PURPOSE: To always keep the phase of an input/output signal to a prescribed relation by using an output of a phase coincidence detection circuit so as to change the load of a frequency division counter of a frequency divider.
CONSTITUTION: The frequency divider 5 generates a frequency being a common measure to an input signal frequency Fin and an output signal frequency Fout. The phase of a frequency being a common measure to a frequency from a frequency divider 6 obtained from an input signal and the phase of a frequency being a common measure to a frequency of the frequency divider 5 are compared by a phase coincidence detection circuit 9. An output signal of the phase coincidence detection circuit 9 changes a load value of the frequency division counter of the frequency divider 5 to approach the phase of the output signal to the phase to be stabilized and the phase of an input/output signal is matched accurately by a phase discrimination circuit 7.
OKINO TAKAYUKI
MORIMOTO AKIO
