Next-Generation Sigma-Delta Converters: Trends and Challenges in a Digital-Driven World

This lecture presents an overview of emerging circuits and systems techniques, which are at the forefront of the state of the art in Sigma-Delta Modulators (ΣΔMs), giving rise to a new generation of data converters that will enable an efficient implementation of the so-called software-defined-electronics paradigm. A number of trends, design challenges and new approaches – like RF/GHz-range ΣΔ digitization in wireless transceivers, digital-assisted analog circuits, time/frequency-to-digital conversion and hybrid ΣΔ/Nyquist-rate Analog-to-Digital Converters (ADCs) – are discussed, as well as the implications derived from their integration in deep nanometer CMOS technologies. Main limitations and problems faced by cutting-edge designs are identified, giving a didactic explanation of them, well supported by an exhaustive statistics-based analysis of over 500 outstanding ΣΔM Integrated Circuits (ICs) in the frontiers of data conversion. Main tendencies, research opportunities and perspectives on the evolution of data converters are envisioned, highlighting how ΣΔM-based analog/digital interfaces can improve their performance and efficiency in an increasingly digital-driven world.