植物电信号前置放大电路的设计与仿真

Design and simulation of pre-amplification circuit for plant electrical signals

研究表明,植物电信号的幅度在μV级,为了检测如此微弱的电信号,前置级放大电路是最关键的环节,其设计优劣直接关系到植物电信号数据采集系统的精度。本文根据ICL7650芯片的特点及仪用放大器的设计原理,设计了一种微弱信号放大电路并详细阐述了其工作原理,经过multisim8软件仿真和测试,其增益、幅频特性、信噪比等性能指标都能达到设计的要求。该电路结构简单,调试方便,对直流、低频微弱电信号放大都具有一定的参考使用价值。

Some studies indicated that the plant electric signals scope locates in μⅤ level. In order to examine the weak electrical signal,the pre-amplification circuit is the most important link. Whether the design is excellent or inferior is related to the electrical signal detection system of plant directly. In this paper, one kind of weak signal pre-amplification circuit is designed and its principle of work is elaborated according to the ICL7650 chip characteristic and operational amplifier principle. The Multisim 8 simulation and testing results indicate that the circuit＇s performance indexes, which include gain,amplitude-frequency characteristic, signal-to-noise and so on, achieve the design demand. This circuit has the advantages of simple structure, convenient debugging, and has certain reference use value for directs current, and the low frequency weak electrical signal amplification.