Phase detection circuit, resolver/digital converter using the circuit, method performing digital conversion of an analog signal, and control system using the converter

摘要

A small-sized and low-cost phase detection circuit (500) which has improved noise immunity. The phase detection circuit (500) comprises a multiplier (510) for multiplying an input signal by a reference signal (546) and outputting a first signal, an integration circuit (520) for integrating the first signal and outputting a second signal, a phase estimation circuit (530) for estimating phase information based on the second signal, and a reference signal generation circuit (540) for generating the reference signal based on the estimated phase information. Since the phase is detected based on information representing an entire waveform, the influence of local noise can be diluted and noise immunity can be improved.