A display panel includes a display pixel displaying an image in response to a common voltage and a data voltage and a sensing pixel outputting a feedback voltage in response to the common voltage and a reference voltage; and a driving circuit unit supplying the data voltage and the reference voltage to the display pixel and the sensing pixel, respectively. The driving circuit unit includes a common voltage estimating part comparing the reference voltage and the feedback voltage to generate a counter signal having a counter value that is stepwise varied according to the comparing of the reference voltage and the feedback voltage; and a common voltage adjusting part stepwise varying the common voltage supplied to the display panel in response to the counter value.