A semiconductor device includes a plurality of synchronization blocks configured to sequentially synchronize a plurality of input signals swinging in a complementary metal oxide semiconductor (CMOS) region with multi-phase clock signals to output a plurality of output signals swinging in a current mode logic (CML) region, a plurality of first swing region converting blocks configured to convert the plurality of output signals to a plurality of converted output signals swinging in the CMOS region, a serialization block configured to serialize a plurality of converted output signals, thereby outputting a serialized signal swinging in the CML region, and a second swing region converting block configured to convert the serialized signal to a serialized output signal swinging in the CMOS region.