| 摘要 |
PURPOSE:To improve the synchronizing frequency range and the synchronizing time by counting lead information and lag information being phase difference information, counting them for a prescribed time respectively, obtaining the ratio of respective counts, changing the pulse insertion or elimination depending on the ratio as on or plural changes. CONSTITUTION:Number of pulses of pulse insertion/elimination is changed to a signal of a fixed oscillator 26 fed to a terminal 24 of a pulse insertion/ elimination circuit 23 depending on kinds of a control signal and the result is outputted from a terminal 25. The signal from the terminal 25 is fed to a frequency divider 28 through a terminal 27. The frequency division ratio R of the frequency divider is represented as R=f0/fi, where f0 is a frequency of the fixed oscillator outputted at the terminal 24 and fi is a frequency of the input signal to a terminal 1 of a digital phase synchronizing circuit. Thus, an output signal from a terminal 29 of the frequency divider 28 is fed to a terminal 6 of a phase comparator 3 to obtain the phase synchronization. Thus, the synchronization output is obtained from a terminal 30 connected to an output terminal 29 of the frequency divider 28. |
