wilkinson resistive element RW1 are coupled in series between the first internal node and the second internal node. The first Wilkinson in-phase side capacitive element CWI1 is coupled between the first internal node and the ground. The first Wilkinson quadrature-phase side capacitive element CWQ1 is coupled between the first internal node and the ground. The first Wilkinson in-phase side inductive element LWI1 is coupled in series with the third DC blocking capacitive element CD3 between the first internal node and the first quadrature combiner output FCO. The first Wilkinson quadrature-phase side inductive element LWQ1 is coupled in series with the fourth DC blocking capacitive element CD4 between the second internal node and the first quadrature combiner output FCO. The first Wilkinson capacitive element CW1 is coupled between the first quadrature combiner output FCO and the ground.

[0347] FIG. 33 shows details of the second non-quadrature PA path 104 illustrated in FIG. 16 and details of the second quadrature PA path 106 illustrated in FIG. 18 according to one embodiment of the second non-quadrature PA path 104 and the second quadrature PA path 106. Further, FIG. 33 shows details of the second quadrature RF combiner 138 illustrated in FIG. 18 according to one embodiment of the second quadrature RF combiner 138 illustrated in FIG. 18. The second input PA impedance matching circuit 116, the second input PA stage 118, the second in-phase driver PA impedance matching circuit 160, the second in-phase driver PA stage 162, the second in-phase combiner impedance matching circuit 168, the second quadrature-phase driver PA impedance matching circuit 170, the second quadrature-phase driver PA stage 172, and the second quadrature-phase combiner impedance matching circuit 178 have been omitted from the second non-quadrature PA path 104 and the second quadrature PA path 106.

[0348] The second quadrature RF combiner 138 includes second phase-shifting circuitry 212 and a second Wilkinson RF combiner 214. The second phase-shifting circuitry 212 has the second in-phase input SII and the second quadrature-phase input SQI, and the second Wilkinson RF combiner 214 has the second quadrature combiner output SCO.

[0349] During the second PA operating mode, the second phase-shifting circuitry 212 receives and phase-aligns RF signals from the second in-phase final PA stage 166 and the second quadrature-phase final PA stage 176 via the second in-phase input SII and the second quadrature-phase input SQI, respectively, to provide phase-aligned RF signals to the second Wilkinson RF combiner 214. The second Wilkinson RF combiner 214 combines phase-aligned RF signals to provide the second RF output signal SRFO via the second quadrature combiner output SCO. The second phase-shifting circuitry 212 and the second Wilkinson RF combiner 214 may provide stable input impedances presented at the second in-phase input SII and the second quadrature-phase input SQI, respectively, which allows elimination of the second in-phase combiner impedance matching circuit 168 and the second quadrature-phase combiner impedance matching circuit 178.

[0350] FIG. 34 shows details of the second feeder PA stage 122, the second quadrature RF splitter 132, the second in-phase final PA impedance matching circuit 164, the second in-phase final PA stage 166, the second quadrature-phase final PA impedance matching circuit 174, and the second quadrature-phase final PA stage 176 illustrated in FIG. 33 according to one embodiment of the second feeder PA stage 122, the second quadrature RF splitter 132, the second in-phase final PA impedance matching circuit 164, the second in-phase final PA stage 166, the second quadrature-phase final PA impedance matching circuit 174, and the second quadrature-phase final PA stage 176. Further, FIG. 34 shows a portion of the second phase-shifting circuitry 212 illustrated in FIG. 33.

[0351] The second in-phase final PA stage 166 includes a second in-phase final transistor element 216, second in-phase biasing circuitry 218, and a second in-phase collector inductive element LLI. The second quadrature-phase final PA stage 176 includes a second quadrature-phase final transistor element 220, a second quadrature-phase biasing circuitry 222, and a second quadrature-phase collector inductive element LLQ. The second in-phase final PA impedance matching circuit 164 includes a third in-phase series capacitive element CSI3, a fourth in-phase series capacitive element CSI4, and a second in-phase shunt inductive element LNI. The second quadrature-phase final PA impedance matching circuit 174 includes a third quadrature-phase series capacitive element CSQ3, a fourth quadrature-phase series capacitive element CSQ4, and a second quadrature-phase shunt inductive element LNQ.

[0352] The second quadrature RF splitter 132 includes a second pair 224 of tightly coupled inductors and a second isolation port resistive element RI2. The second pair 224 of tightly coupled inductors has second parasitic capacitance 226 between the second pair 224 of tightly coupled inductors. Additionally, the second quadrature RF splitter 132 has the second single-ended input SSI, the second in-phase output SIO, and the second quadrature-phase output SQO. The second feeder PA stage 122 includes a second output transistor element 228, second feeder biasing circuitry 230, a fifth DC blocking capacitive element CD5, a second base resistive element RB2, and a second collector inductive element LC2. Additionally, the second feeder PA stage 122 has the second single-ended output SSO.

[0353] The second output transistor element 228 shown is an NPN bipolar transistor element. Other embodiments of the second output transistor element 228 may use other types of transistor elements, such as field effect transistor elements (FET) elements. The fifth DC blocking capacitive element CD5 is coupled between the second feeder PA impedance matching circuit 120 (FIG. 33) and the second base resistive element RB2. A base of the second output transistor element 228 and the second feeder biasing circuitry 230 are coupled to the second base resistive element RB2. In alternate embodiments of the second feeder PA stage 122, the second base resistive element RB2, the fifth DC blocking capacitive element CD5, or both may be omitted. The second feeder biasing circuitry 230 receives the second driver bias signal SDB. An emitter of the second output transistor element 228 is coupled to a ground. A collector of the second output transistor element 228 is coupled to the second single-ended output SSO. One end of the second collector inductive element LC2 is coupled to the second single-ended output SSO. An opposite end of the second collector inductive element LC2 receives the envelope power supply signal EPS. The second single-ended output SSO is coupled to the second single-ended input SSI.

[0354] During the second PA operating mode, the second output transistor element 228 receives and amplifies an RF signal from the second feeder PA impedance matching circuit 120 (FIG. 33) via the fifth DC blocking capacitive element CD5 and the second base resistive element RB2 to provide the second RF feeder output signal SFO (FIG. 33) to the second single-ended input SSI via the second single-ended output SSO. The envelope power supply signal EPS provides power for amplification via the second collector inductive element LC2. The second feeder biasing circuitry 230 biases the second output transistor element 228. The second driver bias signal SDB provides power for biasing the second output transistor element 228 to the second feeder biasing circuitry 230.

[0355] The second quadrature RF splitter 132 illustrated in FIG. 34 is a quadrature hybrid coupler. In this regard, the second pair 224 of tightly coupled inductors, the second parasitic capacitance 226, and the second isolation port resistive element RI2 provide quadrature hybrid coupler functionality. As such, the second single-ended input SSI functions as an input port to the quadrature hybrid coupler, the second in-phase output SIO functions as a zero degree output port from the quadrature hybrid coupler, and the second quadrature-phase output SQO functions as a 90 degree output port from the quadrature hybrid coupler. One of the second pair 224 of tightly coupled inductors is coupled between the second single-ended input SSI and the second in-phase output SIO. Another of the second pair 224 of tightly coupled inductors has a first end coupled to the second quadrature-phase output SQO and a second end coupled to the second isolation port resistive element RI2. As such, the second end functions as an isolation port of the quadrature hybrid coupler. In this regard, the second isolation port resistive element RI2 is coupled between the isolation port and the ground. The second in-phase output SIO is coupled to the third in-phase series capacitive element CSI3 and the second quadrature-phase output SQO is coupled to the third quadrature-phase series capacitive element CSQ3.

[0356] During the second PA operating mode, the second pair 224 of tightly coupled inductors receives, splits, and phase-shifts the second RF feeder output signal SFO (FIG. 33) from the second single-ended output SSO via the second single-ended input SSI to provide split, phase-shifted output signals to the third in-phase series capacitive element CSI3 and the third quadrature-phase series capacitive element CSQ3. As previously mentioned, the second input impedance is presented at the second single-ended input SSI. As such, the second input impedance is substantially based on the second parasitic capacitance 226 and inductances of the second pair 224 of tightly coupled inductors.

[0357] The third in-phase series capacitive element CSI3 and the fourth in-phase series capacitive element CSI4 are coupled in series between the second in-phase output SIO and a base of the second in-phase final transistor element 216. The second in-phase shunt inductive element LNI is coupled between the ground and a junction between the third in-phase series capacitive element CSI3 and the fourth in-phase series capacitive element CSI4. The third quadrature-phase series capacitive element CSQ3 and the fourth quadrature-phase series capacitive element CSQ4 are coupled in series between the second quadrature-phase output SQO and a base of the second quadrature-phase final transistor element 220. The second quadrature-phase shunt inductive element LNQ is coupled between the ground and a junction between the third quadrature-phase series capacitive element CSQ3 and the fourth quadrature-phase series capacitive element CSQ4.

[0358] The third in-phase series capacitive element CSI3, the fourth in-phase series capacitive element CSI4, and the second in-phase shunt inductive element LNI form a “T” network, which may provide at least an approximate impedance match between the second in-phase output SIO and the base of the second in-phase final transistor element 216. Similarly, the third quadrature-phase series capacitive element CSQ3, the fourth quadrature-phase series capacitive element CSQ4, and the second quadrature-phase shunt inductive element LNQ form a “T” network, which may provide at least an approximate impedance match between the second quadrature-phase output SQO and the base of the second quadrature-phase final transistor element 220.

[0359] During the second PA operating mode, the second in-phase final PA impedance matching circuit 164 receives and forwards an RF signal from the second in-phase output SIO to the base of the second in-phase final transistor element 216 via the third in-phase series capacitive element CSI3 and the fourth in-phase series capacitive element CSI4. During the second PA operating mode, the second quadrature-phase final PA impedance matching circuit 174 receives and forwards an RF signal from the second quadrature-phase output SQO to the base of the second quadrature-phase final transistor element 220 via the third quadrature-phase series capacitive element CSQ3 and the fourth quadrature-phase series capacitive element CSQ4. The second in-phase final transistor element 216 shown is an NPN bipolar transistor element. Other embodiments of the second in-phase final transistor element 216 may use other types of transistor elements, such as FET elements. The base of the second in-phase final transistor element 216 and the second in-phase biasing circuitry 218 are coupled to the fourth in-phase series capacitive element CSI4.

[0360] The second in-phase biasing circuitry 218 receives the second final bias signal SFB. An emitter of the second in-phase final transistor element 216 is coupled to the ground. A collector of the second in-phase final transistor element 216 is coupled to the second in-phase input SII. One end of the second in-phase collector inductive element LLI is coupled to the collector of the second in-phase final transistor element 216. An opposite end of the second in-phase collector inductive element LLI receives the envelope power supply signal EPS.

[0361] During the second PA operating mode, the second in-phase final transistor element 216 receives and amplifies an RF signal from the fourth in-phase series capacitive element CSI4 to provide an RF output signal to the second in-phase input SII. The envelope power supply signal EPS provides power for amplification via the second in-phase collector inductive element LLI. The second in-phase biasing circuitry 218 biases the second in-phase final transistor element 216. The second final bias signal SFB provides power for biasing the second in-phase final transistor element 216 to the second in-phase biasing circuitry 218.

[0362] The second quadrature-phase final transistor element 220 shown is an NPN bipolar transistor element. Other embodiments of the second quadrature-phase final transistor element 220 may use other types of transistor elements, such as FET elements. The base of the second quadrature-phase final transistor element 220 and the second quadrature-phase biasing circuitry 222 are coupled to the fourth quadrature-phase series capacitive element CSQ4. The second quadrature-phase biasing circuitry 222 receives the second final bias signal SFB. An emitter of the second quadrature-phase final transistor element 220 is coupled to the ground. A collector of the second quadrature-phase final transistor element 220 is coupled to the second quadrature-phase input SQI. One end of the second quadrature-phase collector inductive element LLQ is coupled to the collector of the second quadrature-phase final transistor element 220. An opposite end of the second quadrature-phase collector inductive element LLQ receives the envelope power supply signal EPS.

[0363] During the second PA operating mode, the second quadrature-phase final transistor element 220 receives and amplifies an RF signal from the fourth quadrature-phase series capacitive element CSQ4 to provide an RF output signal to the second quadrature-phase input SQI. The envelope power supply signal EPS provides power for amplification via the second quadrature-phase collector inductive element LLQ. The second quadrature-phase biasing circuitry 222 biases the second quadrature-phase final transistor element 220. The second final bias signal SFB provides power for biasing the second quadrature-phase final transistor element 220 to the second quadrature-phase biasing circuitry 222.

[0364] In one embodiment of the RF PA circuitry 30 (FIG. 5), the RF PA circuitry 30 includes a second PA semiconductor die 232. In one embodiment of the second PA semiconductor die 232, the second PA semiconductor die 232 includes the second output transistor element 228, second in-phase final transistor element 216, second in-phase biasing circuitry 218, the second quadrature-phase final transistor element 220, second quadrature-phase biasing circuitry 222, the second pair 224 of tightly coupled inductors, the second feeder biasing circuitry 230, the third in-phase series capacitive element CSI3, the fourth in-phase series capacitive element CSI4, the third quadrature-phase series capacitive element CSQ3, the fourth quadrature-phase series capacitive element CSQ4, the second isolation port resistive element RI2, the second base resistive element RB2, and the fifth DC blocking capacitive element CD5.

[0365] In alternate embodiments of the second PA semiconductor die 232, the second PA semiconductor die 232 may not include any or all of the second output transistor element 228, the second in-phase final transistor element 216, the second in-phase biasing circuitry 218, the second quadrature-phase final transistor element 220, the second quadrature-phase biasing circuitry 222, the second pair 224 of tightly coupled inductors, the second feeder biasing circuitry 230, the third in-phase series capacitive element CSI3, the fourth in-phase series capacitive element CSI4, the third quadrature-phase series capacitive element CSQ3, the fourth quadrature-phase series capacitive element CSQ4, the second isolation port resistive element RI2, the second base resistive element RB2, and the fifth DC blocking capacitive element CD5.

[0366] FIG. 35 shows details of the second phase-shifting circuitry 212 and the second Wilkinson RF combiner 214 illustrated in FIG. 33 according to one embodiment of the second phase-shifting circuitry 212 and the second Wilkinson RF combiner 214. The second phase-shifting circuitry 212 includes a second in-phase phase-shift capacitive element CPI2, a second quadrature-phase phase-shift capacitive element CPQ2, a second in-phase phase-shift inductive element LPI2, and a second quadrature-phase phase-shift inductive element LPQ2. The second Wilkinson RF combiner 214 includes a second Wilkinson resistive element RW2, a second Wilkinson capacitive element CW2, a second Wilkinson in-phase side capacitive element CWI2, a second Wilkinson quadrature-phase side capacitive element CWQ2, a second Wilkinson in-phase side inductive element LWI2, a second Wilkinson quadrature-phase side inductive element LWQ2, a sixth DC blocking capacitive element CD6, a seventh DC blocking capacitive element CD7, and a eighth DC blocking capacitive element CD8.

[0367] The second in-phase phase-shift capacitive element CPI2 is coupled between the second in-phase input SII and a third internal node (not shown). The second in-phase phase-shift inductive element LPI2 is coupled between the third internal node and the ground. The second quadrature-phase phase-shift inductive element LPQ2 is coupled between the second quadrature-phase input SQI and a fourth internal node (not shown). The second quadrature-phase phase-shift capacitive element CPQ2 is coupled between the fourth internal node and the ground. The sixth DC blocking capacitive element CD6 and the second Wilkinson resistive element RW2 are coupled in series between the third internal node and the fourth internal node. The second Wilkinson in-phase side capacitive element CWI2 is coupled between the third internal node and the ground. The second Wilkinson quadrature-phase side capacitive element CWQ2 is coupled between the third internal node and the ground. The second Wilkinson in-phase side inductive element LWI2 is coupled in series with the seventh DC blocking capacitive element CD7 between the third internal node and the second quadrature combiner output SCO. The second Wilkinson quadrature-phase side inductive element LWQ2 is coupled in series with the eighth DC blocking capacitive element CD8 between the fourth internal node and the second quadrature combiner output SCO. The second Wilkinson capacitive element CW2 is coupled between the second quadrature combiner output SCO and the ground.

[0368] FIG. 36 shows details of the first PA semiconductor die 210 illustrated in FIG. 30 according to one embodiment of the first PA semiconductor die 210. The first PA semiconductor die 210 includes a first substrate and functional layers 234, multiple insulating layers 236, and multiple metallization layers 238. Some of the insulating layers 236 may be used to separate some of the metallization layers 238 from one another. In one embodiment of the metallization layers 238, each of the metallization layers 238 is about parallel to at least another of the metallization layers 238. In this regard the metallization layers 238 may be planar. In an alternate embodiment of the metallization layers 238, the metallization layers 238 are formed over a non-planar structure, such that spacing between pairs of the metallization layers 238 is about constant. In one embodiment of the metallization layers 238, each of the first pair 204 of tightly coupled inductors (FIG. 30) is constructed using at least one of the metallization layers 238.

[0369] A summary of linear mode and non-linear mode quadrature PA circuitry is presented, followed by a detailed description of the linear mode and non-linear mode quadrature PA circuitry according to one embodiment of the present disclosure. Multi-mode multi-band RF PA circuitry includes a multi-mode multi-band quadrature RF PA coupled to multi-mode multi-band switching circuitry via a single output. The switching circuitry provides at least one non-linear mode output and multiple linear mode outputs. The non-linear mode output may be associated with at least one non-linear mode RF communications band and each linear mode output may be associated with a corresponding linear mode RF communications band. The outputs from the switching circuitry may be coupled to an antenna port via front-end aggregation circuitry. The quadrature nature of the quadrature PA path may provide tolerance for changes in antenna loading conditions.

[0370] One embodiment of the RF PA circuitry includes a highband multi-mode multi-band quadrature RF PA coupled to highband multi-mode multi-band switching circuitry and a lowband multi-mode multi-band quadrature RF PA coupled to lowband multi-mode multi-band switching circuitry. The highband switching circuitry may be associated with at least one highband non-linear mode RF communications band and multiple highband linear mode RF communications bands. The lowband switching circuitry may be associated with at least one lowband non-linear mode RF communications band and multiple lowband linear mode RF communications bands.

[0371] FIG. 37 shows details of the RF PA circuitry 30 illustrated in FIG. 5 according to one embodiment of the RF PA circuitry 30. The RF PA circuitry 30 illustrated in FIG. 37 is similar to the RF PA circuitry 30 illustrated in FIG. 8, except in the RF PA circuitry 30 illustrated in FIG. 37, the first RF PA 50 is a first multi-mode multi-band quadrature RF PA; the second RF PA 54 is a second multi-mode multi-band quadrature RF PA; the alpha switching circuitry 52 is multi-mode multi-band RF switching circuitry; the first RF PA 50 includes a single alpha PA output SAP; the second RF PA 54 includes a single beta PA output SBP; the alpha switching circuitry 52 further includes a first alpha non-linear mode output FANO, a first alpha linear mode output FALO, and up to and including an R^TH alpha linear mode output RALO; and the beta switching circuitry 56 further includes a first beta non-linear mode output FBNO, a first beta linear mode output FBLO, and up to and including an S^TH beta linear mode output SBLO. In general, the alpha switching circuitry 52 includes a group of alpha linear mode outputs FALO, RALO and the beta switching circuitry 56 includes a group of beta linear mode outputs FBLO, SBLO.

[0372] The first RF PA 50 is coupled to the alpha switching circuitry 52 via the single alpha PA output SAP. The second RF PA 54 is coupled to the beta switching circuitry 56 via the single beta PA output SBP. In one embodiment of the first RF PA 50, the single alpha PA output SAP is a single-ended output. In one embodiment of the second RF PA 54, the single beta PA output SBP is a single-ended output. In one embodiment of the alpha switching circuitry 52, the first alpha non-linear mode output FANO is associated with a first non-linear mode RF communications band and each of the group of alpha linear mode outputs FALO, RALO is associated with a corresponding one of a first group of linear mode RF communications bands. In one embodiment of the beta switching circuitry 56, the first beta non-linear mode output FBNO is associated with a second non-linear mode RF communications band and each of the group of beta linear mode outputs FBLO, SBLO is associated with a corresponding one of a second group of linear mode RF communications bands.

[0373] In an alternate embodiment of the alpha switching circuitry 52, the first alpha non-linear mode output FANO is associated with a first group of non-linear mode RF communications bands, which includes the first non-linear mode RF communications band. In an alternate embodiment of the beta switching circuitry 56, the first beta non-linear mode output FBNO is associated with a second group of non-linear mode RF communications bands, which includes the second non-linear mode RF communications band.

[0374] In one embodiment of the RF communications system 26 (FIG. 5), the RF communications system 26 operates in one of a group of communications modes. Control circuitry, which may include the control circuitry 42 (FIG. 5), the PA control circuitry 94 (FIG. 13), or both, selects one of the group of communications modes. In one embodiment of the RF communications system 26, the group of communications modes includes a first alpha non-linear mode and a group of alpha linear modes. In an alternate embodiment of the RF communications system 26, the group of communications modes includes the first alpha non-linear mode, the group of alpha linear modes, a first beta non-linear mode, and a group of beta non-linear modes. In an additional embodiment of the RF communications system 26, the group of communications modes includes a group of alpha non-linear modes, the group of alpha linear modes, a group of beta non-linear modes, and the group of beta non-linear modes. Other embodiments of the RF communications system 26 may omit any or all of the communications modes.

[0375] In one embodiment of the first alpha non-linear mode, the first alpha non-linear mode is a half-duplex mode. In one embodiment of the first beta non-linear mode, the beta alpha non-linear mode is a half-duplex mode. In one embodiment of the group of alpha linear modes, each of the group of alpha linear modes is a full-duplex mode. In one embodiment of the group of beta linear modes, each of the group of beta linear modes is a full-duplex mode.

[0376] In one embodiment of the first RF PA 50, during the first alpha non-linear mode and during each of the group of alpha linear modes, the first RF PA 50 receives and amplifies the first RF input signal FRFI to provide the first RF output signal FRFO via the single alpha PA output SAP. Further, during the first beta non-linear mode and during each of the group of beta linear modes, the first RF PA 50 does not receive or amplify the first RF input signal FRFI to provide the first RF output signal FRFO.

[0377] In one embodiment of the second RF PA 54, during the first beta non-linear mode and during each of the group of beta linear modes, the second RF PA 54 receives and amplifies the second RF input signal SRFI to provide the second RF output signal SRFO via the single beta PA output SBP. Further, during the first alpha non-linear mode and during each of the group of alpha linear modes, the second RF PA 54 does not receive or amplify the second RF input signal SRFI to provide the second RF output signal SRFO.

[0378] In one embodiment of the alpha switching circuitry 52, during the first alpha non-linear mode, the alpha switching circuitry 52 receives and forwards the first RF output signal FRFO to provide the first alpha RF transmit signal FATX via the first alpha non-linear mode output FANO. During a first alpha linear mode, the alpha switching circuitry 52 receives and forwards the first RF output signal FRFO to provide the second alpha RF transmit signal SATX via the first alpha linear mode output FALO. During an R^TH alpha linear mode, the alpha switching circuitry 52 receives and forwards the first RF output signal FRFO to provide the P^TH alpha RF transmit signal PATX. In general, during each of the group of alpha linear modes, the alpha switching circuitry 52 receives and forwards the first RF output signal FRFO to provide a corresponding one of a group of alpha RF transmit signals SATX, PATX via a corresponding one of the group of alpha linear mode outputs FALO, RALO.

[0379] In one embodiment of the beta switching circuitry 56, during the first beta non-linear mode, the beta switching circuitry 56 receives and forwards the second RF output signal SRFO to provide the first beta RF transmit signal FBTX via the first beta non-linear mode output FBNO. During a first beta linear mode, the beta switching circuitry 56 receives and forwards the second RF output signal SRFO to provide the second beta RF transmit signal SBTX via the first beta linear mode output FBLO. During an S^TH beta linear mode, the beta switching circuitry 56 receives and forwards the second RF output signal SRFO to provide the Q^TH beta RF transmit signal QBTX. In general, during each of the group of beta linear modes, the beta switching circuitry 56 receives and forwards the second RF output signal SRFO to provide a corresponding one of a group of beta RF transmit signals SBTX, QBTX via a corresponding one of the group of beta linear mode outputs FBLO, SBLO.

[0380] FIG. 38 shows details of the RF PA circuitry 30 illustrated in FIG. 5 according to an alternate embodiment of the RF PA circuitry 30. The RF PA circuitry 30 illustrated in FIG. 38 is similar to the RF PA circuitry 30 illustrated in FIG. 9, except in the RF PA circuitry 30 illustrated in FIG. 38, the first RF PA 50 is the first multi-mode multi-band quadrature RF PA; the second RF PA 54 is the second multi-mode multi-band quadrature RF PA; the alpha switching circuitry 52 is multi-mode multi-band RF switching circuitry; the first RF PA 50 includes the single alpha PA output SAP; the second RF PA 54 includes the single beta PA output SBP; the alpha switching circuitry 52 further includes the first alpha non-linear mode output FANO, a second alpha non-linear mode output SANO, the first alpha linear mode output FALO, and up to and including the R^TH alpha linear mode output RALO; and the beta switching circuitry 56 further includes the first beta non-linear mode output FBNO, a second beta non-linear mode output SBNO, the first beta linear mode output FBLO, and up to and including the S^TH beta linear mode output SBLO. In general, the alpha switching circuitry 52 includes the group of alpha linear mode outputs FALO, RALO and the beta switching circuitry 56 includes the group of beta linear mode outputs FBLO, SBLO. Additionally, in general, the alpha switching circuitry 52 includes at least the first alpha harmonic filter 70 and the beta switching circuitry 56 includes at least the first beta harmonic filter 74.

[0381] A summary of dual-path PA circuitry with harmonic filters is presented, followed by a detailed description of the dual-path PA circuitry with harmonic filters according to one embodiment of the present disclosure. The dual-path PA circuitry includes a first transmit path and a second transmit path. Each transmit path has an RF PA and switching circuitry having at least one harmonic filter. Each RF PA may be coupled to its corresponding switching circuitry via a single output. Each switching circuitry provides at least one output via a harmonic filter and multiple outputs without harmonic filtering. The output via the harmonic filter may be a non-linear mode output and the outputs without harmonic filtering may be linear mode outputs. The non-linear mode output may be associated with at least one non-linear mode RF communications band and the linear mode outputs may be associated with multiple linear mode RF communications bands. As such, each RF PA may be a multi-mode multi-band RF PA.

[0382] The outputs from the switching circuitry may be coupled to an antenna port via front-end aggregation circuitry. The quadrature nature of the quadrature PA path may provide tolerance for changes in antenna loading conditions. One embodiment of the RF PA circuitry includes a highband multi-mode multi-band quadrature RF PA coupled to highband multi-mode multi-band switching circuitry and a lowband multi-mode multi-band quadrature RF PA coupled to lowband multi-mode multi-band switching circuitry. The highband switching circuitry may be associated with at least one highband non-linear mode RF communications band and multiple highband linear mode RF communications bands. The lowband switching circuitry may be associated with at least one lowband non-linear mode RF communications band and multiple lowband linear mode RF communications bands.

