PURPOSE: To adjust optionally a start time location of a generated pulse by providing a means instructing the width of an input pulse to be modulated, a count means for a clock signal, a means comparing outputs of both the said means and a means generating a pulse having a pulse width corresponding to the result of comparison.

CONSTITUTION: The titled modulator differs from a conventional modulator in that input code information K as an initial value or a preset value is preset or loaded to a counter 900 via a latch circuit 88 by using a signal (g) as a load signal. The counter 900 is constituted as a ring counter and the value at count start is preset, then an output (i) with different timewise position of pulse generation is obtained in response to the output L of the latch circuit 88 even when the content of the code signal A indicating the pulse width to be modulated is the same and the pulse width is the same. Finally, a pulse whose pulse width varies with the timewise center position as the reference and a pulse whose pulse width varies gradually from the timewidth start position of the pulse width are obtained depending on the combination of the code signal A and the output L.