A fully digital-compatible BIST strategy for ADC linearity testing

Digital testing is much easier and cheaper than analog and mixed-signal testing because of the straightforward connections and the low-cost testers. This paper presents a fully digital-compatible built-in self-test strategy for ADC linearity testing using all digital testing environments. On-chip, low-accuracy DACs, which are area efficient and simple to design, are implemented as the stimulus generator. ADCs´ nonlinearities are tested using a histogram-based method under the control of a logic block. The described strategy is capable of characterizing ADC transition levels one by one with small hardware overhead. Simulation and experimental results show that the proposed circuitry and BIST strategy can test the INL_k error of 12-bit ADCs to plusmn0.2 LSB accuracy level using only 7-bit linear DACs.