Power Inductors from Wurth Electronics Midcom

Wurth Electronics Midcom carries a variety of power inductor products and resources to suit your design needs.

On this page, you’ll find everything you need to know about power inductors, including:

  • What power inductors are
  • The different types of power inductors
  • Tips for selecting power inductors
  • Popular power inductors from Wurth Electronics Midcom
  • Our special Trilogy of Magnetics design guide
  • And more!

Overview of Power Inductors

Power inductors are used to store energy, provide lower signal losses, filter EMI noise, and yield lower core losses in applications where voltage conversion is necessary.

Before you can gain a good understanding of power inductors, it’s important to first familiarize yourself with the larger category of inductors.

What Are Inductors?

To understand inductors as a whole, you need a basic knowledge of magnetism and a few fundamental electromagnetic field laws. You can learn more about the basic principles of inductive components in our Trilogy of Magnetics design guide.

Basically, an inductor is a passive electrical component with two terminals that store energy in their magnetic field. Inductors are designed to create inductance for conductors. Generally, inductors are wrapped around a core material (such as iron) to increase inductance.

There are many different types of inductors, including multilayer inductors, RF inductors, toroid inductors, wire-wound inductors, and, of course, power inductors.

What Are Power Inductors?

A power inductor is an electronic component that both receives and stores electrical energy by using a magnetic field (usually created with a tightly coiled conductive wire). Power inductors serve to maintain a steady current in an electrical circuit with a varying current and/or voltage.

With switched-mode power supplies becoming increasingly common, semiconductor manufacturers have begun offering a wide range of power inductors with simplified circuit design.

To fully utilize the advantages of switching regulators, you should take care in selecting the appropriate storage choke.

Power inductors can be differentiated using criteria such as inductance, DCR, rated current, saturation current, and frequency range. They can also be categorized by type (see “Types of Power Inductors” below).

Applications of Power Inductors

The applications of power magnetics in general are vast and varied:

  • Filter circuits
  • Audio circuitry
  • Video circuitry
  • Interfaces
  • RF circuits
  • Motor control units
  • SMPS basics circuits
  • Mains filters
  • Power supply

The smaller subset of power inductors has more specific applications. There are three main applications of power inductors:

  • Conducted EMI noise filters in AC inputs
  • Low-pass frequency noise filters for low-frequency ripple current noise
  • Energy storage in DC/DC converters

Types of Power Inductors

While there are several types of power inductors, they can be divided into three main categories: flatwire inductors, coupled inductors, and compact SMD power inductors.

Flatwire Inductors

Flatwire inductors use a flat wire inside the choke in place of the conventional round wire. There are several advantages of flatwire inductors:

  • Large wire surface (thus low high-frequency losses)
  • Low winding capacity (thus high self-resonant frequency)
  • Low DC resistance (thus low self-heating at high prolonged currents)
  • High packing density (thus smaller component size than comparable chokes with round wire)
  • High operating temperature (up to max. 150°C)

The WE-PDF flatwire inductors from Wurth Electronics Midcom are great inductors for high performance and low wire losses. It comes in two different sizes and is optimized for power supplies running high switching frequencies.

Coupled Inductors

Coupled inductors consist of two discrete inductors that are magnetically coupled. Benefits of coupled inductors include:

  • Current-ripple cancellation
  • Low leakage inductance
  • Increased efficiency

Wurth Electronics Midcom offers two coupled inductor families: WE-DD and WE-TDC.

The WE-DD series is one of the industry’s most-used coupled inductor families. The best feature of WE-DD is its great flexibility in size. It offers two standard footprints, each with different heights, and is available with both a crossed and a straight pin layout.

For applications in which board space or height is restricted, the WE-TDC series is the perfect alternative. This new generation of low-profile coupled inductors offers low self losses, low leakage inductance, and high mechanical stability on PCB.

To learn more about coupled inductors from Wurth Electronics Midcom or to order your coupled inductor design kit today, check out this page.

Compact SMD Power Inductors

Compact SMD power inductors are low-profile inductors that are intended for surface-mount devices. Benefits of compact SMD power inductors include:

  • Wide inductance
  • Low DC resistance

Wurth Electronics Midcom carries two new series of compact SMD power inductors: WE-PMMI (Power Multilayer Metal-Alloy Inductor) and WE-PMCI (Power Molded Chip Inductor).

These power inductors are ideal for highly efficient DC/DC switching controllers for a low space requirement. You can learn more about them here.

Tips for Selecting Power Inductors

With so many power inductors available, it can be tough to know which one to pick for your design. Luckily, Wurth Electronics Midcom has plenty of resources to help you select the right power inductor.

First, you can download this PDF with eight design tips for power inductors. It’s a practical, handy guide for choosing the right power inductor for your DC/DC converter.

Also, you can try our top-rated REDEXPERT design tool. With REDEXPERT, developers can simulate our power inductors from Wurth Electronics Midcom with the click of a button. It features the world’s most precise AC loss calculation, so you can determine your power inductor losses with confidence. The best part? It’s completely free!

Popular Power Inductors from Wurth Electronics Midcom

In addition to the power inductors already listed, Wurth Electronics Midcom features several popular power inductor products, including WE-MAPI and WE-EHPI.


WE-MAPI is the world’s smallest power inductor made from magnetic iron alloy. With a package height of just 1 millimeter and a footprint of 1.6 x 1.6 mm, WE-MAPI is extremely tiny — but extremely strong.

There are many advantages to the WE-MAPI series of SMD shielded power inductors:

  • High rated currents
  • Compact design
  • Magnetically shielded
  • High current capability
  • High saturation currents
  • Low leakage flux noise
  • Several sizes available

To learn more about the world’s most efficient power inductor, you can watch this video or visit our WE-MAPI information page.

Ready for free samples or more product info? See our design kits and WE-MAPI product page.


The WE-EHPI series of power inductors is designed for energy harvesting applications. These power inductors offer high efficiency based on a very low ohmic resistance of each winding und a core especially developed for a rugged environment.

Other benefits of WE-EHPI include:

  • Low profile (4 mm)
  • Small footprint (6 x 6 mm)
  • Very low secondary RDC
  • Multiple options of turn ratios available
  • Separated welding/soldering pads for increased reliability
  • Optimized winding technology for increased performance

To learn more, visit our WE-EHPI product page. You’ll be able to see a full list of energy harvesting applications as well as order free samples.

More Power Inductors from Wurth Electronics Midcom

That’s just the beginning of our resources available for power inductors.

To see our full range of product offerings, browse our power inductors in our online catalog, or use our search tool. You can also read our blog posts on power magnetics.

Trilogy of Magnetics Design Guide

Last but not least, you need to know about our Trilogy of Magnetics design guide.

Now in its fourth edition, the new and improved Trilogy of Magnetics is a complete design guide for all things power magnetics. The guide is divided into three main sections — Basic Principles, Components, and Applications — and serves as your one-stop shop for information on inductive components.

If you’re interested in learning more about power inductors, you can read free extracts from the book, or order the Trilogy of Magnetics today!