OPTICAL BURST SIGNAL RECEIVING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To realize high sensitivity and a wide dynamic range without using a special level detecting circuit.

SOLUTION: An automatic threshold control circuit 9 detects the peak value of an electric burst signal to be output from an APD 1. A reference voltage of an AGC circuit 5 is set on the basis of the peak value, a voltage switching signal generating circuit 10 is controlled to control an APD bias voltage of an APD driving circuit 2. If the peak value is higher than a threshold value previously set in the voltage switching signal generating circuit 10, the APD bias voltage of the APD driving circuit 2 is switched to a low voltage so that the peak value becomes lower than the threshold value.

COPYRIGHT: (C)2008,JPO&INPIT