Touch display device, data driving circuit, and driving method for independently performing display and touch sensing

A driving circuit that drives data lines which are arranged in a display panel, comprising:

• a digital-analog converter configured to receive an image digital signal and a gamma reference voltage, and output an image analog signal according to the gamma reference voltage;
• and
• an output buffer circuit that outputs a data signal corresponding to the image analog signal to the data lines,
• wherein the gamma reference voltage is a swing signal having a predetermined amplitude during a first period and a direct current (DC) voltage having a constant voltage level during a second period,
• wherein, when the gamma reference voltage is the swing signal having the predetermined amplitude during the first period,
• the data signals change a voltage level according to the predetermined amplitude of the gamma reference voltage, and a first touch electrode driving signal having a first amplitude corresponding to the predetermined amplitude of the gamma reference voltage is applied to all or some of a plurality of touch electrodes in the display panel, and
• wherein, when the gamma reference voltage is the DC voltage having the constant voltage level during the second period that is different from the first period,
• according to the DC voltage of the gamma reference voltage, the data signals are output in a signal form different from a signal form of the data signals during the first period, and a second touch electrode driving signal in the form of a DC voltage signal is applied to all or some of the plurality of touch electrodes.