Bit rate discrimination device with temperature compensation function

摘要

A bit rate discrimination device accurately discriminates a bit rate regardless of variations in the operating temperature. A photoelectric converter converts an input optical signal to an electric signal, and a bit rate detector detects a bit rate of the optical signal from the electric signal and outputs a discrimination signal indicating the bit rate. A DC amplifier outputs a bit rate detection signal by amplifying the discrimination signal, and a temperature detector detects an operating temperature of the DC amplifier and outputs a temperature signal indicating the detected operating temperature. A variation amplifier outputs a temperature compensation signal by amplifying a voltage level difference between the temperature signal and a predetermined reference signal, so as to cancel variations in an output voltage of the DC amplifier according to the operating temperature. A voltage adder outputs a temperature-compensated bit rate detection signal by combining the bit rate detection signal with the temperature compensation signal. A bit rate discriminator determines a bit rate of the input optical signal depending on a voltage level of the temperature-compensated bit rate detection signal.