基于可重构差分对和数字辅助技术的仪表放大器  

Instrumentation Amplifier Based on Reconfigurable Difference Pair and Digitally Assisted Technique

作　　者：孙小智[1] 曾强 SUN Xiaozhi;ZENG Qiang(School of Intelligent Manufacturing,Dazhou Vocational and Technical College,Dazhou 635001,China;School of Intelligent Manufacturing,Sichuan University of Arts and Science,Dazhou 635000,China)

机构地区：[1]达州职业技术学院智能制造学院,达州635001 [2]四川文理学院智能制造学院,达州635000

出　　处：《核电子学与探测技术》2023年第4期743-752,共10页Nuclear Electronics & Detection Technology

基　　金：达州市科技计划项目(21DWHZ0003)。

摘　　要：小面积、低功耗和低噪声的仪表放大器广泛应用于核辐射和核环境监测系统的模拟前端作为弱电流放大器。对此,提出了一种新的方案来实现这种高精度斩波稳定仪表放大器;具体来说,在对仪表放大器中的偏移来源的分析基础上,为了减少仪表放大器中第一级差分对的不匹配,提出了采用可重构差分对来校正不匹配。同时为了稳定和提高偏移电压的检测精度,提出了一种新的数字辅助技术——自动差分对匹配环路来检测并最小化偏移电压;采用标准180 nm CMOS工艺制作了一个完整的仪表放大器,实现了0.05 mm^(2)的有效面积,小于3.4μV的偏移电压,13.3 nV/√Hz的输入参考噪声,以及190μA的电流消耗和7.1的放大器的噪声效率因子。实验结果充分证明了所提出方案的有效性。Instrument amplifiers with small area,low power consumption and low noise are widely used as low current amplifiers in the analog front-end of nuclear radiation and environmental monitoring systems.A new scheme to realize high precision chopper stabilized instrumentation amplifier is proposed.Specifically,based on the analysis of the offset source in the instrumentation amplifier,in order to reduce the mismatch of the first differential pair in the instrumentation amplifier,a reconfigurable differential pair is proposed to correct the mismatch.At the same time,in order to stabilize and improve the detection accuracy of the offset voltage,a new digitally assisted technique,namely automatic differential-pair matching loop,is proposed to detect and minimize the offset voltage.A complete instrumentation amplifier was fabricated using A standard 180 nm CMOS process,achieving an active area of 0.05 mm^(2),an offset voltage less than 3.4μV,an input reference noise of 13.3 nV/√Hz,as well as a current consumption of 190μA and a noise efficiency factor of 7.1.The experimental results fully demonstrate the effectiveness of the proposed scheme.

关 键 词：核辐射/核环境监测 仪表放大器 纹波抑制 偏移电压 可重构 自动差分对匹配 有效面积 低功耗 

分 类 号：TN432[电子电信—微电子学与固体电子学]