D-A CONVERTER

摘要

A D-A converter for converting a digital signal to a duty factor of a pulse train signal and averaging the pulse signal by a low-pass filter to convert it to an analog signal is disclosed. A plurality of pulses which are to be selected in accordance with the input digital signal comprise a plurality of basic pulses of different phases and pulse widths derived by frequency division and auxiliary basic pulses which occur at a cycle period which is at least twice as long as a repetition cycle period of the basic pulses, and the basic pulses are selected by high order signals of the digital signal while the auxiliary basic pulses are selected by low order digit signals of said digital signal to produce an output pulse train signal a duty factor of which changes in accordance with the digital signal. The pulse train signal is then averaged to convert it to an analog signal.