Patent ID: 8579823

Claim:
An ultrasonic diagnostic apparatus comprising: an ultrasonic probe containing at least one transducer therein; and a transceiver containing a transmission amplifier and a reception circuit therein, wherein the ultrasonic probe and the transceiver are used in connection with each other through a cable, and wherein the ultrasonic probe comprises: at least one reception preamplifier that is provided per transducer element and connected to the transducer at an input side thereof and to a cable at an output side thereof; a transmission bypass unit that is connected between the cable and the transducer, blocks off a reception signal and allows a transmission signal to pass therethrough; and a floating unit that is connected between a power supply terminal of the reception preamplifier and a driving power source and increases impedance thereof for a high-voltage transmission signal, whereby a bias potential of the reception preamplifier is electrically set to a floating state and returned to an original bias potential by a reception time, wherein the floating unit is constructed by a backflow preventing diode connected between the power supply terminal of the preamplifier and the driving power source, and a capacitor connected to the diode.