A semiconductor device, a spread spectrum clock generator and method thereof are provided. The example semiconductor device may include a frequency dividing unit receiving an output signal, generating a first feedback signal and a second feedback signal by dividing a frequency of the received output signal, and a phase offset unit outputting the output signal having a predetermined or desired phase difference with a reference signal in response to the second feedback signal, wherein the second feedback signal having a higher frequency than the first feedback signal. The example spread spectrum clock generator may include a plurality of frequency dividers which are connected in series and a selector selecting and outputting one of a plurality of output signals, each of the plurality of output signals having a different phase difference with respect to a reference signal, in response to at least one output from one or more of the plurality of frequency dividers. The example method may include receiving a reference signal with a first frequency, generating a feedback signal having a second frequency, the second frequency higher than the first frequency and outputting at least one of a sequentially selected set of output signals in response to the generated feedback signal.