Touch controller having increased sensing sensitivity, and display driving circuit and display device and system having the touch controller

A printed circuit board (PCB) structure of a touch display driver integrated chip (TDDI) comprising:

• a display driver configured to drive a source line of a display panel;
• and
• a touch controller configured to detect an electrical change of sensing units on the display panel,
• wherein the display driver and the touch controller are included in a same semiconductor chip,
• wherein the TDDI is configured to receive a signal from a host controller via a connection terminal on a flexible printed circuit board,
• wherein the TDDI comprises a first pad region including a plurality of first pads for receiving a voltage signal from the sensing units and a second pad region including a plurality of second pads for transmitting gray-scale data to the display panel, the first pad region being separated apart from the second pad region on the TDDI, and
• wherein the display driver provides power to the touch controller when the display driver is in a low-power consumption mode and an operation for driving the source line of the display panel is kept deactivated, and the touch controller is configured to periodically check the electrical change of the sensing units by using the power from the display driver during the low-power consumption mode of the display driver.