OPTICAL RECEPTION MODULE AND METHOD FOR OUTPUTTING INPUT DISCONNECTION SIGNAL

摘要

PROBLEM TO BE SOLVED: To provide an optical reception module which transmits LOS with desired intensity of an optical input signal according to extinction ratio of the optical input signal, and to provide a method for outputting an input disconnection signal.

SOLUTION: The optical reception module 1 includes: a photodiode 3 which converts a received optical signal into a current signal and outputs it; a current-voltage conversion part 7 which converts the current signal into a voltage signal; an average voltage detection circuit 13 which detects the average voltage of the voltage signal; a TIA 21 which converts the current signal into a positive-phase voltage signal and a reverse-phase voltage signal; a voltage amplitude detection circuit 33 which detects voltage amplitude of the positive-phase voltage signal and the reverse-phase voltage signal; a comparator circuit 17 which outputs a first signal showing disconnection of input of the optical signal on the basis of the average voltage and a first reference voltage; and a comparator circuit 37 which outputs a second signal showing disconnection of input of the optical signal on the basis of the voltage amplitude and a second reference voltage, wherein the optical reception module corrects the first reference voltage and the second reference voltage according to the extinction ratio of the optical signal.

COPYRIGHT: (C)2011,JPO&INPIT