微机械角速率传感器CMOS闭环驱动电路  

A CMOS closed-loop driving circuits for micro-mechanical angular rate sensor

作　　者：尹亮[1] 刘晓为[1,2] 陈伟平[1,2] 周治平[1] 

机构地区：[1]哈尔滨工业大学微电子技术与科学系,哈尔滨150001 [2]哈尔滨工业大学微系统与微结构制造教育部重点实验室,哈尔滨150001

出　　处：《哈尔滨工业大学学报》2011年第11期6-10,共5页Journal of Harbin Institute of Technology

基　　金：国家高技术研究发展计划资助项目(2008AA042201)

摘　　要：为解决微机械角速率传感器的驱动信号对检测电极的耦合问题,提出一种基于电压频率调制闭环静电力驱动方法.该方法将驱动电压调制到高频,有效地将机械谐振频率与电压驱动频率分离,同时不改变驱动静电力的相位与频率.采用自动增益控制电路使得闭环驱动幅值非稳定性为0.01%,片上集成跨阻放大器可实现1 aF/sqrt(Hz)电容变化测量.闭环驱动电路采用18 V高压N阱CMOS工艺设计,芯片面积18.9 mm2.在±9 V电源条件下,角速率传感器输出刻度因子10 mV.((°).s-1)-1,线性度0.3%,偏置稳定性190((°)/h).测试结果表明,该方法在机械表头常压封装下(品质因子为80),无需后续电路相位调整,即能有效的实现传感器的闭环自激驱动.To solve the coupling problem from driving electrode to sensing electrode of micro-mechanical angular rate sensor, a closed-loop driving approach of electrostatic force based on voltage frequency modulation is proposed, which separates the mechanical resonance frequency from voltage drive frequency without changing the phase and frequency of electrostatic force. Automatic gain control circuits are adopted to get 0.01% amplitude instability of closed-loop drive, and integrated transimpedance amplifier on chip has capacitive resolution of 1 aF/sqrt（Hz）. The chip is fabricated in the 2 μm two-metal and two-poly n-well CMOS process with an area of 18.9 mm^2. The complete module operates from ± 9 V supply and has a measured sensitivity of 10 mV/（ °）/s with bias instability is 190 （ °）/h. Test results show that the proposed approach can be applied to closed-loop drive of micro-mechanical angular rate sensor without adjusting circuits phase in atmospheric package （ Q is 80）.

关 键 词：角速率传感器 寄生电容 跨阻放大器 专用集成电路 

分 类 号：TH824[机械工程—仪器科学与技术]