A semiconductor device comprises an input circuit that includes a first comparator configured to output a first output signal and a second output signal having a phase opposite to that of the first output signal, based on a comparison result of a first input signal and a second input signal which is a complementary signal of the first input signal. A duty ratio of the first output signal and a duty ratio of the second output signal are different from a duty ratio of the first input signal and a duty ratio of the second input signal, respectively.