System and method for power management

1. A power management device, comprising:

a first port configured to be coupled to a first power source;

a second port configured to be coupled to a second power source;

a switched capacitor converter;

an inductor coupled in parallel with a switch;

wherein the switched capacitor converter is coupled between the first port and one end of the inductor coupled in parallel with the switch;

wherein another end of the inductor coupled in parallel with the switch, is coupled to the second port;

a first power controller configured to regulate power transfer between the first power source and the second power source using commands sent to the first power source; and

a second power controller configured to regulate power transfer between the first power source and the second power source using commands sent to the switch.

2. The device of claim 1 :

wherein the first power source is at least one of: a power adaptor, an AC:DC adaptor, a rechargeable battery, a mobile device, a computer, or a USB-bus compatible device; and

wherein the second power source is at least one of: an energy storage device, a battery, a mobile device, or a USB-bus compatible device.

3. The device of claim 1 :

wherein the power management device is configured in a forward mode such that the first power source supplies power to the second power source.

4. The device of claim 3 , wherein the forward mode is a direct second port charging mode:

wherein the switch, in parallel with the inductor, is closed, and

wherein the switched capacitor converter is configured as a stepdown converter.

5. The device of claim 3 , wherein the forward mode is a limited second port current mode:

wherein the switched capacitor converter, inductor and switch are configured as a current source; and

wherein the switched capacitor converter and switch are modulated by coarse and fine power controllers respectively.

6. The device of claim 3 , wherein the forward mode is a regulated second port voltage mode:

wherein the switched capacitor converter and the switch are configured as a low dropout voltage regulator; and

wherein the switched capacitor converter and switch are modulated by coarse and fine power controllers respectively.

7. The device of claim 1 :

wherein the power management device is configured in a three-level buck mode such that the first power source supplies power to the second power source.

8. The device of claim 7 :

wherein the switch, in parallel with the inductor, is opened; and

wherein the switched capacitor converter and inductor are configured as a 3 level buck converter.

9. The device of claim 1 :

wherein the power management device is configured in a reverse mode such that the second power source supplies power to the first port.

10. The device of claim 9 , wherein the reverse mode is a three-level boost converter mode:

wherein the switch, in parallel with the inductor, is opened, and

wherein the switched capacitor converter and inductor are configured as a 3 level boost converter.

11. The device of claim 1 :

wherein the second power controller is an inner loop power control coupled to the switch;

wherein the switch and the inner loop power control are configured to regulate power transfer between the first and second ports such that either a voltage or current at the second port is within a first range of voltages or currents.

12. The device of claim 11 :

wherein the first power controller is an outer loop power control coupled to the inner loop power control, the switched capacitor converter, and is configured to control the first power source;

wherein the outer loop power control is configured to regulate power transfer between the first port and the first power source such that either a voltage or current at the one end of the inductor and switch is within a second range of voltages or currents.

13. The device of claim 12 :

wherein an absolute value of the second range of voltages or currents is greater than an absolute value of the first range of voltages or currents.

14. The device of claim 1 :

wherein the switch is a MOSFET.

15. The device of claim 1 :

wherein the switched capacitor converter is configured as a step-down converter.

16. The device of claim 1 :

wherein the power management device is an end-to-end battery power device.

17. A method for power management, comprising:

coarsely regulating power transfer between a first power source and a second power source using a switched capacitor converter and voltage or current commands sent to the first power source; and

finely regulating power transfer between the first power source and the second power source using an inductor in parallel with a switch, and commands sent to the switch.