[0383] In one embodiment of the RF PA circuitry 30, the first alpha non-linear mode output FANO is a first alpha output, the second alpha non-linear mode output SANO is a second alpha output, the first beta non-linear mode output FBNO is a first beta output, the second beta non-linear mode output SBNO is a second beta output, the group of alpha linear mode outputs FALO, RALO is a group of alpha outputs, and the group of beta linear mode outputs FBLO, SBLO is a group of beta outputs. The alpha switching circuitry 52 provides the first alpha output via the first alpha harmonic filter 70. The alpha switching circuitry 52 provides the second alpha output via the second alpha harmonic filter 76. The alpha switching circuitry 52 provides the group of alpha outputs without harmonic filtering. The beta switching circuitry 56 provides the first beta output via the first beta harmonic filter 74. The beta switching circuitry 56 provides the second beta output via the second beta harmonic filter 78. The beta switching circuitry 56 provides the group of beta outputs without harmonic filtering.

[0384] In one embodiment of the RF communications system 26 (FIG. 5), the RF communications system 26 operates in one of a group of communications modes. Control circuitry, which may include the control circuitry 42 (FIG. 5), the PA control circuitry 94 (FIG. 13), or both, selects one of the group of communications modes. In one embodiment of the RF communications system 26, the group of communications modes includes the first alpha non-linear mode, the group of alpha linear modes, the first beta non-linear mode, and the group of beta non-linear modes. Other embodiments of the RF communications system 26 may omit any or all of the communications modes. In one embodiment of the first alpha non-linear mode, the first alpha non-linear mode is a half-duplex mode. In one embodiment of the first beta non-linear mode, the beta alpha non-linear mode is a half-duplex mode. In one embodiment of the group of alpha linear modes, each of the group of alpha linear modes is a full-duplex mode. In one embodiment of the group of beta linear modes, each of the group of beta linear modes is a full-duplex mode.

[0385] In one embodiment of the first RF PA 50, during the first alpha non-linear mode and during each of the group of alpha linear modes, the first RF PA 50 receives and amplifies the first RF input signal FRFI to provide the first RF output signal FRFO via the single alpha PA output SAP. Further, during the first beta non-linear mode and during each of the group of beta linear modes, the first RF PA 50 does not receive or amplify the first RF input signal FRFI to provide the first RF output signal FRFO.

[0386] In one embodiment of the second RF PA 54, during the first beta non-linear mode and during each of the group of beta linear modes, the second RF PA 54 receives and amplifies the second RF input signal SRFI to provide the second RF output signal SRFO via the single beta PA output SBP. Further, during the first alpha non-linear mode and during each of the group of alpha linear modes, the second RF PA 54 does not receive or amplify the second RF input signal SRFI to provide the second RF output signal SRFO.

[0387] In one embodiment of the alpha switching circuitry 52, during the first alpha non-linear mode, the alpha switching circuitry 52 receives and forwards the first RF output signal FRFO to provide the first alpha RF transmit signal FATX via the first alpha harmonic filter 70 and the first alpha output. During each of the group of alpha linear modes, the alpha switching circuitry 52 receives and forwards the first RF output signal FRFO to provide a corresponding one of a group of alpha RF transmit signals TATX, PATX via a corresponding one of the group of alpha outputs.

[0388] In one embodiment of the beta switching circuitry 56, during the first beta non-linear mode, the beta switching circuitry 56 receives and forwards the second RF output signal SRFO to provide the first beta RF transmit signal FBTX via the first beta harmonic filter 74 and the first beta output. During each of the group of beta linear modes, the beta switching circuitry 56 receives and forwards the second RF output signal SRFO to provide a corresponding one of a group of beta RF transmit signals TBTX, QBTX via a corresponding one of the group of beta outputs.

[0389] FIG. 39 shows details of the RF PA circuitry 30 illustrated in FIG. 5 according to an additional embodiment of the RF PA circuitry 30. The RF PA circuitry 30 illustrated in FIG. 39 is similar to the RF PA circuitry 30 illustrated in FIG. 37, except the RF PA circuitry 30 illustrated in FIG. 39 further includes the switch driver circuitry 98 (FIG. 13) and shows details of the alpha RF switch 68 and the beta RF switch 72. The alpha RF switch 68 includes a first alpha switching device 240, a second alpha switching device 242, and a third alpha switching device 244. The beta RF switch 72 includes a first beta switching device 246, a second beta switching device 248, and a third beta switching device 250. Alternate embodiments of the alpha RF switch 68 may include any number of alpha switching devices. Alternate embodiments of the beta RF switch 72 may include any number of beta switching devices.

[0390] The first alpha switching device 240 is coupled between the single alpha PA output SAP and the first alpha harmonic filter 70. As such, the first alpha switching device 240 is coupled between the single alpha PA output SAP and the first alpha non-linear mode output FANO via the first alpha harmonic filter 70. The second alpha switching device 242 is coupled between the single alpha PA output SAP and the first alpha linear mode output FALO. The third alpha switching device 244 is coupled between the single alpha PA output SAP and the R^TH alpha linear mode output RALO. In general, the alpha RF switch 68 includes the first alpha switching device 240 and a group of alpha switching devices, which includes the second alpha switching device 242 and the third alpha switching device 244. As previously mentioned, the alpha switching circuitry 52 includes the group of alpha linear mode outputs FALO, RALO. As such, each of the group of alpha switching devices 242, 244 is coupled between the single alpha PA output SAP and a corresponding one of the group of alpha linear mode outputs FALO, RALO. Additionally, each of the alpha switching devices 240, 242, 244 has a corresponding control input, which is coupled to the switch driver circuitry 98.

[0391] The first beta switching device 246 is coupled between the single beta PA output SBP and the first beta harmonic filter 74. As such, the first beta switching device 246 is coupled between the single beta PA output SBP and the first beta non-linear mode output FBNO via the first beta harmonic filter 74. The second beta switching device 248 is coupled between the single beta PA output SBP and the first beta linear mode output FBLO. The third beta switching device 250 is coupled between the single beta PA output SBP and the S^TH beta linear mode output SBLO. In general, the beta RF switch 72 includes the first beta switching device 246 and a group of beta switching devices, which includes the second beta switching device 248 and the third beta switching device 250. As previously mentioned, the beta switching circuitry 56 includes the group of beta linear mode outputs FBLO, SBLO. As such, each of the group of beta switching devices 248, 250 is coupled between the single beta PA output SBP and a corresponding one of the group of beta linear mode outputs FBLO, SBLO. Additionally, each of the beta switching devices 246, 248, 250 has a corresponding control input, which is coupled to the switch driver circuitry 98.

[0392] In one embodiment of the alpha RF switch 68, the first alpha switching device 240 includes multiple switching elements (not shown) coupled in series. Each of the group of alpha switching devices 242, 244 includes multiple switching elements (not shown) coupled in series. In one embodiment of the beta RF switch 72, the first beta switching device 246 includes multiple switching elements (not shown) coupled in series. Each of the group of beta switching devices 248, 250 includes multiple switching elements (not shown) coupled in series.

[0393] A summary of a PA bias supply using boosted voltage is presented, followed by a detailed description of the PA bias supply using boosted voltage according to one embodiment of the present disclosure. An RF PA bias power supply signal is provided to RF PA circuitry by boosting a voltage from a DC power supply, such as a battery. In this regard, a DC-DC converter receives a DC power supply signal from the DC power supply. The DC-DC converter provides the bias power supply signal based on the DC power supply signal, such that a voltage of the bias power supply signal is greater than a voltage of the DC power supply signal. The RF PA circuitry has an RF PA, which has a final stage that receives a final bias signal to bias the final stage, such that the final bias signal is based on the bias power supply signal. Boosting the voltage from the DC power supply may provide greater flexibility in biasing the RF PA.

[0394] In one embodiment of the DC-DC converter, the DC-DC converter includes a charge pump, which may receive and pump-up the DC power supply signal to provide the bias power supply signal. Further, the DC-DC converter may operate in one of a bias supply pump-up operating mode and at least one other operating mode, which may include any or all of a bias supply pump-even operating mode, a bias supply pump-down operating mode, and a bias supply bypass operating mode. Additionally, the DC-DC converter provides an envelope power supply signal to the RF PA, which uses the envelope power supply signal to provide power for amplification. In one embodiment of the RF PA circuitry, the RF PA circuitry includes PA bias circuitry, which receives the bias power supply signal to provide the final bias signal. The PA bias circuitry may include a final stage current analog-to-digital converter (IDAC) to receive and use the bias power supply signal in a digital-to-analog conversion to provide the final bias signal.

[0395] In an alternate embodiment of the RF PA circuitry, the RF PA circuitry includes a first RF PA and a second RF PA, which include a first final stage and a second final stage, respectively. The first RF PA may be used to receive and amplify a highband RF input signal and the second RF PA may be used to receive and amplify a lowband RF input signal. The RF PA circuitry operates in one of a first PA operating mode and a second PA operating mode, such that during the first PA operating mode, the first RF PA is active and the second RF PA is disabled. Conversely, during the second PA operating mode, the first RF PA is disabled and the second RF PA is active. The PA bias circuitry may include the final stage IDAC and a final stage multiplexer. The final stage IDAC receives and uses the bias power supply signal in a digital-to-analog conversion to provide a final stage bias signal to the final stage multiplexer. During the first PA operating mode, the final stage multiplexer receives and forwards the final stage bias signal to provide a first final bias signal to the first RF PA to bias the first final stage. During the second PA operating mode, the final stage multiplexer receives and forwards the final stage bias signal to provide a second final bias signal to the second RF PA to bias the second final stage.

[0396] FIG. 40 shows details of the first RF PA 50, the second RF PA 54, and the PA bias circuitry 96 illustrated in FIG. 13 according to one embodiment of the first RF PA 50, the second RF PA 54, and the PA bias circuitry 96. The first RF PA 50 includes a first driver stage 252 and a first final stage 254. The second RF PA 54 includes a second driver stage 256 and a second final stage 258. The PA bias circuitry 96 includes driver stage IDAC circuitry 260 and final stage IDAC circuitry 262. In general, the first RF PA 50 receives and amplifies the first RF input signal FRFI to provide the first RF output signal FRFO. Similarly, the second RF PA 54 receives and amplifies the second RF input signal SRFI to provide the second RF output signal SRFO. Specifically, the first driver stage 252 receives and amplifies the first RF input signal FRFI to provide a first final stage input signal FFSI, and the first final stage 254 receives and amplifies the first final stage input signal FFSI to provide the first RF output signal FRFO. Similarly, the second driver stage 256 receives and amplifies the second RF input signal SRFI to provide a second final stage input signal SFSI, and the second final stage 258 receives and amplifies the second final stage input signal SFSI to provide the second RF output signal SRFO.

[0397] The first driver stage 252 receives the envelope power supply signal EPS, which provides power for amplification; the first final stage 254 receives the envelope power supply signal EPS, which provides power for amplification; the second driver stage 256 receives the envelope power supply signal EPS, which provides power for amplification; and the second final stage 258 receives the envelope power supply signal EPS, which provides power for amplification. In general, the first RF PA 50 receives the first driver bias signal FDB to bias first driver stage 252 and receives the first final bias signal FFB to bias the first final stage 254. Specifically, the first driver stage 252 receives the first driver bias signal FDB to bias the first driver stage 252 and the first final stage 254 receives the first final bias signal FFB to bias the first final stage 254. Similarly, the second RF PA 54 receives the second driver bias signal SDB to bias the second driver stage 256 and receives the second final bias signal SFB to bias the second final stage 258. Specifically, the second driver stage 256 receives the second driver bias signal SDB to bias the second driver stage 256 and the second final stage 258 receives the second final bias signal SFB to bias the second final stage 258.

[0398] In general, the PA bias circuitry 96 provides the first driver bias signal FDB based on the bias power supply signal BPS, the first final bias signal FFB based on the bias power supply signal BPS, the second driver bias signal SDB based on the bias power supply signal BPS, and the second final bias signal SFB based on the bias power supply signal BPS. Specifically, the driver stage IDAC circuitry 260 provides the first driver bias signal FDB based on the bias power supply signal BPS and provides the second driver bias signal SDB based on the bias power supply signal BPS. Similarly, the final stage IDAC circuitry 262 provides the first final bias signal FFB based on the bias power supply signal BPS and provides the second final bias signal SFB based on the bias power supply signal BPS.

[0399] In one embodiment of the driver stage IDAC circuitry 260 and the final stage IDAC circuitry 262, the driver stage IDAC circuitry 260 and the final stage IDAC circuitry 262 receive the bias power supply signal BPS and the bias configuration control signal BCC. The driver stage IDAC circuitry 260 provides the first driver bias signal FDB and the second driver bias signal SDB based on the bias power supply signal BPS and the bias configuration control signal BCC. The final stage IDAC circuitry 262 provides the first final bias signal FFB and the second final bias signal SFB based on the bias power supply signal BPS and the bias configuration control signal BCC. The bias power supply signal BPS provides the power necessary to generate the bias signals FDB, FFB, SDB, SFB. A selected magnitude of each of the bias signals FDB, FFB, SDB, SFB is provided by the driver stage IDAC circuitry 260 and the final stage IDAC circuitry 262. In one embodiment of the RF PA circuitry 30, the PA control circuitry 94 selects the magnitude of any or all of the bias signals FDB, FFB, SDB, SFB and communicates the magnitude selections to the driver stage IDAC circuitry 260 and the final stage IDAC circuitry 262 via the bias configuration control signal BCC. The magnitude selections by the PA control circuitry 94 may be based on the PA configuration control signal PCC. In an alternate embodiment of the RF PA circuitry 30, the control circuitry 42 (FIG. 5) selects the magnitude of any or all of the bias signals FDB, FFB, SDB, SFB and communicates the magnitude selections to the driver stage IDAC circuitry 260 and the final stage IDAC circuitry 262 via the PA control circuitry 94.

[0400] As previously discussed, in one embodiment of the RF PA circuitry 30, the RF PA circuitry 30 operates in one of the first PA operating mode and the second PA operating mode. During the first PA operating mode, the first RF PA 50 receives and amplifies the first RF input signal FRFI to provide the first RF output signal FRFO, and the second RF PA 54 is disabled. During the second PA operating mode, the second RF PA 54 receives and amplifies the second RF input signal SRFI to provide the second RF output signal SRFO, and the first RF PA 50 is disabled.

[0401] In one embodiment of the first RF PA 50, during the second PA operating mode, the first RF PA 50 is disabled via the first driver bias signal FDB. As such, the first driver stage 252 is disabled. In an alternate embodiment of the first RF PA 50, during the second PA operating mode, the first RF PA 50 is disabled via the first final bias signal FFB. As such, the first final stage 254 is disabled. In an additional embodiment of the first RF PA 50, during the second PA operating mode, the first RF PA 50 is disabled via both the first driver bias signal FDB and the first final bias signal FFB. As such, both the first driver stage 252 and the first final stage 254 are disabled.

[0402] In one embodiment of the second RF PA 54, during the first PA operating mode, the second RF PA 54 is disabled via the second driver bias signal SDB. As such, the second driver stage 256 is disabled. In an alternate embodiment of the second RF PA 54, during the first PA operating mode, the second RF PA 54 is disabled via the second final bias signal SFB. As such, the second final stage 258 is disabled. In an additional embodiment of the second RF PA 54, during the first PA operating mode, the second RF PA 54 is disabled via both the second driver bias signal SDB and the second final bias signal SFB. As such, both the second driver stage 256 and the second final stage 258 are disabled.

[0403] In one embodiment of the RF PA circuitry 30, the PA control circuitry 94 selects the one of the first PA operating mode and the second PA operating mode. As such, the PA control circuitry 94 may control any or all of the bias signals FDB, FFB, SDB, SFB via the bias configuration control signal BCC based on the PA operating mode selection. The PA operating mode selection may be based on the PA configuration control signal PCC. In an alternate embodiment of the RF PA circuitry 30, the control circuitry 42 (FIG. 5) selects the one of the first PA operating mode and the second PA operating mode. As such, the control circuitry 42 (FIG. 5) may indicate the operating mode selection to the PA control circuitry 94 via the PA configuration control signal PCC. In an additional embodiment of the RF PA circuitry 30, the RF modulation and control circuitry 28 (FIG. 5) selects the one of the first PA operating mode and the second PA operating mode. As such, the RF modulation and control circuitry 28 (FIG. 5) may indicate the operating mode selection to the PA control circuitry 94 via the PA configuration control signal PCC. In general, selection of the PA operating mode is made by control circuitry, which may be any of the PA control circuitry 94, the RF modulation and control circuitry 28 (FIG. 5), and the control circuitry 42 (FIG. 5).

[0404] Further, during the first PA operating mode, the control circuitry selects a desired magnitude of the first driver bias signal FDB, a desired magnitude of the first final bias signal FFB, or both. During the second PA operating mode, the control circuitry selects a desired magnitude of the second driver bias signal SDB, a desired magnitude of the second final bias signal SFB, or both As such, during the first PA operating mode, the PA control circuitry 94 provides the bias configuration control signal BCC to the PA bias circuitry 96 in general and to the driver stage IDAC circuitry 260 in particular based on the desired magnitude of the first driver bias signal FDB, and the PA control circuitry 94 provides the bias configuration control signal BCC to the PA bias circuitry 96 in general and to the final stage IDAC circuitry 262 in particular based on the desired magnitude of the first final bias signal FFB. During the second PA operating mode, the PA control circuitry 94 provides the bias configuration control signal BCC to the PA bias circuitry 96 in general and to the driver stage IDAC circuitry 260 in particular based on the desired magnitude of the second driver bias signal SDB, and the PA control circuitry 94 provides the bias configuration control signal BCC to the PA bias circuitry 96 in general and to the final stage IDAC circuitry 262 in particular based on the desired magnitude of the second final bias signal SFB. In one embodiment of the PA control circuitry 94, the bias configuration control signal BCC is a digital signal.

[0405] FIG. 41 shows details of the driver stage IDAC circuitry 260 and the final stage IDAC circuitry 262 illustrated in FIG. 40 according to one embodiment of the driver stage IDAC circuitry 260 and the final stage IDAC circuitry 262. The driver stage IDAC circuitry 260 includes a driver stage IDAC 264, a driver stage multiplexer 266, and driver stage current reference circuitry 268. The final stage IDAC circuitry 262 includes a final stage IDAC 270, a final stage multiplexer 272, and final stage current reference circuitry 274.

[0406] The driver stage IDAC 264 receives the bias power supply signal BPS, the bias configuration control signal BCC, and a driver stage reference current IDSR. As such, the driver stage IDAC 264 uses the bias power supply signal BPS and the driver stage reference current IDSR in a digital-to-analog conversion to provide a driver stage bias signal DSBS. A magnitude of the digital-to-analog conversion is based on the bias configuration control signal BCC. The driver stage current reference circuitry 268 is coupled to the driver stage IDAC 264 and provides the driver stage reference current IDSR to the driver stage IDAC 264, such that during the first PA operating mode, the first driver bias signal FDB is based on the driver stage reference current IDSR, and during the second PA operating mode, the second driver bias signal SDB is based on the driver stage reference current IDSR. The driver stage current reference circuitry 268 may be disabled based on the bias configuration control signal BCC. The driver stage current reference circuitry 268 and the driver stage multiplexer 266 receive the bias configuration control signal BCC. The driver stage multiplexer 266 receives and forwards the driver stage bias signal DSBS, which is a current signal, to provide either the second driver bias signal SDB or the first driver bias signal FDB based on the bias configuration control signal BCC. During the first PA operating mode, the driver stage multiplexer 266 receives and forwards the driver stage bias signal DSBS to provide the first driver bias signal FDB based on the bias configuration control signal BCC. During the second PA operating mode, the driver stage multiplexer 266 receives and forwards the driver stage bias signal DSBS to provide the second driver bias signal SDB based on the bias configuration control signal BCC.

[0407] In this regard, during the first PA operating mode, the driver stage IDAC 264 provides the first driver bias signal FDB via the driver stage multiplexer 266, such that a magnitude of the first driver bias signal FDB is about equal to the desired magnitude of the first driver bias signal FDB. During the second PA operating mode, the driver stage IDAC 264 provides the second driver bias signal SDB via the driver stage multiplexer 266, such that a magnitude of the second driver bias signal SDB is about equal to the desired magnitude of the second driver bias signal SDB.

[0408] In one embodiment of the driver stage multiplexer 266, during the first PA operating mode, the driver stage multiplexer 266 disables the second RF PA 54 via the second driver bias signal SDB. In one embodiment of the second RF PA 54, the second RF PA 54 is disabled when the second driver bias signal SDB is about zero volts. In one embodiment of the driver stage multiplexer 266, during the second PA operating mode, the driver stage multiplexer 266 disables the first RF PA 50 via the first driver bias signal FDB. In one embodiment of the first RF PA 50, the first RF PA 50 is disabled when the first driver bias signal FDB is about zero volts. As such, in one embodiment of the driver stage multiplexer 266, during the first PA operating mode, the driver stage multiplexer 266 provides the second driver bias signal SDB, which is about zero volts, such that the second RF PA 54 is disabled, and during the second PA operating mode, the driver stage multiplexer 266 provides the first driver bias signal FDB, which is about zero volts, such that the first RF PA 50 is disabled.

[0409] The final stage IDAC 270 receives the bias power supply signal BPS, the bias configuration control signal BCC, and a final stage reference current IFSR. As such, the final stage IDAC 270 uses the bias power supply signal BPS and the final stage reference current IFSR in a digital-to-analog conversion to provide a final stage bias signal FSBS. A magnitude of the digital-to-analog conversion is based on the bias configuration control signal BCC. The final stage current reference circuitry 274 is coupled to the final stage IDAC 270 and provides the final stage reference current IFSR to the final stage IDAC 270, such that during the first PA operating mode, the first final bias signal FFB is based on the final stage reference current IFSR, and during the second PA operating mode, the second final bias signal SFB is based on the final stage reference current IFSR. The final stage current reference circuitry 274 and the final stage IDAC 270 receive the bias configuration control signal BCC. The final stage current reference circuitry 274 may be disabled based on the bias configuration control signal BCC. The final stage multiplexer 272 receives and forwards the final stage bias signal FSBS, which is a current signal, to provide either the second final bias signal SFB or the first final bias signal FFB based on the bias configuration control signal BCC. During the first PA operating mode, the final stage multiplexer 272 receives and forwards the final stage bias signal FSBS to provide the first final bias signal FFB based on the bias configuration control signal BCC. During the second PA operating mode, the final stage multiplexer 272 receives and forwards the final stage bias signal FSBS to provide the second final bias signal SFB based on the bias configuration control signal BCC.

[0410] In this regard, during the first PA operating mode, the final stage IDAC 270 provides the first final bias signal FFB via the final stage multiplexer 272, such that a magnitude of the first final bias signal FFB is about equal to the desired magnitude of the first final bias signal FFB. Specifically, the final stage IDAC 270 receives and uses the bias power supply signal BPS and the bias configuration control signal BCC in a digital-to-analog conversion to provide the first final bias signal FFB. During the second PA operating mode, the final stage IDAC 270 provides the second final bias signal SFB via the final stage multiplexer 272, such that a magnitude of the second final bias signal SFB is about equal to the desired magnitude of the second final bias signal SFB. Specifically, the final stage IDAC 270 receives and uses the bias power supply signal BPS and the bias configuration control signal BCC in a digital-to-analog conversion to provide the second final bias signal SFB.

[0411] In one embodiment of the final stage multiplexer 272, during the first PA operating mode, the final stage multiplexer 272 disables the second RF PA 54 via the second final bias signal SFB. In one embodiment of the second RF PA 54, the second RF PA 54 is disabled when the second final bias signal SFB is about zero volts. In one embodiment of the final stage multiplexer 272, during the second PA operating mode, the final stage multiplexer 272 disables the first RF PA 50 via the first final bias signal FFB. In one embodiment of the first RF PA 50, the first RF PA 50 is disabled when the first final bias signal FFB is about zero volts. As such, in one embodiment of the final stage multiplexer 272, during the first PA operating mode, the final stage multiplexer 272 provides the second final bias signal SFB, which is about zero volts, such that the second RF PA 54 is disabled, and during the second PA operating mode, the final stage multiplexer 272 provides the first final bias signal FFB, which is about zero volts, such that the first RF PA 50 is disabled.

[0412] FIG. 42 shows details of the driver stage current reference circuitry 268 and the final stage current reference circuitry 274 illustrated in FIG. 41 according to one embodiment of the driver stage current reference circuitry 268 and the final stage current reference circuitry 274. The driver stage current reference circuitry 268 includes a driver stage temperature compensation circuit 276 to temperature compensate the driver stage reference current IDSR. The final stage current reference circuitry 274 includes a final stage temperature compensation circuit 278 to temperature compensate the final stage reference current IFSR.

[0413] A summary of a charge pump based PA envelope power supply and bias power supply is presented, followed by a detailed description of the charge pump based PA envelope power supply according to one embodiment of the present disclosure. The present disclosure relates to a DC-DC converter, which includes a charge pump based RF PA envelope power supply and a charge pump based PA bias power supply. The DC-DC converter is coupled between RF PA circuitry and a DC power supply, such as a battery. As such, the PA envelope power supply provides an envelope power supply signal to the RF PA circuitry and the PA bias power supply provides a bias power supply signal to the RF PA circuitry. Both the PA envelope power supply and the PA bias power supply receive power via a DC power supply signal from the DC power supply. The PA envelope power supply includes a charge pump buck converter and the PA bias power supply includes a charge pump.

[0414] By using charge pumps, a voltage of the envelope power supply signal may be greater than a voltage of the DC power supply signal, a voltage of the bias power supply signal may be greater than the voltage of the DC power supply signal, or both. Providing boosted voltages may provide greater flexibility in providing envelope power for amplification and in biasing the RF PA circuitry. The charge pump buck converter provides the functionality of a charge pump feeding a buck converter. However, the charge pump buck converter requires fewer switching elements than a charge pump feeding a buck converter by sharing certain switching elements.

[0415] The charge pump buck converter is coupled between the DC power supply and the RF PA circuitry. The charge pump is coupled between the DC power supply and the RF PA circuitry. In one embodiment of the PA envelope power supply, the PA envelope power supply further includes a buck converter coupled between the DC power supply and the RF PA circuitry. The PA envelope power supply may operate in one of a first envelope operating mode and a second envelope operating mode. During the first envelope operating mode, the charge pump buck converter is active, and the buck converter is inactive. Conversely, during the second envelope operating mode, the charge pump buck converter is inactive, and the buck converter is active. As such, the PA envelope power supply may operate in the first envelope operating mode when a voltage above the voltage of the DC power supply signal may be needed. Conversely, the PA envelope power supply may operate in the second envelope operating mode when a voltage above the voltage of the DC power supply signal is not needed.

