Patent ID: 8144143

Claim:
A charge pump, comprising: an output terminal; a first capacitor, having a first terminal and a second terminal; a plurality of first switches, coupled in parallel between a first reference voltage and the first terminal of the first capacitor; a plurality of second switches, coupled in parallel between a second reference voltage and a first node that is coupled to the second terminal of the first capacitor; a plurality of third switches, coupled in parallel between the first terminal of the first capacitor and the output terminal; a plurality of fourth switches, coupled in parallel between a third reference voltage and a second node that is coupled to the second terminal of the first capacitor; a voltage detector, detecting voltage value of the output terminal; and a charge pump controller, controlling the first, second, third and fourth switches, wherein, in a charge period, the charge pump controller selectively turns on the first and second switches according to the detected voltage value of the output terminal and turns off all third and fourth switches and, in a pump period, the charge pump controller selectively turns on the third and fourth switches according to the detected voltage value of the output terminal and turns off all first and second switches.