A display device includes a display panel, a plurality of pixels formed on the display panel, a plurality of sensing units formed on the display panel and generating sensor output signals in response to a touch exerted on the display panel, a sensing signal processor receiving and processing an analog sensor data signal originated from the sensor output signals to generate a digital sensor data signal, a first touch-determination unit detecting whether a touch exists based on the digital sensor data signal for a plurality of frames, and operating in a power saving mode, and a second touch-determination unit detecting whether and where a touch exists based on the digital sensor data signal for the plurality of frames, and operating in a normal mode. The display device includes hardwired logic units for detecting the touch, it detects the touch using the hardwired logic units in the power saving mode and converts the operation mode to the normal mode when the touch is detected, thus reducing power consumption.