METHOD AND SYSTEM FOR OPERATING A PORTABLE ELECTRONIC DEVICE IN A POWER-LIMITED MANNER

• US 20090174367A1
• Filed: 03/09/2009
• Published: 07/09/2009
• Est. Priority Date: 12/10/2004
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Tupman, David John, Bollinger, Steven
• Granted Patent: US 7,746,032 B2
• Time in Patent Office: Days
• US Class Current: 320/134
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence

Abstract

Improved techniques to manage operation of a portable electronic device having a substantially depleted battery when power is available from an external, power-limited source are disclosed. In one embodiment of the invention, the substantially depleted battery can be initially charged while a power-intensive operation is delayed. Once the battery has adequate charge to assist the external, power-limited source in powering the portable electronic device, the power-intensive operation can be performed. In this manner, power consumption of a portable electronic device can be managed so that reliable operation is achieved without exceeding limits on power being drawn from an external, power-limited source.

Claims

1. A method for managing power in a battery powered portable electronic device coupled to an external power-limited source, comprising:

when the battery is substantially depleted,

delaying a power intensive operation;

charging the substantially depleted battery from the external power limited source while the power intensive operation is delayed; and

performing the delayed power intensive operation once the battery has adequate charge to assist the external power-limited source in powering the portable electronic device, wherein power consumption of the portable electronic device is managed such that reliable operation is achieved without exceeding limits on power being drawn from the external power-limited source.

2. The method as recited in claim 1 wherein the external power-limited source is connected to the battery powered portable electronic device by way of a peripheral bus having data and power lines.

3. The method as recited in claim 2 wherein a plurality of power levels can be provided over the peripheral bus to the portable electronic device.

4. The method as recited in claim 3 wherein said method further comprises:

negotiating for a higher power level of the plurality of power levels provided to the portable electronic device, wherein if the higher power level is sufficient to perform the power-intensive operation, then the power intensive operation is performed and not delayed.

5. A method as recited in claim 1, wherein the portable electronic device includes a display screen, and

wherein said method further comprises:

displaying a low power indication on the display screen while the power intensive operation is delayed.

6. A method as recited in claim 1, wherein the portable electronic device is a portable media player having a data storage device that stores media items.

7. A method as recited in claim 1, wherein the portable electronic device is a mobile telephone or a personal digital assistant.

8. A power manager system included in a battery powered electronic device having a battery, comprising:

a battery monitor coupled to the battery arranged to determine a charge status of the battery; and

a processor coupled to the battery monitor arranged to;

delay a power intensive operation performed by the battery powered electronic device when the battery monitor determines that the battery is substantially discharged,

charge the battery while the power intensive operation is delayed, and

cause the battery powered electronic device to perform the power intensive operation when the battery monitor determines that the battery is not substantially discharged.

9. The power manager system as recited in claim 8 wherein the power manager system is coupled to an external power limited source that provides at least the power to charge the battery.

10. The power manager system as recited in claim 9, wherein the external power limited source is arranged to provide a plurality of power levels and wherein the processor is arranged to negotiate for a higher power level.

11. The power manager system as recited in claim 10 wherein when the processor negotiates the higher power level and the power intensive operation is delayed, then the power manager commences the power intensive operation regardless of the charge state of the battery.

12. The power manager system as recited in claim 8, wherein the portable electronic device includes a display screen, and wherein a low power indication is displayed on the display screen when the power intensive operation is delayed.

13. The power manager system as recited in claim 8, wherein the portable electronic device is a portable media player having a data storage device that stores media items.

14. The power manager system as recited in claim 8, wherein the portable electronic device is a mobile telephone or a personal digital assistant.

15. A portable media player comprising:

a battery;

a processor;

a media store for storing media items;

a communication interface for interfacing with a host device having an external power limited source via a cable that provides media data and power to the portable media player when the cable is connected between the media player and the host device; and

a power manager for managing power in the portable media player, said power manager comprising;

a battery monitor coupled to the battery and the processor arranged to determine a charge status of the battery, wherein when the battery monitor signals the processor that the battery is substantially discharged, the processor;

delays a power intensive operation,

charges the battery via the communication interface while the power intensive operation is delayed, otherwise

performs the power intensive operation.

16. The portable media player as recited in claim 15 wherein the cable is a peripheral bus having data and power lines.

17. The portable media player as recited in claim 16 wherein a plurality of power levels may be provided over the peripheral bus to the portable electronic device.

18. The portable media player as recited in claim 17 wherein the processor negotiates for a higher power level of the plurality of power levels provided to the portable electronic device, wherein if the higher power level is sufficient to perform the power-intensive operation, the power intensive operation is performed and not delayed.

19. The portable media player as recited in claim 15, wherein the portable electronic device includes a display screen arranged to display a low power indication on the display screen while the power intensive operation is delayed.

20. The portable media player as recited in claim 15, wherein the portable electronic device is a portable media player having a data storage device that stores media items.

21. The portable media player as recited in claim 15, wherein the portable electronic device is a mobile telephone or a personal digital assistant.

22. A computer readable medium for storing a computer program executable by a processor for performing power management in a portable electronic device coupled to an external power limited source, said computer program comprising:

computer program code for examining a charge level of a battery;

computer program code for determining whether the charge level of the battery is substantially discharged;

computer program code for delaying performance of a power intensive operation if the charge level of the battery is determined to be substantially discharged; and

computer program code for performing the delayed power intensive operation once the battery has adequate charge to assist the external power-limited source in powering the power intensive operation, wherein power consumption of the portable electronic device is managed such that reliable operation is achieved without exceeding limits on power being drawn from the external power-limited source.

23. The computer program as recited in claim 22 wherein the external power-limited source is connected to the battery powered portable electronic device by way of a peripheral bus having data and power lines.

24. The computer program as recited in claim 23 wherein a plurality of power levels are provided over the peripheral bus to the portable electronic device.

25. The computer program as recited in claim 24 further comprising:

computer program code for negotiating for a higher power level of the plurality of power levels provided to the portable electronic device, wherein if the higher power level is sufficient to assist the battery in performing the power-intensive operation, the power intensive operation is performed.