微弱信号检测的前置放大电路设计

The design of preamplifier circuit based on weak signal detection

针对精准农业中对微弱信号检测的技术需求,论文设计了以电流电压转换器,仪表放大器和低通滤波器为主要结构的微弱信号检测前置放大电路。结合微弱信号的特点讨论了电路中噪声的抑制和隔离,提出了电路元件的选择方法与电路设计中降低噪声干扰的注意事项。本文利用集成程控增益仪表放大器PGA202设计了微弱信号检测前置放大电路,并利用微弱低频信号进行了测试,得到了理想的效果。

Combined with the demand of the detection of weak signal in precision agriculture, the article introduced the circuit principle of deigning preamplifier circuit whit I/V Conversion level, instrumentation amplifier level and low-pass filter level. At the same time the article discussed the circuit＇s noise suppression and isolation according to the characteristics of the weak signal, and gave the method of choosing elements and noise reduction. Finally, gave the design of the weak signal detection pre-amplifier using the program-controlled integrated instrumentation amplifier PGA202.