The present invention discloses an analogue-to-digital converter comprising at least two voltage comparator devices. Each of the voltage comparator devices comprises a differential structure of transistors and is arranged for being fed with a same input signal and for generating an own internal voltage reference by means of an imbalance in the differential structure, said two internal voltage references being different. Each voltage comparator is arranged for generating an output signal indicative of a bit position of a digital approximation of the input signal.