Abstract: An integrated circuit chip has terminals comprising an input terminal, an output terminal to be connected to a load, a power supply terminal to be connected to the positive terminal of a power supply, and a ground terminal to be connected to ground potential (car body). A ground-side common line is associated with the internal circuitry of the integrated circuit chip, and a current-limiting resistor is connected between the ground-side common line and the ground terminal. A diode is connected in parallel with the resistor to limit a surge voltage. The diode is connected with its anode connected to the ground-side common line and its cathode connected to the ground terminal.