Collapsing Adaptor Battery Charger

• US 20090091300A1
• Filed: 10/06/2008
• Published: 04/09/2009
• Est. Priority Date: 10/04/2007
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Radke, Russell Eliot, Rutherford, Mark David
• Granted Patent: US 9,413,188 B2
• Time in Patent Office: Days
• US Class Current: 320/163
• CPC Class Codes: H02J 7/007184 in response to battery voltage gradient

Abstract

A method and apparatus is disclosed to charge a battery. A wall adapter may provide a power to a battery charger in a collapsed mode of operation. In the collapsed mode of operation, the wall adapter may provide the battery charger with a collapsed power. The battery charger may provide a charging current and/or voltage in a constant current charge mode of operation and/or a constant voltage charge mode of operation using the collapsed power. When operating in the constant current charge mode of operation, the battery charger provides the charging current and/or voltage having a constant current until the voltage of the battery is less than or substantially equal to a constant charge voltage. Alternatively, when operating in the constant voltage charge mode of operation, the battery provides the charging current and/or voltage having a constant voltage until the voltage of the battery is less than or substantially equal to a float voltage.

Claims

1. A battery charger, comprising:

a regulator module configured to regulate a collapsed power based upon a regulator control to provide a battery charging current;

a sensing module configured to provide a sensed voltage based upon the battery charging current;

a wall charger module configured to provide one or more indicators based upon at least one of;

a voltage of the battery and the sensed voltage and to provide the regulator control based upon a current enable; and

a controller module configured to provide the current enable based upon the one or more indicators.

2. The battery charger of claim 1, wherein the regulator module includes a PNP device.

3. The battery charger of claim 1, further comprising:

a sensing resistor configured to provide a voltage differential based upon the battery charging current,

wherein the sensing module is configured to provide the sensed voltage based upon the voltage differential.

4. The battery charger of claim 3, wherein the sensing module comprises:

a first amplifier to amplify the voltage differential by a first gain to provide a first intermediate sensed voltage;

a second amplifier to amplify the first intermediate sensed voltage by a second gain to provide a second intermediate sensed voltage; and

a multiplexer to provide the first intermediate sensed voltage or the second intermediate sensed voltage as the sensed voltage based upon a sensed voltage control.

5. The battery charger of claim 1, wherein the regulator control causes the battery charging current to be a substantially constant current when the voltage of the battery is substantially less than or equal to a constant charge voltage.

6. The battery charger of claim 5, wherein the regulator module provides the substantially constant current by adjusting the battery charging current in response to the voltage of the battery.

7. The battery charger of claim 1, wherein the regulator control causes the voltage of the battery to be a substantially constant voltage when the voltage of the battery is substantially less than or equal to a float voltage.

8. The battery charger of claim 5, wherein the regulator module provides the substantially constant voltage by adjusting the battery charging current in response to the voltage of the battery.

9. The battery charger of claim 5, wherein the regulator module provides the substantially constant voltage by pulse width modulating the battery charging current.

10. The battery charger of claim 1, wherein the wall charger module comprises:

a current control integrator to provide a current control based upon the sensed voltage and a constant current reference; and

a regulator control module to provide the regulator control based upon the current control.

11. The battery charger of claim 10, wherein the current control integrator compares the sensed voltage and the constant current reference and integrates a difference between the sensed voltage and the constant current reference to provide the current control.

12. The battery charger of claim 10, wherein the regulator control module comprises:

a switching device configured to provide the regulator control based upon the current enable and a base current limit.

13. The battery charger of claim 12, wherein the switching device comprises:

a first switching device configured to receive the current enable; and

a second switching device configured to receive the base current limit,

wherein the first switching device and the second switching device are configured to operate as a logical conjunction.

14. The battery charger of claim 1, wherein the wall charger module comprises:

a current modulating comparator to provide a current modulating indicator based upon the battery voltage and a current modulating reference; and

a regulator control module to provide the regulator control based upon the current modulating indicator.

15. The battery charger of claim 14, further comprising:

a current modulating reference generator configured to provide the current modulating reference based upon a reference control.

16. The battery charger of claim 15, wherein the current modulating reference generator comprises:

a digital to analog converter (DAC) having at least two or more output levels to provide the current modulating reference,

wherein the DAC provides the current modulating reference by incrementally stepping through each of the at least two or more output levels to produce a ramp pulse.

17. The battery charger of claim 15, wherein the current modulating reference generator comprises:

a digital to analog converter (DAC) to produce a ramp pulse based upon the reference control.

18. The battery charger of claim 14, wherein the current modulating comparator provides the current modulating indicator indicating an existence of no substantial difference between at least one of:

the battery voltage and a fraction of the battery voltage and the current modulating reference when the sensed voltage is substantially equal to the current modulating reference.

19. The battery charger of claim 14, wherein the current modulating comparator provides the current modulating indicator indicating an existence of a substantial difference between at least one of:

the battery voltage and a fraction of the battery voltage and the current modulating reference when the sensed voltage is not substantially equal to the current modulating reference.

