Patent ID: 7907072

Claim:
A digital-to-analog converter for generating an output current corresponding to a digital code, the digital-to-analog converter comprising: a current supply transistor that generates current having a predetermined current value; and a DAC unit, connected to the current supply transistor, that receives the current generated by the current supply transistor, with the DAC unit including: a plurality of first control transistors connected in parallel to each other, in which each of the plurality of first control transistors is connected in series to the current supply transistor, and the plurality of first control transistors drive currents having different current values in response to a single bias voltage; and a plurality of second control transistors connected in parallel to each other, in which each of the plurality of second control transistors being connected in series to the current supply transistor and driving current having a current value that is the same as one of the plurality of first control transistors in response to the single bias voltage; wherein the first and second control transistors that drive the currents having the same current value operate in a complementary manner based on part of the digital code, and the DAC unit generates the output current by selectively combining at least one of the currents driven by the plurality of first control transistors, and further comprising a current adjustment transistor connected in series between the current supply transistor and ground to retrieve some of the current flowing to the current supply transistor and adjust the amount of output current of the DAC unit.