基于FPGA高速数据采集的电化学阻抗分析仪的研制

Study on EIS analysis instruemnt based on FPGA and high-speed data acquisition

以FPGA、C8051f单片机及高速AD/DA转换器、DDS信号发生器、频率响应分析器配合恒电位仪,设计一套包括正弦波输出、高速数据采集、实时图形显示的电化学阻抗测试系统。系统采用数字相关算法来测量电压与电流信号的相位差和幅值,提高测试精度,通过双通道信号积分和自动去偏置电路,极大地提高信噪比。通过试验发现,所设计的仪器与国外同类型仪器的测量结果几乎一致。并较后者具有更宽的频率分析范围。

An Electrochemistry Impedance Spectrum （EIS） measuring instrument based on FPGA and C8051 F MCU has been designed in this paper, which include a DDS sine-wave generator, a frequency response analyzer composed of dual channel synchronic highspeed A/DD/A data acquisitions and a real-time graphic display. In the design, the digital correlation method was applied to measure phase difference and signal amplitude, which is characterized of high precision and signal to noise ratio, the measure rult of this system is similar to that of oversea similar device by comparable experiment.