Patent ID: 8710911

Claim:
A charge pump circuit, comprising: a power receiving end, for receiving a source voltage; a ground end; a positive output end, for outputting a positive output voltage; a negative output end, for outputting a negative output voltage; a first storage capacitor, coupled between the positive output end and the ground end; a second storage capacitor, coupled between the negative output end and the ground end; a first flying capacitor; a second flying capacitor; a pump unit, for controlling at least a connection relation of the first flying capacitor, the second flying capacitor, the first storage capacitor, and the second storage capacitor according to a first clock and a second clock with non-overlapping working phases, to convert the source voltage into the positive output voltage and the negative output voltage, thereby providing one of a first power-supply mode, a second power-supply mode and a third power-supply mode with different power conversion efficiencies; and an amplitude detector, for detecting an amplitude of an input signal or an output signal of a post-stage circuit powered with the positive output voltage and the negative output voltage, so as to select one of the three power-supply modes of the pump unit; wherein the amplitude detector selects the first power-supply mode when the amplitude is smaller than a first threshold, the amplitude detector selects the second power-supply mode when the amplitude is higher than the first threshold and smaller than a second threshold, and the amplitude detector selects the third power-supply mode when the amplitude is higher than the second threshold.