A channel circuit of a source driver, including a first digital-to-analog converter (DAC), a second DAC, a first switch, a second switch and an output buffer circuit, is provided. The output terminal of the output buffer circuit is configured to be coupled to a data line of a display panel. An output terminal of the first DAC is coupled to a first input terminal among the input terminals of the output buffer circuit. An output terminal of the second DAC is coupled to a second input terminal among the input terminals of the output buffer circuit. The first switch is disposed along a first signal path between the output terminal of the first DAC and the output terminal of the output buffer circuit. The second switch is disposed along a second signal path between the output terminal of the second DAC and the output terminal of the output buffer circuit.