Mathematical study of successive approximation ADC's channel width

Abstract

The influence of input and weight voltage variations, on channel width is examined. To obtain a mathematical expression for the differential linearity, the channel width is treated as a function of L tn - the channel width defined by the weights only. In a second step, L tn is supposed to be variable. To avoid errors due to the nonideal stretcher and transients during weights setting, the method of supplementary tests is examined. This method leads to improvements of very fast successive approximation ADC's.