A High Dynamic Range Feedback Compensation Front-End for Unlimited Sampling ASDM ADC

The development of the novel theory of unlimited sampling (US) has enabled analog-to-digital converters (ADCs) to effectively manage input signals with dynamic ranges that far exceed the threshold voltage. However, the existing design of the US asynchronous sigma-delta modulator ADC (US-ASDM-ADC) employs a nonlinear modulo operation within a two-channel architecture to generate the remainder and integer parts, leading to significant amplitude loss due to non-ideal phenomena. To address this issue, we propose a novel single-channel architecture and feedback compensation mechanism for the US-ASDM-ADC. Our approach entails a single-channel folding module to generate the remaining modulo operation while simultaneously generating the integer part of the modulo operation and initiating amplitude correction via a Schmitt trigger-based feedback system. We validate our proposed approach through transistor-level simulations.