Output buffer having high slew rate in source driver of liquid crystal display

PURPOSE: An output buffer having a high slew rate in a source driver of a liquid crystal display device is provided to improve the driving capability by controlling the voltage level with the control transistor or the invertor, thereby improving the slew rate characteristics. CONSTITUTION: An output buffer having a high slew rate in a source driver of a liquid crystal display device includes a differential amplifying circuit(100), a control circuit(110) and an output circuit(120). The differential amplifying circuit(100) generates a first control signal obtained by differential amplifying the input signal and the pull-up(or -down) signal having a characteristics inverted to the input signal by inputting the input signal and the feedback output signal. The control circuit(110) is driven in response to a predetermined bias voltage and the first control signal and has a characteristics inverted to the first control signal. And, the output circuit(120) generates an output signal following the input signal while it is charged and discharged to the supply power level or the ground power level in response to the pull-up(or -down) signal and the second control signal.