Patent ID: 7741871

Claim:
An integrated circuit device comprising: a high-speed serial interface circuit that includes a receiver circuit that receives differential signals through a serial bus; a first guard terminal that prevents radiation; a second guard terminal that prevents the radiation; a first terminal that is disposed between the first guard terminal and the second guard terminal and receives a first signal of the differential signals; a second terminal that is disposed between the first guard terminal and the second guard terminal and receives a second signal of the differential signals; a first power supply terminal, a high-voltage-side power supply voltage of the receiver circuit being supplied to the first power supply terminal; and a second power supply terminal, a low-voltage-side power supply voltage being supplied to the second power supply terminal, a first switch element being provided between a line from the first guard terminal and a line from the second power supply terminal, and a second switch element being provided between a line from the second guard terminal and a line from the second power supply terminal, the first switch element and the second switch element being turned ON in a high-speed serial interface mode.