A transition detector includes a first integrator configured to provide a first integral signal by integrating a first training pattern signal according to a first compensation clock signal, a second integrator configured to provide a second integral signal by integrating the first training pattern signal according to a second compensation clock signal, and a third integrator configured to provide a third integral signal by integrating the first training pattern signal according to a third compensation clock signal, wherein occurrence of a transition of the first training pattern signal is detected when the first integral signal and the second integral signal are larger than, and the third integral signal is smaller than, a first reference voltage.