A source driver adapted to drive a display panel is provided herein. The source driver includes a first output buffer, a detection module and a conversion module. The first output buffer enhances a first pixel signal and thereby outputs a first enhanced pixel signal. The detection module detects a rise time of the first enhanced pixel signal. The conversion module adjusts a driving capability of the first output buffer in response to the rise time for adjusting a slew rate of the first output buffer. Therefore, the first output buffer in the source driver can dynamically and automatically adjusts the slew rate of the first output buffer through a feedback mechanism composed of the detection module and the conversion module.