Patent ID: 7068978

Claim:
A current cell type digital-to-analog converter comprising: a current cell matrix including a plurality of upper current cells and at least one lower current cell so as to form a matrix pattern, in which all of the current cells have the same number of constant current transistors connected in parallel, and the constant current transistors are the same size; an upper control circuit provided within each of the upper current cells for outputting currents of all the constant current transistors within the upper current cell when the upper current cell is selected; at least one lower control circuit provided within each of the at least one lower current cell for outputting only current of a predetermined number of constant current transistors within the lower current cell when the lower current cell is selected; a plurality of power supply lines respectively provided in rows of the current cell matrix so that each power supply line supplies currents to the constant current transistors provided in the upper current cell and the lower current cell provided in the corresponding row; an upper decoder for selecting none or at least one of the upper control circuits in accordance with predetermined one or more upper bits of a digital value; a lower decoder for selecting none or at least one of the lower control circuits in accordance with predetermined one or more lower bits of the digital value; and an analog output terminal for outputting a summation of output currents of the upper current cells and the at least one lower current cell.