A sample rate converter for an oversampled data stream develops interpolated samples at a first oversample rate, from samples at a second oversample rate; wherein the first oversample rate is a non-integer multiple of the second oversample rate. When the samples at the second oversample rate are changing state, at least two interpolated samples are generated or the interpolation is at least second order. When the sample at the second oversample rate is not changing state, the sample at the second oversample rate is passed substantially unchanged. In one embodiment of the invention, asynchronous sample rate conversion is performed, and the first oversample rate is a varying non-integer multiple of the second oversample rate.