Equalisation of analogue to digital converter nonlinearities

A signal-processing technique called threshold tracking is presented which can improve the linearity of any analog-to-digital conversion circuit (ADC). The basic idea is to use a mapping of the original output codes and their associated nonideal quantization levels to a set of codes whose corresponding quantization levels more closely match those of an ideal ADC. When the mapped codes are then assumed to be associated with ideal quantization levels by the rest of the signal processing system, the error between the actual and the ideal levels is reduced. The equalization system is described and the convergence and equalization performance in the presence of training signal noise is shown.<>