可变增益放大器在脉冲振幅调制式藻类光合活性荧光测量中的应用  

Variable Gain Amplifier Used in Fluorescence Signal Detection of Chlorophyll Activity Based on Pulse Amplitude Modulation

作　　者：刘晶[1,2] 刘文清[1] 张玉钧[1] 赵南京[1] 殷高方[1] 钟留勇[1] 段静波[1] 凌六一[1] 

机构地区：[1]中国科学院安徽光学精密机械研究所,安徽合肥230031 [2]中国科学技术大学地球与空间学院,安徽合肥230026

出　　处：《光学与光电技术》2011年第5期48-51,共4页Optics & Optoelectronic Technology

摘　　要：微弱信号探测中信号幅度很宽会导致幅度小的信号分辨率低,结合脉冲振幅调制叶绿素光合活性荧光仪中不同强度光源激发下光电倍增管光电流响应,采用多路选择开关D5201G芯片选择I/V转换电路中不同阻值的反馈电阻实现了对输入信号可变增益放大。0～118mV以下输入信号的理论增益值最高可达28.25dB,同时输入信号的电压幅值最高可达11.11V。Detection of weak signals is often encountered in greate range of amplitude, so it would lead to small signal low resolution. Pulse amplitude modulated chlorophyll fluorescence in photosynthetic activity of different intensity excitation light photocurrent response by photomultiplier tube is intnoduced in this paper. Multiple selector switch D5201G chip and HC 374 are used to select different values of feedback resistor in I/V conversion which work as a variable gain amplifier. The theo- retical gain of input signal under 0-118 mV is up to 28. 25 dB, while the input signal amplitude would be up to 11.11 V.

关 键 词：可变增益 信号探测 叶绿素荧光 

分 类 号：TN274[电子电信—物理电子学]