Patent ID: 7129876

Claim:
A digital-analog converter, comprising: a counter that performs a counting operation responsive to an externally provided clock; a comparator that compares a count value of the counter with a value of input digital data, wherein the comparator outputs the clock until the count value of the counter and the input digital data value match each other; a capacitor that charges and discharges responsive to a constant current supply; a switch that turns a connection between the constant current supply and the capacitor on and off responsive to the clock output from the comparator; an oversampling circuit that oversamples the input digital data, wherein the comparator compares the count value of the counter with the value of the oversample data generated by the oversampling circuit, and outputs the clock until the count value and the oversample data value match each other; wherein the oversampling circuit comprises a circuit that performs a moving arithmetic average or a convolutional arithmetic operation on data of a basic waveform having an amplitude depending on values of n pieces of input discrete data.