The microcomputer 1 operates a control signal for controlling the state of an automobile on the basis of an input signal from a sensor. The output driver ICs 2A and 2B include the output driver 22 having power transistors in correspondence to a plurality of channels, the serial communication interface 23 for executing serial communication with the microcomputer, and the timer circuits 20A and 20B for generating a pulse width modulation signal and a pulse signal and are structured as a semiconductor circuit with these units integrated. The timer circuits 20A and 20B, on the basis of a control data signal received from the microcomputer by the serial communication interface 23, generates a pulse width modulation signal and a pulse signal.