基于ADS7945的微弱信号采集系统  

Weak Signal Acquisition System Based on ADS7945

作　　者：白旭[1] 胡辉[1] 李万军[1] 褚越强[1] 

机构地区：[1]北华航天工业学院电子与控制工程学院,河北廊坊065000

出　　处：《北华航天工业学院学报》2015年第5期15-18,共4页Journal of North China Institute of Aerospace Engineering

基　　金：河北省高等学校科学技术研究重点项目(ZH2011234);北华航天工业学院课题(KY201204)

摘　　要：针对实际测试测量过程中微弱信号容易被噪声淹没且处理困难的问题,本文设计了一种基于ADS7945的微弱信号采集系统。该采集系统的设计以ADS7945、程控增益放大器PGA202和累加平均算法为基础。在硬件设计过程中综合分析了供电电源、电压基准以及屏蔽对系统性能的影响,并给出了相应的设计方法。在软件设计过程中使用FPGA完成对ADS7945的采集数据解串及实现累加平均算法。实验结果表明该微弱信号采集系统可以对10KHz,50μVpp的正弦信号进行有效测量。在输入10KHz,50μVpp正弦信号时,系统的信噪比达24.6d B。In view of the problem that weak signal is easily drowned by noise and difficult to process,a weak signal acquisition system is designed based on ADS7945. The acquisition system is founded on ADS7945,programmable gain instrumentation amplifier PGA202 and cumulative average algorithm. During the hardware design the impacts of power supply,voltage reference and shield are comprehensively considered and the corresponding design method is proposed. During the software design FPGA is used to complete the acquisition data from ADS7945 and to realize the cumulative average algorithm. The experiment shows that the weak signal acquisition system can effectively measure a 10 KHz,50 μVpp sinusoidal signals. The signal to noise ratio（ SNR） of the system is 24. 6 d B when a10 KHz,50 μVpp sinusoidal signal is inputted.

关 键 词：微弱信号采集 累加平均 程控增益放大器 蔽 ADC 

分 类 号：TM932[电气工程—电力电子与电力传动]