Patent attributes
A leakage path through a parasitic diode in a charge transfer MOS transistor is cut off to prevent increase in the power consumption and loss of control of a charge pump circuit. A first charge transfer MOS transistor and a second charge transfer MOS transistor are N-channel type and are connected in series with each other. A ground electric potential VSS is supplied to a source of the first charge transfer MOS transistor as an input electric potential, and an output electric potential is obtained from an output terminal connected with a drain of the second charge transfer MOS transistor. A back gate of the first charge transfer MOS transistor is set by a first switching circuit to either an electric potential at a connecting node between the first and the second charge transfer MOS transistors or the ground electric potential VSS.