抗混叠滤波设计在数据采集系统中的应用

Applications of Anti-aliasing Filter Design in Data Acquisition System

数据采集的抗混叠滤波,在电路设计中是很重要的考虑因素;在数据采集系统中,对一定带宽的模拟信号,采样率必须满足奈奎斯特采样定理,否则将产生混叠现象,这将导致原始信号无法从取样信号还原,严重影响测量结果;本设计在信号调理部分及A/D采集部分均采用了抗混叠设计,FPGA采用XILINX公司的XC3S400作为主控制器;综合各个环节,提出了高精度数据采集中抗混叠滤波设计的方法,并简单介绍了AD采样与模拟开关切换时序设计,为高精度数据采集系统的设计提供了十分有益的参考。

The anti-aliasing filter in data collection is a very important consideration in circuit design.In the data acquisition system,for an analog signal of certain bandwidth,the sampling rate must satisfy the Nyquist sampling theory,otherwise it will cause aliasing.This will lead to the original signal cannot be restored from the sampled signal,seriously affects the measurement result.The design of the signal conditioning and A/D acquisition part have adopted anti-aliasing design,FPGA using XC3S400 of the XILINX company as the main controller.Integrating all aspects,we propose the anti-aliasing filter design methods for the high-precision data acquisition system,give a brief introduction AD sampling and the sequential design of channel multiplexers＇ switching.This provides a very useful reference for the system.