DUTY VARIABLE PULSE WAVE GENERATOR

PURPOSE:To provide a pulse wave generator capable of highly, accurately and continuously varying the duty of pulse waves by outputting the pulses of the duty related to duty data from a comparator. CONSTITUTION:A phase computing element 10 generates digital data which increase by a prescribed amount in synchronism with clocks and pulses are generated at the head of a waveform cycle based on the most significant bit MSB of the digital data in a pulse generation part 80. Then, when the pulses are generated, the duty data set beforehand are latched to an FF 100. The comparator 110 outputs the pulses to be an H level when the output of the computing element 10 is smaller than the duty data and be an L level in an opposite case. The output pulses are of the duty corresponding to the duty data and the duty of the output pulses of the comparator 110 is continuously changed when the duty data are changed. Thus, the duty of the pulse waves is highly accurately and continuously varied.