A pulse transformer includes a drum core having a winding core, a first flange provided at one end of the winding core in a first direction, and a second flange provided at the other end of the winding core in the first direction. The pulse transformer also includes a plurality of the first electrodes provided in the first flange and arranged in a second direction substantially perpendicular to the first direction, a plurality of second electrodes provided in the second flange and arranged in the second direction, and a plurality of wires wound around the winding core. A length of the pulse transformer in the first and second directions are substantially equal, and a length of the pulse transformer in a third direction substantially perpendicular to the first and second directions is smaller than the length of the pulse transformer in the first and second directions.