Data driver and driving method of organic light emitting display device using the same

An organic light emitting display device comprising:

• a display region including a plurality of pixels connected to a plurality of scan lines and a plurality of data lines;
• a scan driver for driving the scan lines;
• and
• a data driver for driving the data lines,
• wherein the data driver comprises:
• a first digital-analog converter including a plurality of first switches, the first digital-analog converter being adapted to select two reference voltages from among a plurality of reference voltages by turning on two of the first switches corresponding to high level bits of data;
• and
• a second digital-analog converter including a transistor turned on by a bias voltage with a voltage level to compensate for a turn-on resistance of the two of the first switches, a plurality of voltage division resistors for dividing the two reference voltages into a plurality of voltages, and a plurality of second switches for supplying any one of the two reference voltages and the divided voltages corresponding to low level bits of the data as a data signal to an output terminal.

A driving method of an organic light emitting display device, the method comprising:

• supplying a plurality of reference voltages to a first digital-analog converter;
• selecting two reference voltages from among the plurality of reference voltages by turning on two of a plurality of first switches included in the first digital-analog converter corresponding to high level bits of data,
• compensating for a turn-on resistance of the two of the first switches using a bias voltage level of a transistor included in a second digital-analog converter,
• dividing the two reference voltages using a plurality of voltage division resistors included in the second digital-analog converter, and
• supplying any one of the two reference voltages and the divided voltages as a data signal to an output terminal of the second digital-analog converter.