基于C8051F单片机的测量放大器设计  

Design of measurement amplifier based on C8051F020 MCU

作　　者：贾俊荣 薛小铃 刘志群 JIA Junrong;XUE Xiaoling;LIU Zhiqun(College of Physics&Electronic Information,Minjiang University,Fuzhou 350108,China)

机构地区：[1]闽江学院物理与电子信息工程学院,福建福州350108

出　　处：《黑龙江工程学院学报》2018年第6期37-41,共5页Journal of Heilongjiang Institute of Technology

基　　金：福建省中青年教师教育科研项目(JT180412)

摘　　要：常用的测量放大器多存在差模放大倍数不可预置、调节范围小、系统扩展性差等问题。本系统由电桥电路、信号变换电路、测量放大器、数控衰减器及单片机最小系统等模块构成。信号源经过前端信号变换电路把单端信号转为双端信号,然后将输出的双端信号经过同相并联放大器转为单端信号,再通过后级放大电路进行放大,测量放大器的放大倍数由C8051F020单片机控制继电器切换不同的放大档位,后经数字衰减器电路,由单片机对其编码输出。该系统实现0～100Hz频率信号的放大,放大倍数1～1 000倍可预置,输出电压噪声小于1 Vpp,最大输出电压±10V,共模抑制比≥10-5。系统方案简单,测量精度高,适合于大多数小信号测量的场合。Most of the measurement amplifiers have such problems that the amplification of difference-mode input cannot be setup,the adjustable range is small and the expandability is weak.The system module circuit comprises the bridge circuit,the signal conversion circuit,the measurement amplifier and MCU minimum system.The signal source converts the single-ended signal into a double-ended signal through the front-end signal conversion circuit,and then outputs the double-ended signal to the single-ended signal through the in-phase parallel amplifier,enlarge the signal further by the post amplifier.The magnification of the measurement amplifier changed by the C8051F020 MCU controlling relays to switch the different zoom gear.The signal passes through the digital attenuator circuit,then encodes and outputs the data by the microcontroller.The system achieves the 0~100 Hz frequency signal amplification,magnification 1~1 000 times can be preset,the output voltage is noise is less than 1 Vpp,the maximum output voltage±10 V,and common mode rejection ratio is≥10^-5.The system is simple,with high precision,and suitable for most small signal measurement occasions.

关 键 词：测量放大器 信号变换 C8051F020 可预置 

分 类 号：TN722[电子电信—电路与系统]