20. The battery charger of claim 14, wherein the current modulating comparator provides a first current modulating indicator when at least one of:

the battery voltage and a fraction of the battery voltage is substantially equal to the current modulating reference, and

a second current modulating indicator when the at least one of;

the battery voltage and the fraction of the battery voltage is substantially equal to the current modulating reference,

wherein the current modulating comparator selects between the first current modulating indicator and the second current modulating indicator based upon the difference between the at least one of;

the battery voltage and a fraction of the battery voltage and the current modulating reference.

21. A system, comprising:

a wall adapter configured to operate in a nominal mode of operation and a collapsed mode of operation, wherein the wall adapter provides a collapsed power in the collapsed mode of operation and a nominal power in the nominal mode of operation; and

a battery charger configured to provide a battery charging current based upon the collapsed power, wherein the battery charger comprises;

a regulator module configured to regulate a collapsed power based upon a regulator control to provide a battery charging current,

a sensing module configured to provide a sensed voltage based upon the battery charging current,

a wall charger module configured to provide one or more indicators based upon at least one of;

a voltage of the battery and the sensed voltage and to provide the regulator control based upon a current enable, and

a controller module configured to provide the current enable based upon the one or more indicators.

22. The system of claim 21, wherein the regulator module includes a PNP device.

23. The system of claim 21, wherein the battery charger further comprises:

a sensing resistor configured to provide a voltage differential based upon the battery charging current,

wherein the sensing module is configured to provide the sensed voltage based upon the voltage differential.

24. The system of claim 23, wherein the sensing module comprises:

a first amplifier to amplify the voltage differential by a first gain to provide a first intermediate sensed voltage;

a second amplifier to amplify the first intermediate sensed voltage by a second gain to provide a second intermediate sensed voltage; and

a multiplexer to provide the first intermediate sensed voltage or the second intermediate sensed voltage as the sensed voltage based upon a sensed voltage control.

25. The system of claim 21, wherein the regulator control causes the battery charging current to be a substantially constant current when the voltage of the battery is substantially less than or equal to a constant charge voltage.

26. The system of claim 25, wherein the regulator module provides the substantially constant current by adjusting the battery charging current in response to the voltage of the battery.

27. The system of claim 21, wherein the regulator control causes the voltage of the battery to be a substantially constant voltage when the voltage of the battery is substantially less than or equal to a float voltage.

28. The system of claim 25, wherein the regulator module provides the substantially constant voltage by adjusting the battery charging current in response to the voltage of the battery.

29. The system of claim 25, wherein the regulator module provides the substantially constant voltage by pulse width modulating the battery charging current.

30. The system of claim 21, wherein the wall charger module comprises:

a current control integrator to provide a current control based upon the sensed voltage and a constant current reference; and

a regulator control module to provide the regulator control based upon the current control.

31. The system of claim 30, wherein the current control integrator compares the sensed voltage and the constant current reference and integrates a difference between the sensed voltage and the constant current reference to provide the current control.

32. The system of claim 30, wherein the regulator control module comprises:

a switching device configured to provide the regulator control based upon the current enable and a base current limit.

33. The system of claim 32, wherein the switching device comprises:

a first switching device configured to receive the current enable; and

a second switching device configured to receive the base current limit,

wherein the first switching device and the second switching device are configured to operate as a logical conjunction.

34. The system of claim 21, wherein the wall charger module comprises:

a current modulating comparator to provide a current modulating indicator based upon the battery voltage and a current modulating reference; and

a regulator control module to provide the regulator control based upon the current modulating indicator.

35. The system of claim 34, wherein the battery charger further comprises:

a current modulating reference generator configured to provide the current modulating reference based upon a reference control.

36. The system of claim 35, wherein the current modulating reference generator comprises:

a digital to analog converter (DAC) having at least two or more output levels to provide the current modulating reference,

wherein the DAC provides the current modulating reference by incrementally stepping through each of the at least two or more output levels to produce a ramp pulse.

37. The system of claim 35, wherein the current modulating reference generator comprises:

a digital to analog converter (DAC) to produce a ramp pulse based upon the reference control.

38. The system of claim 34, wherein the current modulating comparator provides the current modulating indicator indicating an existence of no substantial difference between at least one of:

the battery voltage and a fraction of the battery voltage and the current modulating reference when the sensed voltage is substantially equal to the current modulating reference.

39. The system of claim 34, wherein the current modulating comparator provides the current modulating indicator indicating an existence of a substantial difference between at least one of:

the battery voltage and a fraction of the battery voltage and the current modulating reference when the sensed voltage is not substantially equal to the current modulating reference.

40. The system of claim 34, wherein the current modulating comparator provides a first current modulating indicator when at least one of:

the battery voltage and a fraction of the battery voltage is substantially equal to the current modulating reference, and

a second current modulating indicator when the at least one of;

the battery voltage and the fraction of the battery voltage is substantially equal to the current modulating reference,

wherein the current modulating comparator selects between the first current modulating indicator and the second current modulating indicator based upon the difference between the at least one of;

the battery voltage and a fraction of the battery voltage and the current modulating reference.