基于跨阻放大器的动态微弱电容检测电路  

Micro Capacitance Detection Circuit Based on Transimpedance Amplifier

作　　者：穆林枫 张文栋[1,2] 何常德[1,2] 薛晨阳[1,2] 

机构地区：[1]中北大学电子测试国家重点实验室,山西太原030051 [2]中北大学仪器科学与动态测试教育部重点实验室,山西太原030051

出　　处：《测试技术学报》2015年第1期31-35,共5页Journal of Test and Measurement Technology

基　　金：国家863计划资助项目(2011AA040404);国家自然科学基金资助项目(61127008)

摘　　要：基于MEMS技术的微电容超声传感器(CMUT),因具有易制造、易阵列化、噪声低、稳定性好以及批量化生产等众多优点,成为未来高频超声传感器发展的主要方向.本文介绍了微电容超声传感器的工作原理,提出了跨阻放大器检测电路,它能将电容信号转换为相应的电压信号(C/V转换),再通过放大、滤波得出电容的变化量.该电路能很好地抑制杂散电容的影响,有很好的线性和稳定性,在400kHz的超声波作用下的灵敏度为1.64mV/fF,基本满足对超声传感器电容变化量的检测.The Capacitance Micro-machined Ultrasonic Transducers （CMUT）based on MEMS has de-veloped,which has been the main direction for the research of high frequency because of the advantages of easily fabricated,suitable for manufacturing array,low noise,well performed in stability and mass production.The operating principle of CMUT is introduced in this paper.The transimpedance amplifier capacitance detection circuit is presented,which can convert the capacitance changes into voltage signals. Through the later magnify and filter,capacitance changes can be detected.The circuit can restrain the influence of stray capacity,and the linearity and stability of the circuit are good.The sensitivity is 1.64 mV/fF under the ultrasonic wave of 400 kHz,and basically meets the needs of capacitance detec-tion.

关 键 词：CMUT 跨阻放大器 检测电路 杂散电容 灵敏度 

分 类 号：TN707[电子电信—电路与系统]