| 摘要 |
PROBLEM TO BE SOLVED: To effectively suppress the sudden fluctuation of a control signal to a control oscillator against a sudden phase fluctuation of an input signal and to relieve the rapid fluctuation of of a phase or a frequency in an output signal of a control oscillator. SOLUTION: A voltage supervisory circuit 17 supervises an output voltage of a 1st phase comparator 11 and supplies a signal that corresponds to the fluctuation of the output voltage of the comparator 11 to a phase comparator control circuit 18. The circuit 18 controls a 2nd phase comparator 12 so that a control signal of a voltage control oscillator 16 may not overshoot when a large input phase fluctuation occurs in the comparator 11 based on a signal that is given from the circuit 17. |
