Dynamic port power allocation apparatus and methods

• US 20090100275A1
• Filed: 10/15/2007
• Published: 04/16/2009
• Est. Priority Date: 10/15/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chang, Ray, Ferguson, David
• Granted Patent: US 8,266,456 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries

Abstract

Methods and apparatus for dynamically adjusting the amount of power (or current) distributed to one or more connected devices via electrical interfaces. In one embodiment, the apparatus comprises a first module adapted to detect current drawn by a first set of ports, and a second module adapted to adjust the current provided to a second set of ports based on the detected current. The second module is also optionally adapted to distribute unreserved current among the devices according to an allocation protocol. In the exemplary context of a plurality of interconnected serial bus devices, the invention enables a device to draw more current than that required to be reserved for that device (such as to comply with a specification such as USB), yet without increasing the total amount of power which must be dedicated to the serial ports as a whole. Power supply efficiency may also be advantageously optimized.

Claims

1. For use in a high-speed serialized bus protocol device having a plurality of ports capable of transferring both data and electrical power, apparatus for dynamically allocating the distribution of the electrical power over said plurality of serial ports, comprising:

a first module adapted to determine an amount of electrical current drawn over a first portion of said plurality of serial ports; and

a second module adapted to adjust an amount of current available to a second portion of said plurality of serial ports, said adjustment being based at least in part upon the amount of current drawn over the first portion of said plurality of serial ports.

2. The apparatus of claim 1, wherein the first portion of said plurality of serial ports comprises one or more ports that are not part of the second portion of said plurality.

3. The apparatus of claim 1, wherein the serial bus protocol comprises an IEEE 1394-compliant protocol.

4. The apparatus of claim 1, wherein the serial bus protocol comprises a Universal Serial Bus (USB)-compliant protocol.

5. The apparatus of claim 1, wherein the first module is adapted to determine said current based on a current sensor.

6. The apparatus of claim 1, wherein the first module is adapted to determine said current using discrete circuitry.

7. The apparatus of claim 1, wherein the second module is adapted to perform said adjustment using at least one of (i) a switch;

and (ii) a software controlled integrated circuit controller.

8. The apparatus of claim 1, wherein the serial bus protocol device comprises a laptop computer, and said serial ports each are capable of being coupled to a portable device selected from the group consisting of:

(i) a cellular smartphone; and

(ii) a personal media device.

9. A method of optimizing the power use characteristics within a first device, said first device having a power source useful for the supply of power to a plurality of second devices, the method comprising:

placing a first one of said plurality of second devices in communication with said first device;

determining the power requirements of said first one of said plurality of second devices;

allocating power to said first one of said plurality of second devices based at least in part on said act of determining; and

allocating power to others of said plurality of second devices when placed in communication with said first device, said allocating power to others being based at least in part on;

(i) said allocating to said first one of said second devices, and (ii) a characteristic of said power source.

10. The method of claim 9, wherein the first device comprises a laptop computer, and said second devices each comprise a portable device selected from the group consisting of:

(i) a cellular smartphone; and

(ii) a personal media device.

11. The method of claim 9, wherein the characteristic of said power source comprises an efficiency-related parameter of said source.

12. The method of claim 11, wherein the efficiency-related parameter of said source comprises an output-versus-input efficiency metric or ratio.

13. The method of claim 11, wherein the act of allocating power to others based at least in part on said allocating to said first one and a characteristic of said power source comprises:

determining an optimal efficiency value or range for said power source; and

allocating said power to others of said second devices so as to achieve said optimal value or range when said power allocated to said first one of said second devices is considered.

14. The method of claim 9, wherein said placing a first one of said plurality of second devices in communication with said first device comprises placing said first one in data and electrical power communication with said first device via a substantially unitary interface cable and associated ports of said first device and said first one of said second devices.

15. The method of claim 14, wherein said substantially unitary interface cable and associated ports of said first device and said first one of said second devices are compliant with a high-speed serialized bus protocol selected from the group consisting of:

(i) universal serial bus (USB), and (ii) IEEE Std. 1394.

16. The method of claim 15, wherein the first device comprises a laptop computer, and said second devices each comprise a portable device selected from the group consisting of:

(i) a cellular smartphone; and

(ii) a personal media device.

17. An apparatus for regulating current delivered over a plurality of ports within an electronic device, said apparatus comprising:

a first apparatus adapted to detect an amount of current drawn over a first of said ports; and

a second apparatus adapted to adjust an amount of current available to a second of said ports based at least in part upon the amount of current drawn over the first port.

18. The apparatus of claim 17, wherein the apparatus is adapted to interface with a host controller.

19. The apparatus of claim 18, wherein the host controller comprises an IEEE Std. 1394-compliant host controller.

20. The apparatus of claim 18, wherein the host controller comprises a USB-compliant host controller.

21. The apparatus of claim 17, wherein the electronic device comprises a power supply that has peak efficiency occurring at an output current that is below its maximum rated output current.

22. The apparatus of claim 21, wherein the power supply has peak efficiency occurring at an output of approximately 1600 milliamps (mA), and a maximum rated output of approximately 2200 mA.

23. The apparatus of claim 21, wherein the second apparatus adapted to adjust an amount of current available to a second of said ports based at least in part upon the amount of current drawn over the first port is further adapted to maintain the total amount of current drawn by all of said plurality of ports at or proximate to said output current corresponding to said peak efficiency.

24. The apparatus of claim 17, wherein the second apparatus is further adapted to adjust the amount of current available to the second of said ports based at least in part upon a minimum required value.

25. The apparatus of claim 24, wherein the minimum required value comprises 500 milliamps (mA).

26. A method of regulating current in a computerized device having a plurality of interfaces, said interfaces further adapted to transfer power between said computerized device and one or more electronic devices, said method comprising:

detecting an amount of current provided to a first interface having a first of said electronic devices coupled thereto;

communicating with said first electronic device so as to adjust said amount of current provided; and

determining an amount of current provided to a second of said interfaces based at least in part upon the amount of current provided said first electronic device.

27. The method of claim 26, wherein both detecting the amount of current provided to the first interface and adjusting the amount of current provided to said first interface are performed by a host controller of said computerized device.

28. The method of claim 26, wherein said determining an amount of current provided to a second of said interfaces is based at least in part upon a per-interface threshold requirement.

29. The method of claim 28, wherein the port threshold requirement comprises 500 milliamps.

30. The method of claim 26, wherein the computerized device is in data and power communication with said first electronic device via said first interface and an interconnection cable having data and power pathways, and said act of communicating comprises sending a signal or message over a data pathway of said cable.

31. The method of claim 26, wherein the computerized device is in data and power communication with said first electronic device via said first interface and an interconnection cable having data and power pathways, and said act of communicating comprises sending a signal or message over a power pathway of said cable.