There is provided a circuit whose output is free from high impedance to improve wrong transmission and waveform overshoot and realizing a semiconductor integrated circuit device in which plural channels is integrated with transmitter circuit as unit channel, in the transmitter circuit used in a medical ultrasound system and drives a transducer by voltage pulses having plural positive and negative electric potentials including ground potential. The transmitter circuit includes a conventional pulse generating circuit supplied with positive and negative voltage largest in absolute value, a P-channel analog switching pulse generating circuit supplied with positive voltage being the second largest therein, an N-channel analog switching pulse generating circuit supplied with negative voltage being the second largest and an N-channel analog switching ground level damping circuit supplied with ground potential. The circuits are connected to output terminal. Switch control signals drive ultrasound transducers by turning ON and OFF the circuits.
