A system is disclosed, in particular for digitizing a time-continuous and value-continuous periodic signal with a respective firmly predefined number of samples per period. In at least one embodiment, the system includes an A/D converter for digitizing an analog AC signal applied to the input of the A/D converter, the converter including a single-bit modulator which converts the AC signal into a first data stream of temporally immediately successive single-bit data words at a predefined operating clock rate; and a downstream decimation filter which respectively aggregates a predefined number of temporally immediately successive single-bit data words in the first data stream into respective temporally immediately successive n-bit data words which form a second data stream which corresponds to a digitization of the AC signal at a sampling frequency which is derived from the operating clock rate and the predefined number by way of division. In order to achieve digitization with a respective firmly predefined number of samples per period with relatively little technical complexity, it is proposed in at least one embodiment that the operating clock rate be respectively generated by a digitally adjustable oscillator on the basis of a signal characteristic of the AC signal.