A display driver integrated circuit (IC) is provided. The display driver IC includes a shift register configured to output a digital signal, and a digital-analog converter configured to receive the digital signal and generate a data voltage corresponding to the digital signal, wherein the digital-analog converter includes a delta-sigma modulator configured to output a modulated signal by receiving the digital signal and a first voltage, and performing delta-sigma modulation on the digital signal using the first voltage, and a level shifter configured to receive the modulated signal and a second voltage higher than the first voltage, and amplify the modulated signal using the second voltage.