Würth Elektronik is launching the 4th edition of the application manual "Trilogy of Inductive Components." This application manual for EMC filters, switched-mode power supplies, and RF circuits has been completely revised, restructured, and includes a wide range of new components and applications. The technical book is divided into three main chapters: Fundamentals, Components, and Applications. A glossary of terms and a collection of formulas complete the book. The aim of the technical book "Trilogy of Inductive Components" is to present inductive components to customers and users in a practical manner, highlighting their properties and applications without unnecessary complexity. First published 8 years ago, this book has become a standard reference in many development departments and universities, with over 15,000 copies sold. In the new 4th edition, older techniques and components have been deliberately omitted to give more space to new components and applications. Notably, there is a large number of external authors from the customer base as well as from renowned manufacturers, whose experiences and solutions in fundamentals and circuit technology can be found in this book. The following is a list of new articles that exemplify many other innovations: - Calculation, dimensioning, and construction of custom transformers - Effects of a transformer's properties on reflection attenuation - Class-D audio amplifiers - Principles of frequency response correction for switch-mode power supplies - Fundamentals of Ethernet and Power-over-Ethernet - Additionally, over 200 practical examples for the following applications: filter circuits, audio circuits, video circuits, interfaces, RF circuits, motor control, switch-mode power supplies, line filters, and power supplies.