新型低噪声微机械陀螺闭环驱动电路  

New low noise closed-loop driving circuit for the micro-gyroscope

作　　者：孙明[1] 谭晓昀[1] 李子芃[1] 刘晓为[1,2] 

机构地区：[1]哈尔滨工业大学MEMS中心,哈尔滨150001 [2]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9期38-41,共4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：为将陀螺结构引入到闭环驱动电路的仿真系统中,建立了与微机械陀螺结构等价的电学模型.微机械陀螺闭环驱动电路基于电荷泵锁相环技术,用低噪声跨阻放大器代替传统的电荷放大器实现I-V转换,有效避免了电荷放大器在实现I-V转换时所产生的随陀螺固有频率变化而变化的相位误差.用基于CCCII+技术的有源电阻代替无源电阻,大大降低了电路的噪声,并且提高了电路的集成度.仿真结果表明,微机械陀螺结构的固有频率为2.7 kHz,陀螺结构在驱动方向位移的相位滞后于驱动方向驱动力相位90°;在50μA的偏置电流下,有源电阻阻值为250 kΩ,在工作频率下的噪声为0.037 fV2/Hz,大大低于无源电阻的噪声.闭环接口电路实现了在陀螺固有频率下的自激振荡.To bring the fabric of the micro-gyroscope into simulation of total closed-loop system,the equivalent electrical analogue of drive part of the micro-gyroscope is built.The new low noise closed-loop driving circuit is based on the phase-locked technology using the transimpedance amplifier to realize I-V transformation which effectively avoids phase error caused by the charge amplifier.By using the CCCII＋technology to realize the floating resistor,the noise of the total closed-loop driving circuit is reduced.In simulation,the natural frequency of the micro-gyroscope is 2.7 kHz.The displacement in the drive direction of the micro-gyroscope has 90°phase leg comparing to the driving force in the drive direction.The value of floating resistor is 250 kΩ where the bias current is 50 μA.The active resistor is 0.037 fV2/Hz.The micro-gyroscope is vibrated at its natural frequency.

关 键 词：闭环驱动电路 微机械陀螺 CCCII+ 

分 类 号：TN432[电子电信—微电子学与固体电子学]