Simultaneous compensation of previous sample and slope dependent errors in analog to digital converters

Compensation of analog to digital converters (ADCs) has historically been concerned with choosing the dominant error mechanism and then compensating based on the one error mechanism. Compensating on only one error mechanism presents a problem when the dominant error mechanism changes with frequency. This paper presents a way to confront multiple error mechanisms at once and successfully compensate across the full band. Two error mechanisms addressed here are previous sample and signal slope dependent errors. This paper presents a model for error and estimates the error from the harmonics in the spectrum of the calibration signal. The error present in the fundamental component is treated as additional unknowns in the error estimate. Compensation of a simulated ADC resulted in a complete removal of all previous sample and slope dependent error. Hardware results were almost as impressive, showing gains in spurious free dynamic range (SFDR) of up to 17 dB.