[0416] In one embodiment of the charge pump buck converter, the charge pump buck converter operates in one of a pump buck pump-up operating mode and at least one other pump buck operating mode, which may include any or all of a pump buck pump-down operating mode, a pump buck pump-even operating mode, and a pump buck bypass operating mode. In one embodiment of the charge pump, the charge pump operates in one of a bias supply pump-up operating mode and at least one other bias supply operating mode, which may include any or all of a bias supply pump-down operating mode, a bias supply pump-even operating mode, and a bias supply bypass operating mode.

[0417] In one embodiment of the RF PA circuitry, the RF PA circuitry has an RF PA, which is biased based on the bias power supply signal and receives the envelope power supply signal to provide power for amplification. In one embodiment of the RF PA circuitry, the RF PA has a final stage that receives a final bias signal to bias the final stage, such that the final bias signal is based on the bias power supply signal. Additionally, the DC-DC converter provides the envelope power supply signal to the RF PA, which uses the envelope power supply signal to provide power for amplification. In one embodiment of the RF PA circuitry, the RF PA circuitry includes PA bias circuitry, which receives the bias power supply signal to provide the final bias signal. In one embodiment of the PA bias circuitry, the PA bias circuitry includes a final stage IDAC to receive and use the bias power supply signal in a digital-to-analog conversion to provide the final bias signal.

[0418] In one embodiment of the RF PA circuitry, the RF PA circuitry includes a first RF PA and a second RF PA, which may include a first final stage and a second final stage, respectively. The first RF PA is used to receive and amplify a highband RF input signal and the second RF PA is used to receive and amplify a lowband RF input signal. The RF PA circuitry may operate in one of a first PA operating mode and a second PA operating mode, such that during the first PA operating mode, the first RF PA is active and the second RF PA is disabled. Conversely, during the second PA operating mode, the first RF PA is disabled and the second RF PA is active. The PA bias circuitry includes the final stage IDAC and a final stage multiplexer. The final stage IDAC receives and uses the bias power supply signal in a digital-to-analog conversion to provide a final stage bias signal to the final stage multiplexer. During the first PA operating mode, the final stage multiplexer receives and forwards the final stage bias signal to provide a first final bias signal to the first RF PA to bias the first final stage. During the second PA operating mode, the final stage multiplexer receives and forwards the final stage bias signal to provide a second final bias signal to the second RF PA to bias the second final stage.

[0419] FIG. 43 shows the RF communications system 26 according to one embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 43 is similar to the RF communications system 26 illustrated in FIG. 11; except in the RF communications system 26 illustrated in FIG. 43; the DC-DC converter 32 shows a PA envelope power supply 280 instead of showing the first power filtering circuitry 82, the charge pump buck converter 84, the buck converter 86, and the first inductive element L1; and shows a PA bias power supply 282 instead of showing the second power filtering circuitry 88 and the charge pump 92. The PA envelope power supply 280 is coupled to the RF PA circuitry 30 and the PA bias power supply 282 is coupled to the RF PA circuitry 30. Further, the PA envelope power supply 280 is coupled to the DC power supply 80 and the PA bias power supply 282 is coupled to the DC power supply 80.

[0420] The PA bias power supply 282 receives the DC power supply signal DCPS from the DC power supply 80 and provides the bias power supply signal BPS based on DC-DC conversion of the DC power supply signal DCPS. The PA envelope power supply 280 receives the DC power supply signal DCPS from the DC power supply 80 and provides the envelope power supply signal EPS based on DC-DC conversion of the DC power supply signal DCPS.

[0421] FIG. 44 shows details of the PA envelope power supply 280 and the PA bias power supply 282 illustrated in FIG. 43 according to one embodiment of the PA envelope power supply 280 and the PA bias power supply 282. The PA envelope power supply 280 includes the charge pump buck converter 84, the first inductive element L1, and the first power filtering circuitry 82. The PA bias power supply 282 includes the charge pump 92. In general, the charge pump buck converter 84 is coupled between the RF PA circuitry 30 and the DC power supply 80. Specifically, the first inductive element L1 is coupled between the charge pump buck converter 84 and the first power filtering circuitry 82. The charge pump buck converter 84 is coupled between the DC power supply 80 and the first inductive element L1. The first power filtering circuitry 82 is coupled between the first inductive element L1 and the RF PA circuitry 30. The charge pump 92 is coupled between the RF PA circuitry 30 and the DC power supply 80.

[0422] The charge pump buck converter 84 receives and converts the DC power supply signal DCPS to provide the first buck output signal FBO, such that the envelope power supply signal EPS is based on the first buck output signal FBO. The charge pump 92 receives and charge pumps the DC power supply signal DCPS to provide the bias power supply signal BPS.

[0423] FIG. 45 shows details of the PA envelope power supply 280 and the PA bias power supply 282 illustrated in FIG. 43 according to an alternate embodiment of the PA envelope power supply 280 and the PA bias power supply 282. The PA envelope power supply 280 illustrated in FIG. 45 is similar to the PA envelope power supply 280 illustrated in FIG. 44, except the PA envelope power supply 280 illustrated in FIG. 45 further includes the buck converter 86 coupled across the charge pump buck converter 84. The PA bias power supply 282 illustrated in FIG. 45 is similar to the PA bias power supply 282 illustrated in FIG. 44, except the PA bias power supply 282 illustrated in FIG. 45 further includes the second power filtering circuitry 88 coupled between the RF PA circuitry 30 and ground.

[0424] In one embodiment of the DC-DC converter 32, the DC-DC converter 32 operates in one of multiple converter operating modes, which include the first converter operating mode, the second converter operating mode, and the third converter operating mode. In an alternate embodiment of the DC-DC converter 32, the DC-DC converter 32 operates in one of the first converter operating mode and the second converter operating mode. In the first converter operating mode, the charge pump buck converter 84 is active, such that the envelope power supply signal EPS is based on the DC power supply signal DCPS via the charge pump buck converter 84. In the first converter operating mode, the buck converter 86 is inactive and does not contribute to the envelope power supply signal EPS. In the second converter operating mode, the buck converter 86 is active, such that the envelope power supply signal EPS is based on the DC power supply signal DCPS via the buck converter 86. In the second converter operating mode, the charge pump buck converter 84 is inactive, such that the charge pump buck converter 84 does not contribute to the envelope power supply signal EPS. In the third converter operating mode, the charge pump buck converter 84 and the buck converter 86 are active, such that either the charge pump buck converter 84; the buck converter 86; or both may contribute to the envelope power supply signal EPS. As such, in the third converter operating mode, the envelope power supply signal EPS is based on the DC power supply signal DCPS via the charge pump buck converter 84, via the buck converter 86, or both.

[0425] In one embodiment of the DC-DC converter 32, selection of the converter operating mode is made by the DC-DC control circuitry 90. In an alternate embodiment of the DC-DC converter 32, selection of the converter operating mode is made by the RF modulation and control circuitry 28 and may be communicated to the DC-DC converter 32 via the DC configuration control signal DCC. In an additional embodiment of the DC-DC converter 32, selection of the converter operating mode is made by the control circuitry 42 (FIG. 5) and may be communicated to the DC-DC converter 32 via the DC configuration control signal DCC. In general, selection of the converter operating mode is made by control circuitry, which may be any of the DC-DC control circuitry 90, the RF modulation and control circuitry 28, and the control circuitry 42 (FIG. 5).

[0426] FIG. 46 shows details of the PA envelope power supply 280 and the PA bias power supply 282 illustrated in FIG. 43 according to an additional embodiment of the PA envelope power supply 280 and the PA bias power supply 282. The PA envelope power supply 280 illustrated in FIG. 46 is similar to the PA envelope power supply 280 illustrated in FIG. 44, except the PA envelope power supply 280 illustrated in FIG. 46 further includes the buck converter 86 and the second inductive element L2 coupled in series to form a first series coupling 284. The charge pump buck converter 84 and the first inductive element L1 are coupled in series to form a second series coupling 286, which is coupled across the first series coupling 284. The PA bias power supply 282 illustrated in FIG. 45 is similar to the PA bias power supply 282 illustrated in FIG. 44, except the PA bias power supply 282 illustrated in FIG. 45 further includes the second power filtering circuitry 88 coupled between the RF PA circuitry 30 and ground.

[0427] In the first converter operating mode, the charge pump buck converter 84 is active, such that the envelope power supply signal EPS is based on the DC power supply signal DCPS via the charge pump buck converter 84, and the first inductive element L1. In the first converter operating mode, the buck converter 86 is inactive and does not contribute to the envelope power supply signal EPS. In the second converter operating mode, the buck converter 86 is active, such that the envelope power supply signal EPS is based on the DC power supply signal DCPS via the buck converter 86 and the second inductive element L2. In the second converter operating mode, the charge pump buck converter 84 is inactive, such that the charge pump buck converter 84 does not contribute to the envelope power supply signal EPS. In the third converter operating mode, the charge pump buck converter 84 and the buck converter 86 are active, such that either the charge pump buck converter 84; the buck converter 86; or both may contribute to the envelope power supply signal EPS. As such, in the third converter operating mode, the envelope power supply signal EPS is based on the DC power supply signal DCPS either via the charge pump buck converter 84, and the first inductive element L1; via the buck converter 86 and the second inductive element L2; or both.

[0428] A summary of an automatically configurable 2-wire/3-wire serial communications interface (AC23SCI) is presented, followed by a detailed description of the AC23SCI according to one embodiment of the present disclosure. The present disclosure relates to the AC23SCI, which includes start-of-sequence (SOS) detection circuitry and sequence processing circuitry. When the SOS detection circuitry is coupled to a 2-wire serial communications bus, the SOS detection circuitry detects an SOS of a received sequence based on a serial data signal and a serial clock signal. When the SOS detection circuitry is coupled to a 3-wire serial communications bus, the SOS detection circuitry detects the SOS of the received sequence based on a chip select (CS) signal. The SOS detection circuitry provides an indication of detection of the SOS to the sequence processing circuitry, which initiates processing of the received sequence using the serial data signal and the serial clock signal upon the detection of the SOS. As such, an SOS detection signal, which is indicative of the detection of the SOS, is provided to the sequence processing circuitry from the SOS detection circuitry. In this regard, the AC23SCI automatically configures itself for operation with some 2-wire and some 3-wire serial communications buses without external intervention.

[0429] Since some 2-wire serial communications buses have only the serial data signal and the serial clock signal, some type of special encoding of the serial data signal and the serial clock signal is used to represent the SOS. However, some 3-wire serial communications buses have a dedicated signal, such as the CS signal, to represent the SOS. As such, some 3-wire serial communications devices, such as test equipment, RF transceivers, baseband controllers, or the like, may not be able to provide the special encoding to represent the SOS, thereby mandating use of the CS signal. As a result, the first AC23SCI must be capable of detecting the SOS based on either the CS signal or the special encoding.

[0430] FIG. 47 shows a first AC23SCI 300 according to one embodiment of the first AC23SCI 300. The first AC23SCI 300 includes SOS detection circuitry 302 and sequence processing circuitry 304. In this regard, the SOS detection circuitry 302 and the sequence processing circuitry 304 provide the first AC23SCI 300. The SOS detection circuitry 302 has a CS input CSIN, a serial clock input SCIN, and a serial data input SDIN. The SOS detection circuitry 302 is coupled to a 3-wire serial communications bus 306. The SOS detection circuitry 302 receives a CS signal CSS, a serial clock signal SCLK, and a serial data signal SDATA via the 3-wire serial communications bus 306. As such, the SOS detection circuitry 302 receives the CS signal CSS via the CS input CSIN, receives the serial clock signal SCLK via the serial clock input SCIN, and receives the serial data signal SDATA via the serial data input SDIN.

[0431] The serial clock signal SCLK is used to synchronize to data provided by the serial data signal SDATA. A received sequence is provided to the first AC23SCI 300 by the serial data signal SDATA. The SOS is the beginning of the received sequence and is used by the sequence processing circuitry 304 to initiate processing the received sequence. In one embodiment of the SOS detection circuitry 302, the SOS detection circuitry 302 detects the SOS based on the CS signal CSS. In an alternate embodiment of the SOS detection circuitry 302, the SOS detection circuitry 302 detects the SOS based on special encoding of the serial data signal SDATA and the serial clock signal SCLK. In either embodiment of the SOS detection circuitry 302, the SOS detection circuitry 302 provides an SOS detection signal SSDS, which is indicative of the SOS. The sequence processing circuitry 304 receives the SOS detection signal SSDS, the serial data signal SDATA, and the serial clock signal SCLK. As such, the sequence processing circuitry 304 initiates processing of the received sequence using the serial data signal SDATA and the serial clock signal SCLK upon detection of the SOS. In one embodiment of the 3-wire serial communications bus 306, the 3-wire serial communications bus 306 is the digital communications bus 66. In one embodiment of the 3-wire serial communications bus 306, the 3-wire serial communications bus 306 is a bi-directional bus, such that the sequence processing circuitry 304 may provide the serial data input SDIN, the serial clock signal SCLK, or both.

[0432] FIG. 48 shows the first AC23SCI 300 according an alternate embodiment of the first AC23SCI 300. The first AC23SCI 300 illustrated in FIG. 48 is similar to the first AC23SCI 300 illustrated in FIG. 47, except in the first AC23SCI 300 illustrated in FIG. 48, the SOS detection circuitry 302 is coupled to a 2-wire serial communications bus 308 instead of the 3-wire serial communications bus 306 (FIG. 47). The SOS detection circuitry 302 receives the serial clock signal SCLK and the serial data signal SDATA via the 2-wire serial communications bus 308. As such, the SOS detection circuitry 302 receives the serial clock signal SCLK via the serial clock input SCIN, and receives the serial data signal SDATA via the serial data input SDIN. The 2-wire serial communications bus 308 does not include the CS signal CSS (FIG. 47). As such, the CS input CSIN may be left unconnected as illustrated.

[0433] The serial clock signal SCLK is used to synchronize to data provided by the serial data signal SDATA. A received sequence is provided to the first AC23SCI 300 by the serial data signal SDATA. The SOS is the beginning of the received sequence and is used by the sequence processing circuitry 304 to initiate processing the received sequence. The SOS detection circuitry 302 detects the SOS based on the special encoding of the serial data signal SDATA and the serial clock signal SCLK. The SOS detection circuitry 302 provides the SOS detection signal SSDS, which is indicative of the SOS. The sequence processing circuitry 304 receives the SOS detection signal SSDS, the serial data signal SDATA, and the serial clock signal SCLK. As such, the sequence processing circuitry 304 initiates processing of the received sequence using the serial data signal SDATA and the serial clock signal SCLK upon detection of the SOS. In one embodiment of the 2-wire serial communications bus 308, the 2-wire serial communications bus 308 is the digital communications bus 66. In one embodiment of the 2-wire serial communications bus 308, the 2-wire serial communications bus 308 is a bi-directional bus, such that the sequence processing circuitry 304 may provide the serial data input SDIN, the serial clock signal SCLK, or both.

[0434] In one embodiment of the SOS detection circuitry 302, when the SOS detection circuitry 302 is coupled to the 2-wire serial communications bus 308, the SOS detection circuitry 302 receives the serial data signal SDATA and receives the serial clock signal SCLK via the 2-wire serial communications bus 308, and the SOS detection circuitry 302 detects the SOS based on the serial data signal SDATA and the serial clock signal SCLK. When the SOS detection circuitry 302 is coupled to the 3-wire serial communications bus 306 (FIG. 47), the SOS detection circuitry 302 receives the CS signal CSS (FIG. 47), receives the serial data signal SDATA, and receives the serial clock signal SCLK via the 3-wire serial communications bus 306; and the SOS detection circuitry 302 detects the SOS based on the CS signal CSS (FIG. 47).

[0435] In an alternate embodiment of the SOS detection circuitry 302, when the SOS detection circuitry 302 is coupled to the 3-wire serial communications bus 306 (FIG. 47), the SOS detection circuitry 302 receives the CS signal CSS (FIG. 47), receives the serial data signal SDATA, and receives the serial clock signal SCLK via the 3-wire serial communications bus 306; and the SOS detection circuitry 302 detects the SOS based on either the CS signal CSS (FIG. 47) or the serial data signal SDATA and the serial clock signal SCLK.

[0436] FIG. 49 shows details of the SOS detection circuitry 302 illustrated in FIG. 47 according to one embodiment of the SOS detection circuitry 302. The SOS detection circuitry 302 includes a sequence detection OR gate 310, CS detection circuitry 312, start sequence condition (SSC) detection circuitry 314, and a CS resistive element RCS. The CS resistive element RCS is coupled to the CS input CSIN. In one embodiment of the SOS detection circuitry 302, the CS resistive element RCS is coupled between the CS input CSIN and a ground. As such, when the CS input CSIN is left unconnected, the CS input CSIN is in a LOW state. In an alternate embodiment of the SOS detection circuitry 302, the CS resistive element RCS is coupled between the CS input CSIN and a DC power supply (not shown).

[0437] The CS detection circuitry 312 is coupled to the serial clock input SCIN and the CS input CSIN. As such, the CS detection circuitry 312 receives the serial clock signal SCLK and the CS signal CSS via the serial clock input SCIN and the CS input CSIN, respectively. The CS detection circuitry 312 feeds one input to the sequence detection OR gate 310 based on the serial clock signal SCLK and the CS signal CSS. In an alternate embodiment of the CS detection circuitry 312, the CS detection circuitry 312 is not coupled to the serial clock input SCIN. As such, the CS detection circuitry 312 feeds one input to the sequence detection OR gate 310 based on only the CS signal CSS. In an alternate embodiment of the SOS detection circuitry 302, the CS detection circuitry 312 is omitted, such that the CS input CSIN is directly coupled to one input to the sequence detection OR gate 310.

[0438] The SSC detection circuitry 314 is coupled to the serial clock input SCIN and the serial data input SDIN. As such, the SSC detection circuitry 314 receives the serial clock signal SCLK and the serial data signal SDATA via the serial clock input SCIN and the serial data input SDIN, respectively. The SSC detection circuitry 314 feeds another input to the sequence detection OR gate 310 based on the serial clock signal SCLK and the serial data signal SDATA. An output from the sequence detection OR gate 310 provides the SOS detection signal SSDS to the sequence processing circuitry 304 based on signals received from the CS detection circuitry 312 and the SSC detection circuitry 314. In this regard, the CS detection circuitry 312, the SSC detection circuitry 314, or both may detect an SOS of a received sequence.

[0439] FIGS. 50A, 50B, 50C, and 50D are graphs illustrating the chip select signal CSS, the SOS detection signal SSDS, the serial clock signal SCLK, and the serial data signal SDATA, respectively, of the first AC23SCI 300 illustrated in FIG. 49 according to one embodiment of the first AC23SCI 300. The serial clock signal SCLK has a serial clock period 316 (FIG. 50C) and the serial data signal SDATA has a data bit period 318 (FIG. 50D) during a received sequence 320 (FIG. 50D). In one embodiment of the first AC23SCI 300, the serial clock period 316 is about equal to the data bit period 318. As such, the serial clock signal SCLK may be used to sample data provided by the serial data signal SDATA. An SOS 322 of the received sequence 320 is shown in FIG. 50D.

[0440] The SOS detection circuitry 302 may detect the SOS 322 based on a LOW to HIGH transition of the CS signal CSS as shown in FIG. 50A. The CS detection circuitry 312 may use the CS signal CSS and the serial clock signal SCLK, such that the SOS detection signal SSDS is a pulse. A duration of the pulse may be about equal to the serial clock period 316. The pulse may be a positive pulse as shown in FIG. 50B. In an alternate embodiment (not shown) of the CS detection circuitry 312, the CS detection circuitry 312 may use the CS signal CSS and the serial clock signal SCLK, such that the SOS detection signal SSDS is a negative pulse. In an alternate embodiment (not shown) of the SOS detection circuitry 302, the SOS detection circuitry 302 may detect the SOS 322 based on a HIGH to LOW transition of the CS signal CSS.

[0441] FIGS. 51A, 51B, 51C, and 51D are graphs illustrating the chip select signal CSS, the SOS detection signal SSDS, the serial clock signal SCLK, and the serial data signal SDATA, respectively, of the first AC23SCI 300 illustrated in FIG. 49 according to one embodiment of the first AC23SCI 300. The CS signal CSS illustrated in FIG. 51A is LOW during the received sequence 320 (FIG. 51D). As such, the CS signal CSS is not used to detect the SOS 322 (FIG. 51D). Instead, detection of the SOS 322 is based on the special encoding of the serial data signal SDATA and the serial clock signal SCLK. Specifically, the SOS detection circuitry 302 uses the SSC detection circuitry 314 to detect the SOS 322 based on a pulse of the serial data signal SDATA, such that during the pulse of the serial data signal SDATA, the serial clock signal SCLK does not transition. The pulse of the serial data signal SDATA may be a positive pulse as shown in FIG. 51D. A duration of the serial data signal SDATA may be about equal to the data bit period 318.

[0442] The SSC detection circuitry 314 may use the serial data signal SDATA and the serial clock signal SCLK, such that the SOS detection signal SSDS is a pulse. A duration of the pulse may be about equal to the serial clock period 316. The pulse may be a positive pulse as shown in FIG. 51B. In an alternate embodiment (not shown) of the SSC detection circuitry 314, the SSC detection circuitry 314 may use the serial data signal SDATA and the serial clock signal SCLK, such that the SOS detection signal SSDS is a negative pulse. In an alternate embodiment (not shown) of the SOS detection circuitry 302, the SOS detection circuitry 302 may detect the SOS 322 based on a negative pulse of the serial data signal SDATA while the serial clock signal SCLK does not transition.

[0443] In one embodiment of the sequence processing circuitry 304, if another SOS 322 is detected before processing of the received sequence 320 is completed; the sequence processing circuitry 304 will abort processing of the received sequence 320 in process and initiate processing of the next received sequence 320. In one embodiment of the first AC23SCI 300, the first AC23SCI 300 is a mobile industry processor interface (MiPi). In an alternate embodiment of the first AC23SCI 300, the first AC23SCI 300 is an RF front-end (FE) interface. In an additional embodiment of the first AC23SCI 300, the first AC23SCI 300 is a slave device. In another embodiment of the first AC23SCI 300, the first AC23SCI 300 is a MiPi RFFE interface. In a further embodiment of the first AC23SCI 300, the first AC23SCI 300 is a MiPi RFFE slave device. In a supplemental embodiment of the first AC23SCI 300, the first AC23SCI 300 is a MiPi slave device. In an alternative embodiment of the first AC23SCI 300, the first AC23SCI 300 is an RFFE slave device.

[0444] FIGS. 52A, 52B, 52C, and 52D are graphs illustrating the chip select signal CSS, the SOS detection signal SSDS, the serial clock signal SCLK, and the serial data signal SDATA, respectively, of the first AC23SCI 300 illustrated in FIG. 49 according to one embodiment of the first AC23SCI 300. FIGS. 52A, 52C, and 52D are duplicates of FIGS. 50A, 50C, and 50D, respectively for clarity. The SOS detection circuitry 302 may detect the SOS 322 based on the LOW to HIGH transition of the CS signal CSS as shown in FIG. 52A. The CS detection circuitry 312 may uses the CS signal CSS, such that the SOS detection signal SSDS follows the CS signal CSS as shown in FIG. 52B. In an alternate embodiment of the SOS detection circuitry 302, the CS detection circuitry 312 is omitted, such that the CS input CSIN is directly coupled to the sequence detection OR gate 310. As such, the SOS detection signal SSDS follows the CS signal CSS as shown in FIG. 52B.

[0445] FIG. 53 shows the RF communications system 26 according to one embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 53 is similar to the RF communications system 26 illustrated in FIG. 6, except in the RF communications system 26 illustrated in FIG. 53, the RF PA circuitry 30 further includes the first AC23SCI 300, the DC-DC converter 32 further includes a second AC23SCI 324, and the front-end aggregation circuitry 36 further includes a third AC23SCI 326. In one embodiment of the RF communications system 26, the first AC23SCI 300 is the PA-DCI 60, the second AC23SCI 324 is the DC-DC converter DCI 62, and the third AC23SCI 326 is the aggregation circuitry DCI 64. In an alternate embodiment (not shown) of the RF communications system 26, the first AC23SCI 300 is the DC-DC converter DCI 62. In an additional embodiment (not shown) of the RF communications system 26, the first AC23SCI 300 is the aggregation circuitry DCI 64.

[0446] In one embodiment of the RF communications system 26, the S-wire serial communications bus 306 (FIG. 47) is the digital communications bus 66. The control circuitry 42 is coupled to the SOS detection circuitry 302 (FIG. 47) via the 3-wire serial communications bus 306 (FIG. 47) and via the control circuitry DCI 58. As such, the control circuitry 42 provides the CS signal CSS (FIG. 47) via the control circuitry DCI 58, the control circuitry 42 provides the serial clock signal SCLK (FIG. 47) via the control circuitry DCI 58, and the control circuitry 42 provides the serial data signal SDATA (FIG. 47) via the control circuitry DCI 58.

[0447] In an alternate embodiment of the RF communications system 26, the 2-wire serial communications bus 308 (FIG. 48) is the digital communications bus 66. The control circuitry 42 is coupled to the SOS detection circuitry 302 (FIG. 48) via the 2-wire serial communications bus 308 (FIG. 48) and via the control circuitry DCI 58. As such, the control circuitry 42 provides the serial clock signal SCLK (FIG. 48) via the control circuitry DCI 58 and the control circuitry 42 provides the serial data signal SDATA (FIG. 48) via the control circuitry DCI 58.

[0448] A summary of look-up table (LUT) based configuration of multi-mode multi-band RF PA circuitry is presented, followed by a detailed description of the LUT based configuration of the multi-mode multi-band RF PA circuitry according to one embodiment of the present disclosure. Circuitry includes the multi-mode multi-band RF power amplification circuitry, the PA control circuitry, and the PA-DCI. The PA control circuitry is coupled between the amplification circuitry and the PA-DCI, which is coupled to a digital communications bus, and configures the amplification circuitry. The amplification circuitry includes at least a first RF input and multiple RF outputs, such that at least some of the RF outputs are associated with multiple communications modes and at least some of the RF outputs are associated with multiple frequency bands. Configuration of the amplification circuitry associates one RF input with one RF output, and is correlated with configuration information defined by at least a first defined parameter set. The PA control circuitry stores at least a first LUT, which provides the configuration information.

[0449] The PA control circuitry configures the amplification circuitry to operate in a selected communications mode and a selected frequency band or group of frequency bands based on information received via the digital communications bus. Specifically, the PA control circuitry uses the information as an index to at least the first LUT to retrieve the configuration information. As such, the PA control circuitry configures the amplification circuitry based on the configuration information.

[0450] In one embodiment of the amplification circuitry, the amplification circuitry includes at least a first transmit path, which has a first RF PA and alpha switching circuitry. The first RF PA has a single alpha PA output, which is coupled to the alpha switching circuitry. The alpha switching circuitry has multiple alpha outputs, including at least a first alpha output and multiple alpha outputs. The first alpha output is associated with a first alpha non-linear mode and at least one non-linear mode RF communications band. The multiple alpha outputs are associated with multiple alpha linear modes and multiple linear mode RF communications bands. Configuration of the amplification circuitry includes operation in one of the multiple communications modes, which includes at least the first alpha non-linear mode and the multiple alpha linear modes.

