DIGITAL ISOLATOR MODULE HAVING ADDITIONAL DELAY PATH

[0001] The present invention is related to a digital isolator diagram. And more particularly, the present invention is related to a digital isolator module having additional delay path, such that the signal at the receiver input terminal can be enhanced by at least two times, which results in greatly improving the robustness of data transmission and avoiding the common mode voltage instability at the same time.

[0002] As we know, many electronic systems have certain needs to isolate electrical signals in one portion of the system from electrical signals in another portion of the system. In many control systems, for example, both high voltage and low voltage signals may be generated and monitored, and isolation between these signals is required for proper operation of the system. Therefore, isolation circuits are known as the interface circuits that provide galvanic isolation between two communicating blocks, for example, a transmitter circuit (TX) and a receiver circuit (RX). Such isolation circuits are required to eliminate avoidable ground loops, and also to protect high voltage sensitive circuits. These circuits ensure electric insulation and signal isolation between the circuits, ensuring reliable data transmission between the two circuits, isolating the signal from fast transient common mode noise.

[0003] In general, a variety of different devices and techniques have been utilized to communicate signals from one portion of a system to another portion of the system while maintaining isolation between the portions. Devices that provide this communication and isolation are generally referred to as digital isolators. In operation, a digital isolator receives an input electrical signal from a first portion of a system and converts this signal into a corresponding signal that is then communicated across an isolation barrier. The signal communicated across the isolation barrier is received and converted into an isolated output electrical signal that is then applied to a second portion of the system, with the received electrical signal corresponding to the input electrical signal from the first portion of the system.

[0004] Please refer to FIG. 1, which schematically shows a circuit block diagram of a conventional digital isolator structure in the prior arts. As can be seen, the digital isolator structure 1 includes a first portion 10, a second portion 20 of the system and a signal coupling portion 30 connected in between the first portion 10 and the second portion 20 of the system. The first portion 10 of the system is electrically connected to a first ground voltage level V_ss1 and is operable to receive an input signal V_I. The second portion 20 of the system is electrically connected to a second ground voltage level V_ss2 and is operable to generate an output signal V_OUT in response to the received input signal V_I of the system. The signal coupling portion 30 of the system is electrically connected between the first portion 10 and the second portion 20 of the system, such that the signal communicated across the signal coupling portion 30 is received and converted into an isolated output electrical signal that is then applied to and received by the second portion 20 of the system.

[0005] However, what draws our attention is that, since it has been known that Common Mode Transient Immunity (CMTI) is one of the critical characteristics associated with digital isolator structure designs, the CMTI characteristic is important because high slew rate and/or high frequency transients can corrupt data transmission across the signal coupling portion 30 in FIG. 1 (also known as an isolation barrier). The capacitance across the isolation barrier (i.e., between the isolated ground planes, which are the first ground voltage level V_ss1 and the second ground voltage level V_ss2 in FIG. 1) provides the path for these fast transients to cross the isolation barrier and corrupt the output waveform. Such phenomena are undesirable and therefore are expected to be solved. Meanwhile, how to effectively improve the robustness of data transmission across the isolation barrier and avoiding the drift of common mode voltage (V_CM) as well as common mode voltage instability have also remained desirable. In order to achieve these above mentioned objectives, several techniques have been discussed these days in the current technology and yet, challenges have still remained. Further improvements and alternative methodologies in the field are still to be expected.

[0006] As a result, it, in view of all, should be apparent and obvious that there is indeed an urgent need for the professionals in the field for a novel and inventive digital isolator structure to be developed, so as to solve the above-mentioned issues, and to enhance the received signal at the receiving terminal of a digital isolator structure at the same time. In particular, the full detailed specific descriptions and implementations are now to be provided by the Applicant of the present invention in the following paragraphs as below for your references.

[0007] In order to overcome the above mentioned disadvantages, one major objective in accordance with the present invention is provided for a novel and creative digital isolator module which is characterized by having an additional delay path for a transmitter circuit to generate a delayed transmitter output signal in response to a data input signal. Meanwhile, an inventive pulse carrier modulation technique is also provided in the present invention. By employing the proposed pulse carrier modulation technique to a transmitter circuit, the transmitter circuit is operable to generate a first transmitter output signal, which comprises different number of pulse carrier responsive to a rising edge and a falling edge of a data input signal, respectively. And therefore, the digital isolator module with pulse carrier modulation is able to transmit data signals and main accurate data transmission result in the communication channel architecture structure. And after that, a delayed transmitter output signal (second transmitter output signal) will be generated according to the first transmitter output signal, such that the receiving signal at the receiver input terminal can be enhanced by at least two times, which results in greatly improving the robustness of data transmission and avoiding the common mode voltage instability at the same time.

[0008] Another objective in accordance with the present invention is provided for a novel digital isolator module to have a pulse carrier modulation mechanism. As for the transmitter circuit operable to generate the first transmitter output signal, including different number of pulse carrier respectively responsive to a rising edge and a falling edge of a data input signal, a number of a first plurality of pulse carrier of the first division signal of the first transmitter output signal and that of a second plurality of pulse carrier of the second division signal of the first transmitter output signal are different. Unlike the conventional transmitter output signal which generates continuous and indefinite pulse carriers when the data input signal is kept at a high or even low voltage level, the first transmitter output signal of the present invention is well modified and modulated, so as to include less number of pulse carriers, and therefore, the prior power consumption and severe electromagnetic interference issues are believed to be eliminated in the present invention.

[0009] And therefore, it is believed that the present invention achieves in providing a digital isolator module having not only an additional delay path but also a pulse carrier modulation technique. Through the detailed technical descriptions that will be discussed and provided in the following paragraphs, it is believed that the technical solution provided by the present invention is advantageous of a great number of merits, and jitter disturbances of the data output signals from the transmitter circuit can be effectively prevented at the same time. Thereby, it is worthy of full attentions that the present invention achieves to successfully solves the problems of prior arts and meanwhile maintain precise data transmission result as well as superior system robustness. As a result, the proposed digital isolator module having an additional delay path involving with the pulse carrier modulation technique is apparent as being highly competitive and able to be widely utilized in any related industries.

