The "Trilogy of Magnetics" is a renowned design guide published by Würth Elektronik, widely considered a standard reference for engineers working with inductive components. While the full 700+ page book is a paid resource, you can access substantial "chapter extracts" in PDF format directly from the manufacturer and other engineering resources to get a deep dive into specific topics. Top PDF Resources for "Trilogy of Magnetics"
Official Chapter Extracts (Würth Elektronik): The publisher provides free PDF snippets covering the core pillars of the book.
Basic Principles Extract: Covers Ampère's Law, magnetic field strength, and the physics of conductors and solenoids.
Components Extract: Details various forms of ferrites (beads, cores, rods) and their EMC applications. Comprehensive Online Previews:
Internet Archive: You can find older versions (like the 4th edition) available for digital borrowing or community-uploaded previews that include technical dictionaries and simulation models.
Scribd: Offers a 5th Edition eBook preview that focuses on layout recommendations and EMC perspectives.
Magnetics-on-Silicon Technology White Paper: For a more modern spin, Würth released a specific technical paper (SN029) on miniaturization and next-generation IC development. Key Topics in the Latest (5th) Edition
The most recent updates to this "paper" or guide include critical emerging technologies that go beyond standard filter design:
New Transistors: In-depth coverage of SiC (Silicon Carbide) and GaN (Gallium Nitride) switching transistors. trilogy of magnetics pdf upd
Advanced Power: Updated sections on Wireless Power Transfer (WPT) and Energy Harvesting.
Connectivity: Expanded applications for Ethernet and Power over Ethernet (PoE). Where to Buy the Full Book
If you need the complete version for professional use, it is available from several retailers:
Reference Guide Trilogy of Magnetics English - Würth Elektronik
Learn more * Chapter extract: Basic principles. PDF. * Chapter extract: Components. PDF. * Chapter Extract: Applications. PDF. Würth Elektronik
Reference Guide Trilogy of Magnetics German | Passive Components
The Trilogy of Magnetics is a comprehensive technical design guide published by Würth Elektronik, currently in its 5th edition. It serves as a standard reference for engineers and students, focusing on the practical application of inductive components in electronic circuits from an EMC (Electromagnetic Compatibility) perspective. Core Structure
The book is divided into three major sections designed to guide a developer from theory to real-world implementation: The " Trilogy of Magnetics " is a
Basic Principles: Covers the fundamental laws of magnetism, inductive components, equivalent circuit diagrams, and simulation models.
Components: Explains the properties and selection of specific parts, including EMC components, inductors, transformers, RF components, and shielding materials.
Applications: Provides over 200 practical examples across diverse fields such as filter circuits, audio/video circuitry, interfaces, motor control units, and Switched Mode Power Supplies (SMPS). Key Updates in the 5th Edition (March 2026)
The latest version has been significantly expanded to address modern power electronics and communication standards:
New Technologies: Added chapters on Wireless Power Transfer (WPT), energy harvesting, and the use of wide-bandgap semiconductors like SiC (Silicon Carbide) and GaN (Gallium Nitride).
Modern Applications: Includes updated sections on Ethernet & Power-over-Ethernet (PoE), Class-D amplifiers, and RF design basics.
Design Tools: Features integration with simulation platforms like LTspice and Würth Elektronik's REDEXPERT online design tool.
Expanded Theory: The "Basic Principles" section alone was expanded by over 100 pages to cover skin effect, proximity effect, and AC losses in greater detail. Technical Resources What is the "Trilogy of Magnetics"
Engineers can access further information or order the full hardback or e-book versions through: Würth Elektronik Official Product Page Elektor Store (E-book version)
Reference Guide Trilogy of Magnetics English - Würth Elektronik
Originally published by Kangus Dynamics (and later distributed by companies like Magnetics, Inc., and Coltronics), the Trilogy of Magnetics breaks down the complex subject of magnetic design into three logical "books" or sections:
What sets McLyman apart is his engineering shorthand—he provides practical, battle-tested formulas without excessive theoretical jargon. For a working power supply engineer, this is pure gold.
Open the PDF. Navigate to the updated Appendix C: "Core Selection for Single-Ended Converters." Use the formula: [ K_g = \fracP_o \cdot T_on\Delta B \cdot K_u \cdot J \cdot K_f ] In the UPD version, the constant for K_f (waveform factor) now includes a note for squarewave vs. sinewave (critical for GaN).
Old versions assume fringing flux adds 10% to inductance. The UPD version provides a curve-fit formula for fringing factor (F) as a function of gap length / bobbin width. You will reduce your primary turns by 15% using this.
Old PDFs list ferrite grades like 3C8 or N27. Modern equivalents (e.g., 3C95, N97, or TDK PC95) have different saturation flux densities (Bsat) and core loss coefficients (K, alpha, beta). Using an old table means your transformer might saturate 20% earlier than calculated.