A display device includes a display panel including data lines and scan lines coupled, a data driver configured to supply data voltages to the data lines based on digital video data, a scan driver configured to supply scan signals to the scan lines, a timing controller configured to select one of a normal mode and a self-refresh mode based on a panel self-refresh enable signal, where the data and scan drivers are driven by a first frame frequency in the normal mode and by a second frame frequency lower than the first frame frequency in the self-refresh mode, and a power supply source configured to supply driving voltages to the data and scan drivers and the timing controller and to transmits a direct current power voltage to an outside thereof, where a transmission of the direct current power voltage is blocked during a blank period in the self-refresh mode.