A charge pump includes a first switch to a eighth switch, a first capacitor to a second capacitor. The first switch coupled between a first voltage source and a first node, the second switch coupled between the first node and a second node, the third switch coupled between the second node and a third node, the third node is for outputting from the charge pump. The fourth switch is coupled betweenthe output node and a fourth node, the fifth switch is coupled between the fourth node and a fifth node, and the sixth switch is coupled between the fifth node and ground. The seventh switch is coupled between ground and the first node and the eighth switch is coupled between a second voltage source and the fifth node. The first capacitor is coupled between the second node and a first voltage signal and the second capacitor is coupled between the fourth node and a second voltage signal.