[0451] In an alternate embodiment of the amplification circuitry, the amplification circuitry includes the first transmit path and a second transmit path. The first transmit path includes the first RF PA and the second path includes a second RF PA. Configuration of the amplification circuitry includes operation in one of a first PA operating mode and a second PA operating mode. During the first PA operating mode, the first RF PA receives and amplifies a first RF input signal to provide a first RF output signal, and the second RF PA is disabled. Conversely, during the second PA operating mode, the second RF PA receives and amplifies a second RF input signal to provide a second RF output signal, and the first RF PA is disabled. The first RF input signal may be a highband RF input signal associated with at least one highband RF communications band. The second RF input signal may be a lowband RF input signal associated with at least one lowband RF communications band.

[0452] In an additional embodiment of the amplification circuitry, the amplification circuitry includes the first transmit path and the second transmit path. The first transmit path includes the first RF PA and the alpha switching circuitry. The second transmit path includes a second RF PA and beta switching circuitry. The first RF PA has the single alpha PA output, which is coupled to the alpha switching circuitry. The second RF PA has a single beta PA output, which is coupled to the beta switching circuitry. The alpha switching circuitry has multiple outputs, including at least the first alpha output and multiple alpha outputs. The first alpha output is associated with the first alpha non-linear mode and at least one non-linear mode RF communications band. The multiple alpha outputs are associated with multiple alpha linear modes and multiple linear mode RF communications bands. The beta switching circuitry has multiple outputs, including at least a first beta output and multiple beta outputs. The first beta output is associated with a first beta non-linear mode and at least one non-linear mode RF communications band. The multiple beta outputs are associated with multiple beta linear modes and multiple linear mode RF communications bands. Configuration of the amplification circuitry includes operation in one of the multiple communications modes, which includes at least the first alpha non-linear mode, the multiple alpha linear modes, the first beta non-linear mode and the multiple beta linear modes.

[0453] FIG. 54 shows details of the RF PA circuitry 30 illustrated in FIG. 6 according to an additional embodiment of the RF PA circuitry 30. The RF PA circuitry 30 illustrated in FIG. 54 is similar to the RF PA circuitry 30 illustrated in FIG. 14, except the RF PA circuitry 30 illustrated in FIG. 54 shows multi-mode multi-band RF power amplification circuitry 328 in place of the first transmit path 46 and the second transmit path 48 that are shown in FIG. 14. The PA control circuitry 94 is coupled between the multi-mode multi-band RF power amplification circuitry 328 and the PA-DCI 60. The PA-DCI 60 is coupled to the digital communications bus 66. The PA control circuitry 94 receives information via the digital communications bus 66. In general, configuration of the multi-mode multi-band RF power amplification circuitry 328 is based on the information received via the digital communications bus 66.

[0454] In one embodiment of the PA-DCI 60, the PA-DCI 60 is a serial digital interface. In one embodiment of the PA-DCI 60, the PA-DCI 60 is a mobile industry processor interface (MiPi). In an alternate embodiment of the PA-DCI 60, the PA-DCI 60 is an RFFE interface. In an additional embodiment of the PA-DCI 60, the PA-DCI 60 is a slave device. In another embodiment of the PA-DCI 60, the PA-DCI 60 is a MiPi RFFE interface. In a further embodiment of the PA-DCI 60, the PA-DCI 60 is a MiPi RFFE slave device. In a supplemental embodiment of the PA-DCI 60, the PA-DCI 60 is a MiPi slave device. In an alternative embodiment of the PA-DCI 60, the PA-DCI 60 is an RFFE slave device.

[0455] FIG. 55 shows details of the multi-mode multi-band RF power amplification circuitry 328 illustrated in FIG. 54 according to one embodiment of the multi-mode multi-band RF power amplification circuitry 328. The multi-mode multi-band RF power amplification circuitry 328 includes the first transmit path 46 and the second transmit path 48. The first transmit path 46 and the second transmit path 48 illustrated in FIG. 55 are similar to the first transmit path 46 and the second transmit path 48 illustrated in FIG. 37, except in the first transmit path 46 and the second transmit path 48 illustrated in FIG. 55, the first RF PA 50 has a first RF input FRI and the second RF PA 54 has a second RF input SRI. As such, the first transmit path 46 includes the first RF PA 50 and the alpha switching circuitry 52, and the second transmit path 48 includes the second RF PA 54 and the beta switching circuitry 56. The first RF PA 50 receives and amplifies the first RF input signal FRFI to provide the first RF output signal FRFO. The second RF PA 54 receives and amplifies the second RF input signal SRFI to provide the second RF output signal SRFO. As such, the first RF PA 50 receives the first RF input signal FRFI via the first RF input FRI and provides the first RF output signal FRFO via the single alpha PA output SAP. The second RF PA 54 receives the second RF input signal SRFI via the second RF input SRI and provides the second RF output signal SRFO via the single beta PA output SBP.

[0456] In general, the multi-mode multi-band RF power amplification circuitry 328 has at least the first RF input FRI and a group of RF outputs FANO, FALO, RALO, FBNO, FBLO, SBLO. The configuration of the multi-mode multi-band RF power amplification circuitry 328 associates one of the RF inputs FRI, SRI with one of the group of RF outputs FANO, FALO, RALO, FBNO, FBLO, SBLO. In one embodiment of the multi-mode multi-band RF power amplification circuitry 328, configuration of the multi-mode multi-band RF power amplification circuitry 328 includes operation in one of the first PA operating mode and the second PA operating mode. During the first PA operating mode, the first transmit path 46 is active and the second transmit path 48 is inactive. During the second PA operating mode, the first transmit path 46 is inactive and the second transmit path 48 is active. In one embodiment of the first RF PA 50 and the second RF PA 54, during the second PA operating mode, the first RF PA 50 is disabled, and during the first PA operating mode, the second RF PA 54 is disabled. In one embodiment of the alpha switching circuitry 52 and the beta switching circuitry 56, during the second PA operating mode, the alpha switching circuitry 52 is disabled, and during the first PA operating mode, the beta switching circuitry 56 is disabled.

[0457] During the first PA operating mode, the first RF PA 50 receives and amplifies the first RF input signal FRFI via the first RF input FRI to provide the first RF output signal FRFO via the single alpha PA output SAP. During the second PA operating mode, the second RF PA 54 receives and amplifies the second RF input signal SRFI via the second RF input SRI to provide the second RF output signal SRFO via the single beta PA output SBP.

[0458] FIGS. 56A and 56B show details of the PA control circuitry 94 illustrated in FIG. 54 according to one embodiment of the PA control circuitry 94. The PA control circuitry 94 stores at least a first LUT 330 as shown in FIG. 56A. The first LUT 330 provides configuration information 332 as shown in FIG. 56B. The PA control circuitry 94 uses the information received via the digital communications bus 66 (FIG. 54) as an index to at least the first LUT 330 to retrieve the configuration information 332. The configuration information 332 may be defined by at least a first defined parameter set. The PA control circuitry 94 configures the multi-mode multi-band RF power amplification circuitry 328 based on the configuration information 332 to provide the configuration of the multi-mode multi-band RF power amplification circuitry 328. In this regard, the configuration of the multi-mode multi-band RF power amplification circuitry 328 is based on and correlated with the configuration information 332.

[0459] A summary of a LUT based configuration of a DC-DC converter is presented, followed by a detailed description of the LUT based configuration of a DC-DC converter according to one embodiment of the present disclosure. The present disclosure relates to RF PA circuitry and a DC-DC converter, which includes an RF PA envelope power supply and DC-DC control circuitry. The PA envelope power supply provides an envelope power supply signal to the RF PA circuitry. The DC-DC control circuitry has a DC-DC look-up table (LUT) structure, which has at least a first DC-DC LUT. The DC-DC control circuitry uses DC-DC LUT index information as an index to the DC-DC LUT structure to obtain DC-DC converter operational control parameters. The DC-DC control circuitry then configures the PA envelope power supply using the DC-DC converter operational control parameters. Using the DC-DC LUT structure provides flexibility in configuring the DC-DC converter for different applications, for multiple static operating conditions, for multiple dynamic operating conditions, or any combination thereof. Such flexibility may provide a system capable of supporting many different options and applications. Configuration may be done in a manufacturing environment, in a service depot environment, in a user operation environment, the like, or any combination thereof.

[0460] The DC-DC LUT index information may include DC-DC converter configuration information, which may be used to statically configure the DC-DC converter for a specific application or specific operating conditions, and operating status information, which may be used to dynamically configure the DC-DC converter based on changing conditions. The DC-DC converter operational control parameters may be indicative of a number of DC-DC converter configurations, such as an envelope power supply setpoint, a selected converter operating mode, a selected pump buck operating mode, a selected charge pump buck base switching frequency, a selected charge pump buck switching frequency dithering mode, a selected bias supply pump operating mode, a selected bias supply base switching frequency, a selected bias supply switching frequency dithering mode, the like, or any combination thereof. The contents of the DC-DC LUT structure may be based on DC-DC converter operating criteria, such as one or more operating efficiencies, one or more operating limits, at least one operating headroom, electrical noise reduction, PA operating linearity, the like, or any combination thereof.

[0461] FIG. 57 shows the RF communications system 26 according to one embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 57 is similar to the RF communications system 26 illustrated in FIG. 43; except in the RF communications system 26 illustrated in FIG. 57; the DC-DC converter 32 further includes the DC-DC converter DCI 62; and the digital communications bus 66 is coupled between the RF modulation and control circuitry 28, the RF PA circuitry 30, and the DC-DC converter DCI 62. As such, the digital communications bus 66 provides the DC configuration control signal DCC (FIG. 6) and the envelope control signal ECS (FIG. 6) to the DC-DC control circuitry 90 via the DC-DC converter DCI 62. Additionally, the DC-DC control circuitry 90 provides the buck control signal BCS to the PA envelope power supply 280, the PA envelope power supply 280 provides an envelope power supply status signal EPSS to the DC-DC control circuitry 90, and the PA bias power supply 282 provides a bias power supply status signal BPSS to the DC-DC control circuitry 90.

[0462] The envelope power supply signal EPS has an envelope power supply voltage EPSV and an envelope power supply current EPSI. The bias power supply signal BPS has a bias power supply voltage BPSV and a bias power supply current BPSI. The DC power supply signal DCPS has a DC power supply voltage DCPV. The PA envelope power supply 280 provides the envelope power supply signal EPS to the RF PA circuitry 30 based on DC-DC conversion of the DC power supply signal DCPS. The PA bias power supply 282 provides the bias power supply signal BPS to the RF PA circuitry 30 based on DC-DC conversion of the DC power supply signal DCPS.

[0463] In one embodiment of the PA envelope power supply 280, the PA envelope power supply 280 includes the charge pump buck converter 84 (FIG. 45), which provides the envelope power supply signal EPS based on DC-DC conversion of the DC power supply signal DCPS. In an alternate embodiment of the PA envelope power supply 280, the PA envelope power supply 280 includes the charge pump buck converter 84 (FIG. 45) and the buck converter 86 (FIG. 45), which is coupled across the charge pump buck converter 84 (FIG. 45). In one embodiment of the DC-DC converter 32, the DC-DC converter 32 includes the PA bias power supply 282, as shown. The PA bias power supply 282 provides the bias power supply signal BPS to the RF PA circuitry 30 based on a DC-DC conversion of the DC power supply signal DCPS. In one embodiment of the PA bias power supply 282, the PA bias power supply 282 includes the charge pump 92 (FIG. 45), which provides the bias power supply signal BPS to the RF PA circuitry 30 based on the DC-DC conversion of the DC power supply signal DCPS. In an alternate embodiment of the DC-DC converter 32, the PA bias power supply 282 is omitted. In an additional embodiment of the DC-DC converter 32, the PA envelope power supply 280 is omitted.

[0464] In one embodiment of the DC-DC converter 32, the DC-DC converter 32 operates in one of the multiple converter operating modes, which include at least the first converter operating mode and the second converter operating mode. During the first converter operating mode, the charge pump buck converter 84 (FIG. 45) is active and the buck converter 86 (FIG. 45) is inactive, such that the charge pump buck converter 84 (FIG. 45) provides the envelope power supply signal EPS based on DC-DC conversion of the DC power supply signal DCPS. In the second converter operating mode, the buck converter 86 (FIG. 45) is active and the charge pump buck converter 84 (FIG. 45) is inactive, such that the buck converter 86 (FIG. 45) provides the envelope power supply signal EPS based on DC-DC conversion of the DC power supply signal DCPS.

[0465] In one embodiment of the charge pump buck converter 84 (FIG. 45), the charge pump buck converter 84 (FIG. 45) operates in one of the multiple pump buck operating modes. During the pump buck pump-up operating mode of the charge pump buck converter 84 (FIG. 45), the charge pump buck converter 84 (FIG. 45) pumps-up the DC power supply signal DCPS to provide an internal signal (not shown), such that a voltage of the internal signal is greater than a voltage of the DC power supply signal DCPS. During the pump buck pump-down operating mode of the charge pump buck converter 84 (FIG. 45), the charge pump buck converter 84 (FIG. 45) pumps-down the DC power supply signal DCPS to provide the internal signal, such that a voltage of the internal signal is less than a voltage of the DC power supply signal DCPS. During the pump buck pump-even operating mode of the charge pump buck converter 84 (FIG. 45), the charge pump buck converter 84 (FIG. 45) pumps the DC power supply signal DCPS to the internal signal, such that a voltage of the internal signal is about equal to a voltage of the DC power supply signal DCPS.

[0466] One embodiment of the DC-DC converter 32 includes the pump buck bypass operating mode of the charge pump buck converter 84 (FIG. 45), such that during the pump buck bypass operating mode, the charge pump buck converter 84 (FIG. 45) by-passes charge pump circuitry (not shown) using by-pass circuitry (not shown) to forward the DC power supply signal DCPS to provide the internal signal, such that a voltage of the internal signal is about equal to a voltage of the DC power supply signal DCPS. In one embodiment of the charge pump buck converter 84 (FIG. 45), the pump buck operating modes include the pump buck pump-up operating mode and at least one other pump buck operating mode of the charge pump buck converter 84 (FIG. 45).

[0467] The charge pump 92 (FIG. 45) may operate in one of multiple bias supply pump operating modes. During the bias supply pump-up operating mode of the charge pump 92 (FIG. 45), the charge pump 92 (FIG. 45) receives and pumps-up the DC power supply signal DCPS to provide the bias power supply signal BPS, such that a voltage of the bias power supply signal BPS is greater than a voltage of the DC power supply signal DCPS. During the bias supply pump-down operating mode of the charge pump 92 (FIG. 45), the charge pump 92 (FIG. 45) pumps-down the DC power supply signal DCPS to provide the bias power supply signal BPS, such that a voltage of the bias power supply signal BPS is less than a voltage of the DC power supply signal DCPS. During the bias supply pump-even operating mode of the charge pump 92 (FIG. 45), the charge pump 92 (FIG. 45) pumps the DC power supply signal DCPS to provide the bias power supply signal BPS, such that a voltage of the bias power supply signal BPS is about equal to a voltage of the DC power supply signal DCPS.

[0468] One embodiment of the DC-DC converter 32 includes the bias supply bypass operating mode of the charge pump 92 (FIG. 45), such that during the bias supply bypass operating mode, the charge pump 92 (FIG. 45) by-passes charge pump circuitry (not shown) using by-pass circuitry (not shown) to forward the DC power supply signal DCPS to provide the bias power supply signal BPS, such that a voltage of the bias power supply signal BPS is about equal to a voltage of the DC power supply signal DCPS. In one embodiment of the charge pump 92 (FIG. 45), the bias supply pump operating modes include the bias supply pump-up operating mode and at least one other bias supply pump operating mode of the charge pump 92 (FIG. 45).

[0469] FIGS. 58A and 58B show details of the DC-DC control circuitry 90 illustrated in FIG. 57 according to one embodiment of the DC-DC control circuitry 90. The DC-DC control circuitry 90 illustrated in FIG. 58A includes a DC-DC LUT structure 334. Contents of the DC-DC LUT structure 334 are based on DC-DC converter operating criteria 336. FIG. 58B shows details of the DC-DC LUT structure 334 illustrated of the DC-DC LUT structure 334 illustrated in FIG. 58A according to one embodiment of the DC-DC LUT structure 334. The DC-DC LUT structure 334 includes at least a first DC-DC LUT 338.

[0470] The DC-DC control circuitry 90 uses DC-DC LUT index information 340 as an index to the DC-DC LUT structure 334 to obtain DC-DC converter operational control parameters 342. The DC-DC control circuitry 90 configures the DC-DC converter 32 (FIG. 57) using the DC-DC converter operational control parameters 342. In one embodiment of the DC-DC control circuitry 90, the DC-DC control circuitry 90 configures the PA envelope power supply 280 (FIG. 57) using the DC-DC converter operational control parameters 342. In an alternate embodiment of the DC-DC control circuitry 90, the DC-DC control circuitry 90 configures the PA bias power supply 282 (FIG. 57) using the DC-DC converter operational control parameters 342. In an additional embodiment of the DC-DC control circuitry 90, the DC-DC control circuitry 90 configures the PA envelope power supply 280 (FIG. 57) and the PA bias power supply 282 (FIG. 57) using the DC-DC converter operational control parameters 342.

[0471] The DC-DC control circuitry 90 may receive the DC-DC LUT index information 340 from the DC-DC converter DCI 62 (FIG. 57), from the DC power supply 80 (FIG. 57) via the DC power supply signal DCPS, from the PA envelope power supply 280 (FIG. 57) via the envelope power supply status signal EPSS, from the PA bias power supply 282 (FIG. 57) via the bias power supply status signal BPSS, or any combination thereof. The DC-DC control circuitry 90 may provide the DC-DC converter operational control parameters 342 to the DC-DC converter DCI 62 (FIG. 57), to the PA envelope power supply 280 (FIG. 57) via the charge pump buck control signal CPBS, to the PA envelope power supply 280 (FIG. 57) via the buck control signal BCS, to the PA bias power supply 282 (FIG. 57) via the charge pump control signal CPS, or any combination thereof.

[0472] FIG. 59 shows details of the DC-DC LUT index information 340 and the DC-DC converter operational control parameters 342 illustrated in FIG. 58B according to one embodiment of the DC-DC LUT index information 340 and the DC-DC converter operational control parameters 342. The DC-DC LUT index information 340 includes DC-DC converter configuration information 344 and operating status information 346. The DC-DC converter configuration information 344 may be used to configure the DC-DC converter 32 (FIG. 57) for different applications, for specific operating conditions, or both. As such, the DC-DC control circuitry 90 may receive the DC-DC converter configuration information 344 from the DC-DC converter DCI 62 (FIG. 57), from the DC power supply 80 (FIG. 57) via the DC power supply signal DCPS, from the PA envelope power supply 280 (FIG. 57) via the envelope power supply status signal EPSS, from the PA bias power supply 282 (FIG. 57) via the bias power supply status signal BPSS, or any combination thereof.

[0473] The operating status information 346 may be used to dynamically configure the DC-DC converter 32 (FIG. 57) based on changing conditions. As such, the DC-DC control circuitry 90 may receive the operating status information 346 from the DC-DC converter DCI 62 (FIG. 57), from the DC power supply 80 (FIG. 57) via the DC power supply signal DCPS, from the PA envelope power supply 280 (FIG. 57) via the envelope power supply status signal EPSS, from the PA bias power supply 282 (FIG. 57) via the bias power supply status signal BPSS, or any combination thereof.

[0474] The DC-DC converter operational control parameters 342 may be indicative of an envelope power supply setpoint 348, a selected converter operating mode 350, a selected pump buck operating mode 352, a selected charge pump buck base switching frequency 354, a selected charge pump buck switching frequency dithering mode 356, a selected charge pump buck dithering characteristics 358, a selected charge pump buck dithering frequency 360, a selected bias supply pump operating mode 362, a selected bias supply base switching frequency 364, a selected bias supply switching frequency dithering mode 366, a selected bias supply dithering characteristics 368, a selected bias supply dithering frequency 370, the like, or any combination thereof.

[0475] The DC-DC control circuitry 90 (FIG. 57) configures a setpoint of the PA envelope power supply 280 (FIG. 57) using the envelope power supply setpoint 348. The selected converter operating mode 350 is one of at least the first converter operating mode and the second converter operating mode. The DC-DC control circuitry 90 (FIG. 57) configures the PA envelope power supply 280 (FIG. 57) using the selected converter operating mode 350. The selected pump buck operating mode 352 is one of the pump buck pump-up operating mode and at least one other pump buck operating mode of the charge pump buck converter 84 (FIG. 45). The DC-DC control circuitry 90 (FIG. 57) configures the charge pump buck converter 84 (FIG. 45) using the selected pump buck operating mode 352.

[0476] The DC-DC control circuitry 90 (FIG. 57) configures a base switching frequency of the charge pump buck converter 84 (FIG. 45) using the selected charge pump buck base switching frequency 354. The DC-DC control circuitry 90 (FIG. 57) configures a frequency dithering mode of the charge pump buck converter 84 (FIG. 45) using the selected charge pump buck switching frequency dithering mode 356. The DC-DC control circuitry 90 (FIG. 57) configures dithering characteristics of the charge pump buck converter 84 (FIG. 45) using the selected charge pump buck dithering characteristics 358. The DC-DC control circuitry 90 (FIG. 57) configures a dithering frequency of the charge pump buck converter 84 (FIG. 45) using the selected charge pump buck dithering frequency 360,

[0477] The selected bias supply pump operating mode 362 is one of the bias supply pump-up operating mode and at least one other bias supply pump operating mode of the charge pump 92 (FIG. 45). The DC-DC control circuitry 90 (FIG. 57) configures the PA bias power supply 282 (FIG. 57) using the selected bias supply pump operating mode 362. The DC-DC control circuitry 90 (FIG. 57) configures a base switching frequency of the charge pump 92 (FIG. 45) using the selected bias supply base switching frequency 364. The DC-DC control circuitry 90 (FIG. 57) configures a frequency dithering mode of the charge pump 92 (FIG. 45) using the selected bias supply switching frequency dithering mode 366. The DC-DC control circuitry 90 (FIG. 57) configures dithering characteristics of the charge pump 92 (FIG. 45) using the selected bias supply dithering characteristics 368. The DC-DC control circuitry 90 (FIG. 57) configures a dithering frequency of the charge pump 92 (FIG. 45) using the selected bias supply dithering frequency 370.

[0478] FIG. 60 shows details of the DC-DC LUT index information 340 illustrated in FIG. 59 and details of the DC-DC converter operating criteria 336 illustrated in FIG. 58A according to one embodiment of the DC-DC LUT index information 340 and the DC-DC converter operating criteria 336. The operating status information 346 may be indicative of a desired envelope power supply setpoint 372 of the PA envelope power supply 280 (FIG. 57), a DC-DC converter temperature 374 of the DC-DC converter 32 (FIG. 57), an RF PA circuitry temperature 376 of the RF PA circuitry 30 (FIG. 57), the envelope power supply voltage EPSV, the envelope power supply current EPSI, the DC power supply voltage DCPV, the bias power supply voltage BPSV, the bias power supply current BPSI, the like, or any combination thereof. The DC-DC converter operating criteria 336 includes one or more operating efficiencies 378, one or more operating limits 380, at least one operating headroom 382, electrical noise reduction 384, PA operating linearity 386, the like, or any combination thereof.

[0479] FIG. 61 is a graph showing eight efficiency curves of the PA envelope power supply 280 illustrated in FIG. 57 according to one embodiment of the PA envelope power supply 280. Specifically, the graph includes a first efficiency curve 388, a second efficiency curve 390, a third efficiency curve 392, a fourth efficiency curve 394, a fifth efficiency curve 396, a sixth efficiency curve 398, a seventh efficiency curve 400, and an eighth efficiency curve 402. The horizontal axis is indicative of the envelope power supply voltage EPSV and the vertical axis is indicative of efficiency of the PA envelope power supply 280 (FIG. 57).

[0480] The first, second, third, and fourth efficiency curves 388, 390, 392, 394 are associated with operation of the PA envelope power supply 280 (FIG. 57) at a first magnitude of the envelope power supply voltage EPSV (FIG. 57). The fifth, sixth, seventh, and eighth efficiency curves 396, 398, 400, 402 are associated with operation of the PA envelope power supply 280 (FIG. 57) at a second magnitude of the envelope power supply voltage EPSV (FIG. 57). The first and fifth efficiency curves 388, 396 are associated with operation of the PA envelope power supply 280 (FIG. 57) using a first base switching frequency. The second and sixth efficiency curves 390, 398 are associated with operation of the PA envelope power supply 280 (FIG. 57) using a second base switching frequency. The third and seventh efficiency curves 392, 400 are associated with operation of the PA envelope power supply 280 (FIG. 57) using a third base switching frequency. The fourth and eighth efficiency curves 394, 402 are associated with operation of the PA envelope power supply 280 (FIG. 57) using a fourth base switching frequency.

[0481] As a result, to maximize efficiency of the PA envelope power supply 280 (FIG. 57), the DC-DC control circuitry 90 (FIG. 57) may dynamically select the base switching frequency of the PA envelope power supply 280 (FIG. 57) based on the envelope power supply voltage EPSV, which may be measured or estimated, and based on the DC power supply voltage DCPV (FIG. 57), which may be measured or estimated. For example, when the PA envelope power supply 280 (FIG. 57) is operating using the first magnitude of the DC power supply voltage DCPV (FIG. 57) and a magnitude of the envelope power supply voltage EPSV is relatively low, the first efficiency curve 388 indicates a higher efficiency than the second, third, and fourth efficiency curves 390, 392, 394. As a result, the DC-DC control circuitry 90 (FIG. 57) would select the first base switching frequency to maximize efficiency. Similarly, when the PA envelope power supply 280 (FIG. 57) is operating using the first magnitude of the DC power supply voltage DCPV (FIG. 57) and a magnitude of the envelope power supply voltage EPSV is relatively high, the fourth efficiency curve 394 indicates a higher efficiency than the first, second, and third efficiency curves 388, 390, 392. As a result, the DC-DC control circuitry 90 (FIG. 57) would select the fourth base switching frequency to maximize efficiency. Additionally, when the PA envelope power supply 280 (FIG. 57) is operating using the second magnitude of the DC power supply voltage DCPV (FIG. 57) and a magnitude of the envelope power supply voltage EPSV is relatively low, the sixth efficiency curve 398 indicates a higher efficiency than the fifth, seventh, and eighth efficiency curves 396, 400, 402. As a result, the DC-DC control circuitry 90 (FIG. 57) would select the first base switching frequency to maximize efficiency.

