Static nonlinearity testing of D/A converters

The paper presents a diagnostic tool for analyzing the bit intermodulation in D/A converters. Bit intermodulation causes linearity errors which degrade the performance of the converter. The better understanding of these errors can lead to design and build more accurate converters. A linear transformation of the Walsh transform of the integrated nonlinearity diagram is shown to be sufficient to extract the bit intermodulation terms and their noise sensitivity. Practical applicability of the proposed method is shown by measurements performed on a custom designed test circuit.