摘要
本文对采用光电二极管的荧光信号接收电路的工作模式和噪声进行了分析。并论述了输入失调和暗电流的补偿方法,深入讨论了反馈电阻RF及补偿电容CF的防泄漏措施、输入管脚的“护卫(guarding)”与隔离技术、输入管脚的悬置引出技术、PCB板的清洁和隔离涂敷、屏蔽和滤波等技术。使所设计的接收电路获得较高的信噪比(SNR)。
This paper analyzed the working mode and noise causation in fluorescent signals detecting circuits by using photodiode. The compensating techniques of input offset and diode＇ s dark current are discussed. The methods for holding back leakage on the feedback resistor RF and compensating capacitance CF, the techniques for guarding and insulating input pin, the technique for input pin suspending connecting, cleaning and insulating coating of PCB board, the techniques for shielding and filtering are researched in detail. The designed detecting circuit＇ s SNR is increased.
出处
《生命科学仪器》
2007年第4期46-50,共5页
Life Science Instruments
