微弱信号放大电路设计  

Design of weak signal amplification circuit

作　　者：刘傲东 廖宏宇 刘紫东 LIU Aodong;LIAO Hongyu;LIU Zidong(School of Physics and Electronic Information Engineering,Yan’an University,Yan’an 716000,China;705th Research Institute,Xi’an 710065,China;Xi’an University of Technology,Xi’an 710048,China)

机构地区：[1]延安大学物理与电子信息工程学院,陕西延安716000 [2]第七〇五研究所,陕西西安710065 [3]西安理工大学,陕西西安710048

出　　处：《电子设计工程》2021年第14期149-153,共5页Electronic Design Engineering

摘　　要：针对工程测量领域微弱信号放大的实际需求,采用差分放大、带通滤波和后级放大的方法,设计了一种以仪表放大器为核心的微弱信号放大电路,并制作了实际电路板。实验测试结果显示,放大电路增益达到了90 dB,可以可靠地获取微伏级的微弱信号并进行有效放大,具有抗干扰性好、稳定性强、增益高等特点,信噪比得到了较大提升。Aiming at the actual demand of sensor output weak signal amplification in engineering measurement field,a weak signal amplifier circuit with instrument amplifier as the core is designed by using differential amplification plus bandpass filter plus rear stage amplification method.The actual circuit board is made.Experimental results show that the gain of amplifier circuit reaches 90 dB,and the weak signal of microvolt level can be reliably obtained and amplified effectively.It has the characteristics of good anti-interference,strong stability and high gain,and the SNR is greatly improved.

关 键 词：传感器 微弱信号 低噪声 滤波器 放大电路 

分 类 号：TN72[电子电信—电路与系统]