Noise-coupled ADCs

Abstract

The first-order noise coupling scheme proposed earlier is generalised to the realisation of higher-order enhancement. It is also extended to single-stage ΔΣ loops, and to split structures with self-enhancement. The advantages and limitations of these new ΔΣ architectures are compared with those of conventional single-stage and cascade ΔΣ structures. As demonstrated by an example, they exhibit improved stability and robustness under practical fabrication conditions.