On the Static Accuracy of Digitally Corrected Analog-to-Digital and Digital-to-Analog Converters

Some basic observations are made about the static accuracy of ADCs and DACs with full digital correction. First, the accuracy of flash ADCs is considered. It is pointed out that the loss in effective resolution due to component mismatch is only about 1 bit, independently of the mismatch level (unless the mismatch is very small). Second, the accuracy of current steering DACs is considered. It is noted that current-source mismatch can hugely improve the effective resolution of DACs, and it is shown that an effective resolution of m bits can be achieved with as few as m + 2 “small” current sources.