改进的电容式微加速度计中电路噪声模型  

An improved circuit noise model in a capacitive micromachined accelerometer

作　　者：刘云涛[1] 王颖[1] 邵雷[1] 

机构地区：[1]哈尔滨工程大学信息与通信工程学院,黑龙江哈尔滨150001

出　　处：《哈尔滨工程大学学报》2012年第4期522-527,共6页Journal of Harbin Engineering University

基　　金：中央高校基本科研业务费专项基金资助项目(HEUCF110801)

摘　　要：为了在加速度传感器设计中准确预测系统电路噪声,优化电路设计参数,建立了改进的电容式微加速度计中的电路噪声模型.详细分析了电荷积分器中的运算放大器噪声、开关热噪声、驱动信号参考电压、寄生电容电阻对系统噪声的影响,分析了相关双采样对热噪声和1/f噪声的影响,建立了微加速度计系统的输入参考噪声公式,所建立的电路噪声模型对各个电路噪声源进行综合考虑,没有忽略噪声源间的相互影响.仿真和测试结果表明:所建立的电路噪声模型能够准确的预测噪声水平,且开关热噪声在高精度微加速度计中严重影响着系统噪声水平.In order to predict noise performance of a capacitive micromachined accelerometer as well as optimize parameters of circuits,an improved circuit noise model was established.The influences of the operational amplifier noise in the charge integrator,switch thermal noise,reference voltage of driving signals,parasitic capacitance,and dead resistance on the noise performance of the system were analyzed.The effect of correlated double sampling（CDS） on the thermal noise and 1/f noise was analyzed.An input reference noise model for a micromachined accelerometer was established,in which interaction among noise sources was considered.Simulated and tested results indicate that the noise model can predict noise level exactly,and the switch thermal noise plays an important role in high accuracy accelerometers.

关 键 词：电容式微加速度计 电路噪声模型 电荷积分器 

分 类 号：TP824[自动化与计算机技术—检测技术与自动化装置]