| 摘要 |
PURPOSE:To widen a tracking range, to shorten the pulling-in time and to reduce the jitter quantity of a regenerative signal by detecting a phase difference by using a shift register and when the phase difference exceeds a certain range by controlling the frequency division for converging the phase difference quickly. CONSTITUTION:Phase comparison is executed for a basic (reception) signal and internal extraction signal by using a shift register 11, the phase difference is detected by the content of shift register 11, and when the phase difference is in a predetermined range, a frequency divider selects one of 1/(M-1), 1/M, and 1/(M+1) once in a sampling cycle, and when the phase difference is out of a predetermined range, a particular frequency dividing whose converging time is short is executed to output an internal extraction signal. Thus, the pulling-in time when a phase difference is large, that is, after inputting a reset signal or the like is shortened, thereby obtaining a stable internal extraction signal. |
