光电二极管可分为二类：一类为大面积光电二极管，具有高电容(30pF至3000pF)；另一类是小面积光电二极管，具有相对小的电容(小于10pF)。为提高信噪比，具有反相运算放大器和反馈电阻的跨阻放大器常用于将光电二极管的电流转换为电压。在低噪声放大器设计中，大面积光电二极管放大器需要关注减小运算放大器的输入电压噪声，而小面积光电二极管放大器则更多地关注于减少运算放大器的输入电流噪声和寄生电容。 advertisement
Low Noise Ampliers for Small and Large Area Photodiodes
Design Note 399
Glen Brisebois
Introduction
Photodiodes can be broken into two categories: large er consists of CDM (the amplier’s differential mode
area photodiodes with their attendant high capacitance capacitance) and one CCM (the common mode capacitance
(30pF to 3000pF) and smaller area photodiodes with at the amplier’s - input only), or about 6pF total. The
relatively low capacitance (10pF or less). For optimal small photodiode has 1.8pF, so the input capacitance of
signal-to-noise performance, a transimpedance amplier the amplier is ……
