Implementation of high efficiency battery charger for electronic devices

Patent metadata

Field	Value
Publication number	US-10468898-B2
Application number	US-201715668514-A
Country	US
Kind code	B2
Filing date	Aug 3, 2017
Priority date	May 19, 2017
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A power converter including a buck converter to receive input power and set operating voltages of the power converter, a current sensing circuit to determine an input current of the power converter, a charge pump circuit to store charge delivered by the voltage regulation circuit and output to a load and to a battery pack a current larger than the input current, and a battery pack controller to control switching and provide feedback within the power converter.

First claim

The invention claimed is:

1. A power converter, comprising:
a switched-capacitor converter charge pump circuit;
a buck converter having a target voltage and configured to receive input power;
wherein the buck converter is configured to set a voltage sent to the switched-capacitor converter charge pump circuit based only on the target voltage;
a current sensing circuit to determine an input current of the power converter;
wherein the switched-capacitor converter charge pump circuit is configured to send an output current to a load and/or to a battery pack based only on the voltage set by the buck converter, wherein the output current is larger than the input current; and
a battery pack controller configured to provide the target voltage as feedback to the buck converter within the power converter.

2. The power converter of claim 1 ,
wherein the buck converter is used in reverse-boost mode to supply power from the battery pack back to a voltage input.

3. The power converter of claim 1 , wherein the charge pump circuit includes
a plurality of first transistors at a first voltage rating and
a plurality of second transistors at a second voltage rating twice the first voltage rating.

4. The power converter of claim 3 ,
wherein an output voltage is produced at ratios of 1.5 times, two times, or three times an input voltage.

5. The power converter of claim 1 ,
wherein the buck converter comprises a pair of transistors and an inductor.

6. The power converter of claim 1 ,
wherein the charge pump circuit includes a plurality of back gate transistors to block leakage current from output to input.

7. The power converter of claim 1 ,
wherein the charge pump circuit includes a pair of flying capacitors that are alternatively switched to provide power to a load.

8. The power converter of claim 1 , wherein
the charge pump circuit comprises a pair of input transistors and
the charge pump circuit includes a pair of back gate transistors, a pair of mid-point transistors, and a pair of grounding transistors.

9. The power converter of claim 8 ,
wherein an input transistor and a mid-point transistor are switched ON to charge the charge pump and are switched OFF to discharge the charge pump.

10. The power converter of claim 8 ,
wherein a back gate transistor and a grounding transistor are switched ON to discharge the charge pump and are switched OFF to charge the charge pump.

11. The power converter of claim 8 ,
wherein the back gate transistors are turned ON to prevent reverse current in the power converter from output to input.

12. A method of charging a power adapter having a power converter, comprising:
receiving input power and setting operating voltages of the power converter using a buck converter having a target voltage;
determining an input current of the power converter using a current sensing circuit;
storing charge by a charge pump circuit and outputting to a load and/or to a battery pack an output current larger than the input current;
wherein the buck converter is configured to set a voltage sent to the charge pump circuit based only on the target voltage;
wherein the charge pump circuit is configured to set the output current based only on the voltage set by the buck converter; and
controlling switching and providing the target voltage as feedback to the buck converter within the power converter using a battery pack controller.

13. The method of claim 12 , further comprising
switching ON a first input transistor of the buck converter and switching ON a first mid-point transistor of the charge pump circuit to charge a first flying capacitor of the charge pump circuit in a first half cycle.

14. The method of claim 13 , further comprising
switching ON a second input transistor of the buck converter and switching ON a second mid-point transistor of the charge pump circuit to charge a second flying capacitor of the charge pump circuit in a second half cycle.

15. The method of claim 12 , further comprising
switching OFF a first back gate transistor of the charge pump circuit and switching OFF a first grounding transistor of the charge pump circuit to discharge a first flying capacitor of the charge pump circuit in a first half cycle.

16. The method of claim 15 , further comprising
switching OFF a second back gate transistor of the charge pump circuit and switching OFF a second grounding transistor of the charge pump circuit to discharge a second flying capacitor of the charge pump circuit in a second half cycle.

17. The method of claim 12 , further comprising
switching ON a pair of back gate transistors to prevent reverse current from output to input in the power converter.

Assignees

• Nxp Bv

Inventors

• Crosby Robert Glenn Il
• Christiaans Peter

Classifications

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02J7/865 Primary

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H02J2207/20

  Charging or discharging characterised by the power electronics converter · CPC title

• H02J7/00

  Circuit arrangements for charging or discharging batteries or for supplying loads from batteries · CPC title

• H02M3/158 Primary

  including plural semiconductor devices as final control devices for a single load · CPC title