Signal recovery circuit, optical module, and signal recovery method

Abstract

A signal recovery circuit includes, a voltage controlled oscillator that generate a clock signal, a phase frequency comparison circuit that compares phases of the clock signal and an received input signal and compares frequencies of the clock signal and the received input signal, a voltage adjustment circuit that adjusts the phase of the clock signal by adjusting control voltage of the voltage controlled oscillator based on an output of the phase frequency comparison circuit, and a control circuit that acquires an amplitude of the received input signal, detects continuation of the same sign in the received input signal based on the acquired amplitude, stops an adjustment of the phase of the clock signal generated by the voltage controlled oscillator when the continuation of the same sign is detected, and executes adjustment of the phase of the clock signal when the continuation of the same sign is stopped.