A display driver integrated circuit includes a regulator configured to convert an externally supplied driving voltage to a working voltage corresponding to one of a plurality of power domains of the display driver integrated circuit, a graphic data processing unit configured to process image data input to the graphic data processing unit, and output the image data to a display panel, a control switch configured to control a supply of the working voltage to the graphic data processing unit, and a core logic unit configured to receive the working voltage from the regulator and control the control switch in response to a mode of operation of the display driver integrated circuit.