A data driver for driving a display panel includes a first driving channel coupled to a polarity inversion circuit and configured to generate a first data voltage signal having a positive polarity output to the display panel according to a plurality of first pixel data; a second driving channel coupled to the polarity inversion circuit and configured to generate a second data voltage signal having a negative polarity output to the display panel according to a plurality of second pixel data; wherein the first data voltage signal is output to first output node through the polarity inversion circuit during a first line period and the second data voltage signal is output to the first output node through the polarity inversion circuit during a second line period after the first line period, and the first line period and the second line period respectively belong to two consecutive frame periods.