[0010] For achieving the above mentioned objectives, the present invention is aimed to provide a digital isolator module having additional delay path, comprising a transmitter circuit (TX) adapted to receive a data input signal (DI) and operable to generate a first transmitter output signal (TXO) and a second transmitter output signal (TXOD) in response to the data input signal, wherein the second transmitter output signal (TXOD) is a delay signal of the first transmitter output signal (TXO).

[0011] An isolation barrier is configured as being electrically coupled to the transmitter circuit and receiving the first transmitter output signal (TXO) and the second transmitter output signal (TXOD), wherein the isolation barrier is operable to develop a first isolated output signal and a second isolated output signal respectively in response to the first transmitter output signal (TXO) and the second transmitter output signal (TXOD). According to one embodiment of the present invention, the isolation barrier, for instance, may comprise at least a pair of isolation capacitance, and each of the pair of isolation capacitance is adapted to develop the first isolated output signal and the second isolated output signal respectively upon receiving the first transmitter output signal (TXO) and the second transmitter output signal (TXOD).

[0012] And successively, a receiver circuit is then disposed and configured as being electrically coupled to the isolation barrier and receiving the first isolated output signal and the second isolated output signal, such that the receiver circuit is operable to generate a data output signal (RO) in response to the first isolated output signal and the second isolated output signal.

[0013] According to the embodiment of the present invention, the proposed transmitter circuit is operable to generate the first transmitter output signal (TXO) for the input signal in response to the data input signal, wherein the first transmitter output signal (TXO) comprises a first division signal and a second division signal. The transmitter circuit starts to generate the first division signal of the first transmitter output signal responsive to a first transition of the data input signal from a first logic state to a second logic state and terminate generating the first division signal of the first transmitter output signal when the data input signal is still in the second logic state. And then, the transmitter circuit starts to generate the second division signal of the first transmitter output signal responsive to a second transition of the data input signal from the second logic state to the first logic state and terminate generating the second division signal of the first transmitter output signal when the data input signal is still in the first logic state. According to the embodiment of the present invention, the first division signal of the first transmitter output signal comprises a first plurality of pulse carrier, the second division signal of the first transmitter output signal comprises a second plurality of pulse carrier, and a number of the first plurality of pulse carrier of the first division signal and that of the second plurality of pulse carrier of the second division signal are different.

[0014] According to the embodiment of the present invention, the first transmitter output signal (TXO) is periodic since a voltage level of the data input signal should be followed by the voltage level of the transmitter output signal (TXO) and the data input signal is periodic.

[0015] In addition, since the second transmitter output signal (TXOD) is a delay signal of the first transmitter output signal (TXO), it is believed that the second transmitter output signal is also periodic since a voltage level of the data input signal will be followed by a voltage level of the second transmitter output signal and the data input signal is periodic.

[0016] And furthermore, a frequency of the first plurality of pulse carrier of the first division signal of the first transmitter output signal and that of the second plurality of pulse carrier of the second division signal of the first transmitter output signal can be variable. Similarly, an amplitude of the first plurality of pulse carrier of the first division signal of the first transmitter output signal and that of the second plurality of pulse carrier of the second division signal of the first transmitter output signal can be variable. In addition, according to a preferred embodiment of the present invention, a voltage level of the first transmitter output signal after the transmitter circuit terminates generating the first division signal or the second division signal can be variable. In general, those skilled in the art and having general knowledge are able to make appropriate modifications or variations with respective to the technical contents disclosed in the present invention without departing from the spirits of the present invention. However, the modifications or variations should still fall into the scope of the present invention. The present invention is certainly not restricted by the certain limited frequency, amplitude, or voltage level of the first division signal and the second division signal of the first transmitter output signal disclosed in the embodiments of the present invention.

[0017] In another aspect, when considering the circuit composition of the disclosed transmitter circuit structure of the present invention, it is provided that the disclosed transmitter circuit, according to a preferred embodiment of the present invention, comprises: a rising and falling converter, an oscillator adapted to generate an oscillation signal, an AND gate connected with the rising and falling converter and the oscillator, and a delay circuit being electrically connected with an output terminal of the AND gate. The rising and falling converter is adapted to receive the data input signal and accordingly output a converted data input signal in response to a rising edge and a falling edge of the data input signal. The converted data input signal comprises a first partition signal and a second partition signal, and the rising and falling converter starts to generate the first partition signal responsive to the rising edge of the data input signal and terminate generating the first partition signal before the falling edge of the data input signal. And, the rising and falling converter starts to generate the second partition signal responsive to the falling edge of the data input signal and terminate generating the second partition signal before a next rising edge of the data input signal. And, a first working time of the first partition signal and a second working time of the second partition signal are different.

[0018] The AND gate which is electrically connected with the rising and falling converter and the oscillator is operable to receive the converted data input signal and the oscillation signal, and to generate the first transmitter output signal for outputting.

[0019] And as such, the delay circuit which is electrically connected with the output terminal of the AND gate can be disposed and operable to receive the first transmitter output signal, delay the first transmitter output signal and output the second transmitter output signal.

[0020] According to one embodiment of the present invention, the second transmitter output signal (TXOD) can be obtained, for instance, by delaying the first transmitter output signal (TXO) by a half period of duty time (T*½) of the first transmitter output signal (TXO), wherein T is a duty time of the first transmitter output signal (TXO).

