A system on chip includes a clock generator configured to generate a clock signal, and output the clock signal to a component device external to the system on chip. The system on chip further includes a duty ratio determiner configured to determine a component duty ratio, in response to a response that is received from the component device according to the clock signal, and a duty ratio adjustor configured to adjust a current duty ratio of the clock signal to the component duty ratio, and output the clock signal of which the current duty ratio is adjusted, to the component device.