DC-to-DC converter and method therefor

1. A method of operating a switched capacitor dc-dc converter comprising:

configuring the converter to selectively control a charging configuration and a supply configuration of a plurality of capacitors responsively to a value of a charging current, an input voltage, and an output voltage;

configuring the converter to set the value of the charging current responsively to the value of the output voltage, and

configuring the converter to use the value of the charging current to modulate a reference voltage used to form the charging configuration and the supply configuration including configuring the converter to form a reference control signal that is representative of a current control signal and to use the current control signal to modulate the reference voltage.

2. The method of claim 1 wherein configuring the converter to selectively control the charging configuration includes coupling the plurality of capacitors in series or parallel to receive the input voltage responsively to the value of the charging current, the input voltage, and the output voltage.

3. The method of claim 1 further including subtracting the output voltage from the input voltage and comparing a difference between the output voltage and the input voltage to the reference voltage that is modulated by the value of the charging current.

4. The method of claim 1 further including coupling the plurality of capacitors in the charging configuration during a first time period and in the supply configuration during a second time period.

5. A method of forming a switched capacitor dc-dc converter comprising:

configuring the converter to selectively set an operating state responsively to a value of a charging current, an input voltage, and an output voltage;

configuring the converter to receive the output voltage and responsively form the charging current including configuring the converter to receive the output voltage and responsively form a first charging current to charge a first capacitor of a plurality of capacitors during at least a portion of a first time period; and

configuring the converter to selectively couple the plurality of capacitors together during at least a portion of a second time period to form the output voltage.

6. The method of claim 5 wherein configuring the converter to selectively set the operating state includes configuring the converter to set the charging configuration and the supply configuration responsively to the value of the charging current, the input voltage, and the output voltage.

7. The method of claim 5 wherein configuring the converter to selectively set the operating state includes configuring the converter to selectively set the operating state in a storage element.

8. The method of claim 5 wherein configuring the converter to receive the output voltage and responsively form the charging current includes configuring the converter to couple the plurality of capacitors in the charging configuration to receive the input voltage responsively to the value of the charging current.

9. The method of claim 5 wherein configuring the converter to selectively set the operating state includes configuring the converter to modulate the value of the reference signal responsively to the value of the charging current and responsively set the operating state.

10. A switched capacitor dc-dc converter comprising:

a state circuit operably coupled to set an operating state of the converter responsively to a value of a charging current, an input voltage, and an output voltage wherein the charging current is used to charge a plurality of capacitors to a voltage; and

a modulation circuit configured to modulate a value of a reference signal responsively to the value of the charging current and wherein the state circuit uses the modulated value of the reference signal to form a charging configuration and a supply configuration of the plurality of capacitors.

11. The converter of claim 10 further including control logic coupled to receive the operating state and responsively control a switch matrix to couple the plurality of capacitors in the charging configuration to receive the input voltage during a first time period and to responsively control the switch matrix to couple the plurality of capacitors in the supply configuration to form the output voltage during a second time period.

12. The converter of claim 10 wherein the current control circuit is coupled to receive the input voltage and responsively form a current control signal operably coupled to control the charging current to charge a capacitor of the plurality of capacitors.

13. The converter of claim 12 wherein the current control circuit includes an amplifier coupled to form the current control signal and to form a reference control signal that is representative of the charging current.

14. The converter of claim 10 wherein the state circuit includes a memory circuit coupled to store the operating state of the converter.