A sampling data output circuit capable of Accommodating frequency variations includes a converter portion for sampling an input data signal (402) at an oversampling frequency to output, in parallel, a plurality of fundamental signal series (p1, p2, p3, p4), a first circular shifter for receiving the plurality of fundamental signal series and outputting a plurality of first frequency shift signal series having a higher frequency than the fundamental sampling frequency, and a second circular shifter for receiving the plurality of fundamental signal series and outputting a plurality of second frequency shift signal series having a lower frequency than the fundamental sampling frequency. The first and second circular shifters create each of the signal series by selecting a signal sample out of the input fundamental signal series according to a count value of a phase shift cumulative counter and a predetermined rule related to the frequency shift.