压电MEMS振动传感器调理电路设计与实现

Design and Implementation of Conditioning Circuit for Piezoelectric MEMS Vibration Sensor

针对铌酸锂单晶薄膜的压电MEMS振动传感器输出电荷信号微弱而难以采集的问题,设计了一种基于集成运放芯片TLE 2064 CDR的信号调理电路。该电路由电荷-电压转换电路(Q-V)、电压放大电路、前置低通滤波电路和后置高通滤波电路构成,旨在实现微弱信号的采集。此外,利用ACT 2000振动台进行振动实验,通过标准电荷放大器和设计的信号调理电路对压电MEMS振动传感器测试。测试结果表明,所设计的信号调理电路与标准电荷放大器的输出有较好的一致性,可以满足5~130 pC的宽输入电荷的采集。当加载加速度范围为5~20 g时,输出电荷和输入加速度之间的线性度好;在输入加速度5 g,工作频率范围为50~2000 Hz时,输出电荷偏差控制在±1.6 pC内,具有很好的一致性。综上所述,该电路具有集成度高,灵敏度好等特点,在微弱信号采集方面具有很好的应用前景。

A signal conditioning circuit based on TLE 2064 CDR is designed to solve the problem of the output charge signal of a piezoelectric MEMS vibration sensor with lithium niobate single crystal film being weak and difficult to collect.The circuit is composed of a charge-voltage conversion circuit(Q-V),a voltage amplification circuit,a pre-low-pass filter circuit and a post-high-pass filter circuit for the acquisition of weak signals.In addition,the piezoelectric MEMS vibration sensor is tested by the standard charge amplifier and the signal conditioning circuit designed in this paper.The test results show that the designed signal conditioning circuit has a good agreement with the output of the standard charge amplifier,and can meet the wide input charge acquisition from 5~130 pC.When the loading acceleration range is 5~20 g,the linearity between the output charge and the input acceleration is good.When the input acceleration is 5 g and the operating frequency range is 50~2000 Hz,the output charge deviation is controlled within±1.6 pC,which has a good consistency.In summary,the circuit has the characteristics of high integration and good sensitivity,and has a good application prospect in weak signal acquisition.