A differential charge pump includes a differential charge pump unit, current adjusting device, and common mode voltage control circuit. The differential charge pump unit is used for generating a output voltage signal according to a pump-up signal and a pump-down signal. The current adjusting device is coupled to the differential charge pump unit for providing an adjusting current signal to the differential charge pump unit as the pump-up signal and pump-down signal are both enabled or disabled. The control circuit is coupled to the differential charge pump unit for outputting a feedback signal to the differential charge pump unit according to the output voltage signal.