A voltage multiplying circuit comprising: a first capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the first capacitor is selectively coupled to a first voltage or a second voltage, and the second terminal is selectively coupled to the first voltage or a fourth voltage; a second capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the second capacitor is selectively coupled to the second voltage or the fourth voltage, and the second terminal of the second capacitor is selectively coupled to a third voltage or the fourth voltage; and a third capacitor, comprising a first terminal and a second terminal, wherein the first terminal of the third capacitor is selectively coupled to the second voltage or the fourth voltage, and the second terminal of the third capacitor is selectively coupled to a third voltage or the fourth voltage.