Apparatus and method of controlling clock phase alignment with dual loop of hybrid phase and time domain for clock source synchronization

Abstract

An apparatus and a method of controlling clock phase alignment with a dual loop of a hybrid phase and time domain for clock source synchronization in electronic devices are described. The coarse calibration unit generates a plurality of output signals, the output signals having a plurality of phase intervals therebetween. A predetermined phase angle is divided by the number of the output signals to generate one of the phase intervals. The first fine calibration unit connected to the coarse calibration unit delays the output signals generated from the coarse calibration unit by coupling a programmable delay circuit to adjust the phase of a feedback signal toward the phase of a reference signal. The phase detector connected to the first fine calibration unit is used to detect a phase difference between the reference and the feedback signal and outputting an indicating signal corresponding to the phase difference between the reference and the feedback signal. The controller controls the coarse calibration unit and the first fine calibration unit to align the feedback signal to the reference signal according to the indicating signal generated from the phase detector.