一种改进型微弱电流低噪声放大应用电路  

An improved weak current low noise amplifier application circuit

作　　者：姜利英[1] 岳保磊 梁茂[1] 周鹏磊 肖小楠 

机构地区：[1]郑州轻工业学院电气信息工程学院,河南郑州450002

出　　处：《郑州轻工业学院学报（自然科学版）》2015年第3期118-122,共5页Journal of Zhengzhou University of Light Industry:Natural Science

基　　金：国家自然科学基金项目(61002007);河南省科技创新人才计划项目(124100510001)

摘　　要：针对微弱电流信号检测技术存在的背景噪声、电路噪声、元器件噪声等的干扰往往大于信号本身,从而影响测量结果准确性的问题,设计了一种微弱电流低噪声信号放大应用电路.该设计采用高精度、小阻值的反馈电阻和高性能运算放大器AD795对T型I/V转换电路进行改进,选用高性能分立元件搭建前置放大电路,进而基于调制-解调原理设计锁相放大电路.软件仿真结果表明,电路具有较强的噪声抑制能力和稳定性,可以满足各种传感器微弱信号的测量要求.In order to solve the problem in weak current signal detection technology that the interference of background noise,circuit noise and component noise is stronger than signal itself,a weak current low noise amplifier application circuit was designed. The model improved T-type I / V conversion circuit by adopting high precision and small resistance value feed back resistance and high performance operational amplifier AD795,set up preamplifier circuit by high performance discrete elements and designed phrase-locked amplifier circuit based on modulation and demodulation principle. The simulation analysis showed that the circuit had higher noise suppression capability and stability and could meet the weak current measurement requirement of various sensors.

关 键 词：微弱电流 低噪声 T型I/V转换 前置放大 锁相放大 

分 类 号：TP216[自动化与计算机技术—检测技术与自动化装置]