input circuit 70 of the sixth embodiment refer to fig1 to correspond to a negative potential power supply the first functional block 81 includes an nmos tr 84 first current control circuit and a first differential amplification circuit 141 the first differential amplification circuit 141 includes nmos trs 142 and 143 which receive the first and second input signals ina and inb and pmos trs 144 and 145 which configure a current mirror circuit in the first differential amplification circuit 141 the first current source is shared with the nmos tr 84 the first differential amplification circuit 141 which is configured in this manner is optimal when amplifying an input signal that is close to the ground potential 0195 fig2 is a waveform diagram showing the operation of the input circuit 140 when switching between an activated state and a standby state the voltages of the first to fourth power supplies v 11 to v 14 are the same as in fig2 and the voltage of the first functional block input signal in 1 external input signal is u2212 1 3 v u2212 0 9 v and close to the ground potential in the same manner as in the seventh embodiment when the input circuit 140 is switched to the standby state the voltages of the second and third functional input signals in 2 and in 3 are quickly increased to a value close to.