US Patent 7271452 Analog switch

An analog switch has a first circuit and a second circuit. The first circuit has an NMOS and PMOS connected in series, and the second circuit has a PMOS and NMOS connected in series. The first and second circuits are provided in parallel between an input terminal and output terminal of the analog switch. The gate of each NMOS is connected to a terminal to which a first clock signal is supplied, and the gate of each PMOS is connected to another terminal to which a second clock signal is supplied. The second clock signal is a reversal of the first clock signal. When the analog switch is set to the OFF state and a voltage that is above the supply potential is applied to the input terminal, the NMOSs become reverse-biased diodes. Therefore, an off leak current is not produced.