[0021] According to one embodiment of the present invention, the delay circuit may be configured as comprising at least one inverting unit, and the at least one inverting unit is forming by electrically connecting two inverters in series, such that the least one inverting unit is operable to receive the first transmitter output signal (TXO), delay the first transmitter output signal (TXO) and output the second transmitter output signal (TXOD). In one embodiment, when the delay circuit comprises a plurality of the inverting units, then the plurality of the inverting units can be electrically connected in cascade for receiving the first transmitter output signal (TXO) and outputting the second transmitter output signal (TXOD).

[0022] According to the embodiment of the present invention, the first transition of the data input signal from the first logic state to the second logic state is in response to the rising edge of the data input signal. And the second transition of the data input signal from the second logic state to the first logic state is in response to the falling edge of the data input signal.

[0023] According to the embodiment of the present invention, the first division signal of the first transmitter output signal has a first operational time, and the first operational time is a first time segment between the transmitter circuit starts to generate the first plurality of pulse carrier and to terminate generating the first plurality of pulse carrier. The second division signal of the first transmitter output signal has a second operational time, and the second operational time is a second time segment between the transmitter circuit starts to generate the second plurality of pulse carrier and to terminate generating the second plurality of pulse carrier. The first operational time of the first division signal of the first transmitter output signal and the second operational time of the second division signal of the first transmitter output signal are different.

[0024] In addition, the first operational time of the first division signal of the first transmitter output signal (TXO) is equal to the first working time of the first partition signal of the converted data input signal, and the second operational time of the second division signal of the first transmitter output signal (TXO) is equal to the second working time of the second partition signal of the converted data input signal.

[0025] In another aspect, regarding the rising and falling converter configuration, according to a preferred embodiment of the present invention, the rising and falling converter may comprise an inverter, a first transmission gate, a second transmission gate, a third transmission gate, a fourth transmission gate and an NOR gate, wherein the inverter receives the data input signal and outputs an inverted data input signal, a first input end of the NOR gate is electrically connected with the first transmission gate and the second transmission gate, and a second input end of the NOR gate is electrically connected with the third transmission gate and the fourth transmission gate. The first transmission gate and the third transmission gate are further connected with an input and an output of the inverter, respectively.

[0026] The data input signal is delayed by a first period and a second period to respectively control the first transmission gate and the fourth transmission gate, and the inverted data input signal is delayed by the first period and the second period to respectively control the second transmission gate and the third transmission gate, such that the NOR gate outputs the converted data input signal.

[0027] In one embodiment, when the first period is longer than the second period, the first working time of the first partition signal of the converted data input signal will accordingly be longer than the second working time of the second partition signal of the converted data input signal. However, the present invention is not limited thereto such configuration.

[0028] In an alternative configuration manner, according to another embodiment of the present invention, on the contrary, when the second period is longer than the first period, then it can be obtained that the second working time of the second partition signal of the converted data input signal will be longer than the first working time of the first partition signal of the converted data input signal, instead. Both implementations are applicable for implementing the inventive objectives of the present invention and the present invention is not limited thereby the alternative various modifications.

[0029] As a result, based on the above, it has been proved and verifier that the present invention is sophisticatedly designed and indeed discloses a novel pulse carrier modulation technique for a digital isolator module. The whole new pulse carrier modulation technique can be employed in a transmitting circuit (TX) architecture and has been verified to succeed in minimizing system power consumption and electromagnetic interferences. Meanwhile, jitter disturbances can be significantly and effectively avoided. As a result, the proposed digital isolator module with pulse carrier modulation disclosed by the present invention, is beneficial to maintain and achieve superior system robustness and precise data transmission results. Thus, it is believed that the present invention is advantageous of having excellent control stability over system levels as well as maintaining precise control ability to the isolation circuits while compared to the prior arts.

[0030] In addition, the disclosed digital isolator module having pulse carrier modulation technique is also characterized by having an additional delay path for generating the second transmitter output signal (TXOD) by means of delaying the first transmitter output signal (TXO). And due to such technical manners, it is believed that the receiving signals at the receiver input terminal (i.e. the first isolated output signal and the second isolated output signal) can be enhanced by at least two times, and as a result, the robustness of data transmission of the disclosed digital isolator module having an additional delay path, can be greatly improved. Meanwhile, the common mode voltage instability and common mode voltage drifts of the transmission data system by employing the proposed digital isolator module of the present invention, can be minimized and avoided at the same time.

[0031] These and other objectives of the present invention will become obvious to those of ordinary skill in the art after reading the following detailed description of preferred embodiments.

[0032] It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention as claimed.

[0047] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. In the drawings, the shape and thickness may be exaggerated for clarity and convenience. This description will be directed in particular to elements forming part of, or cooperating more directly with, methods and apparatus in accordance with the present disclosure. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art. Many alternatives and modifications will be apparent to those skilled in the art, once informed by the present disclosure.

[0048] The embodiments described below are illustrated to demonstrate the technical contents and characteristics of the present invention and to enable the persons skilled in the art to understand, make, and use the present invention. However, it shall be noticed that it is not intended to limit the scope of the present invention. Therefore, any equivalent modification or variation according to the spirit of the present invention is to be also included within the scope of the present invention.

[0049] Unless otherwise specified, some conditional sentences or words, such as “can”, “could”, “might”, or “may”, usually attempt to express that the embodiment in the invention has, but it can also be interpreted as a feature, element, or step that may not be needed. In other embodiments, these features, elements, or steps may not be required.

[0050] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment.

[0051] Certain terms are used throughout the description and the claims to refer to particular components. One skilled in the art appreciates that a component may be referred to as different names. This disclosure does not intend to distinguish between components that differ in name but not in function. In the description and in the claims, the term “comprise” is used in an open-ended fashion, and thus should be interpreted to mean “include, but not limited to.” The phrases “be coupled to,” “couples to,” and “coupling to” are intended to compass any indirect or direct connection. Accordingly, if this disclosure mentioned that a first device is coupled with a second device, it means that the first device may be directly or indirectly connected to the second device through electrical connections, wireless communications, optical communications, or other signal connections with/without other intermediate devices or connection means.

