A liquid crystal display (LCD) driver integrated circuit (IC) includes a grayscale voltage generating circuit generating grayscale voltages from a set of supply reference voltages. A converting section having connection terminals drives each of data lines of an LCD display panel through one of the connection terminals based on one of the grayscale voltages. The grayscale voltage generating circuit includes a resistance circuit having resistances connected in series and voltage buffers connected to the resistance circuit to bias the resistance circuit. When two of the LCD driver ICs are used, non-inversion input terminals of pairs of the voltage buffers in a first of the two LCD driver ICs and a corresponding voltage buffer in the second LCD driver IC are commonly connected to the reference voltage generating circuit, and connection terminals in the first LCD driver IC are connected to connection terminals in the second LCD driver IC.