Patent ID: 6842063

Claim:
An analog switch circuit for sampling an analog input signal, the circuit comprising: an analog switch section including a first n-channel MOS field effect transistor and a first p-channel MOS field effect transistor, sources of which are connected, drains of which are connected, and therefore said first n-channel and first p-channel MOS field transistors are connected in parallel, for receiving the analog input signal and for outputting a sampled analog output signal; a comparator circuit for receiving the analog input signal and a reference signal and for comparing the input potential of the analog input signal and the reference potential of the reference signal; and a voltage boost circuit for setting a potential of a gate of the first n-channel MOS field effect transistor to a potential of positive power supply voltage in the case of the input potential of the analog input signal being lower than the reference potential at the time of the analog switch section being in a continuity state and for boosting the potential of the gate to a potential higher than the potential of the positive power supply voltage in the case of the input potential of the analog input signal being higher than the reference potential at the time of the analog switch section being in the continuity state.