电容式微机械陀螺接口电路噪声分析  

Noise analysis of the interface circuit of capacitive microgyroscope

作　　者：蒋庆华[1] 苑伟政[2] 谢建兵[2] 

机构地区：[1]中国空空导弹研究院,洛阳410079 [2]西北工业大学微/纳米系统实验室,西安710072

出　　处：《电子测量技术》2012年第5期25-28,共4页Electronic Measurement Technology

摘　　要：电容式微机械陀螺接口电路的噪声抑制特性直接影响了其关键性能指标,是微机械陀螺研究的重点。基于电荷放大器为前置放大电路的微机械陀螺接口电路为研究对象,建立了包含运放输入电容、输入电阻、噪声电流、噪声电压、反馈电阻噪声、寄生电容在内的电荷放大器电容分辨率的模型,提出了通过增大载波电压、选择低噪声电压和噪声电流运放、增大反馈电阻提高分辨率的方法。采用厚膜电路实现的电荷放大器进行了实验,结果表明电荷放大器的输出噪声和理论计算值处于同一数量级,电容分辨率可以到达10-19 F。The noise characters of the interface circuit are the key factor of the performance of microgyroscopes. In this paper, the interface circuit based on the charge amplifier circuit was analyzed the model of the capacitance resolution of the charge amplifier,which includes noise of non-ideal operational amplifier and the noise of feedback resistor,was built. The influence of all noise sources on circuit at different frequency was analyzed. Choosing operational amplifier with low noise voltage and noise current, increasing the operation frequency, the performance of circuit can get better. The experiment showed the prototype circuit can get the theoretical level.

关 键 词：微机电系统 接口电路 噪声分析 微机械陀螺 

分 类 号：TH7[机械工程—仪器科学与技术] V241.5[机械工程—精密仪器及机械]