Blind adaptive estimation of integral nonlinear errors in ADCs using arbitrary input stimulus

Abstract

An adaptive digital test procedure for the static characterization of analog-to-digital converters (ADCs) is described in this paper. The proposed technique performs a blind and accurate estimation of the integral nonlinearity (INL) of the ADC under test (ADCUT) without requiring any particular test stimulus. Its practical implementation implies no modifications on the ADCUT analog section and needs a very simple low-cost digital logic, which makes this useful for: 1) simple digital automatic test equipment (ATE)-based ADC static test and 2) built-in self-test (BIST) for ADCs test working either in concurrent (online) or nonconcurrent (offline) modes. The validation of these test methods has been performed through realistic behavioral simulations including noise, mismatch, and nonlinear errors. Experimental results for a custom-designed pipeline ADC and for the commercial AD664 chip are also reported.