Integrated circuit device

An integrated circuit (IC) device includes a functional circuit electrically coupled to a first power supply node and operable by a first power supply voltage on the first power supply node, and a power control circuit including a first transistor and a second transistor of different types. The first transistor includes a first gate terminal configured to receive a control signal, a first terminal electrically coupled to the first power supply node, and a second terminal electrically coupled to a second power supply node. The second transistor includes a second gate terminal configured to receive the control signal, and third and fourth terminals configured to receive a predetermined voltage. The first transistor is configured to, in response to the control signal, connect or disconnect the first and second power supply nodes to provide or cutoff power supply to the functional circuit.