PURPOSE: To attain the high path driving force and at the same time to decrease the noises regardless of the temperature and the power voltage.

CONSTITUTION: The phase comparators 21c and 22c control the variable frequency oscillators 21b and 22b so as to secure the equal phase differences among the signals outputted from the reference oscillators 21a and 22a forming the PLL control circuits 21 and 22 and the signals outputted from the oscillators 21b and 22b. The resistance which decides the oscillation frequencies of both oscillators 21a and 22a is set at the ideal ON resistance values of the output transistors TR 25 and 26. The sizes of the TRs forming the circuits 21 and 22 are proportional to the sizes of the TR 25 and 26. Thus it is possible to attain the high path driving force and to decrease the noises regardless of the temperature and the power voltage by supplying the voltage outputted from both comparators 21c and 22c to both TR 25 and 26 via the drive control circuits 23 ant 24.