一种改进型微弱电流低噪声放大应用电路
An improved weak current low noise amplifier application circuit
-
摘要: 针对微弱电流信号检测技术存在的背景噪声、电路噪声、元器件噪声等的干扰往往大于信号本身,从而影响测量结果准确性的问题,设计了一种微弱电流低噪声信号放大应用电路.该设计采用高精度、小阻值的反馈电阻和高性能运算放大器AD795对T型I/V转换电路进行改进,选用高性能分立元件搭建前置放大电路,进而基于调制-解调原理设计锁相放大电路.软件仿真结果表明,电路具有较强的噪声抑制能力和稳定性,可以满足各种传感器微弱信号的测量要求.Abstract: In order to solve the problem in weak current signal detection technology that the interference of background noise,circuit noise and component noise is stronger than signal itself,a weak current low noise amplifier application circuit was designed.The model improved T-type I/V conversion circuit by adopting high precision and small resistance value feed back resistance and high performance operational amplifier AD795,set up preamplifier circuit by high performance discrete elements and designed phrase-locked amplifier circuit based on modulation and demodulation principle.The simulation analysis showed that the circuit had higher noise suppression capability and stability and could meet the weak current measurement requirement of various sensors.
-
Key words:
- weak current /
- low noise /
- T-type I/V conversion /
- preamplifier /
- phase-locked amplifier
-
-
[1]
高晋占.微弱信号检测[M].2版.北京:清华大学出版社,2011:7-12.
-
[2]
刘鹏民,莫德举.T型反馈电阻网络在微弱信号放大电路中的应用[J].电测与仪表,2009,12(36):31.
-
[3]
李圣昆,郑永秋,安盼龙,等.T型反馈网络在谐振式光纤陀螺频率锁定中的应用[J].红外与激光工程,2014,43(4):1161.
-
[4]
张金利,景占荣,梁亮,等.微弱信号的调理电路设计和噪声分析[J].电子测量技术,2007,30(11):40.
-
[5]
侯跃新,周东亮,肖丹,等.传感器弱信号的放大应用电路[J].自动化技术与应用,2008,27(11):65.
-
[6]
姜利英,胡杰,陈青华,等.基于核酸适体传感器的便携式循环伏安测试系统[J].郑州轻工业学院学报:自然科学版,2014,29(2):38.
-
[1]
计量
- PDF下载量: 57
- 文章访问数: 1278
- 引证文献数: 0