传统的光电二极管放大器采用FET输入运算放大器将来自光电二极管的小电流转换成单端电压,如图1所示。这种电路的一个主要缺点是,如果地噪声较大,则会破坏以地电压为基准的输出电压。通过将光电二极管电流转换成差分电压而非单端电压,我们可以利用差分信号更高的抗扰度和更高的动态范围,同时还可更加轻松地与现代高性能差分ADC接口。图2所示电路采用ADA6617低输入电流JFET运算放大器和 The traditional photodiode amplifier uses a FET input op amp to convert the small current from the photodiode into a single-ended voltage, as shown in Figure 1. A major disadvantage of this type of circuit is that if the ground noise is large, the output voltage based on the ground voltage is destroyed. By converting the photodiode current to a differential voltage instead of a single-ended voltage, we can take advantage of the higher immunity and higher dynamic range of the differential signal while making it easier to interface with modern high-performance differential ADCs. The circuit shown in Figure 2 uses the ADA6617 low input current JFET op amp and