A signal processing device has a first discrete time analog signal processing section, which has an input, an output, a plurality of charge storage elements, and plurality of switch elements coupling the charge storage elements. The device has a controller coupled to the first signal processing section configured to couple different subsets of the charge elements of the first signal processing section in successive operating phases to apply a signal processing function to an analog signal presented at the input of the first signal processing section and provide a result of the applying of the signal processing function as an analog signal to the output of first signal processing section. The signal processing function of the first signal processing section comprises a combination of a filtering function operating at a first sampling rate and one or more modulation functions operating at corresponding modulation rates lower than the first sampling rate.