[0482] FIG. 61 is one example of certain operational dependencies in the RF communications system 26 (FIG. 57) between the DC-DC converter 32 (FIG. 57) and the RF PA circuitry 30 (FIG. 57). In general, there may be many operational dependencies within the DC-DC converter 32 (FIG. 57) and between the DC-DC converter 32 (FIG. 57) and the RF PA circuitry 30 (FIG. 57). As a result, the DC-DC control circuitry 90 (FIG. 57) may configure the DC-DC converter 32 (FIG. 57) using the DC-DC LUT structure 334 (FIG. 58A) to optimize operation of the RF communications system 26 (FIG. 57) based on the operational dependencies.

[0483] A summary of a configurable 2-wire/3-wire serial communications interface C23SCI is presented, followed by a detailed description of the C23SCI according to one embodiment of the present disclosure. The present disclosure relates to the C23SCI, which includes start-of-sequence (SOS) detection circuitry and sequence processing circuitry. When the SOS detection circuitry is coupled to a 2-wire serial communications bus, the SOS detection circuitry detects an SOS of a received sequence based on a serial data signal and a serial clock signal. When the SOS detection circuitry is coupled to a 3-wire serial communications bus, the SOS detection circuitry detects the SOS of the received sequence based on a chip select (CS) signal. In response to detecting the SOS, the SOS detection circuitry provides an SOS detection signal to the sequence processing circuitry, which initiates processing of the received sequence using the serial data signal and the serial clock signal. The received sequence is associated with one of multiple serial communications protocols.

[0484] Since some 2-wire serial communications buses have only the serial data signal and the serial clock signal, some type of special encoding of the serial data signal and the serial clock signal is used to represent the SOS. However, some 3-wire serial communications buses have a dedicated signal, such as the CS signal, to represent the SOS. As such, some 3-wire serial communications devices, such as test equipment, RF transceivers, baseband controllers, or the like, may not be able to provide the special encoding to represent the SOS, thereby mandating use of the CS signal. As a result, the first C23SCI must be capable of detecting the SOS based on either the CS signal or the special encoding.

[0485] Certain 2-wire serial communications protocols may have compatibility issues with certain 3-wire serial communications protocols. Further, the C23SCI may be used in a system using certain serial communications protocols having sequences that cannot be properly processed by the sequence processing circuitry. As a result, in one embodiment of the C23SCI, the sequence processing circuitry receives a protocol configuration signal, such that the sequence processing circuitry inhibits processing of certain serial communications protocols based on the protocol configuration signal. Additionally, in a system using certain serial communications protocols having sequences that cannot be properly processed by the sequence processing circuitry, the sequence processing circuitry may stall or react incorrectly. As a result, in one embodiment of the C23SCI, the sequence processing circuitry receives a sequence abort signal, such that the sequence processing circuitry aborts processing of a received sequence based on the sequence abort signal, which may be based on the CS signal.

[0486] FIG. 62 shows a first C23SCI 404 according to one embodiment of the first C23SCI 404. The first C23SCI 404 includes the SOS detection circuitry 302 and the sequence processing circuitry 304. In this regard, the SOS detection circuitry 302 and the sequence processing circuitry 304 provide the first C23SCI 404. The SOS detection circuitry 302 has the CS input CSIN, the serial clock input SCIN, and the serial data input SDIN. The SOS detection circuitry 302 is coupled to the 3-wire serial communications bus 306. The SOS detection circuitry 302 receives the CS signal CSS, the serial clock signal SCLK, and the serial data signal SDATA via the 3-wire serial communications bus 306. As such, the SOS detection circuitry 302 receives the CS signal CSS via the CS input CSIN, receives the serial clock signal SCLK via the serial clock input SCIN, and receives the serial data signal SDATA via the serial data input SDIN.

[0487] The serial clock signal SCLK is used to synchronize to data provided by the serial data signal SDATA. A received sequence is provided to the first C23SCI 404 by the serial data signal SDATA. The SOS is the beginning of the received sequence and is used by the sequence processing circuitry 304 to initiate processing the received sequence. The received sequence is associated with one of multiple serial communications protocols. In one embodiment of the SOS detection circuitry 302, the SOS detection circuitry 302 detects the SOS based on the CS signal CSS. In an alternate embodiment of the SOS detection circuitry 302, the SOS detection circuitry 302 detects the SOS based on special encoding of the serial data signal SDATA and the serial clock signal SCLK. In either embodiment of the SOS detection circuitry 302, the SOS detection circuitry 302 provides the SOS detection signal SSDS, which is indicative of the SOS. The sequence processing circuitry 304 receives the SOS detection signal SSDS, the serial data signal SDATA, and the serial clock signal SCLK. As such, the sequence processing circuitry 304 initiates processing of the received sequence using the serial data signal SDATA and the serial clock signal SCLK upon detection of the SOS. In one embodiment of the 3-wire serial communications bus 306, the 3-wire serial communications bus 306 is the digital communications bus 66. In one embodiment of the 3-wire serial communications bus 306, the S-wire serial communications bus 306 is a bi-directional bus, such that the sequence processing circuitry 304 may provide the serial data input SDIN, the serial clock signal SCLK, or both.

[0488] Certain 2-wire serial communications protocols may have compatibility issues with certain 3-wire serial communications protocols. Further, the first C23SCI 404 may be used in a system using certain serial communications protocols having sequences that cannot be properly processed by the sequence processing circuitry 304. As a result, in one embodiment of the first C23SCI 404, the sequence processing circuitry 304 receives a protocol configuration signal PCS, such that the sequence processing circuitry 304 is inhibited from processing a received sequence associated with at least one of the multiple serial communications protocols based on the protocol configuration signal PCS.

[0489] FIG. 63 shows the first C23SCI 404 according to an alternate embodiment of the first C23SCI 404. The first C23SCI 404 illustrated in FIG. 63 is similar to the first C23SCI 404 illustrated in FIG. 62, except in the first C23SCI 404 illustrated in FIG. 63, the SOS detection circuitry 302 is coupled to a 2-wire serial communications bus 308 instead of the 3-wire serial communications bus 306 (FIG. 62). The SOS detection circuitry 302 receives the serial clock signal SCLK and the serial data signal SDATA via the 2-wire serial communications bus 308. As such, the SOS detection circuitry 302 receives the serial clock signal SCLK via the serial clock input SCIN, and receives the serial data signal SDATA via the serial data input SDIN. The 2-wire serial communications bus 308 does not include the CS signal CSS (FIG. 62). As such, the CS input CSIN may be left unconnected as illustrated.

[0490] The serial clock signal SCLK is used to synchronize to data provided by the serial data signal SDATA. A received sequence is provided to the first C23SCI 404 by the serial data signal SDATA. The SOS is the beginning of the received sequence and is used by the sequence processing circuitry 304 to initiate processing the received sequence. The SOS detection circuitry 302 detects the SOS based on the special encoding of the serial data signal SDATA and the serial clock signal SCLK. The SOS detection circuitry 302 provides the SOS detection signal SSDS, which is indicative of the SOS. The sequence processing circuitry 304 receives the SOS detection signal SSDS, the serial data signal SDATA, and the serial clock signal SCLK. As such, the sequence processing circuitry 304 initiates processing of the received sequence using the serial data signal SDATA and the serial clock signal SCLK upon detection of the SOS. In one embodiment of the 2-wire serial communications bus 308, the 2-wire serial communications bus 308 is the digital communications bus 66. In one embodiment of the 2-wire serial communications bus 308, the 2-wire serial communications bus 308 is a bi-directional bus, such that the sequence processing circuitry 304 may provide the serial data input SDIN, the serial clock signal SCLK, or both.

[0491] In one embodiment of the SOS detection circuitry 302, when the SOS detection circuitry 302 is coupled to the 2-wire serial communications bus 308, the SOS detection circuitry 302 receives the serial data signal SDATA and receives the serial clock signal SCLK via the 2-wire serial communications bus 308, and the SOS detection circuitry 302 detects the SOS based on the serial data signal SDATA and the serial clock signal SCLK. When the SOS detection circuitry 302 is coupled to the 3-wire serial communications bus 306 (FIG. 62), the SOS detection circuitry 302 receives the CS signal CSS (FIG. 62), receives the serial data signal SDATA, and receives the serial clock signal SCLK via the 3-wire serial communications bus 306; and the SOS detection circuitry 302 detects the SOS based on the CS signal CSS (FIG. 62).

[0492] In an alternate embodiment of the SOS detection circuitry 302, when the SOS detection circuitry 302 is coupled to the 3-wire serial communications bus 306 (FIG. 62), the SOS detection circuitry 302 receives the CS signal CSS (FIG. 62), receives the serial data signal SDATA, and receives the serial clock signal SCLK via the 3-wire serial communications bus 306; and the SOS detection circuitry 302 detects the SOS based on either the CS signal CSS (FIG. 62) or the serial data signal SDATA and the serial clock signal SCLK.

[0493] FIG. 64 shows the first C23SCI 404 according an additional embodiment of the first C23SCI 404. The SOS detection circuitry 302 includes the sequence detection OR gate 310, the CS detection circuitry 312, the start sequence condition (SSC) detection circuitry 314, the CS resistive element RCS, and a sequence abort inverter 406. The CS resistive element RCS is coupled to the CS input CSIN. In one embodiment of the SOS detection circuitry 302, the CS resistive element RCS is coupled between the CS input CSIN and a DC reference VDC. As such, in one embodiment of the SOS detection circuitry 302, when the CS input CSIN is left unconnected, the CS input CSIN is in a LOW state. In an alternate embodiment of the SOS detection circuitry 302, when the CS input CSIN is left unconnected, the CS input CSIN is in a HIGH state.

[0494] The CS detection circuitry 312 is coupled to the serial clock input SCIN and the CS input CSIN. As such, the CS detection circuitry 312 receives the serial clock signal SCLK and the CS signal CSS via the serial clock input SCIN and the CS input CSIN, respectively. The CS detection circuitry 312 feeds one input to the sequence detection OR gate 310 based on the serial clock signal SCLK and the CS signal CSS. In an alternate embodiment of the CS detection circuitry 312, the CS detection circuitry 312 is not coupled to the serial clock input SCIN. As such, the CS detection circuitry 312 feeds one input to the sequence detection OR gate 310 based on only the CS signal CSS. In an alternate embodiment of the SOS detection circuitry 302, the CS detection circuitry 312 is omitted, such that the CS input CSIN is directly coupled to one input to the sequence detection OR gate 310.

[0495] The SSC detection circuitry 314 is coupled to the serial clock input SCIN and the serial data input SDIN. As such, the SSC detection circuitry 314 receives the serial clock signal SCLK and the serial data signal SDATA via the serial clock input SCIN and the serial data input SDIN, respectively. The SSC detection circuitry 314 feeds another input to the sequence detection OR gate 310 based on the serial clock signal SCLK and the serial data signal SDATA. An output from the sequence detection OR gate 310 provides the SOS detection signal SSDS to the sequence processing circuitry 304 based on signals received from the CS detection circuitry 312 and the SSC detection circuitry 314. In this regard, the CS detection circuitry 312, the SSC detection circuitry 314, or both may detect an SOS of a received sequence.

[0496] In a system using certain serial communications protocols having sequences that cannot be properly processed by the sequence processing circuitry 304, the sequence processing circuitry 304 may stall or react incorrectly. As a result, if a stall occurs during a read operation from the first C23SCI 404, the first C23SCI 404 may hang or lock-up the digital communications bus 66. To remove the stall or recover from an incorrect reaction, the sequence processing circuitry 304 may need to abort processing of a received sequence. In this regard, in one embodiment of the C23SCI 404, the sequence processing circuitry 304 receives a sequence abort signal SAS, such that the sequence processing circuitry 304 aborts processing of a received sequence based on the sequence abort signal SAS, which may be based on the CS signal CSS. The CS input CSIN is coupled to an input to the sequence abort inverter 406. As such, the sequence abort inverter 406 receives and inverts the CS signal CSS to provide the sequence abort signal SAS to the sequence processing circuitry 304. In this regard, when the SOS detection circuitry 302 is coupled to the 3-wire serial communications bus 306, the sequence abort signal SAS is based on the CS signal CSS. The sequence abort signal SAS may be used by the sequence processing circuitry 304 to abort commands, to abort read operations, to abort write operations, to abort configurations, the like, or any combination thereof.

[0497] FIG. 65 shows the first C23SCI 404 according to another embodiment of the first C23SCI 404. The first C23SCI 404 illustrated in FIG. 65 is similar to the first C23SCI 404 illustrated in FIG. 64, except the first C23SCI 404 illustrated in FIG. 65 further includes a sequence abort AND gate 408. Additionally, the SOS detection circuitry 302 is coupled to the 2-wire serial communications bus 308 instead of the 3-wire serial communications bus 306. The CS input CSIN is coupled to the input to the sequence abort inverter 406 and an output from the sequence abort inverter 406 is coupled to a first input to the sequence abort AND gate 408. A second input to the sequence abort AND gate 408 receives a sequence abort enable signal ANS. The sequence abort AND gate 408 provides the sequence abort signal SAS to the sequence processing circuitry 304 based on the sequence abort enable signal ANS. In this regard, the capability of the first C23SCI 404 to abort processing of a received sequence may be either enabled or disabled based on the sequence abort enable signal ANS.

[0498] FIGS. 50A, 50B, 50C, and 50D are graphs illustrating the chip select signal CSS, the SOS detection signal SSDS, the serial clock signal SCLK, and the serial data signal SDATA, respectively, of the first C23SCI 404 illustrated in FIG. 64 according to one embodiment of the first C23SCI 404. The serial clock signal SCLK has the serial clock period 316 (FIG. 50C) and the serial data signal SDATA has the data bit period 318 (FIG. 50D) during the received sequence 320 (FIG. 50D). In one embodiment of the first C23SCI 404, the serial clock period 316 is about equal to the data bit period 318. As such, the serial clock signal SCLK may be used to sample data provided by the serial data signal SDATA. An SOS 322 of the received sequence 320 is shown in FIG. 50D.

[0499] The SOS detection circuitry 302 may detect the SOS 322 based on a LOW to HIGH transition of the CS signal CSS as shown in FIG. 50A. The CS detection circuitry 312 may use the CS signal CSS and the serial clock signal SCLK, such that the SOS detection signal SSDS is a pulse. A duration of the pulse may be about equal to the serial clock period 316. The pulse may be a positive pulse as shown in FIG. 50B. In an alternate embodiment (not shown) of the CS detection circuitry 312, the CS detection circuitry 312 may use the CS signal CSS and the serial clock signal SCLK, such that the SOS detection signal SSDS is a negative pulse. In an alternate embodiment (not shown) of the SOS detection circuitry 302, the SOS detection circuitry 302 may detect the SOS 322 based on a HIGH to LOW transition of the CS signal CSS.

[0500] FIGS. 51A, 51B, 51C, and 51D are graphs illustrating the chip select signal CSS, the SOS detection signal SSDS, the serial clock signal SCLK, and the serial data signal SDATA, respectively, of the first C23SCI 404 illustrated in FIG. 64 according to one embodiment of the first C23SCI 404. The CS signal CSS illustrated in FIG. 51A is LOW during the received sequence 320 (FIG. 51D). As such, the CS signal CSS is not used to detect the SOS 322 (FIG. 51D). Instead, detection of the SOS 322 is based on the special encoding of the serial data signal SDATA and the serial clock signal SCLK. Specifically, the SOS detection circuitry 302 uses the SSC detection circuitry 314 to detect the SOS 322 based on a pulse of the serial data signal SDATA, such that during the pulse of the serial data signal SDATA, the serial clock signal SCLK does not transition. The pulse of the serial data signal SDATA may be a positive pulse as shown in FIG. 51D. A duration of the serial data signal SDATA may be about equal to the data bit period 318.

[0501] The SSC detection circuitry 314 may use the serial data signal SDATA and the serial clock signal SCLK, such that the SOS detection signal SSDS is a pulse. A duration of the pulse may be about equal to the serial clock period 316. The pulse may be a positive pulse as shown in FIG. 51B. In an alternate embodiment (not shown) of the SSC detection circuitry 314, the SSC detection circuitry 314 may use the serial data signal SDATA and the serial clock signal SCLK, such that the SOS detection signal SSDS is a negative pulse. In an alternate embodiment (not shown) of the SOS detection circuitry 302, the SOS detection circuitry 302 may detect the SOS 322 based on a negative pulse of the serial data signal SDATA while the serial clock signal SCLK does not transition.

[0502] In one embodiment of the sequence processing circuitry 304, if another SOS 322 is detected before processing of the received sequence 320 is completed; the sequence processing circuitry 304 will abort processing of the received sequence 320 in process and initiate processing of the next received sequence 320. In one embodiment of the first C23SCI 404, the first C23SCI 404 is a mobile industry processor interface (MiPi). In an alternate embodiment of the first C23SCI 404, the first C23SCI 404 is an RF front-end (FE) interface. In an additional embodiment of the first C23SCI 404, the first C23SCI 404 is a slave device. In another embodiment of the first C23SCI 404, the first C23SCI 404 is a MiPi RFFE interface. In a further embodiment of the first C23SCI 404, the first C23SCI 404 is a MiPi RFFE slave device. In a supplemental embodiment of the first C23SCI 404, the first C23SCI 404 is a MiPi slave device. In an alternative embodiment of the first C23SCI 404, the first C23SCI 404 is an RFFE slave device.

[0503] FIGS. 52A, 52B, 52C, and 52D are graphs illustrating the chip select signal CSS, the SOS detection signal SSDS, the serial clock signal SCLK, and the serial data signal SDATA, respectively, of the first C23SCI 404 illustrated in FIG. 64 according to one embodiment of the first C23SCI 404. FIGS. 52A, 52C, and 52D are duplicates of FIGS. 50A, 50C, and 50D, respectively for clarity. The SOS detection circuitry 302 may detect the SOS 322 based on the LOW to HIGH transition of the CS signal CSS as shown in FIG. 52A. The CS detection circuitry 312 may uses the CS signal CSS, such that the SOS detection signal SSDS follows the CS signal CSS as shown in FIG. 52B. In an alternate embodiment of the SOS detection circuitry 302, the CS detection circuitry 312 is omitted, such that the CS input CSIN is directly coupled to the sequence detection OR gate 310. As such, the SOS detection signal SSDS follows the CS signal CSS as shown in FIG. 52B.

[0504] FIG. 66 shows the RF communications system 26 according to one embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 66 is similar to the RF communications system 26 illustrated in FIG. 6, except in the RF communications system 26 illustrated in FIG. 66, the RF PA circuitry 30 further includes the first C23SCI 404, the DC-DC converter 32 further includes a second C23SCI 410, and the front-end aggregation circuitry 36 further includes a third C23SCI 412. In one embodiment of the RF communications system 26, the first C23SCI 404 is the PA-DCI 60, the second C23SCI 410 is the DC-DC converter DCI 62, and the third C23SCI 412 is the aggregation circuitry DCI 64. In an alternate embodiment (not shown) of the RF communications system 26, the first C23SCI 404 is the DC-DC converter DCI 62. In an additional embodiment (not shown) of the RF communications system 26, the first C23SCI 404 is the aggregation circuitry DCI 64.

[0505] In one embodiment of the RF communications system 26, the S-wire serial communications bus 306 (FIG. 62) is the digital communications bus 66. The control circuitry 42 is coupled to the SOS detection circuitry 302 (FIG. 62) via the 3-wire serial communications bus 306 (FIG. 62) and via the control circuitry DCI 58. As such, the control circuitry 42 provides the CS signal CSS (FIG. 62) via the control circuitry DCI 58, the control circuitry 42 provides the serial clock signal SCLK (FIG. 62) via the control circuitry DCI 58, and the control circuitry 42 provides the serial data signal SDATA (FIG. 62) via the control circuitry DCI 58.

[0506] In an alternate embodiment of the RF communications system 26, the 2-wire serial communications bus 308 (FIG. 63) is the digital communications bus 66. The control circuitry 42 is coupled to the SOS detection circuitry 302 (FIG. 63) via the 2-wire serial communications bus 308 (FIG. 63) and via the control circuitry DCI 58. As such, the control circuitry 42 provides the serial clock signal SCLK (FIG. 63) via the control circuitry DCI 58 and the control circuitry 42 provides the serial data signal SDATA (FIG. 63) via the control circuitry DCI 58.

[0507] FIG. 67 shows details of the RF PA circuitry 30 illustrated in FIG. 6 according to one embodiment of the RF PA circuitry 30. The RF PA circuitry 30 illustrated in FIG. 67 is similar to the RF PA circuitry 30 illustrated in FIG. 54, except in the RF PA circuitry 30 illustrated in FIG. 67, the first C23SCI 404 is the PA-DCI 60 and the PA control circuitry 94 provides the sequence abort signal SAS and the protocol configuration signal PCS to the PA-DCI 60. In alternate embodiments of the PA control circuitry 94, the sequence abort signal SAS, the protocol configuration signal PCS, or both are omitted.

[0508] FIG. 68 shows the RF communications system 26 according to an alternate embodiment of the RF communications system 26. The RF communications system 26 illustrated in FIG. 68 is similar to the RF communications system 26 illustrated in FIG. 57, except in the RF communications system 26 illustrated in FIG. 68, the first C23SCI 404 is the DC-DC converter DCI 62 and the DC-DC control circuitry 90 provides the sequence abort signal SAS and the protocol configuration signal PCS to the DC-DC converter DCI 62. In alternate embodiments of the DC-DC control circuitry 90, the sequence abort signal SAS, the protocol configuration signal PCS, or both are omitted.

[0509] A summary of IDAC controlled PA bias is presented followed by a detailed description of the IDAC controlled PA bias according to one embodiment of the present disclosure. The present disclosure relates to RF PA circuitry, which includes an RF PA having a final stage, PA control circuitry, a PA-DCI, and a final stage IDAC. The final stage IDAC is coupled between the PA control circuitry and a final bias input to the final stage of the RF PA. The PA-DCI is coupled between a digital communications bus and the PA control circuitry. The PA control circuitry receives information from the digital communications bus via the PA-DCI. The final stage IDAC biases the final stage of the RF PA via the final bias input based on the information. Specifically, the final stage IDAC provides a final bias signal to the final bias input based on the information. As such, the PA control circuitry controls bias to the final stage by controlling the final stage IDAC via a bias configuration control signal. The PA-DCI may be a serial digital interface (SDI), a mobile industry processor interface (MiPi), or other digital interface.

[0510] In one embodiment of the RF PA circuitry, the RF PA circuitry includes a first RF PA, a second RF PA, the final stage IDAC, the PA control circuitry, the PA-DCI, and a final stage multiplexer coupled between the final stage IDAC and the RF PAs. During a first PA operating mode, the first RF PA is enabled and the second RF PA is disabled. Conversely, during a second PA operating mode, the first RF PA is disabled and the second RF PA is enabled. As such, the final stage multiplexer is controlled by the PA control circuitry based on which PA operating mode is selected. During the first PA operating mode, the PA control circuitry routes the final bias signal from the final stage IDAC though the final stage multiplexer to the first RF PA and disables the second RF PA by providing a disabling final bias signal to the second RF PA from the final stage multiplexer. Conversely, during the second PA operating mode, the PA control circuitry routes the final bias signal from the final stage IDAC though the final stage multiplexer to the second RF PA and disables the first RF PA by providing a disabling final bias signal to the first RF PA from the final stage multiplexer.

[0511] In an alternate embodiment of the RF PA circuitry, the RF PA circuitry further includes a driver stage IDAC and a driver stage multiplexer coupled to driver stages in the first and second RF PAs. During the first PA operating mode, the PA control circuitry routes a driver bias signal from the driver stage IDAC though the driver stage multiplexer to the first RF PA. During the second PA operating mode, the PA control circuitry routes the driver bias signal from the driver stage IDAC though the driver stage multiplexer to the second RF PA.

[0512] FIG. 69 shows details of the RF PA circuitry 30 illustrated in FIG. 6 according to another embodiment of the RF PA circuitry 30. The RF PA circuitry 30 illustrated in FIG. 69 is similar to the RF PA circuitry 30 illustrated in FIG. 40, except the RF PA circuitry 30 illustrated in FIG. 69 further includes the PA-DCI 60, which is coupled to the PA control circuitry 94 and to the digital communications bus 66. The control circuitry 42 (FIG. 6) is coupled to the digital communications bus 66. As such, the control circuitry 42 (FIG. 6) may provide the PA configuration control signal PCC via the control circuitry DCI 58 (FIG. 6) to the PA control circuitry 94 via the PA-DCI 60. Additionally, the first driver stage 252 has a first driver bias input FDBI, the first final stage 254 has a first final bias input FFBI, the second driver stage 256 has a second driver bias input SDBI, and the second final stage 258 has a second final bias input SFBI. The driver stage IDAC circuitry 260 illustrated in FIG. 41 includes the driver stage IDAC 264 and the final stage IDAC circuitry 262 illustrated in FIG. 41 includes the final stage IDAC 270 (FIG. 41).

[0513] In this regard, the final stage IDAC 270 (FIG. 41) is coupled between the PA control circuitry 94 and the first final bias input FFBI through the final stage multiplexer 272 (FIG. 41). As such, the final stage multiplexer 272 (FIG. 41) is coupled between the final stage IDAC 270 (FIG. 41) and the first final bias input FFBI. The final stage IDAC 270 (FIG. 41) is coupled between the PA control circuitry 94 and the second final bias input SFBI through the final stage multiplexer 272 (FIG. 41). As such, the final stage multiplexer 272 (FIG. 41) is coupled between the final stage IDAC 270 (FIG. 41) and the second final bias input SFBI. The driver stage IDAC 264 (FIG. 41) is coupled between the PA control circuitry 94 and the first driver bias input FDBI through the driver stage multiplexer 266 (FIG. 41). As such, the driver stage multiplexer 266 (FIG. 41) is coupled between driver stage IDAC 264 (FIG. 41) and the first driver bias input FDBI. The driver stage IDAC 264 (FIG. 41) is coupled between the PA control circuitry 94 and the second driver bias input SDBI through the driver stage multiplexer 266 (FIG. 41). As such, the driver stage multiplexer 266 (FIG. 41) is coupled between the driver stage IDAC 264 (FIG. 41) and the second driver bias input SDBI.

[0514] The PA-DCI 60 is coupled between the digital communications bus 66 and the PA control circuitry 94. The PA control circuitry 94 receives information from the digital communications bus 66 via the PA-DCI 60. In one embodiment of the PA-DCI 60, the PA-DCI 60 is a serial digital interface. In one embodiment of the PA-DCI 60, the PA-DCI 60 is a mobile industry processor interface (MiPi). The final stage IDAC 270 (FIG. 41) biases the first final stage 254 via the first final bias input FFBI based on the information. As such, the first RF PA 50 receives the first final bias signal FFB via the first final bias input FFBI to bias the first final stage 254. The final stage IDAC 270 (FIG. 41) biases the second final stage 258 via the second final bias input SFBI based on the information. As such, the second RF PA 54 receives the second final bias signal SFB via the second final bias input SFBI to bias the second final stage 258. The driver stage IDAC 264 (FIG. 41) biases the first driver stage 252 via the first driver bias input FDBI based on the information. As such, the first RF PA 50 receives the first driver bias signal FDB via the first driver bias input FDBI to bias the first driver stage 252. The driver stage IDAC 264 (FIG. 41) biases the second driver stage 256 via the second driver bias input SDBI based on the information. As such, the second RF PA 54 receives the second driver bias signal SDB via the second driver bias input SDBI to bias the second driver stage 256.

