Because of the increased degree of automation， all production processes are concentrated control or detection， measurement instruments and measured the distance between distant objects， environmental conditions more In particular， the measured signal is weak and is buried in the noise of how the weak signal was detected more and more people's Weak signal detection is an emerging technology disciplines， cover the application of optical， electrical， magnetic， acoustic， thermal， biological， mechanical， geological， environmental， medical， laser， materials， and other Its equipment has become indispensable to modern scientific Weak signal detection is the purpose of extracting useful from the noise signal， or use some new technologies and new ways to improve the detection system output signal a letter impatient than the paper first to understand the weak signal detection technology development on the basis of the status quo， have weak signal detection technology The basic principle， the weak signal conditioning for the detailed The design chosen photoelectric detector to weak-signal acquisition， preamplifier Yun-partly because of bandwidth limitations and gain the request， using two Selection of low noise， high-bandwidth OPA380 transported to the first-class signal amplification， Wan Fang LM358 completed two to In this paper， the design of second-order Chebyshev low pass filter to enlarge active after the signal filtering， signal filtering， with a voltage signal for increased drive In weak signal processing circuit design， the layout of the circuit boards for the detailed design， to reduce leakage current in the
