A circuit for controlling power supply includes a first switch situated between a first power supply and a first node coupled to a circuit block, a second switch situated between a second power supply having a voltage value different than the first power supply and a second node coupled to a back gate of a transistor of the circuit block, a third switch situated between the first node and the second node, and a control unit configured to place the second switch in an “on” state and the third switch in an “off” state during an “on” state of the first switch, and to place the second switch in an “off” state and the third switch in an “on” state during an “off” state of the first switch.