摘要 |
In an optical signal receiver circuit in which a PIN diode draws current through a load resistor RL of a value dependent upon the level of a received optical signal, a zener diode Z is connected to limit the sum of the voltages developed across the PIN diode and the load resistor so as to reduce the bias voltage available for the PIN diode, and thereby its sensitivity, if received optical signals exceed a given level. <IMAGE> |