A display apparatus including a display driver. The data driver includes a converter to receive and convert image data in digital form into data voltages in analog form, and to provide the data voltages to output buffers. The output buffers receive and buffer the data voltages based on bias voltages generated as part of a feedback path between a bias voltage control circuit and the output buffers. The data voltages are provided to a display part. Before the data voltages output from the output buffers are provided to the display part, the bias voltage control part receives data voltage from the output buffers to count a slew rate of the data voltage, and varies the voltage level of the bias voltage based on the counted result of the slew rate, thereby providing feedback to the output buffers. Accordingly, differences of the slew rate between the data voltages output from the output buffers may be decreased.