A 4.2fJ/cs 2GSps 7.4b ENOB loop-unrolled SAR ADC for UWB receivers, with two comparator types and wide input common-mode range

UWB receivers require a low-power ADC with large common-mode tolerance. This work presents a 2GSps 9 bit 4 x time-interleaved ADC that leverages a loop-unrolled SAR architecture with two comparator types to achieve low power-consumption by saving power in the digital logic. The input common-mode range is increased $3 x$ by utilizing common-mode shifting. The ADC consumes 1.43 mW while achieving an ENOB of 7.4b, leading to a best-in-class $\mathrm{FOM}_{\mathrm{w}}$ of $4.2 \mathrm{fJ} / \mathrm{cs}$.