A/D converters nonlinearity measurement and correction by frequency analysis and dither

In the paper a new frequency-domain approach to measure and correct the static nonlinearity error of A/D converters is analyzed. The nonlinearity is (i) measured as a linear combination of Chebyshev polynomial, whose coefficients are derived via frequency-domain analysis, and (ii) corrected with a nonlinear equation solving method, which makes use of the parametric form of the static characteristic. The proposed methodology is especially suited for dithered converters, due to their particular features of smoother nonlinearity and very high resolution. Both simulation and experimental results are reported, quantifying also the achieved increase of effective bits.