| 摘要 |
PROBLEM TO BE SOLVED: To improve stability at the time of reference signal interrupt by outputting the center frequency voltage of output characteristics corresponding to the characteristics of a loop filter activated by input interrupt detection signals for detecting input interrupt and inputting the output signals of the loop filter and the control voltage of a center frequency voltage output part to a voltage controlled oscillator at the time of the input interrupt of reference signals. SOLUTION: In reference signal interrupt, the detection output of the reference signal interrupt by an input detection part 4 makes the center frequency voltage output part 5 operates, and when the output signal of a phase comparator 2 is a minimum value, the control voltage to be the output signal of a set center frequency by the rising characteristic of the characteristic opposite to the falling characteristic of the output signal of the loop filter 3 is outputted. Also, when the output signal of the phase comparator 2 becomes a maximum value, the control voltage for turning a difference with the output signal of the loop filter 3 to the output signal of the set frequency by the same rising characteristic as the rising characteristic of the output signal of the loop filter 3 is added to the voltage controlled oscillator 1, and step-out is prevented. |
