【摘要】 为了检测物质吸光度微弱信号,根据ICL7650芯片特点,研究了仪用放大器的设计原理,设计出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,电路增益、幅频特性达到高稳定度设计要求。通过实际硬件电路长时间通电测试,电路信噪比满足高精度设计要求,ΔAυ%<1%。将前置电路应用于流动注射分析仪,满足仪器高精度、高稳定度要求。更多还原

【Abstract】 To detect the weak signal of material absorbance,according to the characteristics of ICL7650 chip,the instrumentation amplifier design principle is researched,and a weak signal amplification circuit is designed.By software simulation of multisim 8,the circuit’s gain and amplitude-frequency characteristic achieve the high-stability design demand.By lengthy electricity test of hardware circuit,the circuit’s signal-to-noise achieves the high-precision design demand and ΔAυ%<1%.The pre-amplification circuit is used in the flow injection analyzer and satisfies the instrument’s high-precision and high-stability demand.更多还原