A display device is disclosed. The device includes: a timing controller configured to derive data signals for a display panel from external signals; a date driver configured to derive data voltages from the data signals and apply the data voltage to data lines on the display panel; a gamma IC (integrated circuit) chip configured to apply gamma voltages to the data driver; a power supply IC chip configured to apply a most significant voltage to the data driver; a DAC (digital-to-analog converter) configured to receive the gamma voltages and the most significant voltage from the gamma IC chip and the power supply IC chip and generate the data voltages opposite to the data signals; and a power supply unit configured to convert the gamma voltages and the most significant voltage using the data signals and apply the converted voltages to the DAC.