APPARATUSES AND RELATED METHODS FOR CHARGING CONTROL OF A SWITCHING VOLTAGE REGULATOR

• US 20140266010A1
• Filed: 03/15/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Inventors: Newlin, Trevor
• Granted Patent: US 9,431,838 B2
• Time in Patent Office: Days
• US Class Current: 320/107
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries

Abstract

Charging systems and related methods are disclosed for switching voltage regulators. A charging controller may be configured to generate a control signal indicating a first level of an output current generated by a switching voltage regulator for charging an energy storage device, determine that an output voltage exceeded a predetermined threshold, and generate the control signal indicating a new level of the output current that is reduced from the first level. A method of controlling charging of an energy storage device may comprise monitoring an output voltage charging an energy storage device, comparing a reference signal and a current sense signal to generate a PWM control signal that determines an output current for a switching voltage regulator generating the output voltage, and decrementing the reference signal in response to the output voltage exceeding a predetermined level for a maximum charging voltage for the energy storage device.

Claims

1. A charging system, comprising:

a charging controller configured to;

generate a control signal indicating a first level of an output current generated by a switching voltage regulator for charging an energy storage device;

determine that an output voltage exceeded a predetermined threshold; and

generate the control signal indicating a new level of the output current that is reduced from the first level.

2. The charging system of claim 1, further comprising:

a driver operably coupled with the charging controller, the driver configured to receive the control signal and generate a plurality of switching control signals; and

the switching voltage regulator operably coupled with the driver, the switching voltage regulator configured to receive the plurality of switching control signals and generate the output current and output voltage in response thereto.

3. The charging system of claim 2, wherein the switching voltage regulator includes at least one of a buck voltage converter topology and a buck/boost voltage converter topology.

4. The charging system of claim 1, wherein the charging controller includes:

a current sense block configured to sense a real-time current level of the output current and generate a current sense output signal in response thereto; and

a digital-to-analog converter (DAC) foldback block configured to generate a DAC foldback output signal indicating the new level of the output current.

5. The charging system of claim 4, wherein the charging controller further includes a current control comparator operably coupled with the current sense block and the DAC foldback block to receive the current sense output signal and the DAC foldback output signal.

6. The charging system of claim 5, wherein the current control comparator is configured to generate the control signal based on a comparison of the current sense output signal and the DAC foldback output signal.

7. The charging system of claim 6, wherein the DAC foldback block includes a counter operably coupled with a digital-to-analog converter configured to generate the DAC foldback output signal to decrement in response to a determination that the output voltage exceeded a predetermined threshold.

8. The charging system of claim 1, further comprising valley shut off circuitry operably coupled with an output latch configured to transmit the control signal from the current control comparator to the driver, wherein the valley shut off circuitry is configured to shut off the control signal when the output current is discontinuous.

9. The charging system of claim 8, wherein the valley shut off circuitry is further configured to monitor the output voltage while the output current is discontinuous and generate a charging complete signal when the output voltage reaches a desired maximum charging voltage.

10. A charging system, comprising a charging controller including a plurality of mixed analog and digital circuits configured to monitor an output voltage and an output current from an energy storage device, and control a switching voltage regulator to reduce the output current in response to the output voltage exceeding a predetermined threshold.

11. The charging system of claim 10, wherein the charging controller is configured to control a switching voltage regulator to reduce the output current generating a control signal to control the switching voltage regulator to decrement the output current step-by-step each time the output voltage exceeds the predetermined threshold.

12. The charging system of claim 11, wherein the control signal is a PWM control signal.

13. The charging system of claim 12, further comprising an electronic device including the energy storage device, the switching regulator, and the charging controller.

14. The charging system of claim 12, wherein the energy storage device is selected from the group consisting of a capacitor and a battery.

15. The charging system of claim 12, wherein the capacitor includes at least one of a supercapacitor and an electrolytic capacitor.

16. A method of controlling charging of an energy storage device, the method comprising:

monitoring an output voltage charging an energy storage device;

comparing a reference signal and a current sense signal to generate a PWM control signal that determines an output current for a switching voltage regulator generating the output voltage; and

decrementing the reference signal in response to the output voltage exceeding a predetermined level for a maximum charging voltage for the energy storage device.

17. The method of claim 16, wherein decrementing the reference signal includes adjusting a counter responsive to a feedback voltage pulse generated when the output voltage output voltage exceeds the predetermined level for the maximum charging voltage for the energy storage device.

18. The method of claim 16, further comprising detecting that the output current is in a discontinuous mode.

19. The method of claim 17, further comprising monitoring an actual voltage of the energy storage device while the output current is in the discontinuous mode.

20. A method of charging an energy storage device, the method comprising:

generating a charging output current as a constant current with a switching voltage regulator during a first period while a charging output voltage rises; and

decrementing the charging output current during a second period, wherein decrementing occurs in a step-by-step manner responsive to the charging output voltage rising above a predetermined threshold.