Phase synchronizer and data reproducing apparatus

摘要

A phase synchronizer is disclosed that provides a stable output signal while improving synchronization speed. The phase synchronizer includes one or two feedback circuits. The feedback circuit(s) includes a phase comparator for generating a pulse signal in accordance with a difference between the phases of an input signal and a feedback signal, a charge pump for converting the pulse signal supplied from the phase comparator to an analog voltage signal, a loop filter for removing high-frequency signal components from the analog voltage signal output from the charge pump and supplying as a filtered analog voltage signal (LF1 or LF2), and a voltage-controlled oscillator coupled to the loop filter for generating an oscillation output signal having a frequency which varies in accordance with the filtered analog signal (LF1 or LF2). The oscillation output signal is also supplied as the feedback signal to the phase comparator.