一种双运放差分输入型电荷放大器电路研究

Research on A Dual Operational Amplifier Differential Input Charge Amplifier Ciruit

分析电荷放大器电路模型及相关参数,指出了低阻抗压电传感器对通用电荷放大器可能带来的信号失真饱和问题,同时指出通用型电荷放大器多采用的单端输入方式无法对共模干扰信号进行抑制,在对测量精度与性能要求较高的应用场景下,电荷放大器存在以上问题将不能忽略。在考虑以上问题的基础上,设计了一种双运放差分输入电荷放大及滤波电路,对该电路进行了原理分析及功能仿真。分析和仿真结果表明,该电路结构对通用电荷放大器存在的失真饱和及单端输入方式下的共模干扰问题均具有很好的提高作用,结构简单,性能优越,具有较高的实用性。

Charge amplifier circuit model and related parameters are analyzed,the low impedance of piezoelectric sensor for saturated signal distortion of the problems of general charge amplifier is pointed out.At the same time the universal charge amplifier adopts the single-ended input method can't more for inhibiting common-mode interference signals is proposed.On the measuring accuracy and performance requirements of high application scenarios,the above problems of charge amplifier can not be ignored.On the basis of considering the above problems,we design a double op-amp differential input charge amplifier and filter circuit,analyzed the principle and function of the electric circuit simulation.Analysis and simulation results show that the circuit structure of general charge amplifier distortion existing in the saturated and single-ended input common-mode interference problem under the way have very good improve effect,simple structure,superior performance,it has high practicability.