Universal serial bus powered battery charger

• US 6,507,172 B2
• Filed: 03/19/2001
• Issued: 01/14/2003
• Est. Priority Date: 03/19/2001
• Status: Expired due to Term

• Current Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Original Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Inventors: Sherman, Leonard Harris
• Primary Examiner(s): Tso, Edward H.
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US09/813,040
• Publication Number:
  US 20020130638A1
• Time in Patent Office: 666 Days
• Field of Search: 320/134, 320/128, 320/149, 320/150, 323/273, 323/277
• US Class Current: 320/134
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• 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

Universal serial bus powered battery charger primarily intended for use in battery powered hand-held and other portable devices to charge the battery or batteries within the battery powered device when the same is connected to a host device, powered hub or a bus powered hub through a universal serial bus (USB) port. The battery charger includes one or more current limits to conform to the universal serial bus current supply limit set in the USB specification. Any of the universal serial bus voltage and current limits may be used to charge batteries in the battery powered device, such as single cell lithium-ion batteries. Various features are disclosed.

Claims

1. The improvement comprising:

in a battery operated device having a Universal Serial Buss (USB) port, a linear voltage regulator coupled between a power line of the USB port and a battery in the battery operated device, the voltage regulator having a current limit input, the voltage regulator limiting the current delivered from the power line of the USB port to the battery responsive to a control signal on the current limit input.

2. The improvement of claim 1 wherein the voltage regulator further having a regulation voltage input, the voltage regulator limiting the voltage to the battery to a regulated voltage responsive to a control signal on the regulation voltage input.

3. The improvement of claim 1 wherein the voltage regulator includes an output indicating whether the charger is operating.

4. The improvement of claim 1 wherein the charger includes an enable control for enabling and disabling the voltage regulator.

5. The improvement of claim 1 wherein the battery charger further includes circuitry responsive to the battery voltage to limit the current delivered from a power line of the USB port to the battery below the limits set by the control signal on the current limit input when the battery voltage is below a predetermined voltage.

6. The improvement of claim 1 wherein the battery charger further includes circuitry responsive to the battery voltage to limit the current delivered from the power line of the USB port to the battery to a value below the limits settable by the control signal on the current limit input when the battery voltage is below a predetermined voltage.

7. The improvement of claim 1 wherein the voltage regulator further comprises a thermal control for limiting the current delivered to the battery to limit the temperature of the voltage regulator.

8. The improvement comprising:

in a battery operated device powered by a lithium-ion battery having a Universal Serial Buss (USB) port, a linear voltage regulator coupled between a power line of the USB port and a cell of the lithium-ion battery in the battery operated device, the voltage regulator having a current limit input, the voltage regulator limiting the current delivered from the power line of the USB port to the battery to approximately 100 milliamps or 500 milliamps responsive to a control signal on the current limit input.

9. The improvement of claim 8 wherein the voltage regulator further having a regulation voltage input, the voltage regulator limiting the voltage to the battery cell to a regulated voltage of approximately 4.1 or 4.2 volts responsive to a control signal on the regulation voltage input.

10. The improvement of claim 8 wherein the voltage regulator includes an output indicating whether the charger is operating.

11. The improvement of claim 8 wherein the charger includes an enable control for enabling and disabling the voltage regulator.

12. The improvement of claim 8 wherein the battery charger further includes circuitry responsive to the battery cell voltage to limit the current delivered from a power line of the USB port to the battery cell to below the limit set by the control signal on the current limit input when the battery cell voltage is below a predetermined voltage.

13. The improvement of claim 8 wherein the battery charger further includes circuitry responsive to the battery cell voltage to limit the current delivered from the power line of the USB port to the battery cell to a value below the limits settable by the control signal on the current limit input when the battery cell voltage is below a predetermined voltage.

14. The improvement of claim 8 wherein the voltage regulator further comprises a thermal control for limiting the current delivered to the battery cell to limit the temperature of the voltage regulator.

15. The improvement comprising:

in a battery operated device having a Universal Serial Buss (USB) port, a linear voltage regulator coupled between a power line of the USB port and a battery in the battery operated device, the voltage regulator having a current limit input, the voltage regulator limiting the current delivered from the power line of the USB port to the battery responsive to a control signal on the current limit input, the voltage regulator further having a regulation voltage input, the voltage regulator limiting the voltage to the battery to a regulated voltage responsive to a control signal on the regulation voltage input.

16. The improvement of claim 15 wherein the voltage regulator includes an output indicating whether the charger is operating.

17. The improvement of claim 15 wherein the charger includes an enable control for enabling and disabling the voltage regulator.

18. The improvement of claim 15 wherein the battery charger further includes circuitry responsive to the battery voltage to limit the current delivered from a power line of the USB port to the battery below the limits set by the control signal on the current limit input when the battery voltage is below a predetermined voltage.

19. The improvement of claim 15 wherein the battery charger further includes circuitry responsive to the battery voltage to limit the current delivered from the power line of the USB port to the battery to a value below the limits settable by the control signal on the current limit input when the battery voltage is below a predetermined voltage.

20. The improvement of claim 15 wherein the voltage regulator further comprises a thermal control for limiting the current delivered to the battery to limit the temperature of the voltage regulator.

21. The improvement comprising:

in a battery operated device powered by a lithium-ion battery having a Universal Serial Buss (USB) port, a linear voltage regulator coupled between a power line of the USB port and a cell of the lithium-ion battery in the battery operated device, the voltage regulator having a current limit input, the voltage regulator limiting the current delivered from the power line of the USB port to the battery to approximately 100 milliamps or 500 milliamps responsive to a control signal on the current limit input, the voltage regulator limiting the voltage to the battery cell to a regulated voltage of approximately 4.1 or 4.2 volts responsive to a control signal on the regulation voltage input.

22. The improvement of claim 21 wherein the voltage regulator includes an output indicating whether the charger is operating.

23. The improvement of claim 21 wherein the charger includes an enable control for enabling and disabling the voltage regulator.

24. The improvement of claim 21 wherein the battery charger further includes circuitry responsive to the battery cell voltage to limit the current delivered from a power line of the USB port to the battery cell to below the limit set by the control signal on the current limit input when the battery cell voltage is below a predetermined voltage.

25. The improvement of claim 21 wherein the battery charger further includes circuitry responsive to the battery cell voltage to limit the current delivered from the power line of the USB port to the battery cell to a value below the limits settable by the control signal on the current limit input when the battery cell voltage is below a predetermined voltage.

26. The improvement of claim 21 wherein the voltage regulator further comprises a thermal control for limiting the current delivered to the battery cell to limit the temperature of the voltage regulator.