A data conversion device for synthesizing digital data composed of two or more components (of which each consists of a series of one-bit digital data) so as to output a single analog signal has: a switch circuit for selecting one of the components of the digital data at a time by dividing a predetermined period into intervals having predetermined lengths of time in accordance with a select signal; a timing generator for generating the select signal; a current feeding circuit for feeding a current that flows in one or another direction in accordance with the output of the switch circuit; and a current-to-voltage conversion circuit for converting the current into a voltage so as to produce an analog signal.