【摘要】 针对640×512 InGaAs探测器工作原理和输出信号特点,从低噪声角度出发,设计了由探测器驱动电路、信号缓冲电路、单端转差分电路、差分放大电路、模数转换电路、FPGA时序控制电路构成的InGaAs探测器低噪声采集系统。着重解决了在满足驱动的条件下降低系统噪声,对提供精密偏置电压、温控电路和输出信号处理过程给出了详细的设计思想和实现方法。试验结果表明,系统工作正常并获得了良好的噪声特性,整个采集系统暗电平等效均方根(RMS)噪声低于0.3 mV。更多还原

【Abstract】 According to the working principle and characteristics of 640×512 InGaAs detector,a description of signal processing design procedure on the principle of low noise is given.It consists of detector-drived circuit,signal cushion circuit,single-ended to differential circuit and differential amplifying circuit,differential input analog to digital converting circuit and FPGA digital data processing circuit.It focuses on the problem how to reduce noise under the circumstance of guarantee ability of drive load.A detailed design idea is provided on how to offer precise DC offset voltage,temperature-controlled circuit and the output signal processing.The experiments result demonstrates the system works well and has a comparably good noise characteristic.The RMS noise of the acquisition system is less than 0.3 mV.更多还原