Battery charging circuit and methods for trickle charging and precharging a dead multi-cell-in-series battery

Patent metadata

Field	Value
Publication number	US-12388361-B2
Application number	US-202117336075-A
Country	US
Kind code	B2
Filing date	Jun 1, 2021
Priority date	Jun 2, 2020
Publication date	Aug 12, 2025
Grant date	Aug 12, 2025

Abstract

Methods and apparatus for trickle charging and precharging a dead multi-cell-in-series battery. One battery charging circuit generally includes a charge pump circuit comprising a plurality of switches, being coupled to first and second power supply nodes, and being configured to multiply (or divide) a first voltage at the first power supply node to generate a second voltage at the second power supply node; a driver circuit configured to drive the plurality of switches in the charge pump circuit; and an arbiter having a first input coupled to the first power supply node, a second input coupled to the second power supply node, a third input coupled to a third power supply node having a third voltage, and an output coupled to a power supply terminal of the driver circuit. The arbiter is configured to select between the first, second, and third voltages to power the driver circuit.

First claim

What is claimed is:

1. A battery charging circuit comprising:
a charge pump circuit comprising a plurality of switches and a capacitive element, being coupled to a first power supply node and a second power supply node, and being configured to at least one of:
multiply a first voltage at the first power supply node to generate a second voltage at the second power supply node; or
divide the second voltage at the second power supply node to generate the first voltage at the first power supply node;

a driver circuit coupled to the charge pump circuit and configured to drive the plurality of switches in the charge pump circuit; and
an arbiter having a first input coupled to the first power supply node, a second input coupled to the second power supply node, a third input coupled to a third power supply node having a third voltage, and an output coupled to a power supply terminal of the driver circuit, the arbiter being configured to select between the first voltage, the second voltage, and the third voltage to power the driver circuit, wherein the second power supply node is configured to couple to a terminal of a battery, and wherein the plurality of switches in the charge pump circuit comprises:
a first switch coupled between the second power supply node and a first terminal of the capacitive element;
a second switch coupled in series with the first switch and coupled between the first terminal of the capacitive element and the first power supply node;
a third switch coupled in series with the second switch and coupled between the first power supply node and a second terminal of the capacitive element; and
a fourth switch coupled in series with the third switch and coupled between the second terminal of the capacitive element and a reference potential node.

2. The battery charging circuit of claim 1 , wherein the arbiter is configured to select the third voltage when the third voltage is higher than the first voltage and the second voltage.

3. The battery charging circuit of claim 1 , wherein the arbiter is configured to select the third voltage when the first voltage and the second voltage are indicative of a dead battery coupled to the second power supply node.

4. The battery charging circuit of claim 1 , wherein the first switch is connected to the second power supply node and wherein the second power supply node is connected to the terminal of the battery.

5. The battery charging circuit of claim 1 , wherein the battery charging circuit lacks a trickle charger between the first switch and the second power supply node.

6. The battery charging circuit of claim 1 , wherein the battery charging circuit lacks a fifth switch between the first switch and the second power supply node.

7. The battery charging circuit of claim 1 , wherein the second power supply node is configured to couple to a terminal of a multi-cell battery.

8. The battery charging circuit of claim 1 , wherein the first power supply node is configured to couple to an output of a switched-mode power supply circuit.

9. The battery charging circuit of claim 1 , wherein the charge pump circuit is configured to at least one of:
double the first voltage at the first power supply node to generate the second voltage at the second power supply node; or half the second voltage at the second power supply node to generate the first voltage at the first power supply node.

10. A wireless device comprising the battery charging circuit of claim 1 , the wireless device further comprising a multi-cell battery coupled to the second power supply node of the battery charging circuit.

11. The battery charging circuit of claim 1 , wherein:
the first, second, third, and fourth switches are implemented by first, second, third, and fourth transistors, respectively;
a drain of the first transistor is coupled to the second power supply node;
a drain of the second transistor is coupled to a source of the first transistor;
a drain of the third transistor is coupled to a source of the second transistor; and
a drain of the fourth transistor is coupled to a source of the third transistor.

12. The battery charging circuit of claim 11 , wherein the first, second, third, and fourth transistors comprise n-type metal-oxide-semiconductor (NMOS) transistors.

13. A power supply system comprising the battery charging circuit of claim 1 , the power supply system further comprising a power management circuit, the power management circuit having a switched-mode power supply circuit with an output coupled to the first power supply node of the battery charging circuit.

14. The power supply system of claim 13 , further comprising a voltage regulator having an output coupled to the third power supply node and configured to generate the third voltage.

15. The power supply system of claim 13 , wherein the power management circuit is configured to generate the third voltage.

16. The power supply system of claim 13 , further comprising a switch coupled between the output of the switched-mode power supply circuit and the first power supply node.

17. The power supply system of claim 16 , further comprising a trickle charger coupled in parallel with the switch and coupled between the output of the switched-mode power supply circuit and the first power supply node.

18. A method of supplying power, comprising:
selecting between a first voltage at a first power supply node, a second voltage at a second power supply node for coupling to a terminal of a battery, and a third voltage at a third power supply node to power a driver circuit coupled to a charge pump circuit, wherein the charge pump circuit includes a plurality of switches and a capacitive element and wherein the plurality of switches comprise:
a first switch coupled between the second power supply node and a first terminal of the capacitive element;
a second switch coupled in series with the first switch and coupled between the first terminal of the capacitive element and the first power supply node;
a third switch coupled in series with the second switch and coupled between the first power supply node and a second terminal of the capacitive element; and
a fourth switch coupled in series with the third switch and coupled between the second terminal of the capacitive element and a reference potential node; and

operating at least a portion of the driver circuit powered using the selected first, second, or third voltage.

19. The method of claim 18 , wherein the selecting comprises selecting the third voltage when the third voltage is higher than the first voltage and the second voltage.

20. The method of claim 18 , wherein the selecting comprises selecting the third voltage when the first voltage and the second voltage are indicative of a dead battery coupled to the second power supply node.

21. The method of claim 18 , further comprising multiplying, with the charge pump circuit, the first voltage at the first power supply node to generate the second voltage at the second power supply node.

22. The method of claim 18 , further comprising dividing, with the charge pump circuit, the second voltage at the second power supply node to generate the first voltage at the first power supply node.

23. The method of claim 18 , further comprising generating the third voltage at the third power supply node with a low dropout voltage regulator.

24. The method of claim 18 , wherein the battery comprises a multi-cell battery that is coupled to the second power supply

Assignees

• Qualcomm Inc

Inventors

• Guo Guoyong
• Kun Cheong
• Song Chunping

Classifications

• H02J7/575

  Parallel/serial switching of connection of batteries to charge or load circuit · CPC title

• H02J7/96

  in response to battery voltage · CPC title

• H02M3/072

  adapted to generate an output voltage whose value is lower than the input voltage · CPC title

• H02M3/071

  adapted to generate a negative voltage output from a positive voltage source · CPC title

• H02M3/073

  Charge pumps of the Schenkel-type · CPC title