Integrated Inductor-Transformers for High-Frequency Converters: An Overview

Integrated inductor-transformers, eliminating the need for external series inductors, provide disruptive improvements toward compact, efficient, and cost-effective converters in industries such as automotive and data center power supplies. However, their successful implementation requires thoughtful design considerations; otherwise, their potential benefits are voided. This article exposes the potential of integrated inductor-transformers through a systematic review of existing state-of-the-art designs and synergies with other innovative technologies such as printed circuit board windings, matrix transformers, advanced winding structures, and custom core shapes. The fundamental principles governing their operation are addressed, as well as modeling guidelines for each of the integration methods. These methods are categorized, described, and validated through finite element studies. Three complementary comparison approaches are presented, an analytical comparison, statistical analysis, and qualitative assessment, to evaluate inductor-transformer solutions across key metrics including achievable inductance, power density, manufacturability, and electromagnetic interference performance. Finally, the article presents a forward-looking analysis of emerging trends, critical challenges, and untapped opportunities in high-frequency magnetic component research. Hence, this overview supports the understanding of future developments in integrated magnetic components for compact, efficient, and cost-effective power converters. The article is accompanied by a CSV record of all qualified references to aid future research contributions and statistical analysis.