Linearity analysis of closed-loop capacitive accelerometer due to distance mismatch between plates and the influence of compensation capacitor array  

作　　者：HUANG JingQing ZHAO Meng ZHANG TingTing CHEN ZhongJian HONG LiChen WU Feng ZHANG YaCong LU WenGao GAO ChengChen HAO YiLong 

机构地区：[1]National Key Laboratory of Science and Technology on Micro/Nano Fabrication,Institute of Microelectronics,Peking University

出　　处：《Science China(Information Sciences)》2014年第6期195-206,共12页中国科学（信息科学）（英文版）

基　　金：supported by National High-tech R&D Program of China(863 Program)(Grant No.2008AA04-2201)

摘　　要：This paper presents mathematical formulae showing that the distance mismatch for an uncentered proof mass in an accelerator sensor does not influence the linearity of the closed-loop accelerometer as a whole.This asymmetry in sensors only introduces an output voltage offset in the readout integrated circuit.Numerical simulation using Matlab/Simulink confirms the mathematical conclusion.The linear response after compensation with a conventional capacitor array is also simulated and analyzed.Results show that there is a loss in linearity.Similar results hold not only for the continuous-time architecture,but also for a time-divided architecture.A readout integrated circuit with a time-divided architecture is designed and fabricated using a 0.35μm HV CMOS process.An accelerometer composed of a microelectromechanical system sensor with severe built-in distance mismatch and the designed readout integrated circuit is tested.Test results show that the nonlinearity of such accelerometer is within 0.3%.This paper presents mathematical formulae showing that the distance mismatch for an uncentered proof mass in an accelerator sensor does not influence the linearity of the closed-loop accelerometer as a whole.This asymmetry in sensors only introduces an output voltage offset in the readout integrated circuit.Numerical simulation using Matlab/Simulink confirms the mathematical conclusion.The linear response after compensation with a conventional capacitor array is also simulated and analyzed.Results show that there is a loss in linearity.Similar results hold not only for the continuous-time architecture,but also for a time-divided architecture.A readout integrated circuit with a time-divided architecture is designed and fabricated using a 0.35μm HV CMOS process.An accelerometer composed of a microelectromechanical system sensor with severe built-in distance mismatch and the designed readout integrated circuit is tested.Test results show that the nonlinearity of such accelerometer is within 0.3%.

关 键 词：LINEARITY CLOSED-LOOP ACCELEROMETER capacitive MEMS ROIC 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TN918.1[自动化与计算机技术—控制科学与工程]