Patent ID: 8193853

Claim:
A charge pump, comprising: a plurality of power input terminals for receiving different input voltages; a power output terminal for supplying an output voltage; an output stage switched between one of the power input terminals and the power output terminal; a pumping capacitor connected to the output stage; an output capacitor connected to the power output terminal; a feedback circuit connected to the power output terminal, operative to provide a feedback signal related to the output voltage; and a control circuit connected to the feedback circuit, the output stage, and the plurality of power input terminals, operative to control charging and discharging of the pumping capacitor according to the feedback signal and a target value, to charge the output capacitor to generate the output voltage, wherein the control circuit comprises: an error amplifier connected to the feedback circuit for amplifying a difference between the feedback signal and the target value to generate an error signal; an auto-sensing controller connected to the error amplifier, operative to generate a mode transition signal and a power switching signal according to the error signal; a charge pump control logic connected to the auto-sensing controller, operative to generate a control signal according to the mode transition signal; a driver connected to the pumping capacitor and the charge pump control logic, operative to apply a voltage to a terminal of the pumping capacitor according to the error signal and the control signal; and a power switch connected to the driver for switching the plurality of power input terminals to connect to the driver according to the power switching signal.