| 摘要 |
PROBLEM TO BE SOLVED: To synchronize a video signal with an audio sampling period with high accuracy. SOLUTION: An analog phase comparator 44 compares a phase of a signal of a reference frequency with a phase of a signal from an unequal interval frequency divider 43 and a phase error signal is fed to a voltage controlled oscillator VCO 46 via an LPF 45. The VCO 46 generates a prescribed frequency (e.g. 24.576 MHz) corresponding to a signal from the LPF 45 and the signal is fed to a high accuracy frame counter 48, where the frequency is divided into 1/820020 at one cycle per 5 frames and into 1/820019 at four cycles per 5 frames, and the frequency-divided signals are fed to a digital phase comparator 41. The digital phase comparator 41 detects phase error data with a reference frame signal and the data are fed to a digital loop filter 42. |
