Linearizing average transfer characteristics of ideal ADC´s via analog and digital dither

This paper is a continuation to the previous work by M.F. Wagdy (see ibid., vol. 38, p. 850-855, Aug. 1989). It further investigates the effect of various dither forms, i.e., with different probability density functions (PDF´s), on the average observed transfer characteristics of ideal A/D converters (ADC´s). First the deviation of the ADC characteristics from the ideal straight line is evaluated for analog dither forms using the concept of nonlinearity spectra developed in the above work. Second, two cases of digital (discrete) dither are investigated, one with rectangular envelope and the other with triangular one. Effects of dither peak-to-peak values and number of PDF impulses are investigated. The paper provides a quantitative basis for replacing analog dither with the easier to implement digital dither