The present invention provides a filter circuit, related method of operating the filter circuit and a digital signal processing circuit incorporating the same. In one embodiment, the filter circuit includes a conditioning stage, operable at a rate corresponding to an input signal to be sampled, configured to derive an intermediate signal from the input signal as a function of a parameter. The filter circuit further includes an output stage, operable at a sampling rate, configured to derive a sampled signal as a function of the intermediate signal where the parameter is adapted to govern characteristics of a frequency response associated with the sampled signal.