A touch display device comprising: a display panel (DISP) including a plurality of data lines, a plurality of gate lines, a plurality of touch electrodes, and a plurality of touch routing lines which are disposed on a substrate, wherein the display panel further includes an active area configured to display an image, and a non-active area which is outer to the active area; and a touch circuit configured to sense at least one of the plurality of touch electrodes, wherein the display panel further includes: a plurality of subpixels including a light emitting element including a pixel electrode, a light emitting layer, a common electrode, and a driving transistor to drive the light emitting element; and an encapsulation layer (ENCAP) disposed on the common electrode, wherein the plurality of touch electrodes are disposed on the encapsulation layer, and the plurality of touch routing lines are disposed along an inclined surface of the encapsulation layer, and electrically connected to a plurality of touch pads disposed in the non-active area, wherein the touch circuit includes an operational amplifier (OP-AMP) having a first input terminal for inputting a reference voltage, a second input terminal connected to a sensing target touch electrode, and an output terminal (Vout) for outputting an output voltage, wherein the first input terminal of the operational amplifier is directly connected to the common electrode or electrically connected to the common electrode through a synchronization line (SYNL), such that a common voltage applied to the common electrode and the reference voltage inputted to the first input terminal of the operational amplifier are synchronized with each other, such that noise at the common electrode flows into the first input terminal; and wherein the touch display device is configured such that the common voltage applied to the common electrode and the reference voltage inputted to the first input terminal of the operational amplifier are modulation signals whose voltages are variable and have a frequency and a phase corresponding to each other; wherein an operation mode of the touch display device comprises a pen sensing mode, the touch circuit is configured to detect a pen signal output from a pen through the sensing target touch electrode, the frequency of the reference voltage and of the common voltage corresponds to that of the pen signal, and the reference voltage and the common voltage are in antiphase with the pen signal. a display panel (DISP) including a plurality of data lines, a plurality of gate lines, a plurality of touch electrodes, and a plurality of touch routing lines which are disposed on a substrate, wherein the display panel further includes an active area configured to display an image, and a non-active area which is outer to the active area; and a touch circuit configured to sense at least one of the plurality of touch electrodes, wherein the display panel further includes: a plurality of subpixels including a light emitting element including a pixel electrode, a light emitting layer, a common electrode, and a driving transistor to drive the light emitting element; and an encapsulation layer (ENCAP) disposed on the common electrode, a plurality of subpixels including a light emitting element including a pixel electrode, a light emitting layer, a common electrode, and a driving transistor to drive the light emitting element; and an encapsulation layer (ENCAP) disposed on the common electrode, wherein the plurality of touch electrodes are disposed on the encapsulation layer, and the plurality of touch routing lines are disposed along an inclined surface of the encapsulation layer, and electrically connected to a plurality of touch pads disposed in the non-active area, wherein the touch circuit includes an operational amplifier (OP-AMP) having a first input terminal for inputting a reference voltage, a second input terminal connected to a sensing target touch electrode, and an output terminal (Vout) for outputting an output voltage, wherein the first input terminal of the operational amplifier is directly connected to the common electrode or electrically connected to the common electrode through a synchronization line (SYNL), such that a common voltage applied to the common electrode and the reference voltage inputted to the first input terminal of the operational amplifier are synchronized with each other, such that noise at the common electrode flows into the first input terminal; and wherein the touch display device is configured such that the common voltage applied to the common electrode and the reference voltage inputted to the first input terminal of the operational amplifier are modulation signals whose voltages are variable and have a frequency and a phase corresponding to each other; wherein an operation mode of the touch display device comprises a pen sensing mode, the touch circuit is configured to detect a pen signal output from a pen through the sensing target touch electrode, the frequency of the reference voltage and of the common voltage corresponds to that of the pen signal, and the reference voltage and the common voltage are in antiphase with the pen signal.