摘要 |
PURPOSE:To accelerate a response and to shorten a pull-in time by uniquely determining pull-in operation at the occurance of pull-out in a phase synchronizing circuit. CONSTITUTION:A synchronism detector 5 detects a synchronous state or not from the frequency of an output signal from a phase comparator 1 and opens/ closes a switch 6 in accordance with a detected result so that the switch 6 is closed and an active filter 2 acts as a proportional circuit at the time of pull-out, and at the time of pull-in, the switch 6 is opened and the filter 2 is returned to an integration circuit. |