Which two standard DNL contour levels are defined when applying the DNL method?

• A. 65 and 75
• B. 60 and 70
• C. 70 and 80
• D. 55 and 65

Answer: (A)

In this method, you map the transfer characteristic using two fixed contour thresholds as reference lines. These two standard levels provide consistent markers across the range, so you can easily see where the differential nonlinearity is rising above or dropping below acceptable values. By defining this pair as the standard, the contour plot becomes a reliable, repeatable tool for evaluating linearity.

Choosing the usual, predefined pair ensures alignment with the established procedure, making the interpretation uniform across measurements. Other pairings wouldn’t match the standard setup and would produce contours that aren’t comparable to the approved reference.