An edge detector includes a differential signal generator, a sense amplifier and a latch. The differential signal generator delays an input signal to generate a first differential signal and inverts the input signal to generate a second differential signal. The sense amplifier amplifies a difference between the first differential signal and the second differential signal to generate a first amplification signal and a second amplification signal at a first edge of a test clock signal and resets the first amplification signal and the second amplification signal at a second edge of the test clock signal. The latch generates an edge signal corresponding to edge information of the input signal in response to the first amplification signal and the second amplification signal.