[0515] In one embodiment of the control circuitry 42 (FIG. 6), the control circuitry 42 (FIG. 6) selects a desired magnitude of the first final bias signal FFB and provides the information based on the desired magnitude of the first final bias signal FFB. In one embodiment of the control circuitry 42 (FIG. 6), the control circuitry 42 (FIG. 6) selects a desired magnitude of the second final bias signal SFB and provides the information based on the desired magnitude of the second final bias signal SFB. In one embodiment of the control circuitry 42 (FIG. 6), the control circuitry 42 (FIG. 6) selects a desired magnitude of the first driver bias signal FDB and provides the information based on the desired magnitude of the first driver bias signal FDB. In one embodiment of the control circuitry 42 (FIG. 6), the control circuitry 42 (FIG. 6) selects a desired magnitude of the second driver bias signal SDB and provides the information based on the desired magnitude of the second driver bias signal SDB.

[0516] The PA control circuitry 94 provides the bias configuration control signal BCC based on the information. As such, the PA control circuitry 94 controls bias to the first final stage 254 by controlling the final stage IDAC 270 (FIG. 41) via the bias configuration control signal BCC based on the information. The PA control circuitry 94 controls bias to the second final stage 258 by controlling the final stage IDAC 270 (FIG. 41) via the bias configuration control signal BCC based on the information. The PA control circuitry 94 controls bias to the first driver stage 252 by controlling the driver stage IDAC 264 (FIG. 41) via the bias configuration control signal BCC based on the information. The PA control circuitry 94 controls bias to the second driver stage 256 by controlling the driver stage IDAC 264 (FIG. 41) via the bias configuration control signal BCC based on the information.

[0517] In one embodiment of the first driver stage 252, the first driver stage 252 is a quadrature driver stage. In an alternate embodiment of the first driver stage 252, the first driver stage 252 is a non-quadrature driver stage. In one embodiment of the second driver stage 256, the second driver stage 256 is a quadrature driver stage. In an alternate embodiment of the second driver stage 256, the second driver stage 256 is a non-quadrature driver stage. In one embodiment of the first final stage 254, the first final stage 254 is a quadrature final stage. In an alternate embodiment of the first final stage 254, the first final stage 254 is a non-quadrature final stage. In one embodiment of the second final stage 258, the second final stage 258 is a quadrature final stage. In an alternate embodiment of the second final stage 258, the second final stage 258 is a non-quadrature final stage.

[0518] FIG. 70 shows details of the first final stage 254 illustrated in FIG. 69 according to one embodiment of the first final stage 254. The first final stage 254 includes the first quadrature RF splitter 124, the first in-phase amplification path 126, the first quadrature-phase amplification path 128 and the first quadrature RF combiner 130. The first in-phase amplification path 126 includes the first in-phase final PA impedance matching circuit 144, the first in-phase final PA stage 146, and the first in-phase combiner impedance matching circuit 148. The first in-phase final PA impedance matching circuit 144 is coupled between the first in-phase output FIO and the first in-phase final PA stage 146. The first in-phase combiner impedance matching circuit 148 is coupled between the first in-phase final PA stage 146 and the first in-phase input FII. The first in-phase final PA impedance matching circuit 144 may provide at least an approximate impedance match between the first quadrature RF splitter 124 and the first in-phase final PA stage 146. The first in-phase combiner impedance matching circuit 148 may provide at least an approximate impedance match between the first in-phase final PA stage 146 and the first quadrature RF combiner 130. The first in-phase final PA stage 146 has a first in-phase final bias input FIFI, which is coupled to the first final bias input FFBI. In one embodiment of the first in-phase final PA stage 146, the first in-phase final bias input FIFI is directly coupled to the first final bias input FFBI.

[0519] During the first PA operating mode, the first quadrature RF splitter 124 receives the first final stage input signal FFSI via the first single-ended input FSI. Further, during the first PA operating mode, the first quadrature RF splitter 124 splits and phase-shifts the first final stage input signal FFSI into the first in-phase RF input signal FIN and the first quadrature-phase RF input signal FQN, such that the first quadrature-phase RF input signal FQN is nominally phase-shifted from the first in-phase RF input signal FIN by about 90 degrees.

[0520] During the first PA operating mode, the first in-phase final PA impedance matching circuit 144 receives and forwards the first in-phase RF input signal FIN to the first in-phase final PA stage 146, which receives and amplifies the forwarded first in-phase RF input signal to provide the first in-phase RF output signal FIT via the first in-phase combiner impedance matching circuit 148. During the first PA operating mode, the envelope power supply signal EPS provides power for amplification to the first in-phase final PA stage 146. During the first PA operating mode, the first final bias signal FFB provides biasing to the first in-phase final PA stage 146 via the first in-phase final bias input FIFI.

[0521] The first quadrature-phase amplification path 128 includes the first quadrature-phase final PA impedance matching circuit 154, the first quadrature-phase final PA stage 156, and the first quadrature-phase combiner impedance matching circuit 158. The first quadrature-phase final PA impedance matching circuit 154 is coupled between the first quadrature-phase output FQO and the first quadrature-phase final PA stage 156. The first quadrature-phase combiner impedance matching circuit 158 is coupled between the first quadrature-phase final PA stage 156 and the first quadrature-phase input FQI.

[0522] The first quadrature-phase final PA impedance matching circuit 154 may provide at least an approximate impedance match between the first quadrature RF splitter 124 and the first quadrature-phase final PA stage 156. The first quadrature-phase combiner impedance matching circuit 158 may provide at least an approximate impedance match between the first quadrature-phase final PA stage 156 and the first quadrature RF combiner 130. The first quadrature-phase final PA stage 156 has a first quadrature-phase final bias input FQFI, which is coupled to the first final bias input FFBI. In one embodiment of the first quadrature-phase final PA stage 156, the first quadrature-phase final bias input FQFI is directly coupled to the first final bias input FFBI.

[0523] During the first PA operating mode, the first quadrature-phase final PA impedance matching circuit 154 receives and forwards the first quadrature-phase RF input signal FQN to provide a forwarded first quadrature-phase RF input signal to the first quadrature-phase final PA stage 156 via the first quadrature-phase final PA impedance matching circuit 154. The first quadrature-phase final PA stage 156 receives and amplifies the forwarded first quadrature-phase RF input signal to provide the first quadrature-phase RF output signal FQT via the first quadrature-phase combiner impedance matching circuit 158. During the first PA operating mode, the first quadrature RF combiner 130 receives the first in-phase RF output signal FIT via the first in-phase input FII, and receives the first quadrature-phase RF output signal FQT via the first quadrature-phase input FQI. Further, the first quadrature RF combiner 130 phase-shifts and combines the first in-phase RF output signal FIT and the first quadrature-phase RF output signal FQT to provide the first RF output signal FRFO via the first quadrature combiner output FCO, such that the phase-shifted first in-phase RF output signal FIT and first quadrature-phase RF output signal FQT are about phase-aligned with one another before combining. During the first PA operating mode, the envelope power supply signal EPS provides power for amplification to the first quadrature-phase final PA stage 156. During the first PA operating mode, the first final bias signal FFB provides biasing to the first quadrature-phase final PA stage 156 via the first quadrature-phase final bias input FQFI.

[0524] FIG. 71 shows details of the second final stage 258 illustrated in FIG. 69 according to one embodiment of the second final stage 258. The second final stage 258 includes the second quadrature RF splitter 132, the second in-phase amplification path 134, the second quadrature-phase amplification path 136, and the second quadrature RF combiner 138. The second in-phase amplification path 134 includes the second in-phase final PA impedance matching circuit 164, the second in-phase final PA stage 166, and the second in-phase combiner impedance matching circuit 168. The second in-phase final PA impedance matching circuit 164 is coupled between the second in-phase RF input signal SIN and the second in-phase final PA stage 166. The second in-phase combiner impedance matching circuit 168 is coupled between the second in-phase final PA stage 166 and the second in-phase input SII.

[0525] The second in-phase final PA impedance matching circuit 164 may provide at least an approximate impedance match between the second quadrature RF splitter 132 and the second in-phase final PA stage 166. The second in-phase combiner impedance matching circuit 168 may provide at least an approximate impedance match between the second in-phase final PA stage 166 and the second quadrature RF combiner 138. The second in-phase final PA stage 166 has a second in-phase final bias input SIFI, which is coupled to the second final bias input SFBI. In one embodiment of the second in-phase final PA stage 166, the second in-phase final bias input SIFI is directly coupled to the second final bias input SFBI.

[0526] During the second PA operating mode, the second quadrature RF splitter 132 receives the second final stage input signal SFSI via the second single-ended input SSI. Further, during the second PA operating mode, the second quadrature RF splitter 132 splits and phase-shifts the second final stage input signal SFSI into the second in-phase RF input signal SIN and the second quadrature-phase RF input signal SQN, such that the second quadrature-phase RF input signal SQN is nominally phase-shifted from the second in-phase RF input signal SIN by about 90 degrees.

[0527] During the second PA operating mode, the second in-phase final PA impedance matching circuit 164 receives and forwards the second in-phase RF input signal SIN to the second in-phase final PA stage 166. The second in-phase final PA stage 166 receives and amplifies the forwarded second in-phase RF input signal to provide the second in-phase RF output signal SIT via the second in-phase combiner impedance matching circuit 168. During the second PA operating mode, the envelope power supply signal EPS provides power for amplification to the second in-phase final PA stage 166. During the second PA operating mode, the second final bias signal SFB provides biasing to the second in-phase final PA stage 166 via the second in-phase final bias input SIFI.

[0528] The second quadrature-phase amplification path 136 includes the second quadrature-phase final PA impedance matching circuit 174, the second quadrature-phase final PA stage 176, and the second quadrature-phase combiner impedance matching circuit 178. The second quadrature-phase final PA impedance matching circuit 174 is coupled between the second quadrature-phase output SQO and the second quadrature-phase final PA stage 176. The second quadrature-phase combiner impedance matching circuit 178 is coupled between the second quadrature-phase final PA stage 176 and the second quadrature-phase input SQI.

[0529] The second quadrature-phase final PA impedance matching circuit 174 may provide at least an approximate impedance match between second quadrature RF splitter 132 and the second quadrature-phase final PA stage 176. The second quadrature-phase combiner impedance matching circuit 178 may provide at least an approximate impedance match between the second quadrature-phase final PA stage 176 and the second quadrature RF combiner 138. The second quadrature-phase final PA stage 176 has a second quadrature-phase final bias input SQFI, which is coupled to the second final bias input SFBI. In one embodiment of the second quadrature-phase final PA stage 176, the second quadrature-phase final bias input SQFI is directly coupled to the second final bias input SFBI.

[0530] During the second PA operating mode, the second quadrature-phase final PA impedance matching circuit 174 receives and forwards the second quadrature-phase RF input signal SQN to the second quadrature-phase final PA stage 176. The second quadrature-phase final PA stage 176 receives and amplifies the forwarded the second quadrature-phase RF input signal to provide the second quadrature-phase RF output signal SQT via the second quadrature-phase combiner impedance matching circuit 178. During the second PA operating mode, the second quadrature RF combiner 138 receives the second in-phase RF output signal SIT via the second in-phase input SII, and receives the second quadrature-phase RF output signal SQT via the second quadrature-phase input SQI. Further, the second quadrature RF combiner 138 phase-shifts and combines the second in-phase RF output signal SIT and the second quadrature-phase RF output signal SQT to provide the second RF output signal SRFO via the second quadrature combiner output SCO, such that the phase-shifted second in-phase RF output signal SIT and second quadrature-phase RF output signal SQT are about phase-aligned with one another before combining. During the second PA operating mode, the envelope power supply signal EPS provides power for amplification to the second quadrature-phase final PA stage 176. During the second PA operating mode, the second final bias signal SFB provides biasing to the second quadrature-phase final PA stage 176 via the second quadrature-phase final bias input SQFI.

[0531] A summary of noise reduction of dual switching power supplies using synchronized switching frequencies is followed by a detailed description of the noise reduction of dual switching power supplies using synchronized switching frequencies according to one embodiment of the present disclosure. In this regard, the present disclosure relates to a DC-DC converter having a first switching power supply, a second switching power supply, and frequency synthesis circuitry, which provides a first clock signal to the first switching power supply and a second clock signal to the second switching power supply. The first switching power supply receives and converts a DC power supply signal from a DC power supply, such as a battery, to provide a first switching power supply output signal using the first clock signal, which has a first frequency. The second switching power supply receives and converts the DC power supply signal to provide a second switching power supply output signal using the second clock signal, which has a second frequency. The second clock signal is phase-locked to the first clock signal. A switching frequency of the first switching power supply is equal to the first frequency and a switching frequency of the second switching power supply is equal to the second frequency.

[0532] The first and the second switching power supply output signals are used to provide power to application circuitry. By phase-locking the second clock signal to the first clock signal, an uncontrolled low frequency beat between the first and the second clock signals is avoided. Such a beat could interfere with proper operation of the application circuitry, particularly in applications that have sensitivities to certain frequencies. An uncontrolled low frequency beat may be manifested in ripple in the first switching power supply output signal, in ripple in the second switching power supply output signal, via switching circuitry in the first switching power supply, via switching circuitry in the second switching power supply, or any combination thereof. As a result, filtering out or avoiding such a beat may be difficult. By phase-locking the first and the second clock signals, spectral content of the first and the second switching power supplies is harmonically related and controlled. In one embodiment of the application circuitry, the first switching power supply output signal is an envelope power supply signal for an RF power amplifier (PA) and the second switching power supply output signal is a bias power supply signal used for biasing the RF PA. By avoiding an uncontrolled low frequency beat between the first and the second clock signals, interference in the RF PA and other RF circuitry, may be avoided.

[0533] In one embodiment of the frequency synthesis circuitry, the first frequency divided by the second frequency is about equal to a positive integer. In an alternate embodiment of the frequency synthesis circuitry, the first frequency divided by the second frequency is about equal to a first positive integer divided by a second positive integer. In one embodiment of the frequency synthesis circuitry, the frequency synthesis circuitry includes a first frequency oscillator, which provides the first clock signal, and a second frequency oscillator, which provides the second clock signal, such that the second frequency oscillator is phase-locked to the first frequency oscillator. In one embodiment of the first frequency oscillator, the first frequency oscillator is a programmable frequency oscillator. In one embodiment of the second frequency oscillator, the second frequency oscillator is a programmable frequency oscillator.

[0534] In one embodiment of the frequency synthesis circuitry, the frequency synthesis circuitry includes the first frequency oscillator, which provides a first oscillator output signal, and a first divider, which receives and divides the first oscillator output signal to provide the second clock signal. The first oscillator output signal has the first frequency and the first clock signal is based on the first oscillator output signal. In one embodiment of the frequency synthesis circuitry, the first oscillator output signal is the first clock signal. In an alternate embodiment of the frequency synthesis circuitry, the frequency synthesis circuitry further includes a buffer, which receives and buffers the first oscillator output signal to provide the first clock signal. In one embodiment of the first divider, the first divider is a fractional divider, such that the first frequency divided by the second frequency is about equal to the first positive integer divided by the second positive integer. In an alternate embodiment of the first divider, the first divider is an integer divider, such that the first frequency divided by the second frequency is about equal to the positive integer. In an additional embodiment of the first divider, the first divider is a programmable divider, such that any or all of the first positive integer, the second positive integer, and the positive integer are programmable.

[0535] In another embodiment of the frequency synthesis circuitry, the frequency synthesis circuitry includes the first frequency oscillator, which provides the first oscillator output signal, the first divider, which receives and divides the first oscillator output signal to provide the second clock signal, and a second divider, which receives and divides the first oscillator output signal to provide the first clock signal. In one embodiment of the second divider, the second divider is a fractional divider. In an alternate embodiment of the second divider, the second divider is an integer divider.

[0536] FIG. 72 shows the DC-DC converter 32 according to one embodiment of the DC-DC converter 32. In one embodiment of the DC-DC converter 32, the DC-DC converter 32 illustrated in FIG. 72 is used as the DC-DC converter 32 illustrated in FIG. 6. The DC-DC converter 32 includes the DC-DC converter DCI 62, the DC-DC control circuitry 90, a first switching power supply 450, a second switching power supply 452, and frequency synthesis circuitry 454. The DC-DC converter DCI 62 is coupled between the digital communications bus 66 and the DC-DC control circuitry 90. The DC power supply 80 provides the DC power supply signal DCPS to the first switching power supply 450 and the second switching power supply 452.

[0537] The DC-DC control circuitry 90 provides a first power supply control signal FPCS to the first switching power supply 450, a second power supply control signal SPCS to the second switching power supply 452, and a frequency synthesis control signal FSCS to the frequency synthesis circuitry 454. The first switching power supply 450 provides a first power supply status signal FPSS to the DC-DC control circuitry 90. The second switching power supply 452 provides a second power supply status signal SPSS to the DC-DC control circuitry 90. The frequency synthesis circuitry 454 provides a frequency synthesis status signal FSSS to the DC-DC control circuitry 90.

[0538] The frequency synthesis circuitry 454 provides a first clock signal FCLS to the first switching power supply 450 and a second clock signal SCLS to the second switching power supply 452. The first clock signal FCLS has a first frequency and the second clock signal SCLS has a second frequency. The second clock signal SCLS is phase-locked to the first clock signal FCLS. The first switching power supply 450 receives and converts the DC power supply signal DCPS to provide a first switching power supply output signal FPSO using the first clock signal FCLS, such that a switching frequency of the first switching power supply 450 is equal to the first frequency. The second switching power supply 452 receives and converts the DC power supply signal DCPS to provide a second switching power supply output signal SPSO using the second clock signal SCLS, such that a switching frequency of the second switching power supply 452 is equal to the second frequency.

[0539] In one embodiment of the frequency synthesis circuitry 454, the first frequency divided by the second frequency is about equal to a positive integer. In one embodiment of the frequency synthesis circuitry 454, the first frequency divided by the second frequency is about equal to a first positive integer divided by a second positive integer. In one embodiment of the first switching power supply 450, the first switching power supply 450 is a charge pump buck power supply. In one embodiment of the second switching power supply 452, the second switching power supply 452 is a charge pump power supply.

[0540] FIG. 73 shows details of the first switching power supply 450 illustrated in FIG. 72 according to one embodiment of the first switching power supply 450. The first switching power supply 450 includes a first switching converter 456, a second switching converter 458, the first power filtering circuitry 82, the first inductive element L1, and the second inductive element L2. The first switching converter 456 is coupled between the DC power supply 80 and the first inductive element L1. The first inductive element L1 is coupled between the first switching converter 456 and the first power filtering circuitry 82. The second switching converter 458 is coupled between the DC power supply 80 and the second inductive element L2. The second inductive element L2 is coupled between the second switching converter 458 and the first power filtering circuitry 82. The first power filtering circuitry 82 provides the first switching power supply output signal FPSO.

[0541] During the first converter operating mode, the first switching converter 456 is active and the second switching converter 458 is inactive, such that the first switching converter 456 receives and converts the DC power supply signal DCPS to provide the first switching power supply output signal FPSO via the first inductive element L1 and the first power filtering circuitry 82. During the second converter operating mode, the first switching converter 456 is inactive and the second switching converter 458 is active, such that the second switching converter 458 receives and converts the DC power supply signal DCPS to provide the first switching power supply output signal FPSO via the second inductive element L2 and the first power filtering circuitry 82.

[0542] In an alternate embodiment of the first switching power supply 450, the second switching converter 458 and the second inductive element L2 are omitted. In an additional embodiment of the first switching power supply 450, the second inductive element L2 is omitted, such that the second switching converter 458 is coupled across the first switching converter 456.

[0543] FIG. 74 shows details of the first switching power supply 450 and the second switching power supply 452 illustrated in FIG. 73 according to an alternate embodiment of the first switching power supply 450 and one embodiment of the second switching power supply 452. The first switching power supply 450 is the PA envelope power supply 280. The second switching power supply 452 is the PA bias power supply 282. The first switching converter 456 is the charge pump buck converter 84. The second switching converter 458 is the buck converter 86. The charge pump buck converter 84 has a first output inductance node 460. The buck converter 86 has a second output inductance node 462. The first inductive element L1 is coupled between the first output inductance node 460 and the first power filtering circuitry 82. The second inductive element L2 is coupled between the second output inductance node 462 and the first power filtering circuitry 82.

[0544] The frequency synthesis circuitry 454 provides the first clock signal FCLS to the PA envelope power supply 280 and the second clock signal SCLS to the PA bias power supply 282. A switching frequency of the PA envelope power supply 280 is equal to the first frequency. A switching frequency of the PA bias power supply 282 is equal to the second frequency. The first switching power supply output signal FPSO is the envelope power supply signal EPS. The second switching power supply output signal SPSO is the bias power supply signal BPS. The first power supply control signal FPCS provides the charge pump buck control signal CPBS and the buck control signal BCS. The second power supply control signal SPCS is the charge pump control signal CPS. The first power supply status signal FPSS is the envelope power supply status signal EPSS. The second power supply status signal SPSS is the bias power supply status signal BPSS.

[0545] FIG. 75 shows details of the first switching power supply 450 and the second switching power supply 452 illustrated in FIG. 73 according to an additional embodiment of the first switching power supply 450 and one embodiment of the second switching power supply 452. The first switching power supply 450 illustrated in FIG. 75 is similar to the first switching power supply 450 illustrated in FIG. 74, except in the first switching power supply 450 illustrated in FIG. 75, the second inductive element L2 is omitted. As such, the first output inductance node 460 is coupled to the second output inductance node 462. Specifically, the first output inductance node 460 may be directly coupled to the second output inductance node 462.

[0546] FIG. 76A shows details of the frequency synthesis circuitry 454 illustrated in FIG. 72 according to one embodiment of the frequency synthesis circuitry 454. The frequency synthesis circuitry 454 includes a first frequency oscillator 464, a second frequency oscillator 466, frequency synthesis control circuitry 468, a first buffer 470, and a second buffer 472. The frequency synthesis control circuitry 468 provides the frequency synthesis status signal FSSS to the DC-DC control circuitry 90 (FIG. 72). The DC-DC control circuitry 90 (FIG. 72) provides the frequency synthesis control signal FSCS to the frequency synthesis control circuitry 468. The first frequency oscillator 464 provides a first oscillator output signal FOOS to the first buffer 470, which receives and buffers the first oscillator output signal FOOS to provide the first clock signal FCLS. As such, the first clock signal FCLS is based on the first oscillator output signal FOOS. The second frequency oscillator 466 provides a second oscillator output signal SOOS to the second buffer 472, which receives and buffers the second oscillator output signal SOOS to provide the second clock signal SCLS. As such, the second clock signal SCLS is based on the second oscillator output signal SOOS.

[0547] The first frequency oscillator 464 provides a frequency synchronization signal FSS to the second frequency oscillator 466, which uses the frequency synchronization signal FSS to phase-lock the second frequency oscillator 466 to the first frequency oscillator 464. As such, the second frequency oscillator 466 is phase-locked to the first frequency oscillator 464. In this regard, both the first oscillator output signal FOOS and the first clock signal FCLS have the first frequency, and both the second oscillator output signal SOOS and the second clock signal SCLS have the second frequency. In an alternate embodiment of the first frequency oscillator 464, the frequency synchronization signal FSS is the first oscillator output signal FOOS.

[0548] In one embodiment of the frequency synthesis circuitry 454, the first buffer 470 is omitted, such that the first oscillator output signal FOOS is the first clock signal FCLS. In this regard, the first frequency oscillator 464 provides the first clock signal FCLS. Further, the first oscillator output signal FOOS has the first frequency. In one embodiment of the frequency synthesis circuitry 454, the second buffer 472 is omitted, such that the second oscillator output signal SOOS is the second clock signal SCLS. In this regard, the second frequency oscillator 466 provides the second clock signal SCLS. Further, the second oscillator output signal SOOS has the second frequency.

[0549] In one embodiment of the first frequency oscillator 464, the first frequency oscillator 464 is a programmable frequency oscillator. As such, a frequency of the first oscillator output signal FOOS is programmable by the frequency synthesis control circuitry 468, which provides frequency programming information to the first frequency oscillator 464. The DC-DC control circuitry 90 (FIG. 72) may select the frequency of the first oscillator output signal FOOS and provide indication of the frequency selection to the frequency synthesis control circuitry 468 via the frequency synthesis control signal FSCS.

[0550] In one embodiment of the second frequency oscillator 466, the second frequency oscillator 466 is a programmable frequency oscillator. As such, a frequency of the second oscillator output signal SOOS is programmable by the frequency synthesis control circuitry 468, which provides frequency programming information to the second frequency oscillator 466. The DC-DC control circuitry 90 (FIG. 72) may select the frequency of the second oscillator output signal SOOS and provide indication of the frequency selection to the frequency synthesis control circuitry 468 via the frequency synthesis control signal FSCS.

[0551] FIG. 76B shows details of the frequency synthesis circuitry 454 illustrated in FIG. 72 according to an alternate embodiment of the frequency synthesis circuitry 454. The frequency synthesis circuitry 454 illustrated in FIG. 76B is similar to the frequency synthesis circuitry 454 illustrated in FIG. 76A, except in the frequency synthesis circuitry 454 illustrated in FIG. 76B, the second frequency oscillator 466 is omitted, the second buffer 472 is omitted, and the frequency synthesis circuitry 454 further includes a first divider 474. The first divider 474 receives and divides the first oscillator output signal FOOS to provide the second clock signal SCLS. As such, the first clock signal FCLS and the second clock signal SCLS are based on the first oscillator output signal FOOS. Further, the second frequency is less than the first frequency. In one embodiment of the first divider 474, the first divider 474 is an integer divider, such that the first frequency divided by the second frequency is about equal to a positive integer. In an alternate embodiment of the first divider 474, the first divider 474 is a fractional divider, such that the first frequency divided by the second frequency is about equal to a first positive integer divided by a second positive integer.

[0552] In one embodiment of the first divider 474, the first divider 474 is a programmable divider, such that a ratio of the first frequency divided by the second frequency is programmable. As such, the frequency synthesis control circuitry 468 provides a first divider control signal FDCS to the first divider 474. The first divider control signal FDCS is indicative of division programming information. The DC-DC control circuitry 90 (FIG. 72) may select a desired ratio of the first frequency divided by the second frequency and provide indication of the desired ratio to the frequency synthesis control circuitry 468 via the frequency synthesis control signal FSCS.

