Extended thermal solution for portable personal computers

[0002] One embodiment relates generally to portable personal computers (“PCs”) and, more particularly, to an extended thermal solution for a portable PC.

[0003] Intel Corporation's “Geyserville” processor, expected to be made publicly available in 1999, is an MPP processor designed to support multiple power and performance modes in a portable PC, depending on the power source and auxiliary cooling available. For example, in normal portable (i.e., battery-powered) applications, the processor will be limited to approximately 10.5 watts of power dissipation. In docked modes, where unlimited AC power and additional cooling is available, an additional 10 watts, for a total of approximately 20.5 watts, of power dissipation is possible.

[0004] Clearly, it would be desirable to utilize the additional wattage available during battery-powered operation of the PC. Therefore, what is needed is an extended thermal solution for a portable PC to make this additional wattage available for use during portable, as well as docked, applications.

[0005] One embodiment, accordingly, is an extended cooling unit (“ECU”) for a portable PC having an MPP processor, such as Intel's “Geyserville” processor described above. The ECU is connected to the portable PC via a docking connector of the PC, thereby allowing the presence of the ECU to be detected by the MPP processor of the PC. The ECU includes a horizontally projecting, thermally-conductive plate positioned such that, when the ECU is connected to the PC, the plate projects under the bottom of the PC to allow extension of a passive cooling solution. The ECU also includes a fan attached to a heat exchanger. Connection of the ECU to the PC results in a portion of the thermally conductive path of the ECU being brought into direct contact with the conductive path of the processor of the PC, thereby increasing the cooling capacity in the critical portion of the PC.

[0006] The PC can be connected to an AC power source via an AC adapter inserted into a receptacle in the ECU, which passes the power through to the PC in the same manner as a port replicator.

[0007] A technical advantage achieved with the ECU is that it enables the processor to be operated in a higher power consumption/performance mode than previously possible while the PC is being used in a normal portable (i.e., undocked) application.

[0008] Another technical advantage achieved with the ECU is that its presence is detected by the same software used to detect the presence of a docking station, such that the PC functions as if it is docked.

[0009] FIG. 1 is a system block diagram of a portable PC having an MPP processor and having connected thereto an ECU of one embodiment.

[0010] FIG. 2A is an isometric view of the ECU of FIG. 1.

[0011] FIG. 2B is an exploded view of the ECU of FIG. 1.

[0012] FIGS. 3A and 3B illustrate connection of the ECU of FIG. 1 to the portable PC of FIG. 1.

[0013] FIG. 4A is a cutaway view of the ECU/PC of FIG. 3B along a line IVA—IVA.

[0014] FIG. 4B is a cutaway view of the ECU/PC of FIG. 3B along a line IVB—IVB.

[0015] FIG. 1 is a system block diagram of a portable PC 10 having an ECU 11 of one embodiment connected thereto. The PC 10 includes a multiple power and performance (“MPP”) processor embodied as a CPU 12. The CPU 12 is connected to a PCI controller 14 via a PCI bus 16 and to a power supply 18, memory 20, and media 22 via various other buses. It will be recognized that the PC 10 includes various other subsystems and components that, because they are not essential to facilitate a complete understanding of the present embodiment, are not shown or described herein in greater detail.

[0016] The ECU 11 includes a fan 26, a control circuit 28 for controlling the operation of the fan, and an ID circuit 30, the function of which will be described in greater detail below. The ECU 11 is connected to the PC 10 via a docking connector 40 designed to mate with a conventional docking connector 42 provided on the PC 10. It will be recognized that the usual purpose of the docking connector 42 is to enable the PC 10 to be docked to a docking station (not shown). The ECU 11 is thereby connected through the docking connectors 40, 42 to the CPU 12 in two manners. First, an unused pin on the docking connector is grounded by the ID circuit 30. BIOS detects this pin to inform the CPU 12, via an ID pin line 44, of the presence of the ECU 11, thus permitting the CPU to be run in higher power consumption/performance modes. In addition, the CPU 12 controls the operation of the fan 26 via the PCI bus 16 and PCI controller 14, although a number of different control methods, such as through use of other unused pins of the docking connector 42, may also be possible. Power is passed through the docking connectors 40, 42, to the PC 10 in the same manner as with a port replicator. In particular, an AC adapter (not shown) may be connected to a DC-IN input 48 for providing DC power to the ECU 11 and PC 10 from an AC outlet (not shown).

