高精度数据采集电路设计及通道交叉干扰分析

High Precision Data Acquisition Circuit Design and Channel Cross Interference Analysis

为满足多路远距离电流信号高精度采样的需求,设计了一种基于FPGA的高精度多通道数据采集存储电路。分析了测量电路各模块误差产生的原因,用电路等效理论推导了多通道采集时通道间交叉干扰引入的测量误差,从设计角度出发,提出了减小误差提高测量精度的方法。对设计的多通道采集电路进行了多次测试实验,测试结果表明,采集电路可实现对8路4 m A^20 m A电流信号高精度采集测量,测量精度优于0.1%。

In order to satisfy the demand of high precision sampling for multi-distance current signals,a high precision multi-channel data acquisition and storage circuit based on FPGA is designed.Analysed the causes for the measurement circuit module,the measurement error of cross interference between channels is derived by using circuit equivalent theory.From the point of design,a method is proposed to reduce the error and improve the measurement accuracy.Multi channel acquisition circuit was designed and tested,test results showed that,acquisition circuit could be achieved on the 8 channel 4 m A^20 m A high precision current signal acquisition and measurement accuracy is better than 0.1%.