[0553] FIG. 77A shows details of the frequency synthesis circuitry 454 illustrated in FIG. 72 according to an additional embodiment of the frequency synthesis circuitry 454. The frequency synthesis circuitry 454 illustrated in FIG. 77A is similar to the frequency synthesis circuitry 454 illustrated in FIG. 76B, except in the frequency synthesis circuitry 454 illustrated in FIG. 77A, the first buffer 470 is replaced with a second divider 476. The second divider 476 receives and divides the first oscillator output signal FOOS to provide the first clock signal FCLS. As such, the first clock signal FCLS and the second clock signal SCLS are based on the first oscillator output signal FOOS. Further, the first frequency is less than the frequency of the first oscillator output signal FOOS. In one embodiment of the second divider 476, the second divider 476 is an integer divider, such that the frequency of the first oscillator output signal FOOS divided by the first frequency is about equal to a positive integer. In an alternate embodiment of the second divider 476, the second divider 476 is a fractional divider, such that the frequency of the first oscillator output signal FOOS divided by the first frequency is about equal to a first positive integer divided by a second positive integer.

[0554] In one embodiment of the second divider 476, the second divider 476 is a programmable divider, such that a ratio of the frequency of the first oscillator output signal FOOS divided by the first frequency is programmable. As such, the frequency synthesis control circuitry 468 further provides a second divider control signal SDCS to the second divider 476. The second divider control signal SDCS is indicative of division programming information. The DC-DC control circuitry 90 (FIG. 72) may select a desired ratio of the frequency of the first oscillator output signal FOOS divided by the first frequency and provide indication of the desired ratio to the frequency synthesis control circuitry 468 via the frequency synthesis control signal FSCS.

[0555] FIG. 77B shows details of the frequency synthesis circuitry 454 illustrated in FIG. 72 according to another embodiment of the frequency synthesis circuitry 454. The frequency synthesis circuitry 454 illustrated in FIG. 77B is similar to the frequency synthesis circuitry 454 illustrated in FIG. 76B, except in the frequency synthesis circuitry 454 illustrated in FIG. 77B, the first buffer 470 is omitted and the frequency synthesis circuitry 454 further includes a clock signal comparator 478 coupled between the first frequency oscillator 464 and the first divider 474. An inverting input to the clock signal comparator 478 receives a clock comparator reference signal CCRS and a non-inverting input to the clock signal comparator 478 receives the first oscillator output signal FOOS. An output from the clock signal comparator 478 feeds the first divider 474.

[0556] In one embodiment of the first frequency oscillator 464, the first oscillator output signal FOOS is not a digital signal. Instead, the first oscillator output signal FOOS is a ramping signal, such as a triangle-wave signal or a sawtooth signal, having the first frequency. The clock signal comparator 478 converts the ramping signal into a digital signal, which is fed to the first divider 474. As such, the first clock signal FCLS and the second clock signal SCLS are based on the first oscillator output signal FOOS. Further, the first clock signal FCLS is a ramping signal having the first frequency and the second clock signal SCLS is a digital signal having the second frequency.

[0557] A summary of frequency correction of a programmable frequency oscillator by propagation delay compensation is followed by a detailed description of the frequency correction of a programmable frequency oscillator by propagation delay compensation according to one embodiment of the present disclosure. In this regard, the present disclosure relates to a first programmable frequency oscillator, which includes a first ramp comparator and programmable signal generation circuitry. The programmable signal generation circuitry provides a ramping signal, which has a first frequency, based on a desired first frequency. The first ramp comparator receives the ramping signal and provides a first ramp comparator output signal based on the ramping signal. The first ramp comparator output signal is fed back to the programmable signal generation circuitry, such that the ramping signal is based on the desired first frequency and the first ramp comparator output signal. Normally, the first frequency would be about proportional to one or more slopes of the ramping signal. However, the first ramp comparator has a first propagation delay, which introduces a frequency error into the programmable frequency oscillator. As a result, the first frequency is not proportional to the one or more slopes of the ramping signal. In this regard, the programmable signal generation circuitry compensates for the frequency error based on the desired first frequency.

[0558] In one embodiment of the programmable signal generation circuitry compensates for the frequency error by adjusting a first comparator reference signal to the first ramp comparator. In an alternate embodiment of the programmable signal generation circuitry, the programmable signal generation circuitry compensates for the frequency error by adjusting at least a first slope of the ramping signal. In one embodiment of the programmable signal generation circuitry, the programmable signal generation circuitry frequency dithers the ramping signal. As such, a desired frequency of the ramping signal changes based on the frequency dithering. As a result, the frequency error of the ramping signal changes as the desired frequency of the ramping signal changes. Therefore, the signal generation circuitry must adjust the compensation for the frequency error in response to the desired frequency changes of the ramping signal.

[0559] FIG. 78 shows the frequency synthesis control circuitry 468 and details of the first frequency oscillator 464 illustrated in FIG. 77B according to one embodiment of the first frequency oscillator 464. The first frequency oscillator 464 includes a first ramp comparator 480 and programmable signal generation circuitry 482. The programmable signal generation circuitry 482 provides a ramping signal RMPS having the first frequency based on a desired first frequency. The ramping signal RMPS is the first oscillator output signal FOOS. Further, the first ramp comparator 480 receives the ramping signal RMPS via a non-inverting input and provides a first ramp comparator output signal FRCS based on the ramping signal RMPS. The programmable signal generation circuitry 482 provides a first comparator reference signal FCRS. The first ramp comparator 480 receives the first comparator reference signal FCRS via an inverting input, such that the first ramp comparator output signal FRCS is based on a difference between the ramping signal RMPS and the first comparator reference signal FCRS. The first ramp comparator output signal FRCS is fed back to the programmable signal generation circuitry 482, such that the ramping signal RMPS is based on the desired first frequency and the first ramp comparator output signal FRCS.

[0560] The first frequency oscillator 464 is a first programmable frequency oscillator. As such, the first ramp comparator 480 and the programmable signal generation circuitry 482 provide the first programmable frequency oscillator. The control circuitry 42 (FIG. 6), the DC-DC control circuitry 90 (FIG. 72), or the frequency synthesis control circuitry 468 may select the desired first frequency. In general, control circuitry selects the desired first frequency.

[0561] FIG. 79 shows the frequency synthesis control circuitry 468 and details of the first frequency oscillator 464 illustrated in FIG. 77B according to an alternate embodiment of the first frequency oscillator 464. The first frequency oscillator 464 illustrated in FIG. 79 is similar to the first frequency oscillator 464 illustrated in FIG. 78, except in the first frequency oscillator 464 illustrated in FIG. 79, the first ramp comparator output signal FRCS is the first oscillator output signal FOOS instead of the ramping signal RMPS.

[0562] FIG. 80 is a graph showing the first comparator reference signal FCRS and the ramping signal RMPS illustrated in FIG. 78 according to one embodiment of the first comparator reference signal FCRS and the ramping signal RMPS. The ramping signal RMPS has a first slope 484 and a second slope 486. The graph in FIG. 80 shows the ramping signal RMPS under two different operating conditions. At the left end of the graph, the ramping signal RMPS has a first desired period 488 and at the right end of the graph, the ramping signal RMPS has a second desired period 490. The second desired period 490 is longer than the first desired period 488. As such, the first frequency under the operating condition at the left end of the graph is higher than the first frequency under the operating condition to the right.

[0563] The ramping signal RMPS illustrated in FIG. 80 is a sawtooth signal. As such, the first slope 484 shows the ramping signal RMPS ramping-up in a linear manner and the second slope 486 shows the ramping signal RMPS dropping rapidly. As such, the second slope 486 doesn't change significantly between the ramping signal RMPS at the left end of the graph and the ramping signal RMPS at the right end of the graph. However, the first slope 484 changes significantly between the ramping signal RMPS at the left end of the graph and the ramping signal RMPS at the right end of the graph. The programmable signal generation circuitry 482 transitions the ramping signal RMPS from the first slope 484 to the second slope 486 based on the first ramp comparator output signal FRCS (FIG. 78). As such, when the first ramp comparator 480 detects the ramping signal RMPS exceeding the first comparator reference signal FCRS, the first ramp comparator 480 will transition the first ramp comparator output signal FRCS, thereby triggering the programmable signal generation circuitry 482 to transition the ramping signal RMPS from the first slope 484 to the second slope 486.

[0564] However, the first ramp comparator 480 has a first propagation delay 492. If the first propagation delay 492 was small enough to be negligible, when the ramping signal RMPS reached the first comparator reference signal FCRS, the programmable signal generation circuitry 482 would transitions the ramping signal RMPS from the first slope 484 to the second slope 486. If the first propagation delay 492 is not negligible, the ramping signal RMPS overshoots the first comparator reference signal FCRS. Therefore, the ramping signal RMPS at the left end of the graph has a first actual period 494 instead of the first desired period 488 and the ramping signal RMPS at the right end of the graph has a second actual period 496 instead of the second desired period 490. The ramping signal RMPS at the left end of the graph has a first overshoot 498 and the ramping signal RMPS at the right end of the graph has a second overshoot 500. As such, the ramping signal RMPS at the left end of the graph has a first example slope 502 and the ramping signal RMPS at the right end of the graph has a second example slope 504.

[0565] If the first propagation delay 492 was small enough to be negligible, a product of the first desired period 488 times the first example slope 502 would be about equal to a product of the second desired period 490 times the second example slope 504. As such, the first frequency would be about proportional to the first slope 484. However, if the first propagation delay 492 is not negligible, since the first overshoot 498 is not equal to the second overshoot 500, the first frequency is not equal to the first slope 484. As such, the first propagation delay 492 introduces a frequency error into the first frequency oscillator 464 (FIG. 78) that is frequency dependent. Therefore, the programmable signal generation circuitry 482 (FIG. 78) compensates for the first propagation delay 492 based on the desired first frequency. As such, the compensation for the first propagation delay 492 frequency corrects the first frequency.

[0566] In one embodiment of the programmable signal generation circuitry 482 (FIG. 78), the programmable signal generation circuitry 482 (FIG. 78) adjusts the first comparator reference signal FCRS to compensate for the first propagation delay 492 based on the desired first frequency. In an alternate embodiment of the programmable signal generation circuitry 482 (FIG. 78), the programmable signal generation circuitry 482 (FIG. 78) adjusts the first slope 484 of the ramping signal RMPS to compensate for the first propagation delay 492 based on the desired first frequency. In one embodiment of the programmable signal generation circuitry 482 (FIG. 78), the programmable signal generation circuitry 482 (FIG. 78) operates in one of a first phase 506 and a second phase 508, such that during the first phase 506, the ramping signal RMPS has the first slope 484 and during the second phase 508, the ramping signal RMPS has the second slope 486.

[0567] FIG. 81 is a graph showing the first comparator reference signal FCRS and the ramping signal RMPS illustrated in FIG. 78 according to an alternate embodiment of the first comparator reference signal FCRS and the ramping signal RMPS. The first comparator reference signal FCRS and the ramping signal RMPS illustrated in FIG. 81 are similar to the first comparator reference signal FCRS and the ramping signal RMPS illustrated in FIG. 80, except the ramping signal RMPS illustrated in FIG. 81 is frequency dithered. As such, the programmable signal generation circuitry 482 frequency dithers the ramping signal RMPS, such that the ramping signal RMPS has multiple frequencies based on multiple desired frequencies. Each of the multiple frequencies is based on a corresponding one of the multiple desired frequencies. The multiple frequencies may include the first frequency and the multiple desired frequencies may include the desired first frequency.

[0568] Since the first propagation delay 492 (FIG. 80) introduces a frequency error into the first frequency oscillator 464 (FIG. 78) that is frequency dependent. The programmable signal generation circuitry 482 compensates for the first propagation delay 492 (FIG. 80) based on the multiple desired frequencies.

[0569] FIG. 82 shows details of the programmable signal generation circuitry 482 illustrated in FIG. 78 according to one embodiment of the programmable signal generation circuitry 482. The programmable signal generation circuitry 482 has a ramp capacitive element CRM, a first ramp IDAC 510, a capacitor discharge circuit 512, and a first reference DAC 514. Since the first ramp IDAC 510, the capacitor discharge circuit 512, and the first reference DAC 514 are programmable circuits, the first ramp IDAC 510, the capacitor discharge circuit 512, and the first reference DAC 514 are coupled to the frequency synthesis control circuitry 468. The first ramp IDAC 510, the capacitor discharge circuit 512, and the ramp capacitive element CRM are coupled together to provide the ramping signal RMPS.

[0570] During the first phase 506 (FIG. 80) of the programmable signal generation circuitry 482, the first ramp IDAC 510 provides a charging current to the ramp capacitive element CRM. The charging current provides the first slope 484 (FIG. 80) of the ramping signal RMPS. During the second phase 508 (FIG. 80) of the programmable signal generation circuitry 482, the capacitor discharge circuit 512 provides a discharging current to the ramp capacitive element CRM. The discharging current provides the second slope 486 (FIG. 80) of the ramping signal RMPS. Both the first ramp IDAC 510 and the capacitor discharge circuit 512 receive the first ramp comparator output signal FRCS, which is indicative of a transition from the first phase 506 (FIG. 80) to the second phase 508 (FIG. 80). The first reference DAC 514 provides the first comparator reference signal FCRS.

[0571] The frequency synthesis control circuitry 468 selects the first frequency of the ramping signal RMPS by controlling the charging current to the ramp capacitive element CRM using the first ramp IDAC 510. As such, the frequency synthesis control circuitry 468 adjusts the first comparator reference signal FCRS to compensate for the first propagation delay 492 (FIG. 80) based on the desired first frequency using the first reference DAC 514. During frequency dithering, the frequency synthesis control circuitry 468 may need to rapidly change the first ramp IDAC 510 to switch between the multiple frequencies of the ramping signal RMPS. As such, the frequency synthesis control circuitry 468 may need to rapidly change the first reference DAC 514 to switch between the multiple magnitudes of the first comparator reference signal FCRS necessary to compensate for the first propagation delay 492 (FIG. 80).

[0572] FIG. 83 shows the frequency synthesis control circuitry 468 and details of the first frequency oscillator 464 illustrated in FIG. 77B according to an additional embodiment of the first frequency oscillator 464. The first frequency oscillator 464 illustrated in FIG. 83 is similar to the first frequency oscillator 464 illustrated in FIG. 78, except the first frequency oscillator 464 further includes a second ramp comparator 516. The second ramp comparator 516 receives the ramping signal RMPS via a non-inverting input and provides a second ramp comparator output signal SRCS based on the ramping signal RMPS. The programmable signal generation circuitry 482 further provides a second comparator reference signal SCRS. The second ramp comparator 516 receives the second comparator reference signal SCRS via an inverting input, such that the second ramp comparator output signal SRCS is based on a difference between the ramping signal RMPS and the second comparator reference signal SCRS. The second ramp comparator output signal SRCS is fed back to the programmable signal generation circuitry 482, such that the ramping signal RMPS is based on the desired first frequency, the first ramp comparator output signal FRCS, and the second ramp comparator output signal SRCS. The first frequency oscillator 464 is a first programmable frequency oscillator. As such, the first ramp comparator 480, the second ramp comparator 516, and the programmable signal generation circuitry 482 provide the first programmable frequency oscillator.

[0573] The second ramp comparator 516 has a second propagation delay. The programmable signal generation circuitry 482 further compensates for the second propagation delay based on the desired first frequency. As such, the compensation for the first propagation delay 492 (FIG. 80) and the second propagation delay frequency corrects the first frequency. In one embodiment of the programmable signal generation circuitry 482, the programmable signal generation circuitry 482 adjusts the first comparator reference signal FCRS to compensate for the first propagation delay 492 based on the desired first frequency. Further, the programmable signal generation circuitry 482 adjusts the second comparator reference signal SCRS to compensate for the second propagation delay based on the desired first frequency. In an alternate embodiment of the programmable signal generation circuitry 482, the programmable signal generation circuitry 482 adjusts the first slope 484 (FIG. 80) of the ramping signal RMPS to compensate for the first propagation delay 492 (FIG. 80) based on the desired first frequency. Further, the programmable signal generation circuitry 482 adjusts the second slope 486 (FIG. 80) of the ramping signal RMPS to compensate for the second propagation delay based on the desired first frequency.

[0574] FIG. 84 is a graph showing the first comparator reference signal FCRS, the ramping signal RMPS, and the second comparator reference signal SCRS illustrated in FIG. 83 according to one embodiment of the first comparator reference signal FCRS, the ramping signal RMPS, and the second comparator reference signal SCRS. The ramping signal RMPS illustrated in FIG. 94 is a triangular signal. As such, during the first phase 506 of the programmable signal generation circuitry 482 (FIG. 83), the ramping signal RMPS has the first slope 484 and during the second phase 508 of the programmable signal generation circuitry 482, the ramping signal RMPS has the second slope 486. The first slope 484 is a positive slope and the second slope 486 is a negative slope. However, magnitudes of the first slope 484 and the second slope 486 may be about equal to one another. The ramping signal RMPS has a ramping signal peak 517 when transitioning from the first phase 506 to the second phase 508.

[0575] FIG. 85 shows details of the programmable signal generation circuitry 482 illustrated in FIG. 83 according to an alternate embodiment of the programmable signal generation circuitry 482. The programmable signal generation circuitry 482 has the ramp capacitive element CRM, the first ramp IDAC 510, a second ramp IDAC 518, the first reference DAC 514, and a second reference DAC 520. Since the first ramp IDAC 510, the second ramp IDAC 518, the first reference DAC 514, and the second reference DAC 520 are programmable circuits, the first ramp IDAC 510, the second ramp IDAC 518, the first reference DAC 514, and the second reference DAC 520 are coupled to the frequency synthesis control circuitry 468. The first ramp IDAC 510, the second ramp IDAC 518, and the ramp capacitive element CRM are coupled together to provide the ramping signal RMPS.

[0576] During the first phase 506 (FIG. 84) of the programmable signal generation circuitry 482, the first ramp IDAC 510 provides a first current I1, which is the charging current, to the ramp capacitive element CRM. The charging current provides the first slope 484 (FIG. 84) of the ramping signal RMPS. During the second phase 508 (FIG. 84) of the programmable signal generation circuitry 482, the second ramp IDAC 518 provides a second current I2, which is the discharging current from the ramp capacitive element CRM. The discharging current provides the second slope 486 (FIG. 84) of the ramping signal RMPS. Both the first ramp IDAC 510 and the second ramp IDAC 518 receive both the first ramp comparator output signal FRCS and the second ramp comparator output signal SRCS, which are indicative of a transition from the first phase 506 (FIG. 84) to the second phase 508 (FIG. 84) and a transition from the second phase 508 (FIG. 84) to the first phase 506 (FIG. 84). The first reference DAC 514 provides the first comparator reference signal FCRS and the second reference DAC 520 provides the second comparator reference signal SCRS.

[0577] The frequency synthesis control circuitry 468 selects the first frequency of the ramping signal RMPS by controlling the charging current to the ramp capacitive element CRM using the first ramp IDAC 510 and by controlling the discharging current from the ramp capacitive element CRM using the second ramp IDAC 518. As such, the frequency synthesis control circuitry 468 adjusts the first comparator reference signal FCRS to compensate for the first propagation delay 492 (FIG. 80) based on the desired first frequency using the first reference DAC 514. Further, the frequency synthesis control circuitry 468 adjusts the second comparator reference signal SCRS to compensate for the second propagation delay based on the desired first frequency using the second reference DAC 520.

[0578] During frequency dithering, the frequency synthesis control circuitry 468 may need to rapidly change the first ramp IDAC 510 and the second ramp IDAC 518 to switch between the multiple frequencies of the ramping signal RMPS. As such, the frequency synthesis control circuitry 468 may need to rapidly change the first reference DAC 514 and the second reference DAC 520 to switch between the multiple magnitudes of the first comparator reference signal FCRS and the second comparator reference signal SCRS necessary to compensate for the first propagation delay 492 (FIG. 80) and the second propagation delay, respectively.

[0579] FIG. 86 shows details of the programmable signal generation circuitry 482 illustrated in FIG. 83 according to an additional embodiment of the programmable signal generation circuitry 482. The programmable signal generation circuitry 482 illustrated in FIG. 86 is similar to the programmable signal generation circuitry 482 illustrated in FIG. 85, except in the programmable signal generation circuitry 482 illustrated in FIG. 86, the first reference DAC 514 is replaced with a first fixed supply 522 and the second reference DAC 520 is replaced with a second fixed supply 524. As such, the first fixed supply 522 provides the first comparator reference signal FCRS and the second fixed supply 524 provides the second comparator reference signal SCRS. In this regard, the first comparator reference signal FCRS and the second comparator reference signal SCRS are not selectable. As a result, the programmable signal generation circuitry 482 adjusts the first slope 484 (FIG. 84) of the ramping signal RMPS to compensate for the first propagation delay 492 (FIG. 80) based on the desired first frequency and the programmable signal generation circuitry 482 adjusts the second slope 486 (FIG. 84) of the ramping signal RMPS to compensate for the second propagation delay based on the desired first frequency.

[0580] A summary of voltage compatible charge pump buck and buck power supplies is followed by a summary of dual inductive element charge pump buck and buck power supplies and a summary of a DC-DC converter using continuous and discontinuous conduction modes. The summaries are followed by a detailed description of the voltage compatible charge pump buck and buck power supplies and the dual inductive element charge pump buck and buck power supplies according to one embodiment of the present disclosure. The present disclosure relates to a flexible DC-DC converter, which includes a charge pump buck power supply and a buck power supply. The charge pump buck power supply and the buck power supply are voltage compatible with one another at respective output inductance nodes to provide flexibility. In one embodiment of the DC-DC converter, capacitances at the output inductance nodes are at least partially isolated from one another by using at least an isolating inductive element between the output inductance nodes to increase efficiency. In an alternate embodiment of the DC-DC converter, the output inductance nodes are coupled to one another, such that the charge pump buck power supply and the buck power supply share a first inductive element, thereby eliminating the isolating inductive element, which reduces size and cost but may also reduce efficiency. In both embodiments, the charge pump buck power supply and the buck power supply share an energy storage element. Specifically, the charge pump buck power supply includes a charge pump buck converter having a first output inductance node, a first inductive element, and the energy storage element, such that the first inductive element is coupled between the first output inductance node and the energy storage element. The buck power supply includes a buck converter having a second output inductance node, and the energy storage element. The buck power supply at the second output inductance node is voltage compatible with the charge pump buck power supply at the first output inductance node to provide flexibility.

[0581] Only one of the charge pump buck power supply and the buck power supply is active at any one time. As such, either the charge pump buck power supply or the buck power supply receives and converts a DC power supply signal from a DC power supply to provide a first switching power supply output signal to a load based on a setpoint. In one embodiment of the energy storage element, the energy storage element is a capacitive element. In one embodiment of the DC-DC converter, the buck power supply further includes the first inductive element and a second inductive element, which is coupled between the first output inductance node and the second output inductance node, such that the charge pump buck power supply and the buck power supply further share the first inductive element. In another embodiment of the DC-DC converter, the buck power supply further includes the second inductive element, which is coupled between the second output inductance node and the energy storage element. In an alternate embodiment of the DC-DC converter, the first output inductance node is coupled to the second output inductance node and the buck power supply further includes the first inductive element, such that the charge pump buck power supply and the buck power supply further share the first inductive element.

[0582] The charge pump buck converter combines the functionality of a charge pump with the functionality of a buck converter. However, the charge pump buck converter uses fewer switching elements than a separate charge pump and buck converter by using common switching elements for both charge pump and buck converter functionalities. As such, the charge pump buck power supply is capable of providing an output voltage that is greater than a voltage of the DC power supply signal. Conversely, the buck power supply is only capable of providing an output voltage that is about equal to or less than the voltage of the DC power supply signal. However, for the buck power supply to be voltage compatible with the charge pump buck power supply, the buck power supply must not be damaged or function improperly in the presence of a voltage at the second output inductance node that is equivalent to a voltage at the first output inductance node during normal operation of the charge pump buck power supply.

[0583] In one embodiment of the DC-DC converter, during a first converter operating mode, the charge pump buck power supply receives and converts the DC power supply signal to provide the first switching power supply output signal, and the buck power supply is disabled. During a second converter operating mode, the buck power supply receives and converts the DC power supply signal to provide the first switching power supply output signal, and the charge pump buck power supply is disabled. The setpoint is based on a desired voltage of the first switching power supply output signal.

[0584] In one embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is based on a voltage of the DC power supply signal and the setpoint. The first converter operating mode is selected when the desired voltage of the first switching power supply output signal is greater than the voltage of the DC power supply signal. In one embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on a load current of the load. The second converter operating mode is selected when the desired voltage of the first switching power supply output signal is less than the voltage of the DC power supply signal and the load current is less than a load current threshold.

[0585] In a first exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on maximizing efficiency of the DC-DC converter. In a second exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on exceeding a minimum acceptable efficiency of the DC-DC converter. In a third exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on exceeding a desired efficiency of the DC-DC converter. In one embodiment of the DC-DC converter, the DC-DC converter further includes a charge pump, which receives and converts the DC power supply signal to provide a second switching power supply output signal. In one embodiment of the DC-DC converter, the first switching power supply output signal is an envelope power supply signal for a first RF power amplifier (PA) and the second switching power supply output signal is a bias power supply signal used for biasing the first RF PA.

[0586] As previously mentioned, in one embodiment of the DC-DC converter, the first output inductance node is coupled to the second output inductance node. During the first converter operating mode, the charge pump buck converter may boost the voltage of the DC power supply signal significantly, such that a voltage at the first and second output inductance nodes may be significantly higher than the voltage of the DC power supply signal. As a result, even though the buck converter is disabled during the first converter operating mode, the buck converter must be able to withstand the boosted voltage at the second output inductance node. In an exemplary embodiment of the DC-DC converter, the voltage at the first and second output inductance nodes is equal to about 11 volts and a breakdown voltage of individual switching elements in the buck converter is equal to about 7 volts.

[0587] To withstand boosted voltage at the second output inductance node, in one embodiment of the buck converter, the buck converter includes multiple shunt buck switching elements and multiple series buck switching elements. The shunt buck switching elements are coupled in series between the second output inductance node and a ground, and the series buck switching elements are coupled in series between the DC power supply and the first output inductance node. In one embodiment of the buck converter, the series buck switching elements are configured in a cascode arrangement.

[0588] A summary of dual inductive element charge pump buck and buck power supplies is followed by a summary of a DC-DC converter using continuous and discontinuous conduction modes. Next, a detailed description of the dual inductive element charge pump buck and buck power supplies is presented according to one embodiment of the present disclosure. The present disclosure relates to a DC-DC converter, which includes a charge pump buck power supply and a buck power supply. The charge pump buck power supply includes a charge pump buck converter, a first inductive element, and an energy storage element. The charge pump buck converter and the first inductive element are coupled in series between a DC power supply, such as a battery, and the energy storage element. The buck power supply includes a buck converter, a second inductive element, and the energy storage element. The buck converter and the second inductive element are coupled in series between the DC power supply and the energy storage element. As such, the charge pump buck power supply and the buck power supply share the energy storage element. Only one of the charge pump buck power supply and the buck power supply is active at any one time. As such, either the charge pump buck power supply or the buck power supply receives and converts a DC power supply signal from the DC power supply to provide a first switching power supply output signal to a load based on a setpoint. In one embodiment of the energy storage element, the energy storage element is a capacitive element.

