Patent ID: 7834679

Claim:
A semiconductor switch, comprising: a gray level generation circuit for generating a plurality of gray level voltages; a gray level selector circuit having a plurality of analog switch circuits each for selecting a corresponding one of the plurality of gray level voltages; and a switch control circuit for controlling an operation of the gray level selector circuit, wherein: each of the plurality of analog switch circuits includes a MOS transistor having a source connected to one of the plurality of gray level voltages which is to be selected, the switch control circuit includes: a timing control circuit which supplies a gate voltage of the MOS transistor for controlling an ON/OFF timing of the MOS transistor, and a backgate voltage control circuit which supplies a voltage substantially equal to a source voltage of the MOS transistor as a backgate voltage of the MOS transistor, wherein: the backgate voltage control circuit has an internal structure substantially equal to that of the gray level generation circuit, and each of the gray level generation circuit and the backgate voltage control circuit has a resistor string circuit connected between an H-side power supply and an L-side power supply, and each of the gray level generation circuit and the backgate voltage control circuit has a current source, a resistor string circuit and a diode connected in series between an H-side power supply and an L-side power supply.