Implementation of high efficiency battery charger for electronic devices

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.