A semiconductor device connected to the display panel including the in-cell type touch sensor is configured as follows. The semiconductor device includes a driving circuit of the display panel, a touch sensing circuit of the touch sensor, a power supply circuit that supplies a power source to these circuits, and a bias control circuit that controls a bias current flowing through these circuits. The semiconductor device is able to perform a time-division operation in which one frame period of display is divided into a plurality of display driving periods and sensing periods. In the display driving periods, the supply of power to the touch sensing circuit is suppressed, and/or a bias current is reduced. In the sensing periods, the supply of power to the driving circuit is suppressed, and/or a bias current is reduced.