Switched capacitor converter mode transition control method

A method comprising:

• coupling an input of a switched capacitor power converter to a battery and an output of the switched capacitor power converter to a system load and a charger;
• configuring the switched capacitor converter to operate in a 1:2 fixed PWM mode to charge the battery;
• configuring the switched capacitor converter to operate in a 2:1 fixed PWM mode to discharge the battery;
• and
• configuring the switched capacitor converter to operate in a 2:1 skip mode in a light load operating condition, wherein the switched capacitor converter has automatic transitions among different modes based on comparisons between an output voltage of the switched capacitor converter and a plurality of predetermined voltage thresholds.

A controller comprising:

• a first comparator configured to compare an output voltage of a switched capacitor power converter with a first fixed PWM mode threshold voltage, wherein the first fixed PWM mode threshold voltage is greater than one half of an input voltage of the switched capacitor power converter;
• a second comparator configured to compare the output voltage of the switched capacitor power converter with a skip mode threshold voltage;
• a third comparator configured to compare the output voltage of the switched capacitor power converter with a threshold voltage for initializing a skip mode;
• a fourth comparator configured to compare the output voltage of a switched capacitor power converter with a second fixed PWM mode threshold voltage, wherein the second fixed PWM mode threshold voltage is less than the one half of an input voltage of the switched capacitor power converter;
• and
• a fifth comparator configured to compare a current flowing through the switched capacitor power converter with a predetermined sink current for determining whether the switched capacitor power converter enters into the skip mode under a light load operating condition.