A Cascaded Noise-Shaping SAR Architecture for Robust Order Extension

Abstract

The emerging noise-shaping (NS) successive approx- imation (SAR) architecture is highly efficient and compact; how- ever, the order and signal-to-noise ratio (SNR) of sub-MHz NS SAR ADCs are still lower than conventional sigma–delta ADCs. This work proposes a cascaded NS (CaNS) SAR architecture that increases system order and enables more effective NS for higher SNR. The proposed architecture enhances the robustness of high-order NS performance at the system level and is inherently process, volta