Multi-stage sigma-delta ADC with noise-coupling technology

Abstract

This paper proposes new structures of multi-stage noise-shaping (MASH) sigma-delta ADC by applying second-order noise-coupling technology to conventional MASH modulators. The proposed architectures take advantage of the extra noise-coupled path to achieve a second-order noise-shaping increase as well as save the number of active devices. Theoretical analysis and system-level simulation are given, and the implementation of the modulators is also analyzed. The new structures are suitable for broadband applications.