Linearizing ideal A/D converters via analog and digital dither: Analytical study

This study is a continuation of previous work by M. F. Wagdy (1989). The authors further investigate the effect of various dither forms, i.e., with different probability density functions (PDFs), on the average observed transfer characteristics of ideal A/D converters (ADCs). The effect of analog dither on the averaged transfer characteristics is illustrated. Different dither forms are considered: rectangular, triangular, and Gaussian. The deviation of the ADC characteristics from the ideal straight line is evaluated for these dither forms using the concept of nonlinearity spectra developed earlier. Results are also compared with simulations based on the mean square error criterion. Two cases of digital dither are investigated: one with a rectangular envelope and the other with a triangular envelope. Effects of dither peak-to-peak values and number of PDF impulses are investigated. A quantitative basis is provided for replacing analog dither with the easier to implement digital dither