[0017] In addition, it would be possible to enable variable voltage to the fan 26 from the PCI controller 14 and control circuit 28 to control the speed thereof, as directed by the CPU 12.

[0018] FIG. 2A is an isometric view of an ECU 11 of one embodiment for use with the PC 10. As shown in FIG. 2A, the ECU 11 includes a housing 202 made up of a top housing portion 202aand a bottom housing portion 202b. The docking connector 40, see also FIG. 1, is accessible through the top housing portion 202a, and an inlet vent 206 is provided through the top housing portion 12aat one end thereof for purposes that will be described in greater detail with reference to FIG. 2B. The docking connector 40 is designed to mate with the docking connector 42 of the PC 10 and is positioned such that, when the docking connector 40 is connected to the docking connector 42, a contact area 207 of the ECU 11 projects beneath the bottom of the PC 10, as more clearly shown in FIGS. 3A and 3B.

[0019] Referring again to FIGS. 2A and 2B, a contact area 207 includes a first opening 207athrough which a portion of a CPU thermal path element 208 is exposed. The contact area 207 further includes a plurality of second openings 207bthrough which portions of a system thermal path element 210, specifically, spring elements 210a, are exposed. As shown in FIG. 4A, when the ECU 11 is connected to the PC 10 as previously described, the spring elements 210aof the system thermal path element 210 extend through the openings 207bto make contact with the bottom of the PC 10, thereby to provide additional heat absorption as described in greater detail below.

[0020] Additionally, as shown in FIG. 4B, when the ECU 11 is connected to the PC 10 via the docking connectors 40, 42, the exposed portion of the CPU thermal path element 208 will project into a slot 400 provided in the PC 10 and be forced, via ramped internal ribs 402, into contact with a CPU thermal spreader 404 inside the PC 10. Using the slot 400 avoids potential for contact with hot metal surfaces and the ribs 402 give higher contact pressure appropriate to higher power conduction. In this manner, the ECU 11 is able to absorb a substantial amount of the heat generated by the CPU 12, as described in greater detail below.

[0021] As best shown in FIG. 2B, an exit vent 207 is provided through the top housing portion 202aat an end thereof opposite the inlet vent 206. A fan 212, a heat exchanger 214, and a CPU heat sink 216 are disposed within the housing 200 such that air is drawn into the ECU 11 by the fan 212 though the inlet vent 206, passed through the CPU heat sink 216 to cool the CPU thermal path element 208 and, thereby, to cool the CPU 12. The air is then drawn through the heat exchanger 214, where it is used to cool the system thermal path element 210, and hence to provide additional cooling to the PC 10, after which it is expelled by the fan 212 through the exit vent 207.

[0022] As also best shown in FIG. 2B, the DC-IN receptacle 48 is provided in the top housing portion 202afor receiving an AC adapter such that AC power from an AC outlet (not shown) may be provided to the PC 10 through the ECU 11 via the docking connectors 40, 42.

[0023] FIGS. 3A and 3B illustrate connection of the ECU 11 to the PC 10. As previously suggested, when the docking connector 40 is mated with the docking connector 42, the PC 10, and more specifically, the CPU 12, perceives the PC as having been “docked” and therefore enables the use of a higher power consumption/performance mode than would otherwise be the case for an undocked PC. Accordingly, the PC can be used at a higher power consumption/performance mode without having to be docked. FIG. 3A is a perspective view of the ECU 11 in proper position for connection to the PC 10. FIG. 3B is a perspective view of the ECU 10 once it has been connected to the PC 10.

[0024] FIGS. 4A and 4B, described above, illustrate cutaway views of the PC 10/ECU 11 of FIG. 3B along a line IVA—IVA and IVB—IVB, respectively.

[0025] Accordingly, the embodiment of the ECU described herein enables a portable PC having an MPP processor to make use of higher power consumption/performance modes of the processor without having to dock the PC, as would typically be the case.

[0026] Although an illustrative embodiment has been shown and described, other modifications, changes, and substitutions are intended in the foregoing disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure.