大动态范围高精度AFE程控调理的经典实现方法

Classical Implementation of Programmable Conditioning AFE with Vast-dynamic Range and High Precision

工程实践对数据采集系统提出了越来越高的要求:大动态输入范围、高精度、自动控制等;文章分析了影响数据采集系统性能指标的两大主要因素:ADC转换位数和ADC模拟信号输入的动态范围,从实现ADC最佳输入范围出发,基于PGA(程控增益放大器)、DCP(数控电位)、PGAF(程控增益放大器和滤波器)等新器件技术,提出了大动态范围、高精度AFE(模拟前端)程控调理的经典实现方法;为提高系统精度,简要探讨了实现系统自动校准(包括自动调零和自动标定)的方法和其它一些抑制噪声的措施,在测控领域具有广泛的适用性和可移植性。

Engineering practices bring forward higher and higher requirements to DAQ （data acquisition） system, such as vast--dynamic inputting signal range, high precision, automatic controlling, and etc. The two factors that mostly impress the precision index of DAQ system are analyzed, which include no missing codes bits and input signal dynamic range of ADC. For the sake of implementation of the best inputting range of ADC, based on PGA, DCP, PGAF and other new--type techniques of IC parts, a classleal implementation of programmable conditioning AFE （analog front--end） with vast--dynamic range and high precision is advanced. In order to improve the precision, the article discusses the methods about automatic calibration and zeroing and some solutions for restraining noises briefly. And it has far--ranging applicability and transplanting in the domains of measurement and controlling.