New Dynamic Test Methods for Determination of Nonlinearity and Effective Resolution of A/D Converters

Abstract

This paper presents new methods for determination of differential nonlinearity (DNL) and effective resolution also known as Effective Bits (EB) of an A/D converter. DNL is determined by deviation of histogram of test ADC from histogram of ideal ADC generated through software. Modifications are applied in the standard histogram approach for more accurate estimation of Integral nonlinearity (INL). Combination of histogram and least square error minimization techniques is used for determination of EB of an A/D converter. Computer simulations show that proposed methods give better results as compared to the histogram method. Limitations of standard histogram technique for determination of these parameters are also reported. Effects of uncertainties of slope and intercept of best fit transfer characteristics of the ADC on EB are also analyzed.

Indexing terms:

• Dynamic testing
• Nonlinearity
• Effective bits
• Transfer characteristics
• Uncertainty