Analogue to digital converter

Measures are provided for performing direct radio-frequency to digital conversion. A radio-frequency input signal is compared with a plurality of reference voltages to generate a plurality of comparison signals, each comparison signal corresponding to one of the plurality of reference voltages. One or more of the plurality of generated comparison signals are first filtered to generate a first filtered signal. One or more of the plurality of generated comparison signals are second filtered to generate a second filtered signal. A digital output signal is generated at least on the basis of the first filtered signal and the second filtered signal.