A pulse-width-modulated signal is generated out of a sampled reference signal. The least significant bits of a sample of the reference signal are stored in a comparison register. At the same time, a check is made in a test circuit to find out if the sample considered corresponds to a maximum amplitude of the reference signal. If this is the case, an overflow bit is given. The overflow bit and the least significant bits of the sample considered are then linked together to obtain a comparison word. The comparison word is compared with a number given by the counter to generate the pulse-width-modulated signal.