地磁扰动检测用低噪声低偏置斩波放大电路研究  

Research on Low Noise and Low Offset Chopper Amplifying Circuit Used in Geomagnetic Disturbance

作　　者：李吉生 王言章[1,2] 纪诚 刘飞[1,2] 石佳晴 陈思宇 陈晨 LI Ji sheng;WANG Yan zhang;JI Cheng;LIU Fei;SHI Jia qing;CHEN Si yu;CHEN Chen(Key Laboratory for Geophysical Instrumentation of Ministry of Education,Changchun 130026,China;College of Instrumentation&Electrical Engineering,Jilin University,Changchun 130026,China)

机构地区：[1]地球信息探测仪器教育部重点实验室,吉林长春130026 [2]吉林大学仪器科学与电气工程学院,吉林长春130026

出　　处：《仪表技术与传感器》2020年第4期107-112,共6页Instrument Technique and Sensor

基　　金：国家自然科学基金项目(41274183);吉林省科技创新人才培育计划项目(2016C519023JH);吉林省省校共建计划专项项目(SXGJQY2017-11)。

摘　　要：由离散器件搭建的斩波电路由于电荷注入和时钟溃通效应会产生直流偏置电压,使得低频弱地磁扰动信号淹没,无法有效提取。为了解决上述问题,采用自动置零技术和斩波技术相结合的方法,设计了一种新型的低偏置斩波放大电路,通过提取传统斩波电路的直流偏置电压特征值,进行反馈抵消,从而抑制电路中固有的直流偏置电压。结果表明,低偏置斩波放大电路直流偏置电压为2.2μV,低于低偏置运算ADA4528的2.5μV;在0.1~10Hz的低频段,设计的低偏置斩波放大电路噪声峰峰值为28 nV,低于ADA4528的96 nV,降低到后者的29%。The chopper circuit built by discrete devices generates a DC bias voltage due to charge injection and clock-breaking effects,which makes the low-frequency weak signal flooded and cannot be effectively extracted.In order to solve the above problems,a new low-bias chopper amplifying circuit was designed by combining the automatic zero-setting technology and chopper technology.The DC offset voltage characteristic value of the traditional chopper circuit was extracted to perform feedback cancellation,thereby suppressing the DC bias voltage inherent in the circuit.The results show that the DC bias voltage of the low-biased chopper amplifier circuit is 2.2 μV,which is lower than the 2.5 μV of the low-bias operation ADA4528.In the low frequency range of 0.1~10 Hz,the noise of the designed low-biased chopper amplifier circuit is 28 nV,which is lower than the 96 nV of ADA4528,is reduced to 29% of the latter.

关 键 词：斩波放大技术 自动置零技术 低偏置 低频弱信号 地磁扰动 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]