Circuits and magnetics co-design for ultra-thin vertical power delivery: A snapshot review

This paper presents a comprehensive overview of circuits and magnetics co-design for point-of-load voltage regulator modules (VRMs), which delivers power to microprocessors such as CPUs and GPUs that require low voltages and high currents. We examine the recent shift from the 12-volt to the 48-volt architecture to achieve higher efficiency and power density, and discuss the challenges associated with direct 48-volt power conversion to the point of load below 1 volt. Power delivery architectures for 48-volt VRMs are systematically reviewed and categorized, with emphasis placed the opportunities and challenges of circuits–magnetics co-design for energy efficiency, power density, and control bandwidth. Magnetic components, such as inductors and transformers, are essential components in VRMs, and a discussion on available materials and their limitations is provided. A comprehensive design approach for ultra-thin vertical multiphase coupled magnetics, including modeling magnetic core losses with machine learning, is detailed. This review paper aims to disseminate the progress and challenges in circuit and magnetics co-design, while outlining a vision for future advancements in device technology, magnetic materials, and packaging techniques including hybrid-switched-capacitor and coupled magnetics technologies. Graphical abstract