A display device includes a display panel, pixels on the display panel, data and gate drivers, a timing controller which applies control signals respectively to the data and gate drivers, and a power management integrated circuit (“PMIC”) which applies a driving voltage to the data and gate drivers. The timing controller detects an operational condition of the display panel and selects one of stored power setting values to output the selected one of the power setting values to the PMIC. The PMIC includes, first and second storage banks, a controller which receives the power setting value from the timing controller, stores the power setting value in one of the first and second storage banks, and calls the stored power setting value to determine the driving voltage, and a power generator which applies the driving voltage based on the driving voltage determined by the controller.