The present invention provides a LCD device including: a timing control unit; an oscillator which is included in the timing control unit and generates a clock frequency; a frequency divider which is included in the timing control unit and reduces the clock frequency supplied from the oscillator by dividing the clock frequency by at least 2; and a mode selection part which is included in the timing control unit and changes at least one driving mode of internal logic circuits by using the divided clock frequency supplied from the frequency divider.