A source driver includes a data-receiving device, a data switch device, a voltage generator, a voltage switch set, a digital to analog (DAC) set, an output unit set, and a timing control device. The data-receiving device receives, registers and outputs a data signal, and the data switch set selectively outputs the data signal from the data-receiving device in response to a first timing signal. The voltage generator generates a plurality of voltages according to the reference voltages. The voltage switch set selectively outputs the voltages from the voltage generator in response to a second timing signal. The DAC set receives and outputs the selectively outputted voltages according to the selectively outputted data signal. The output unit set receives the selectively outputted voltages from the DAC and outputs an output voltage in response to a third timing signal. The timing control device provides the first, second and third timing signals.