Patent ID: 7061302

Claim:
A semiconductor integrated circuit device comprising: a first MOS transistor having a first gate, a first backgate, a first conducting region, and a second conducting region, the first MOS transistor having the first backgate and the first conducting region thereof electrically connected together; a second MOS transistor having a second gate, a second backgate, a third conducting region, and a fourth conducting region, the second MOS transistor having the second backgate and the third conducting region thereof electrically connected to the first backgate and the first conducting region, the second MOS transistor receiving a first direct-current voltage at the fourth conducting region thereof; a comparator that compares the first direct-current voltage with a second direct-current voltage outputted from the second conducting region; and a switch that operates according to an output of the comparator so as to connect, when the first direct-current voltage is higher than the second direct-current voltage, the second gate to a predetermined potential and, when the first direct-current voltage is lower than the second direct-current voltage, the second gate to the third conducting region or to the second conducting region.