A data driving circuit including: a voltage digital-analog converter adapted to generate a first gradation voltage corresponding to external data; a current digital-analog converter adapted to generate a gradation current corresponding to the external data; a voltage control unit adapted to receive a feedback pixel current from a pixel via a data line and to generate a second gradation voltage by increasing or decreasing a level of the first gradation voltage in accordance with the feedback pixel current; a buffer unit adapted to selectively supply the first or second gradation voltage to the data line; and a selection unit adapted to selectively connect the data line to either the buffer unit or the voltage control unit. With this configuration, an image is displayed with a desired brightness.