Switching frequency control of switched capacitor circuit using output voltage droop

A switched capacitor voltage converter, comprising:

• a switched capacitor voltage divider which divides an input voltage to provide an output voltage based on an input clock signal, wherein said output voltage has a voltage droop based on output load current;
• a controlled oscillator having a frequency control input receiving a frequency control signal and an output for providing said clock signal at a frequency based on said frequency control signal;
• and
• an amplifier circuit having an input for receiving said output voltage and an output providing said frequency control signal which is continuously adjusted by an amount corresponding to the amount of said voltage droop of the output voltage.

A method of controlling a frequency of a switched capacitor circuit to optimize efficiency, comprising:

• dividing an input voltage to provide an output voltage using a switched capacitor circuit which switches based on a clock signal;
• providing the clock signal with a fixed duty cycle;
• detecting an amount of droop of the output voltage;
• and
• continuously adjusting the frequency of the clock signal by an amount corresponding to the detected amount of droop.