[0052] The invention is particularly described with the following examples which are only for instance. Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the following disclosure should be construed as limited only by the metes and bounds of the appended claims. In the whole patent application and the claims, except for clearly described content, the meaning of the article “a” and “the” includes the meaning of “one or at least one” of the element or component. Moreover, in the whole patent application and the claims, except that the plurality can be excluded obviously according to the context, the singular articles also contain the description for the plurality of elements or components. In the entire specification and claims, unless the contents clearly specify the meaning of some terms, the meaning of the article “wherein” includes the meaning of the articles “wherein” and “whereon”. The meanings of every term used in the present claims and specification refer to a usual meaning known to one skilled in the art unless the meaning is additionally annotated. Some terms used to describe the invention will be discussed to guide practitioners about the invention. Every example in the present specification cannot limit the claimed scope of the invention.

[0053] The terms “substantially,” “around,” “about” and “approximately” can refer to within 20% of a given value or range, and preferably within 10%. Besides, the quantities provided herein can be approximate ones and can be described with the aforementioned terms if are without being specified. When a quantity, density, or other parameters includes a specified range, preferable range or listed ideal values, their values can be viewed as any number within the given range.

[0054] As the Applicants have described earlier in the Description of the Prior Art, since the conventional digital isolator structure designs are mostly in lack of circuit design flexibility, it leads to unfavorable mass production. In addition, in the conventional digital isolator structure designs, the current transmitter circuit (TX) is most likely to use conventional modulation techniques, such as On/Off Keying (OOK) modulation technique, Frequency Shift Keying (FSK) modulation technique, or Amplitude Shift Keying (ASK) modulation technique for data transmission and signal coupling. And these conventional signal modulation techniques have been acknowledged as causing severe power consumption and electromagnetic interferences. As a result, based on such drawbacks to be solved, the present invention is thus provided and aimed to solve these deficiencies by proposing a novel and inventive digital isolator module, which is characterized by having an additional delay path, and using pulse carrier modulation (PCM) technique. By employing such modification and improvements, it is believed that the provided digital isolator module is advantageous of showing extraordinary robustness of data transmission efficiency, while compared with the prior arts. In the following paragraphs, the Applicant of the present invention will be providing the detailed technical descriptions of the disclosed digital isolator module diagram, which will now be provided and illustrated by a plurality of variant embodiments as described in the following sections for your references.

[0055] At first, please refer to FIG. 2, which schematically shows a circuit structural diagram of a proposed digital isolator module having additional delay path in accordance with a main embodiment of the present invention. According to the present invention, the proposed digital isolator module is characterized by having an additional delay path. As can be seen, the disclosed digital isolator module 100 comprises a transmitter circuit (TX) 202, an isolation barrier 204 coupled to the transmitter circuit 202, and a receiver circuit (RX) 206 which is coupled to the isolation barrier 204. The transmitter circuit 202 is electrically connected to a first ground voltage level V_ss1 and the receiver circuit 206 is electrically connected to a second ground voltage level V_ss2. The isolation barrier 204 is electrically connected between the transmitter circuit 202 and the receiver circuit 206 for providing signal coupling and adequate isolation barrier. According to the embodiment of the present invention, the transmitter circuit 202 is adapted to receive a data input signal DI and operable to generate a first transmitter output signal TXO and a second transmitter output signal TXOD in response to the data input signal DI. And the second transmitter output signal TXOD is a delay signal of the first transmitter output signal TXO.

[0056] The isolation barrier 204 coupled with the transmitter circuit 202 is adapted to receiving both the first transmitter output signal TXO and the second transmitter output signal TXOD, such that the isolation barrier 204 is operable to develop a first isolated output signal and a second isolated output signal respectively in response to the first transmitter output signal TXO and the second transmitter output signal TXOD. According to one embodiment of the present invention, the isolation barrier 204, for example can be composed of at least a pair of isolation capacitance or the like. And each isolation capacitance of the isolation barrier 204 is adapted to develop the first isolated output signal and the second isolated output signal respectively upon receiving the first transmitter output signal TXO and the second transmitter output signal TXOD.

[0057] As can be seen from FIG. 2, the developed first isolated output signal and second isolated output signal are the receiving signals of the receiver circuit (RX) 206, which are illustrated as the receiver input signal “RXIN” and “RXIND” respectively in the drawing.

[0058] By such configurations, the receiver circuit 206 coupled with the isolation barrier 204 is operable to receiving the first isolated output signal RXIN and the second isolated output signal RXIND, such that the receiver circuit 206 is operable to generate a data output signal RO in response to the first isolated output signal RXIN and the second isolated output signal RXIND.

[0059] According to a preferred embodiment of the present invention, the proposed transmitter circuit 202 of the present invention is aimed to be operable to generate the first transmitter output signal TXO in response to the data input signal DI. In addition, the second transmitter output signal TXOD is a delay signal of the first transmitter output signal TXO. In order to provide a better understanding, please refer to FIG. 3, which schematically shows a plurality of illustrated waveforms, including the data input signal DI, the first transmitter output signal TXO, the second transmitter output signal TXOD, the first isolated output signal RXIN, the second isolated output signal RXIND and the data output signal RO in accordance with the embodiment architecture in FIG. 2. In view of such waveforms, it is obvious that the second transmitter output signal TXOD is a delay signal of the first transmitter output signal TXO. For instance, by delaying the first transmitter output signal TXO by a half period of duty time (T*½) of the first transmitter output signal TXO is practicable to generate the mentioned second transmitter output signal TXOD, wherein T is a duty time of the first transmitter output signal (TXO). The applicant of the present invention will discuss later in the following paragraphs regarding how to generate the second transmitter output signal TXOD on a basis of the first transmitter output signal TXO.

