Design and implementation of an analog signal isolation conditioning circuit

Abstract

Abstract In control systems, external analog signals need to be converted into digital signals. When sampling external input analog signals, such as voltage or current, it is necessary to process the small analog signal amplification or large signal reduction to the digital signal that can be sampled normally by the ADC; at the same time, the complexity of the external environment will affect the accuracy of sampling, and the input and output isolation processing needs to be carried out. Therefore, in order to solve the problem of low sampling accuracy of analog signal ADC in complex environment, this paper proposes an analog signal isolation conditioning circuit, which can filter out the high-frequency noise in the input signal without affecting the rapid sampling of the ADC, and use two-stage operation amplification to perform gain and zero compensation processing, so that the conditioned signal has high accuracy, good linearity, and strong anti-interference ability, which meets the design requirements. Through functional and stress tests, the functional correctness and performance stability of the analog signal isolation conditioning circuit proposed in this paper are verified.