People-to-people (P2P) technology-assisted interconnections, embedded in a global environment, will be at the core of 21st century communications and will command the technological development of the future. The Internet-of-Things (IoT) comprises only machine-to-machine (M2M) communications handling only data and things. Expanding itself beyond IoT, the Internet-of-Everything (IoE) also incorporates intelligently the interaction of people and process (providing at a precise moment the correct knowledge to the exact person/machine).

In general, IoT comprises all physical or cyber objects (things) with an address that can transmit information without human-to-machine interactions (data), while the IoE also involves communications (processing) among the users (people) and the whole universe of electronic gadgets. Further, they both operate with data acquired from analog sources, thus connecting two different realities, the analog (physical/real) and the digital (cyber/virtual) worlds. Since the interface between the two realms deals with analog signals, its mandatory functions involve sensing, measuring, filtering, converting, processing, and connecting, with the accuracy and precision of the analog layer ruling the entire system. Such interface integrates several analog and mixed-signal subsystems that include signal sensing, transmission and reception, frequency generation, energy harvesting (EH), in-memory processing, and data and power conversion.

This paper presents state-of-the-art designs of the most critical building blocks of the analog/digital interface highlighting new and innovative circuit architectures and techniques. It addresses capacitive sensor interfaces, ultra-low-power wireless transceivers, key technologies for wireline transceivers, oscillators and frequency generators, integrated energy harvesting (EH) interfaces, in-memory processing, as well as, data and power converters, all exhibiting high-quality performance with low power consumption, high energy-efficiency and high speed, thus enabling a reliable and consistent development of the IoE while enlarging its frontiers.