CIRCUIT FOR SUPPLEMENTING ELECTRICAL CURRENT TO A PERIPHERAL DEVICE

• US 20120011376A1
• Filed: 07/09/2010
• Published: 01/12/2012
• Est. Priority Date: 07/09/2010
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Zai, Yu Nang, Chang, James Lai Kein, Gan, Kah Liang, Lee, Pei Koh, NG, Wei Loon, Wang, Lina
• Granted Patent: US 9,092,207 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• 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

Abstract

A data bus can supply power from a first power source to a sink device. The data bus is coupled to a second power source. An electrical current from the second power source supplements an electrical current on the data bus if the voltage on the data bus decreases to less than a threshold value.

Claims

1. An apparatus comprising:

a data bus that is also operable for supplying power from a first power source to a sink device; and

a second power source coupled to said data bus, wherein an electrical current from said second power source supplements an electrical current on said data bus in response to a voltage on said data bus decreasing below a threshold value.

2. The apparatus of claim 1 wherein said data bus comprises a Universal Serial Bus (USB).

3. The apparatus of claim 1 wherein said sink device comprises a storage device.

4. The apparatus of claim 1 wherein said second power source comprises a rechargeable battery.

5. The apparatus of claim 4 further comprising a battery charger coupled to said sink device and said first power source, wherein said battery charger begins charging said rechargeable battery responsive to said sink device transitioning from active mode to standby mode.

6. The apparatus of claim 5 wherein said battery charger is turned on and off responsive to a signal that changes state when said sink device transitions between said active mode and said standby mode.

7. The apparatus of claim 5 wherein said sink device transitions from said active mode to said standby mode after said sink device is inactive for a prescribed period of time.

8. The apparatus of claim 1 further comprising a boost converter coupled between said second power source and said sink device.

9. The apparatus of claim 1 further comprising a switch coupled to said second power source, wherein said switch is closed when said sink device is turned on, and wherein said switch is open when said sink device is turned off to prevent draining of said second power source.

10. A method comprising:

sensing voltage on a data bus that supplies power from a first power source to a sink device; and

in response to said voltage falling to less than a threshold value, providing current from a rechargeable second power source to said sink device to supplement current from said first power source.

11. The method of claim 10 wherein said data bus comprises a Universal Serial Bus (USB), said sink device comprises a storage device, and said rechargeable second power source comprises a battery.

12. The method of claim 10 further comprising initiating charging of said rechargeable second power source responsive to said sink device transitioning from active mode to standby mode.

13. The method of claim 10 further comprising:

closing a switch when said sink device is turned on; and

opening said switch when said sink device is turned off to prevent draining of said second power source.

14. An apparatus comprising:

a powered data cable operable for connecting a host power source and a peripheral device;

a chargeable power source coupled to said powered data cable, wherein said chargeable power source is operable for supplying a current that supplements a current on said powered data cable; and

a charging circuit coupled to said chargeable power source and operable for receiving a signal triggered by said peripheral device, wherein said charging circuit begins charging said chargeable power source in response to a change in state of said signal.

15. The apparatus of claim 14 wherein said peripheral device comprises a storage device.

16. The apparatus of claim 14 wherein said second power source comprises a rechargeable battery.

17. The apparatus of claim 14 wherein said signal changes state in response to said peripheral device transitioning between said active mode and said standby mode.

18. The apparatus of claim 17 wherein said peripheral device transitions from said active mode to said standby mode after said peripheral device is inactive for a prescribed period of time.

19. The apparatus of claim 14 further comprising a boost converter coupled between said second power source and said peripheral device.

20. The apparatus of claim 14 further comprising a switch coupled to said second power source, wherein said switch is closed if said peripheral device is turned on, and wherein said switch is open if said peripheral device is turned off.