Compensation of Analog-to-Digital Converter Nonlinearities using Dither

Abstract

Analog-digital converters are inherently nonlinear. Conventional A/D conversion allows no real remedy afterwards. However, an alternative is to increase the available information by observing the transition instants, even with a conventional ADC. Performing the conversion with significant oversampling data points at threshold level crosses can be used. The values of these samples are precisely known, assuming histogram test was executed on the ADC beforehand. For almost constant signals having too few transition level crossings, dither is added. Interpolation is utilized to ensure uniformly sampled data points. This method reduces the conversion error considerably.