Modulation charging circuitry for battery charging

• US 7,425,815 B2
• Filed: 05/16/2005
• Issued: 09/16/2008
• Est. Priority Date: 05/16/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Palm, Inc. (TCL Technology Group Corp.)
• Inventors: Wong, Yoon Kean, Davidson, Scott J.
• Primary Examiner(s): Nguyen; Matthew V
• Assistant Examiner(s): Zhang; Jue
• Application Number:
  US11/130,637
• Publication Number:
  US 20060255767A1
• Time in Patent Office: 1,219 Days
• Field of Search: 320/114, 320/123, 320/130, 320/133, 320/138, 320/139, 320/141, 320/144, 320/145, 320/150, 320/155, 320/160
• US Class Current: 320/141
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

Circuitry for charging a battery includes a switch for coupling the power source to the battery. The switch is turned on and off in accordance with a periodic control signal including a plurality of periods. Each period includes a first duration during which the control signal is in a first state and a second duration during which the control signal is in a second state. The switch is turned on when the control signal is in the first state to couple the power source to the battery, and turned off when the control signal is in the second state to decouple the power source from the battery. Since the switch is periodically turned off while the battery is being charged, the average amount of heat generated by the switch is reduced, thereby preventing excessive thermal emission from the battery charging circuitry.

Claims

1. A method of charging a battery using a plurality types of power sources, comprising:

providing a first current from a first type of power source to the battery via a path extending from a selection module to the battery responsive to the selection module coupling the first type of power source to the battery;

providing a second current from a second type of power source to the battery via the same path extending from the selection module to the battery responsive to the selection module coupling the second type of power source to the battery;

determining whether a power source coupled to the path is of the first type or of the second type;

generating a periodic control signal including a plurality of periods, wherein each period includes a first duration during which the control signal is in a first state and a second duration during which the control signal is in a second state;

turning a switch on and off in accordance with the periodic control signal, the switch being turned on during the first duration to couple the power source to the battery and being turned off during the second duration to decouple the power source from the battery;

sensing a temperature of an apparatus powered by the battery;

responsive to the sensed temperature being in a first temperature state, decreasing the first duration relative to the second duration; and

responsive to the sensed temperature being in a second temperature state, increasing the first duration relative to the second duration.

2. The method of claim 1, further comprising:

responsive to determining that the power source is of a type providing current exceeding a predetermined threshold, turning the switch on and off based on the periodic control signal.

3. The method of claim 2, wherein determining whether the power source coupled to the path is of the first type or of the second type comprises:

determining the existence of a signal indicative of the type of the power source.

4. The method of claim 3, wherein the signal indicative of the type of the power source is provided if a physical pin indicative of the type of the power source exists on the power source.

5. The method of claim 1, wherein a timer tracks an amount of time during which the switch is on, the timer being reset during the second duration.

6. The method of claim 1, further comprising:

responsive to determining a type of the power source, selecting a first charging path for coupling the switch to a first type of power source or a second charging path for coupling the switch to a second type of power source.

7. The method of claim 1, further comprising:

responsive to determining that a device powered by the battery is in a first operational mode, generating the periodic control signal; and

responsive to determining that the device powered by the battery is in a second operational mode, disabling generating the periodic control signal.

8. The method of claim 1, further comprising:

responsive to determining that a device powered by the battery is in a first operational mode, increasing or decreasing the first duration relative to the second duration to obtain a first duty cycle of the periodic control signal; and

responsive to determining that a device powered by the battery is in a second operational mode, increasing or decreasing the first duration relative to the second duration to obtain a second duty cycle of the periodic control signal.

9. A circuitry for charging a battery using a plurality types of power sources, comprising:

a selection module selectively coupling a first type of power source or a second type of power source to the battery;

a common path extending between the selection module and the battery, the common path providing current from the first type of power source or the second type of power source to the battery;

a switch in the common path for coupling or decoupling the common path to the battery;

a sensor for sensing a temperature of an apparatus powered by the battery; and

a controller determining whether a power source coupled to the path is of the first type or the second type, the controller generating a periodic control signal including a plurality of periods, each period including a first duration during which the control signal is in a first state and a second duration during which the control signal is in a second state, the switch being turned on during the first duration to couple the power source to the battery and being turned off during the second duration to decouple the power source from the battery, the controller decreasing the first duration relative to the second duration responsive to the sensed temperature being in a first temperature state, the controller increasing the first duration relative to the second duration responsive to the sensed temperature being in a second temperature state.

10. The circuitry of claim 9, wherein the controller generates the control signal responsive to determining that the power source is of a type providing current exceeding a predetermined threshold.

11. The circuitry of claim 10, wherein the controller determines that the power source is of a type providing current exceeding a predetermined threshold by determining the existence of a signal indicative of the type of the power source.

12. The circuitry of claim 11, wherein the power source includes a physical pin indicative of the type of the power source.

13. The circuitry of claim 9, further comprising a timer tracking an amount of time during which the switch is on, the timer being reset during the second duration.

14. The circuitry of claim 9, wherein:

responsive to determining that a device powered by the battery is in a first operational mode, the controller generates the periodic control signal; and

responsive to determining that the device powered by the battery is in a second operational mode, the controller disables generating the periodic control signal.

15. The circuitry of claim 9, wherein:

responsive to determining that a device powered by the battery is in a first operational mode, the controller increases or decreases the first duration relative to the second duration to obtain a first duty cycle of the periodic control signal; and

responsive to determining that a device powered by the battery is in a second operational mode, the controller increases or decreases the first duration relative to the second duration to obtain a second duty cycle of the periodic control signal.

16. A circuitry for charging a battery using a plurality types of power sources, comprising:

a selection module selectively coupling a first type of power source or a second type of power source to the battery;

a common path extending between the selection module and the battery, the common path providing current from the first type of power source or the second type of power source to the battery;

switching means in the common path for coupling or decoupling the common path to the battery;

sensing means for sensing a temperature of an apparatus powered by the battery; and

controlling means for determining whether a power source coupled to the path is of the first type or of the second type, the controller means generating a periodic control signal including a plurality of periods, each period including a first duration during which the control signal is in a first state and a second duration during which the control signal is in a second state, the switching means being turned on during the first duration to couple the power source to the battery and being turned off during the second duration to decouple the power source from the battery, the controlling means decreasing the first duration relative to the second duration responsive to the sensed temperature being in a first temperature state, the controlling means increasing the first duration relative to the second duration responsive to the sensed temperature being in a second temperature state.

17. The circuitry of claim 16, wherein the controlling means generates the control signal responsive to determining that the power source is of a type providing current exceeding a predetermined threshold.

18. The circuitry of claim 17, wherein the controlling means determines that the power source is of a type providing current exceeding a predetermined threshold by determining the existence of a signal indicative of the type of the power source.

19. The circuitry of claim 16, further comprising timer means for tracking an amount of time during which the switching means is on, the timer means being reset during the second duration.