[0589] The charge pump buck converter combines the functionality of a charge pump with the functionality of a buck converter. However, the charge pump buck converter uses fewer switching elements than a separate charge pump and buck converter by using common switching elements for both charge pump and buck converter functionalities. As such, the charge pump buck power supply is capable of providing an output voltage that is greater than a voltage of the DC power supply signal. Conversely, the buck power supply is only capable of providing an output voltage that is about equal to or less than the voltage of the DC power supply signal. In one embodiment of the DC-DC converter, during a first converter operating mode, the charge pump buck power supply receives and converts the DC power supply signal to provide the first switching power supply output signal, and the buck power supply is disabled. During a second converter operating mode, the buck power supply receives and converts the DC power supply signal to provide the first switching power supply output signal, and the charge pump buck power supply is disabled. The setpoint is based on a desired voltage of the first switching power supply output signal.

[0590] In one embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is based on a voltage of the DC power supply signal and the setpoint. The first converter operating mode is selected when the desired voltage of the first switching power supply output signal is greater than the voltage of the DC power supply signal. In one embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on a load current of the load. The second converter operating mode is selected when the desired voltage of the first switching power supply output signal is less than the voltage of the DC power supply signal and the load current is less than a load current threshold.

[0591] In a first exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on maximizing efficiency of the DC-DC converter. In a second exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on exceeding a minimum acceptable efficiency of the DC-DC converter. In a third exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on exceeding a desired efficiency of the DC-DC converter. In one embodiment of the DC-DC converter, the DC-DC converter further includes a charge pump, which receives and converts the DC power supply signal to provide a second switching power supply output signal. In one embodiment of the DC-DC converter, the first switching power supply output signal is an envelope power supply signal for a first RF power amplifier (PA) and the second switching power supply output signal is a bias power supply signal used for biasing the first RF PA.

[0592] In one embodiment of the DC-DC converter, the charge pump buck converter has a first output inductance node and the buck converter has a second output inductance node. The first inductive element is coupled between the first output inductance node and the energy storage element, and the second inductive element is coupled between the second output inductance node and the energy storage element. The buck converter has a shunt buck switching element coupled between the second output inductance node and a ground, and a series buck switching element coupled between the DC power supply and the second output inductance node.

[0593] During the first converter operating mode, the charge pump buck converter may boost the voltage of the DC power supply signal significantly, such that a voltage at the first output inductance node may be significantly higher than the voltage of the DC power supply signal. In an exemplary embodiment of the DC-DC converter, the voltage at the first output inductance node is equal to about 11 volts and a breakdown voltage of individual switching elements in the charge pump buck converter is equal to about 7 volts. To withstand boosted voltage at the first output inductance node, in one embodiment of the charge pump buck converter, the charge pump buck converter includes multiple shunt pump switching elements and multiple series pump switching elements.

[0594] A summary of a DC-DC converter using continuous and discontinuous conduction modes is presented followed by a detailed description of the DC-DC converter using continuous and discontinuous conduction modes. As such, the present disclosure relates to circuitry, which includes a DC-DC converter having DC-DC control circuitry and a first switching power supply. The first switching power supply includes switching control circuitry, a first switching converter, an energy storage element, and a first inductive element, which is coupled between the first switching converter and the energy storage element. The first switching power supply receives and converts a DC power supply signal to provide a first switching power supply output signal based on a setpoint. During a continuous conduction mode (CCM), the switching control circuitry allows energy to flow from the energy storage element to the first inductive element. During a discontinuous conduction mode (DCM), the switching control circuitry does not allow energy to flow from the energy storage element to the first inductive element. Selection of either the CCM or the DCM is based on a rate of change of the setpoint.

[0595] If an output voltage of the first switching power supply output signal is above the setpoint, then the energy storage element needs to be depleted of some energy to drive the first switching power supply output signal toward the setpoint. During the CCM, two mechanisms operate to deplete the energy storage element. The first mechanism is provided by a load presented to the first switching power supply. The second mechanism is provided by the first switching converter, which allows energy to flow from the energy storage element to the first inductive element. During the DCM, only the first mechanism is allowed to deplete the energy storage element, which may slow the depletion of the energy storage element. As such, efficiency of the first switching power supply may be higher during the DCM than during the CCM. However, during the DCM, if the setpoint drops quickly, particularly during light loading conditions of the first switching power supply, there may be significant lag between the setpoint and the output voltage, thereby causing an output voltage error. Thus, there is a trade-off between minimizing output voltage error, by operating in the CCM, and maximizing efficiency, by operating in the DCM. To balance the trade-off, selection between the CCM and the DCM is based on the rate of change of the setpoint.

[0596] In one embodiment of the circuitry, selection between the CCM and the DCM is based only on the rate of change of the setpoint. In an alternate embodiment of the circuitry, selection between the CCM and the DCM is based on the rate of change of the setpoint and loading of the first switching power supply. In a first exemplary embodiment of the circuitry, when a negative rate of change of the setpoint is greater than a first threshold, the CCM is selected and when the negative rate of change of the setpoint is less than a second threshold, the DCM is selected, such that the second threshold is less than the first threshold and a difference between the first threshold and the second threshold provides hysteresis. In a second exemplary embodiment of the circuitry, the first threshold and the second threshold are based on loading of the first switching power supply.

[0597] In one embodiment of the first inductive element, the first inductive element has an inductive element current, which is positive when energy flows from the first inductive element to the energy storage element and is negative when energy flows from the energy storage element to the first inductive element. In one embodiment of the energy storage element, the energy storage element is a first capacitive element. In one embodiment of the circuitry, the circuitry includes control circuitry, which provides the setpoint to the DC-DC control circuitry. In one embodiment of the circuitry, the circuitry includes transceiver circuitry, which includes the control circuitry. In one embodiment of the control circuitry, the control circuitry makes the selection between the CCM and the DCM, and provides a DC configuration control signal to the DC-DC control circuitry, such that the DC configuration control signal is based on the selection between the CCM and the DCM. In one embodiment of the DC-DC control circuitry, the DC-DC control circuitry makes the selection between the CCM and the DCM.

[0598] In one embodiment of the first switching power supply, the first switching power supply further includes a second switching converter, which receives the DC power supply signal. The first switching power supply may use the first switching converter for heavy loading conditions and the second switching converter for light loading conditions. In one embodiment of the first switching power supply, the first switching converter is a charge pump buck converter and the second switching converter is a buck converter.

[0599] In one embodiment of the first switching power supply, the second switching converter is coupled across the first switching converter. As such, the second switching converter shares the first inductive element with the first switching converter. In an alternate embodiment of the first switching power supply, the first switching power supply further includes the second switching converter and a second inductive element, which is coupled between the second switching converter and the energy storage element. During the CCM, the switching control circuitry allows energy to flow from the energy storage element to the second inductive element. During the DCM, the switching control circuitry does not allow energy to flow from the energy storage element to the second inductive element.

[0600] In one embodiment of the DC-DC converter, the DC-DC converter further includes a second switching power supply, which receives and converts the DC power supply signal to provide a second switching power supply output signal. In one embodiment of the DC-DC converter, the first switching power supply output signal is an envelope power supply signal for an RF power amplifier (PA) and the second switching power supply output signal is a bias power supply signal, which is used for biasing the RF PA. In one embodiment of the second switching power supply, the second switching power supply is a charge pump.

[0601] FIG. 87 shows details of the first switching power supply 450 illustrated in FIG. 74 according to one embodiment of the first switching power supply 450. The first switching power supply 450 includes a charge pump buck power supply 526 and a buck power supply 528. The charge pump buck power supply 526 includes the first switching converter 456, the first inductive element L1, and the first power filtering circuitry 82. The buck power supply 528 includes the second switching converter 458, the second inductive element L2 and the first power filtering circuitry 82. The first switching converter 456 is the charge pump buck converter 84, which includes pulse width modulation (PWM) circuitry 534 and charge pump buck switching circuitry 536. The second switching converter 458 is the buck converter 86, which includes the PWM circuitry 534 and buck switching circuitry 538. As such, the charge pump buck converter 84 and the buck converter 86 share the PWM circuitry 534. Further, the charge pump buck power supply 526 and the buck power supply 528 share the PWM circuitry 534 and the first power filtering circuitry 82.

[0602] The first power filtering circuitry 82 includes an energy storage element 530 and third power filtering circuitry 532. In one embodiment of the energy storage element 530, the energy storage element 530 is the first capacitive element C1. The charge pump buck switching circuitry 536 includes the first output inductance node 460 and the buck switching circuitry 538 includes the second output inductance node 462. As such, the charge pump buck converter 84 has the first output inductance node 460 and the buck converter 86 has the second output inductance node 462. In this regard, the charge pump buck power supply 526 includes the charge pump buck converter 84, the first inductive element L1, and the energy storage element 530. The buck power supply 528 includes the buck converter 86, the second inductive element L2, and the energy storage element 530.

[0603] The first inductive element L1 is coupled between the first switching converter 456 and the energy storage element 530. The second inductive element L2 is coupled between the second switching converter 458 and the energy storage element 530. Specifically, the first inductive element L1 is coupled between the first output inductance node 460 and the energy storage element 530, and the second inductive element L2 is coupled between the second output inductance node 462 and the energy storage element 530. In this regard, the charge pump buck power supply 526 and the buck power supply 528 share the energy storage element 530. The charge pump buck converter 84 and the first inductive element L1 are coupled in series between the DC power supply 80 (FIG. 74) and the energy storage element 530. The buck converter 86 and the second inductive element L2 are coupled in series between the DC power supply 80 (FIG. 74) and the energy storage element 530.

[0604] As previously mentioned, in one embodiment of the first switching power supply 450, during the first converter operating mode, the charge pump buck power supply 526 receives and converts the DC power supply signal DCPS from the DC power supply 80 (FIG. 74) to provide the first switching power supply output signal FPSO to a load, such as the RF PA circuitry 30 (FIG. 6), based on a setpoint. During the first converter operating mode, the buck power supply 528 is disabled. During the second converter operating mode, the buck power supply 528 receives and converts the DC power supply signal DCPS from the DC power supply 80 (FIG. 74) to provide the first switching power supply output signal FPSO to the load, such as the RF PA circuitry 30 (FIG. 6), based on the setpoint. During the second converter operating mode, the charge pump buck power supply 526 is disabled. The setpoint is based on a desired voltage of the first switching power supply output signal FPSO.

[0605] During the first converter operating mode, the first inductive element L1 and the first capacitive element C1 form a lowpass filter, such that the charge pump buck switching circuitry 536 provides the first buck output signal FBO to the lowpass filter, which receives and filters the first buck output signal FBO to provide a filtered first buck output signal to the third power filtering circuitry 532. The third power filtering circuitry 532 receives and filters the filtered first buck output signal to provide the first switching power supply output signal FPSO. During the second converter operating mode, the second inductive element L2 and the first capacitive element C1 form a lowpass filter, such that the buck switching circuitry 538 provides the second buck output signal SBO to the lowpass filter, which receives and filters the second buck output signal SBO to provide a filtered second buck output signal to the third power filtering circuitry 532. The third power filtering circuitry 532 receives and filters the filtered second buck output signal to provide the first switching power supply output signal FPSO.

[0606] In one embodiment of the first switching power supply 450, selection of either the first converter operating mode or the second converter operating mode is based on a voltage of the DC power supply signal DCPS and the setpoint. As such, the first converter operating mode is selected when the desired voltage of the first switching power supply output signal FPSO is greater than the voltage of the DC power supply signal DCPS. In an alternate embodiment of the first switching power supply 450, selection of either the first converter operating mode or the second converter operating mode is based on the voltage of the DC power supply signal DCPS, the setpoint, and a load current of the load. As such, the second converter operating mode may be selected when the desired voltage of the first switching power supply output signal FPSO is less than the voltage of the DC power supply signal DCPS and the load current is less than a load current threshold. Selection of either the first converter operating mode or the second converter operating mode may be further based on maximizing efficiency.

[0607] In one embodiment of the first switching power supply 450, the control circuitry 42 (FIG. 6) provides the setpoint to the DC-DC control circuitry 90 (FIG. 74), which selects either the first converter operating mode or the second converter operating mode. As such, the DC configuration control signal DCC (FIG. 6) is based on the setpoint. In an alternate embodiment of the first switching power supply 450, the control circuitry 42 (FIG. 6) selects either the first converter operating mode or the second converter operating mode and provides the setpoint and the selection of either the first converter operating mode or the second converter operating mode to the DC-DC control circuitry 90 (FIG. 74). As such, the DC configuration control signal DCC (FIG. 6) is based on the setpoint and the selection of either the first converter operating mode or the second converter operating mode. Further, the DC-DC control circuitry 90 (FIG. 74) provides the first power supply control signal FPCS to the first switching power supply 450. As such, the first power supply control signal FPCS is based on the setpoint and the selection of either the first converter operating mode or the second converter operating mode.

[0608] The PWM circuitry 534 receives the setpoint and the first switching power supply output signal FPSO. The PWM circuitry 534 provides a PWM signal PWMS to the charge pump buck switching circuitry 536 and the buck switching circuitry 538 based on a difference between the setpoint and the first switching power supply output signal FPSO. The PWM signal PWMS has a duty-cycle based on the difference between the setpoint and the first switching power supply output signal FPSO. During the first converter operating mode, a duty-cycle of the charge pump buck switching circuitry 536 is based on the duty-cycle of the PWM signal PWMS. During the second converter operating mode, a duty-cycle of the buck switching circuitry 538 is based on the duty-cycle of the PWM signal PWMS. In this regard, during the first converter operating mode, the PWM circuitry 534, the charge pump buck switching circuitry 536, the first inductive element L1, the first capacitive element C1, and the third power filtering circuitry 532 form a control loop to regulate the first switching power supply output signal FPSO based on the setpoint. Similarly, during the second converter operating mode, the PWM circuitry 534, the buck switching circuitry 538, the second inductive element L2, the first capacitive element C1, and the third power filtering circuitry 532 form a control loop to regulate the first switching power supply output signal FPSO based on the setpoint.

[0609] In one embodiment of the charge pump buck power supply 526 and the buck power supply 528, the buck power supply 528 at the second output inductance node 462 is voltage compatible with the charge pump buck power supply 526 at the first output inductance node 460. Such voltage compatibility between the charge pump buck power supply 526 and the buck power supply 528 provides flexibility and may allow the charge pump buck converter 84 and the buck converter 86 to be used in different configurations. One example of a different configuration is the elimination of the second inductive element L2, such that the first output inductance node 460 is directly coupled to the second output inductance node 462.

[0610] As previously mentioned, the first switching power supply 450 receives and converts the DC power supply signal DCPS to provide the first switching power supply output signal FPSO based on the setpoint. The first switching power supply 450 includes the first switching converter 456, the first inductive element L1, the energy storage element 530, and switching control circuitry. A portion of charge pump buck switching control circuitry 540 (FIG. 92), a portion of buck switching control circuitry 544 (FIG. 92), or both provides the switching control circuitry. In one embodiment of the DC-DC converter 32 (FIG. 74), the DC-DC control circuitry 90 (FIG. 74) provides indication of selection of one of the CCM and the DCM to the first switching power supply 450 via the first power supply control signal FPCS. The selection of the one of the CCM and the DCM is based on a rate of change of the setpoint. During the CCM, the switching control circuitry allows energy to flow from the energy storage element 530 to the first inductive element L1. During the DCM, the switching control circuitry does not allow energy to flow from the energy storage element 530 to the first inductive element L1. The rate of change of the setpoint may be a negative rate of change of the setpoint.

[0611] The first inductive element L1 has a first inductive element current IL1, which is positive when energy flows from the first inductive element L1 to the energy storage element 530, and is negative when energy flows from the energy storage element 530 to the first inductive element L1. In one embodiment of the DC-DC converter 32 (FIG. 74), the control circuitry 42 (FIG. 6) provides the setpoint to the DC-DC control circuitry 90 (FIG. 74) via the envelope control signal ECS (FIG. 6) and the DC-DC control circuitry 90 (FIG. 74) makes the selection of the one of the CCM and the DCM. In an alternate embodiment of the DC-DC converter 32 (FIG. 74), the control circuitry 42 (FIG. 6) provides the setpoint to the DC-DC control circuitry 90 (FIG. 74) via the envelope control signal ECS (FIG. 6), and the control circuitry 42 (FIG. 6) makes the selection of the one of the CCM and the DCM and provides indication of the selection to the DC-DC control circuitry 90 (FIG. 74) via the DC configuration control signal DCC (FIG. 6). As such, the DC configuration control signal DCC (FIG. 6) is based on the selection of the one of the CCM and the DCM.

[0612] In one embodiment of the DC-DC converter 32 (FIG. 74), during the first converter operating mode and during the CCM, the switching control circuitry allows energy to flow from the energy storage element 530 to the first inductive element L1. During the first converter operating mode and during the DCM, the switching control circuitry does not allow energy to flow from the energy storage element 530 to the first inductive element L1. During the second converter operating mode and during the CCM, the switching control circuitry allows energy to flow from the energy storage element 530 to the second inductive element L2. During the second converter operating mode and during the DCM, the switching control circuitry does not allow energy to flow from the energy storage element 530 to the second inductive element L2.

[0613] A summary of parallel charge pump buck and buck power supplies is followed by a summary of shared shunt switching element charge pump buck and buck power supplies. Then, a detailed description of the parallel charge pump buck and buck power supplies is presented according to one embodiment of the present disclosure. The present disclosure relates to a DC-DC converter, which includes a charge pump buck power supply coupled in parallel with a buck power supply. The charge pump buck power supply includes a charge pump buck converter, a first inductive element, and an energy storage element. The charge pump buck converter and the first inductive element are coupled in series between a DC power supply, such as a battery, and the energy storage element. The buck power supply includes a buck converter, the first inductive element, and the energy storage element. The buck converter is coupled across the charge pump buck converter. As such, the charge pump buck power supply and the buck power supply share the first inductive element and the energy storage element. Only one of the charge pump buck power supply and the buck power supply is active at any one time. As such, either the charge pump buck power supply or the buck power supply receives and converts a DC power supply signal from the DC power supply to provide a first switching power supply output signal to a load based on a setpoint. In one embodiment of the energy storage element, the energy storage element is a capacitive element.

[0614] The charge pump buck converter combines the functionality of a charge pump with the functionality of a buck converter. However, the charge pump buck converter uses fewer switching elements than a separate charge pump and buck converter by using common switching elements for both charge pump and buck converter functionalities. As such, the charge pump buck power supply is capable of providing an output voltage that is greater than a voltage of the DC power supply signal. Conversely, the buck power supply is only capable of providing an output voltage that is about equal to or less than the voltage of the DC power supply signal. In one embodiment of the DC-DC converter, during a first converter operating mode, the charge pump buck power supply receives and converts the DC power supply signal to provide the first switching power supply output signal, and the buck power supply is disabled. During a second converter operating mode, the buck power supply receives and converts the DC power supply signal to provide the first switching power supply output signal, and the charge pump buck power supply is disabled. The setpoint is based on a desired voltage of the first switching power supply output signal.

[0615] In one embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is based on a voltage of the DC power supply signal and the setpoint. The first converter operating mode is selected when the desired voltage of the first switching power supply output signal is greater than the voltage of the DC power supply signal. In one embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on a load current of the load. The second converter operating mode is selected when the desired voltage of the first switching power supply output signal is less than the voltage of the DC power supply signal and the load current is less than a load current threshold.

[0616] In a first exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on maximizing efficiency of the DC-DC converter. In a second exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on exceeding a minimum acceptable efficiency of the DC-DC converter. In a third exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on exceeding a desired efficiency of the DC-DC converter. In one embodiment of the DC-DC converter, the DC-DC converter further includes a charge pump, which receives and converts the DC power supply signal to provide a second switching power supply output signal. In one embodiment of the DC-DC converter, the first switching power supply output signal is an envelope power supply signal for a first RF power amplifier (PA) and the second switching power supply output signal is a bias power supply signal used for biasing the first RF PA.

[0617] In one embodiment the DC-DC converter, the charge pump buck converter has a first output inductance node and the buck converter has a second output inductance node, which is coupled to the first output inductance node. The first inductive element is coupled between the first output inductance node and the energy storage element. During the first converter operating mode, the charge pump buck converter may boost the voltage of the DC power supply signal significantly, such that a voltage at the second output inductance node may be significantly higher than the voltage of the DC power supply signal. As a result, even though the buck converter is disabled during the first converter operating mode, the buck converter must be able to withstand the boosted voltage at the second output inductance node. In an exemplary embodiment of the DC-DC converter, the voltage at the second output inductance node is equal to about 11 volts and a breakdown voltage of individual switching elements in the buck converter is equal to about 7 volts.

[0618] To withstand boosted voltage at the second output inductance node, in one embodiment of the buck converter, the buck converter includes multiple shunt buck switching elements and multiple series buck switching elements. The shunt buck switching elements are coupled in series between the second output inductance node and a ground, and the series buck switching elements are coupled in series between the DC power supply and the second output inductance node. In one embodiment of the buck converter, the series buck switching elements are configured in a cascode arrangement. In an exemplary embodiment of the buck converter, the buck converter includes two shunt buck switching elements coupled in series between the second output inductance node and the ground, and the buck converter includes two series buck switching elements coupled in series between the DC power supply and the second output inductance node.

[0619] A summary of shared shunt switching element charge pump buck and buck power supplies is followed by a detailed description of the shared shunt switching element charge pump buck and buck power supplies according to one embodiment of the present disclosure. The present disclosure relates to a DC-DC converter, which includes a charge pump buck power supply and a buck power supply. The charge pump buck power supply includes a first output inductance node, a first inductive element, an energy storage element, and at least a first shunt pump buck switching element. The first inductive element is coupled between the first output inductance node and the energy storage element. The first shunt pump buck switching element is coupled between the first output inductance node and a ground. The buck power supply includes a second output inductance node, the first inductive element, the energy storage element, and the first shunt pump buck switching element. As such, the charge pump buck power supply and the buck power supply share the first inductive element, the energy storage element, and the first shunt pump buck switching element. Only one of the charge pump buck power supply and the buck power supply is active at any one time. As such, either the charge pump buck power supply or the buck power supply receives and converts a DC power supply signal from a DC power supply to provide a first switching power supply output signal to a load based on a setpoint. In one embodiment of the energy storage element, the energy storage element is a capacitive element.

[0620] The charge pump buck power supply combines the functionality of a charge pump with the functionality of a buck converter. However, the charge pump buck power supply uses fewer switching elements than a separate charge pump and buck converter by using common switching elements for both charge pump and buck converter functionalities. As such, the charge pump buck power supply is capable of providing an output voltage that is greater than a voltage of the DC power supply signal. Conversely, the buck power supply is only capable of providing an output voltage that is about equal to or less than the voltage of the DC power supply signal. In one embodiment of the DC-DC converter, during a first converter operating mode, the charge pump buck power supply receives and converts the DC power supply signal to provide the first switching power supply output signal, and the buck power supply is disabled. During a second converter operating mode, the buck power supply receives and converts the DC power supply signal to provide the first switching power supply output signal, and the charge pump buck power supply is disabled. The setpoint is based on a desired voltage of the first switching power supply output signal.

[0621] In one embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is based on a voltage of the DC power supply signal and the setpoint. The first converter operating mode is selected when the desired voltage of the first switching power supply output signal is greater than the voltage of the DC power supply signal. In one embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on a load current of the load. The second converter operating mode is selected when the desired voltage of the first switching power supply output signal is less than the voltage of the DC power supply signal and the load current is less than a load current threshold.

[0622] In a first exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on maximizing efficiency of the DC-DC converter. In a second exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on exceeding a minimum acceptable efficiency of the DC-DC converter. In a third exemplary embodiment of the DC-DC converter, selection of either the first converter operating mode or the second converter operating mode is further based on exceeding a desired efficiency of the DC-DC converter. In one embodiment of the DC-DC converter, the DC-DC converter further includes a charge pump, which receives and converts the DC power supply signal to provide a second switching power supply output signal. In one embodiment of the DC-DC converter, the first switching power supply output signal is an envelope power supply signal for a first RF power amplifier (PA) and the second switching power supply output signal is a bias power supply signal used for biasing the first RF PA.

[0623] During the first converter operating mode, the charge pump buck power supply may boost the voltage of the DC power supply signal significantly, such that a voltage at the first output inductance node may be significantly higher than the voltage of the DC power supply signal. As a result, even though the buck power supply is disabled during the first converter operating mode, the buck power supply must be able to withstand the boosted voltage at the second output inductance node. In an exemplary embodiment of the DC-DC converter, the voltage at the second output inductance node is equal to about 11 volts and a breakdown voltage of individual switching elements in the buck power supply is equal to about 7 volts.

[0624] FIG. 88 shows details of the first switching power supply 450 illustrated in FIG. 74 according to a further embodiment of the first switching power supply 450. The first switching power supply 450 illustrated in FIG. 88 is similar to the first switching power supply 450 illustrated in FIG. 87, except in the first switching power supply 450 illustrated in FIG. 88, the second inductive element L2 is coupled between the first output inductance node 460 and the second output inductance node 462. As such, the buck power supply 528 includes the second inductive element L2 and the charge pump buck power supply 526 and the buck power supply 528 share the first inductive element L1.

[0625] FIG. 89 shows details of the first switching power supply 450 illustrated in FIG. 75 according to an alternate embodiment of the first switching power supply 450. The first switching power supply 450 includes the charge pump buck power supply 526 and the buck power supply 528. The charge pump buck power supply 526 includes the first switching converter 456, the first inductive element L1, and the first power filtering circuitry 82. The buck power supply 528 includes the second switching converter 458, the first inductive element L1 and the first power filtering circuitry 82. The second switching converter 458 is coupled across the first switching converter 456. The first switching converter 456 is the charge pump buck converter 84, which includes the PWM circuitry 534 and the charge pump buck switching circuitry 536. The second switching converter 458 is the buck converter 86, which includes the PWM circuitry 534 and the buck switching circuitry 538. As such, the charge pump buck converter 84 and the buck converter 86 share the PWM circuitry 534. Further, the charge pump buck power supply 526 and the buck power supply 528 share the PWM circuitry 534, the first inductive element L1, and the first power filtering circuitry 82.

[0626] The first power filtering circuitry 82 includes the energy storage element 530 and the third power filtering circuitry 532. In one embodiment of the energy storage element 530, the energy storage element 530 is the first capacitive element C1. The charge pump buck switching circuitry 536 includes the first output inductance node 460 and the buck switching circuitry 538 includes the second output inductance node 462. The first output inductance node 460 is coupled to the second output inductance node 462. As such, the charge pump buck converter 84 has the first output inductance node 460 and the buck converter 86 has the second output inductance node 462. In this regard, the charge pump buck power supply 526 includes the charge pump buck converter 84, the first inductive element L1, and the energy storage element 530. The buck power supply 528 includes the buck converter 86, the first inductive element L1, and the energy storage element 530. As such, the charge pump buck power supply 526 and the buck power supply 528 share the first inductive element L1 and the energy storage element 530.