PURPOSE: To obtain a time base signal having a prescribed frequency out of the 2nd frequency division circuit, by providing the 2nd frequency division circuit operated with an inverted frequency dividing ratio to the frequency dividing ratio, in addition to a variable frequency division circuit inputting selectively plural reference signals to a phase comparator.

CONSTITUTION: An output(90kHz) of a fixed frequency division circuit 16 is frequency-divided by the 1st variable frequency division circuit 17a to 1/9 or 1/10, furthermore, frequency-divided to 1/2 at a fixed frequency divider 17b. An output of a multiplexer 17c is applied to the phase comparator as a reference frequency signal. The switching of the frequency dividing ratio of the frequency division circuit 17a and the selection of the multiplexer 17c are performed with a control signal from a switching circuit 19. The output of the frequency division circuit 17a is frequency-divided at the 2nd variable frequency division circuit 18a. The frequency dividing ratio of the frequency division circuit 18a is set inversely to that of the frequency division circuit 17a.