[0060] An inventive and modified signal modulation technique of the present invention is discussed first. Please refer to FIG. 4, which specifically illustrates the detailed waveforms of the first transmitter output signal TXO in view of the data input signal DI according to the embodiment of FIG. 2 in the present invention. As can be seen from the signal waveforms in FIG. 4, it should be observed that the first transmitter output signal TXO comprises a first division signal TXO_D1 and a second division signal TXO_D2, and the first transmitter output signal TXO is periodic since a voltage level of the data input signal DI should be followed by the voltage level of the first transmitter output signal TXO and the data input signal DI is periodic. On the same basis of technical principles, since the second transmitter output signal TXOD (shown in FIG. 3) is a delay signal of the first transmitter output signal TXO and the voltage level of the data input signal DI is also followed by a voltage level of the second transmitter output signal TXOD, and the data input signal DI is periodic, it is apparent that the second transmitter output signal TXOD is periodic as well.

[0061] Please refer to FIG. 2 and FIG. 4 at the same time. According to the preferred embodiment of the present invention, the transmitter circuit 202 in FIG. 2 is operable to start to generate the first division signal TXO_D1 responsive to a first transition of the data input signal DI from a first logic state to a second logic state and terminate generating the first division signal TXO_D1 when the data input signal DI is still in the second logic state. According to one embodiment of the present invention, the first logic state is indicated by the data input signal DI at a low voltage level, as the digital level “0”. And, the second logic state is indicated by the data input signal DI at a high voltage level, as the digital level “1”. The first transition of the data input signal DI from the first logic state to the second logic state is referred as when the data input signal DI is turning from the digital level “0 ” to the digital level “1” and in response to a rising edge RE of the data input signal DI. Similarly, a second transition of the data input signal DI from the second logic state to the first logic state is referred as when the data input signal DI is turning from the digital level “1” to the digital level “0 ” and in response to a falling edge FE of the data input signal DI.

[0062] As can be seen, the transmitter circuit 202 in FIG. 2 is operable to start to generate the second division signal TXO_D2 responsive to the second transition of the data input signal DI from the second logic state “1” to the first logic state “0 ” and terminate generating the second division signal TXO_D2 when the data input signal DI is still in the first logic state “0”. According to the preferred embodiment of the present invention, the first division signal TXO_D1 of the first transmitter output signal TXO comprises a first plurality of pulse carrier, and the second division signal TXO_D2 of the first transmitter output signal TXO comprises a second plurality of pulse carrier. In addition, a number of the first plurality of pulse carrier of the first division signal TXO_D1 of the first transmitter output signal TXO and that of the second plurality of pulse carrier of the second division signal TXO_D2 of the first transmitter output signal TXO are different. For instance, as shown in the embodiment in FIG. 4, the first division signal TXO_D1 of the first transmitter output signal TXO comprises more numbers of pulse carriers than the second division signal TXO_D2 of the first transmitter output signal TXO does. However, it should also be noted that the present invention is not limited thereto such configuration. According to another alternative embodiment of the present invention, then it may also be practicable for the second division signal TXO_D2 to comprise more numbers of pulse carriers than the first division signal TXO_D1. As long as the numbers of pulse carriers of the first division signal TXO_D1 and of the second division signal TXO_D2 are different, the present invention covers and claims the modifications and its equality.

[0063] To sum above, the present invention is aimed to provide a technical solution that the transmitter circuit is modified to be able to generate different number of pulse carriers according to the data input signal DI turning from the digital level “0 ” to “1” and from the digital level “1” to “0”. Such signal modulation technique is referred to the proposed Pulse Carrier Modulation (PCM) technique of the present invention.

[0064] As a result, according to the pulse carrier modulation technique of the present invention, the first division signal TXO_D1 of the first transmitter output signal TXO, for instance, can be designed to have more numbers of pulse carrier than the second division signal TXO_D2 of the first transmitter output signal TXO as shown in FIG. 4 waveforms. Alternatively, the second division signal TXO_D2 of the first transmitter output signal TXO can be selectively designed to have more numbers of pulse carrier than the first division signal TXO_D1 of the first transmitter output signal TXO according to various embodiment of the present invention. The present invention is not limited thereto. Overall, it is believed that for people who are skilled in the art and having understandings and technical backgrounds to the present invention, it would be allowed for them to make various modifications or changes depending on different circuit regulations and/or specifications without departing from the scope of the invention. That is to say, the present invention is certainly not limited thereto.

[0065] In addition, according to the embodiment of the present invention, it is derived that a frequency of the first plurality of pulse carrier of the first division signal TXO_D1 of the first transmitter output signal TXO and that of the second plurality of pulse carrier of the second division signal TXO_D2 of the first transmitter output signal TXO can be variable. By adopting similar manners, an amplitude of the first plurality of pulse carrier of the first division signal TXO_D1 of the first transmitter output signal TXO and that of the second plurality of pulse carrier of the second division signal TXO_D2 of the first transmitter output signal TXO can be variable as well. The present invention is not limited thereto such details.

[0066] In another aspect, to be more specific, as referring to FIG. 4, it may also be found that the first division signal TXO_D1 of the first transmitter output signal TXO has a first operational time t1, and the first operational time t1 is a first time segment between the transmitter circuit 202 starts to generate the first plurality of pulse carrier of the first division signal TXO_D1 and to terminate generating the first plurality of pulse carrier of the first division signal TXO_D1. In addition, the second division signal TXO_D2 has a second operational time t2, and the second operational time t2 is a second time segment between the transmitter circuit 202 starts to generate the second plurality of pulse carrier of the second division signal TXO_D2 and to terminate generating the second plurality of pulse carrier of the second division signal TXO_D2. According to the embodiment of the present invention, the first operational time t1 of the first division signal TXO_D1 and the second operational time t2 of the second division signal TXO_D2 are different. By employing the pulse carrier modulation technique as disclosed earlier, the first operational time t1 of the first division signal TXO_D1, for instance, can be longer than the second operational time t2 of the second division signal TXO_D2 as shown in FIG. 4 waveforms. Alternatively, the second operational time t2 of the second division signal TXO_D2 can be selectively designed to be longer than the first operational time t1 of the first division signal TXO_D1 according to various embodiment of the present invention. The present invention is not limited thereto.

