Abstract: In order to solve the problems that the portable wave recording device needs to sample AC/DC

voltage samples with different input voltages，AC/DC current signals with different input currents and high sampling rate，an analog signal isolation sampling circuit was designed for portable wave recording device.The MAX11901 conversion chip was used，in which the sampling circuit was divided into large signal sampling circuit and small signal sampling circuit according to the difference of sampling signal. An isolation sampling circuit was built and the accuracy of the test results were analyzd.The analysis result shows that the circuit is suitable for a variety of signal inputs，the accuracy can be better than 0.5%，and the sampling rate can reach 500 kHz. It has high practical and popularizing value.

      Key words: portable wave recording；isolated sampling；0.5% accuracy；500 kHz sampling rate