运用于MEMS磁传感器的数字锁相放大器  

Digital Lock-in Amplifier Applied in MEMS Magnetic Sensor

作　　者：梅晓东 梁亨茂 王文杰[1] 陆仲明 熊斌[1] MEI Xiao-dong;LIANG Heng-mao;WANG Wen-jie;LU Zhong-ming;XIONG Bin(Science and Technology on Microsystem Laboratory,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China;University of Chinese Academy of Sciences(UCAS),Beijing 100049,China)

机构地区：[1]中国科学院上海微系统与信息技术研究所微系统技术重点实验室,上海200050 [2]中国科学院大学,北京100049

出　　处：《仪表技术与传感器》2021年第4期57-61,111,共6页Instrument Technique and Sensor

基　　金：国家自然科学基金资助项目(51577186)。

摘　　要：文中研究了用于静电驱动-电磁感应敏感的MEMS磁传感器的数字锁相放大器电路。为了对该种传感器输出自调制的信号进行解调,基于ARM微控制器设计了一种无需相位调整的双路数字锁相放大器。在参考通道的设计中,将驱动传感器处于谐振状态的正弦信号转为矩形波信号。应用电路测试结果表明:传感器输出信号的非线性度达0.23%,迟滞性误差和重复性误差分别为0.09%和0.29%。数字锁相放大器能够有效而稳定地解调MEMS磁传感器输出信号,为具有输出信号调制特点的传感器提供一种可行的数字信号处理方案。This paper discussed a digital lock-in amplifier circuit for a MEMS magnetic sensor based on electrostatic driving and electromagnetic-induction sensing.In order to demodulate the self-modulated output signal from the sensor,a two-channel digital lock-in amplifier without the phase-adjustment requirement was designed based on the ARM microcontroller.In the design of reference channels,the sinusoidal signal used for driving the sensor in its resonant state was converted into a rectangular wave signal.For the circuit applied on the sensor,the test results show that the non-linearity,the hysteresis error and the repeatability error of the sensor output signal are about 0.23%,0.09%and 0.29%,respectively.The digital lock-in amplifier proposed in this paper can effectively and stably demodulate the output signal of the MEMS magnetic sensor,which provides a feasible strategy of digital signal processing for sensors featured with modulated output signals.

关 键 词：MEMS磁传感器 正交解调 STMF4处理器 数字锁相放大器 微弱信号检测 数字信号处理 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]