基于 AD630的锁相放大器的研究与改进  

RESEARCH AND IMPROMENT OF LOCK - IN AMPLIFIER BASED ON AD630

作　　者：许圣梅[1] 王春静[1] 孙潇[1] 戚玉娟[1] 

机构地区：[1]山东师范大学信息科学与工程学院,济南250014

出　　处：《山东师范大学学报（自然科学版）》2015年第3期45-48,共4页Journal of Shandong Normal University(Natural Science)

基　　金：山东师范大学模拟电路实验教学改革与研究课题基金项目（14syjg302134）.

摘　　要：以 AD630为硬件核心的锁相放大器能够有效的提取出淹没在噪声信号中的微弱有用信号，其高效、准确的特性使其在微弱信号检测方面显示出独特的优势。笔者主要从两个方面对锁相放大器进行了研究与改进：第一，设计一种前置低噪声 LC 谐振放大器，来代替以往锁相放大器所需的前置放大和预滤波部分，以实现放大、滤波合二为一；第二，针对锁相放大器实际输出与期望值之间可能存在误差的问题，设计一种输出信号检测及校正电路，以使输出结果更加贴近期望值。本文最后利用 Proteus 软件对文中所设计的实际电路进行仿真，以验证文中所设计电路的可行性。Lock - in amplifier with AD630 as the core of hardware can effectively extract the weak useful signal submerged in noise signals,whose characteristics of being efficient and accurate have shown its unique advantage in weak signal detection. This paper researches the lock - in amplifier mainly from two aspects. First, one kind of pre low noise LC resonant amplifier is designed to replace the parts of pre amplifier and pre filtering required by the past lock - in amplifiers,and to realize the integration of amplifying and filtering. Secondly,one kind of detection and correction circuit of the output signal for the problem of existence of error between actual output value and expected value of the lock - in amplifier is designed to make the actual output value relatively close to the expected value. In the end,the circuits designed in the paper are simulated by using the Proteus software to verify the feasibility of the circuits.

关 键 词：锁相放大器 微弱信号检测 LC 谐振放大器 输出信号检测及校正 

分 类 号：TN722.5[电子电信—电路与系统]