A source drive integrated circuit includes a source driving circuit, output buffers, and voltage protection circuits. The source driving circuit generates data voltages according to a source timing control signal and digital video data. The output buffers output the data voltages from the source driving circuit to output terminals. The voltage protection circuits are connected between the output buffers and the output terminals. A voltage supplied to at least one of the voltage protection circuits is different from a voltage supplied to remaining ones of the voltage protection circuits.