[0067] As a result, it is evident that the proposed pulse carrier modulation of the present invention achieves to be applicable to the first transmitter output signal TXO of a transmitter circuit such that the first transmitter output signal TXO of the transmitter circuit includes different number of pulse carriers in response to the rising edge and the falling edge of the data input signal DI, respectively. By employing such pulse carrier modulation (PCM) technique, the conventional On/Off Keying (OOK) modulation technique, Frequency Shift Keying (FSK) modulation technique, and Amplitude Shift Keying (ASK) modulation technique for data transmission and signal coupling can be omitted and avoided as well.

[0068] Moreover, according to the illustrated waveform of the first transmitter output signal TXO as shown in FIG. 4, it can be observed that after the transmitter circuit terminates generating the pulse carriers of the first division signal TXO_D1 or the second division signal TXO_D2, the first transmitter output signal TXO enters in a steady state. It is believed that when entering such a steady state, a voltage level of the first transmitter output signal TXO is not necessarily limited to a certain value and can be variable. By employing the design manners for avoiding generating continuous and indefinite pulse carriers during the time period when the data input signal DI is at a high voltage level (digital level=“1”) or at a low voltage level (digital level=“0”), the present invention succeeds in reducing both power consumption and electromagnetic interferences as expected.

[0069] Subsequently, please refer to FIG. 5, which schematically shows a detailed circuit diagram of the transmitter circuit in accordance with the embodiment of the present invention according to FIG. 2. As shown in FIG. 5, the proposed transmitter circuit 202 comprises a rising and falling converter 50, an oscillator 52, an AND gate 54 and a delay circuit 56. The rising and falling converter 50 is adapted to receive the data input signal DI and accordingly output a converted data input signal DI_C. The oscillator 52 is adapted to generate an oscillation signal OSC. The AND gate 54 is electrically connected with the rising and falling converter 50 and the oscillator 52 for receiving the converted data input signal DI_C and the oscillation signal OSC, and by employing an AND logic algorithm, outputting the first transmitter output signal TXO. And the delay circuit 56 is further configured as being electrically connected with the output terminal of the AND gate 54, such that by employing the configuration, the delay circuit 56 is operable to receive the first transmitter output signal TXO, delay the first transmitter output signal TXO and output the second transmitter output signal TXOD. As described earlier in the technical descriptions, since the second transmitter output signal TXOD is a delay signal of the first transmitter output signal TXO, the second transmitter output signal TXOD can be generated and obtained by delaying the first transmitter output signal TXO by a half period of duty time (T*½) of the first transmitter output signal TXO, for instance, wherein T is a duty time of the first transmitter output signal (TXO).

[0070] The corresponding waveforms of the second transmitter output signal TXOD in relation to the first transmitter output signal TXO are illustrated in FIG. 6.

[0071] For a detailed layout configuration of the disclosed delay circuit 56 of the embodiment of the present invention, please refer to FIG. 7, in which FIG. 7 schematically shows a detailed layout configuration of the disclosed delay circuit 56 in accordance with the embodiment of the present invention according to FIG. 5. As referring to FIG. 7, it is illustrated that the disclosed delay circuit 56 comprises at least one inverting unit 70, and the inverting unit 70 is forming by electrically connecting two inverters INV1, INV2 in series, such that the inverting unit 70 is operable to receive the first transmitter output signal TXO, delay the first transmitter output signal TXO and accordingly output the second transmitter output signal TXOD.

[0072] However, the present invention is not limited to such configurations. Please refer to FIG. 8, which schematically shows another alternative detailed layout configuration of the disclosed delay circuit in accordance with the embodiment of the present invention according to FIG. 5. As can be seen in FIG. 8, then the proposed delay circuit 56′ may alternatively comprise a plurality of inverting units 70. In this embodiment, the disclosed delay circuit 56′ is formed by serially connecting three inverting units 70 in cascade. And by employing the plurality of the inverting units 70 which are electrically connected in cascade, the formed delay circuit 56′ is also operable for receiving the first transmitter output signal TXO, delaying the first transmitter output signal TXO and accordingly outputting the second transmitter output signal TXOD. As a result, it is believed that several alternative variations and embodiments may also be achieved by people who are skilled in the art and having ordinary skills of the art. For instance, the number of serially connected inverting units 70 can be any positive integer, which is greater than 1. And the present invention is not limited to serially connecting three inverting units 70 in cascade as the embodiment shown in FIG. 8. In general, the present invention covers the modifications, and its equality based on the disclosed technical contents of the present invention regardless of the number of inverting units and/or inverters used in the circuit layout configuration of the delay circuit. And such embodiments are still applicable to implement the objectives of the present invention in order to generate and provide a delayed transmitter output signal (i.e. the second transmitter output signal TXOD) on the basis of an original transmitter output signal (i.e. the first transmitter output signal TXO).

[0073] As referring to the circuit diagram in FIG. 5, since the rising and falling converter 50 is adapted to receive the data input signal DI and accordingly output the converted data input signal DI_C, the Applicant of the present invention further provide FIG. 9, for showing the corresponding signal waveforms in accordance with the circuit diagram in FIG. 5 for better understandings. Regarding the following technical descriptions, please refer to FIG. 9, in which FIG. 9 specifically shows a plurality of waveforms, including the data input signal DI, the converted data input signal DI_C, the oscillation signal OSC and the generated first transmitter output signal TXO in accordance with the transmitter circuit architecture in FIG. 5.

