力反馈微加速度计的准静态和阶跃响应模型  

RESPONSE MODEL OF CAPACITIVE ACCELEROMETER WITH VOLTAGE FEEDBACK FOR QUASI-STATIC SIGNAL AND STEP SIGNAL

作　　者：车录锋[1] 徐志农[2] 熊斌[1] 王跃林[1] 

机构地区：[1]中国科学院上海微系统与信息技术研究所传感技术国家重点实验室,上海200050 [2]浙江大学机械与能源工程学院,杭州310027

出　　处：《机械工程学报》2004年第10期102-108,共7页Journal of Mechanical Engineering

基　　金：国家973(G1999033101);863(2003AA715121;2002AA430010)资助项目

摘　　要：对于微机械电容式加速度计,为了检测微小电容变化,必须引入交直流电压驱动信号,然而该静电力的存在显著影响传感器的最大可靠工作范围。对准静态惯性信号和阶跃惯性信号,深入研究了力反馈加速度计的可靠工作范围,建立了不同偏压配置的驱动信号对引起吸合失效的临界加速度信号的影响模型。研究结果表明静电力对阶跃信号的影响要比准静态信号大,动态工作条件下所能承受的最大阶跃加速度信号比准静态信号要小一个数量因子。对于双边驱动的力反馈加速度计,正正偏压配置或正负偏压配置可以最大程度地减小驱动信号引起的传感器吸合失效,从而增大可靠工作范围;而负负偏压配置或负正偏压配置增大了驱动信号效应,从而大大减小了可靠工作范围。For MEMS capacitive accelerometer, a driving signal with a DC bias voltage and an AC voltage is usually needed for detecting the variation of capacitance. The maximum inertial signal level for reliable operation is significantly reduced by the electrostatic force caused by the driving signal. The reliable operation ranges of capacitive accelerometer with voltage feedback for quasi-static signal and step signal are investigated. The effect model of driving signal with different bias voltage polarities on the critical acceleration that causes pull-in failure is set up. The results show that the electrostatic force imposes significantly larger restriction on the inertial signal range than that on the quasi-static signal and that the critical signal level of step inertial signal is smaller than that of quasi-static signals by a factor. For double-sided driving with voltage feedback, positive-positive and positive-negative bias voltage configurations may mostly eliminate the pull-in effect caused by the driving signal and increase the reliable operation range, while negative-negative and negative-positive bias voltage configurations maximize the side effects of the driving signal and reduce largely the safe operation range of the device.

关 键 词：加速度计 静电力 偏置电压极性 反馈 

分 类 号：TH7[机械工程—仪器科学与技术]