A simple DA converter circuit which reads in digital voltage value data
and outputs analog current value data is provided. The DA converter
circuit according to the invention can be applied, for example, to a data
driver circuit of an AM-OLED display device. The DA converter circuit
comprises a current output circuit comprising a plurality of drive
transistors. Gate electrodes of the transistors are electrically
connected to each other, and a switch is provided between the gate
electrode and drain electrode of each drive transistor.