[0074] As we can see, the rising and falling converter 50 is adapted to receive the data input signal DI and accordingly output the converted data input signal DI_C in response to the rising edge RE and the falling edge FE of the data input signal DI. The converted data input signal DI_C comprises a first partition signal DI_CP1 and a second partition signal DI_CP2, and the converted data input signal DI_C is periodic since a voltage level of the data input signal DI should be followed by the voltage level of the converted data input signal DI_C and the data input signal DI is periodic. According to the embodiment of the present invention, the rising and falling converter 50 starts to generate the first partition signal DI_CP1 responsive to the rising edge RE of the data input signal DI and terminate generating the first partition signal DI_CP1 before the falling edge FE of the data input signal DI. And then, the rising and falling converter 50 starts to generate the second partition signal DI_CP2 responsive to the falling edge FE of the data input signal DI and terminate generating the second partition signal DI_CP2 before a next rising edge RE of the data input signal DI.

[0075] According to the preferred embodiment of the present invention, the first partition signal DI_CP1 has a first working time t1′, and the first working time t1′ is the time segment between the rising and falling converter 50 starts to generate the first partition signal DI_CP1 and to terminate generating the first partition signal DI_CP1. The second partition signal DI_CP2 has a second working time t2′, and the second working time t2′ is the time segment between the rising and falling converter 50 starts to generate the second partition signal DI_CP2 and to terminate generating second partition signal DI_CP2. In the preferred embodiment of the present invention, the first working time t1′ of the first partition signal DI_CP1 of the converted data input signal DI_C and the second working time t2′ of the second partition signal DI_CP2 of the converted data input signal DI_C are different.

[0076] Subsequently, since the AND gate 54 is electrically connected with the rising and falling converter 50 and the oscillator 52 and receives the converted data input signal DI_C and the oscillation signal OSC as the inputs of the AND gate 54, the first transmitter output signal TXO is generated at the output of the AND gate 54, based on the converted data input signal DI_C and the oscillation signal OSC by employing the AND logic algorithm. It is worth noticing that, due to the AND logic algorithm of the AND gate 54, the first operational time t1 of the first division signal TXO_D1 of the first transmitter output signal TXO will be determined as equal to the first working time t1′ of the first partition signal DI_CP1 of the converted data input signal DI_C, and the second operational time t2 of the second division signal TXO_D2 of the first transmitter output signal TXO will be determined as equal to the second working time t2′ of the second partition signal DI_CP2 of the converted data input signal DI_C.

[0077] Moreover, FIG. 10 schematically shows a detailed circuit diagram of the disclosed rising and falling converter in accordance with a first feasible embodiment of the present invention. And FIG. 11 shows a plurality of the illustrated waveforms of the nodes as indicated in the circuit embodiment in FIG. 10. Please refer to FIG. 10 and FIG. 11 at the same time for the following technical descriptions. It is shown that the rising and falling converter 50 includes an inverter INV, a first transmission gate TG1, a second transmission gate TG2, a third transmission gate TG3, a fourth transmission gate TG4 and an NOR gate NOR. The inverter INV receives the data input signal DI and outputs an inverted data input signal DI_B. The input (DI) and the output (DI_B) of the inverter INV are respectively connected with the first transmission gate TG1 and the third transmission gate TG3. The data input signal DI is delayed by a first period 3Z to form the signal as illustrated as “DI_3D”, and the data input signal DI is delayed by a second period 1Z to form the signal as illustrated as “DI_D” according to the first embodiment of the rising and falling converter of the present invention. In such a first embodiment of the rising and falling converter 50, the first period 3Z is longer than the second period 1Z. And, the delayed signal “DI_3D”, which is formed by delaying the data input signal DI by the first period 3Z, is generated to control the first transmission gate TG1. And, the delayed signal “DI_D”, which is formed by delaying the data input signal DI by the second period 1Z, is generated to control the fourth transmission gate TG4.

[0078] In a similar methodology, the inverted data input signal DI_B is delayed by the first period 3Z and the second period 1Z, respectively to form the delayed signal “DI_3DB” and “DI_DB”. And, the delayed signal “DI_3DB” and “DI_DB” are respectively generated to control the second transmission gate TG2 and the third transmission gate TG3. A first input end N1 of the NOR gate NOR is electrically connected with the first transmission gate TG1 and the second transmission gate TG2, and a second input end N2 of the NOR gate NOR is electrically connected with the third transmission gate TG3 and the fourth transmission gate TG4. According to the embodiment of the present invention, when the control signal of the foregoing transmission gates TG1, TG2, TG3 and TG4 is at a high voltage level (digital level=“1”), the transmission gates TG1, TG2, TG3 and TG4 are connected. Otherwise, if the control signal of the foregoing transmission gates TG1, TG2, TG3 and TG4 is at a low voltage level (digital level=“0”), the transmission gates TG1, TG2, TG3 and TG4 are open. As a result, it is observed that the waveforms of the first input end N1 and the second input end N2 are obtained as shown in FIG. 11. And, the NOR gate NOR outputs the converted data input signal DI_C as shown in FIG. 11 waveform according to the waveforms of the first input end N1 and the second input end N2. In such a first embodiment of the rising and falling converter, the first period 3Z is longer than the second period 1Z, resulting in the first working time t1′ of the first partition signal DI_CP1 of the converted data input signal DI_C being longer than the second working time t2′ of the second partition signal DI_CP2 of the converted data input signal DI_C.

