Abstract:For different effectiveness demands in wideband and smallsignal medical ultrasonic testing, three classes of ultrasonic testing conditioning circuit designs are provided, which mainly consist of discrete components type, discrete components and integrated amplifiers combination type, specific integrated circuits type variable gain amplifier respectively. Moreover, its advantages and disadvantages, applicable scope are also discussed here. An experimental circuit based on the amplifier AD8334 was finally tested, which were used to amplified ultrasound impulse and filtering to obtain a stable 80 dB amplification waveform, as well as 0.7 nV/Hz input noise density according to the signaltonoise ratio, stipulating the ultrasound receiver/ transmitter PR5800 as a standard source. The mentioned circuits can comply with the design requirements include achieving 80 dB maximum gain, 30 MHz bandwidth@80 dB, <5 nV/Hz equivalent input noise voltage well. The program may provide some useful references in the aspects of cost, flexibility, convenience concern in ultrasonic testing design.