Method for testing analog-to-digital converters

Method to characterise and/or test on-chip and/or on-board an analog-to-digital conversion device (10) that performs a conversion operation (f (.)), of the type that includes at least one input stage configured to perform an analog integration operation, and at least one digital conversion stage, and that supplies (21) an integer number (N) of samples of a digital characterisation signal (S) . According to the invention the following operations are provided for: supplying (21) said integer number (N) of samples of a digital characterisation signal (S) as input to said analog integration operation, said digital characterisation signal (S) being a multilevel rectangular wave signal with variable duty cycle (?(i)) ; - varying (211, 212, 213) said variable duty cycle (?(i)) for each sample (i) of said digital characterisation signal (S); - acquiring (22) N corresponding output samples (q(i)) from said conversion operation (f (.) ) and analysing said N corresponding output samples (q(i)) to determine parameters characterising said conversion operation (f (.) ).