Abstract: A semiconductor device configured to drive a display panel in a display period, and perform touch sensing on the display panel in a touch sensing period after the display period. In a last horizontal sync period of the display period, the semiconductor device drives a first source line with a drive voltage of a first polarity, and a second source line with a drive voltage of a second polarity different from the first polarity. is the semiconductor is configured to output a first dummy pulse having first polarity and a voltage level based on the second display data to the first source line in a transition period between the display period and the touch sensing period.