[0079] And furthermore, FIG. 12 additionally shows a detailed circuit diagram of the disclosed rising and falling converter in accordance with a second feasible embodiment of the present invention. And FIG. 13 accordingly shows a plurality of the illustrated waveforms of the nodes as indicated in the circuit embodiment in FIG. 12. Please refer to FIG. 12 and FIG. 13 at the same time for the following technical descriptions. It is shown that the rising and falling converter 50′ may also include the inverter INV, the first transmission gate TG1, the second transmission gate TG2, the third transmission gate TG3, the fourth transmission gate TG4 and the NOR gate NOR. The inverter INV receives the data input signal DI and outputs an inverted data input signal DI_B. A first input end N1 of the NOR gate NOR is electrically connected with the first transmission gate TG1 and the second transmission gate TG2, and a second input end N2 of the NOR gate NOR is electrically connected with the third transmission gate TG3 and the fourth transmission gate TG4. The NOR gate NOR outputs the converted data input signal DI_C as shown in FIG. 13 waveform according to the waveforms of the first input end N1 and the second input end N2. As we compare the second embodiment of the rising and falling converter 50′ with the previous first embodiment of the rising and falling converter 50 (shown in FIG. 10 and FIG. 11), it can be observed that the first period used in the second embodiment for delaying the data input signal DI and the inverted data input signal DI_B is 1Z, and the second period used for delaying the data input signal DI and the inverted data input signal DI_B is 3Z. As such, according to the second embodiment, the control signals of the first transmission gate TG1 and the fourth transmission gate TG4 are the delayed signal “DI_D” and “DI_3D”, respectively. The control signals of the second transmission gate TG2 and the third transmission gate TG3 are the delayed signal “DI_DB” and “DI_3DB”, respectively.

[0080] In such a second embodiment of the rising and falling converter 50′, the second period 3Z is longer than the first period 1Z, resulting in the second working time t2′ of the second partition signal DI_CP2 of the converted data input signal DI_C being longer than the first working time t1′ of the first partition signal DI_CP1 of the converted data input signal DI_C, as shown in the waveform of the converted data input signal DI_C in FIG. 13.

[0081] And therefore, based on the above mentioned embodiments as disclosed in FIG. 10 and FIG. 11 as well as in FIG. 12 and FIG. 13, it is apparent that the present invention achieves to sophisticatedly design the rising and falling converter so as to make the first working time t1′ of the first partition signal DI_CP1 of the converted data input signal DI_C and the second working time t2′ of the second partition signal DI_CP2 of the converted data input signal DI_C are different. It does not matter whether the first working time t1′ of the first partition signal DI_CP1 is longer than the second working time t2′ of the second partition signal DI_CP2, or the second working time t2′ of the second partition signal DI_CP2 is longer than the first working time t1′ of the first partition signal DI_CP1. As long as the first working time t1′ of the first partition signal DI_CP1 and the second working time t2′ of the second partition signal DI_CP2 are different, resulting in the first operational time t1 of the first division signal TXO_D1 of the first transmitter output signal TXO and the second operational time t2 of the second division signal TXO_D2 of the first transmitter output signal TXO are different, the present invention achieves to design a number of the first plurality of pulse carrier of the first division signal TXO_D1 differs from that of the second plurality of pulse carrier of the second division signal TXO_D2. And since the transmitter output signal of the transmitter circuit (TXO_D1, TXO_D2) are designed to comprise different number of pulse carriers in response to the rising edge and the falling edge of the data input signal DI, respectively, the present invention achieves to invent a novel pulse carrier modulation (PCM) technique for the digital isolator module. Such pulse carrier modulation (PCM) technique disclosed by the present invention is effective so as to avoid additional data communication channel for signal coupling. In addition, compared with the prior arts when the transmitter circuit continued to output continuous and indefinite pulse carriers as the data input signal is high (or even low), the present invention is effective and beneficial to reduce power consumption and electromagnetic interferences due to a reduced number of pulse carriers of its transmitter output signal (both in the first transmitter output signal TXO and the second transmitter output signal TXOD).

[0082] Therefore, based on at least one embodiment provided above, it is believed that the proposed digital isolator module of the present invention is characterized by utilizing a novel pulse carrier modulation technique. By employing the proposed pulse carrier modulation to a transmitter circuit, the transmitter circuit is operable to generate different number of pulse carriers respectively responsive to a rising edge and a falling edge of the data input signal. And since the transmitter circuit is adapted to output a first plurality of pulse carrier when the data input signal transitions from a digital level “0 ” to “1” and output a second plurality of pulse carrier when the data input signal transitions from a digital level “1” to “0”, it is easily derived that a number of the first plurality of pulse carrier and that of the second plurality of pulse carrier are different. And as such, it is believed that the present invention is believed as beneficial to reducing IC power consumption and electromagnetic interferences. Meanwhile, by utilizing the proposed digital isolator module with pulse carrier modulation, the present invention assures data transmission accuracy and robustness of the system output voltages without the jitter disturbances.

[0083] And in addition, since the proposed digital isolator module of the present invention is also characterized by having another delay path for generating a delayed transmitter output signal (i.e. the second transmitter output signal TXOD) based on an original transmitter output signal (i.e. the first transmitter output signal TXO), it is believed that the present invention is also advantageous of enhancing the signal at the receiver input terminal by at least two times. And due to such benefits, the robustness of data transmission of the disclosed digital isolator module of the present invention can be significantly improved and the common mode voltage instability can be suppressed at the same time. In addition, data output signals can be maintained accurately, and jitter disturbances can be avoided effectively. The present invention is aimed to additionally solve the enormous power consumption and severe electromagnetic interference issues in the prior arts.

[0084] As can be seen from the embodiments, the present invention is aimed to propose and provide a great number of merits and advantages which can be accomplished by adopting the present invention. Therefore, in view of all, it is obvious that the present invention is not only novel and inventive but also believed to be advantageous of solving and avoiding the conventional issues existing in the prior arts. As a result, when compared to the prior arts, it is ensured that the present invention apparently shows much more effective performances than before. In addition, it is believed that the present invention is instinct, effective and highly competitive for IC technology and industries in the market nowadays, whereby having extraordinary availability and competitiveness for future industrial developments and being in condition for early allowance.

[0085] It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the invention and its equivalent.