Disclosed is a source driver integrated circuit with an improved slew rate by disposing a switching unit, which operates as a resistance component during display driving, before the feedback line of an output buffer. According to the source driver integrated circuit with an improved slew rate, a switching unit, which operates as a resistance component when a signal is transferred, is disposed in the feedback loop of an output buffer, so that the resistance component is not shown to a panel load, thereby improving the slew rate of an output signal. In addition, the improved slew rate makes it possible to easily implement an image through a display.