-
- News
- Books
Featured Books
- design007 Magazine
Latest Issues
Current IssueAll About That Route
Most designers favor manual routing, but today's interactive autorouters may be changing designers' minds by allowing users more direct control. In this issue, our expert contributors discuss a variety of manual and autorouting strategies.
Creating the Ideal Data Package
Why is it so difficult to create the ideal data package? Many of these simple errors can be alleviated by paying attention to detail—and knowing what issues to look out for. So, this month, our experts weigh in on the best practices for creating the ideal design data package for your design.
Designing Through the Noise
Our experts discuss the constantly evolving world of RF design, including the many tradeoffs, material considerations, and design tips and techniques that designers and design engineers need to know to succeed in this high-frequency realm.
- Articles
- Columns
- Links
- Media kit
||| MENU - design007 Magazine
Würth Elektronik Defines an Electrical Property for Molded Inductors
July 18, 2024 | Wurth ElektronikEstimated reading time: 2 minutes

Würth Elektronik has developed a new testing procedure for determining the maximum operating voltage of molded inductors. The manufacturer of electronic and electromechanical components introduces developers to the electrical property of dielectric strength and what happens if it is exceeded in an application which is described in Application Note 126 (www.we-online.com/ANP126). The molded inductors from the Power Magnetics product portfolio (e. g., WE-MAPI, WE-XHMI, WE-LHMI) are now successively supplemented with the value of the maximum operating voltage Vop as a new parameter in the specifications.
Based on the new testing procedure, Würth Elektronik defines the maximum operating voltage Vop in its data sheets. This represents the voltage at which an inductor can be operated continuously in the application without impairing performance, risking damage or overheating the inductor. The operating voltage is therefore a limit value for the input voltage, up to which the inductor can be used reliably in an application without irreversible damage.
The test concept examines the behavior of inductors up to their voltage limits under realistic conditions in a DC-DC full-bridge converter (voltage transients of up to 60 V/ns and frequencies of up to 2 MHz). The approximate voltage limit is firstly evaluated using a short-term test. The operating voltage is then defined on this basis and verified in a long-term test.
Background
Thanks to steady technological advancement in the semiconductor industry, today’s MOSFETs can now achieve high current densities and short switching times. For this reason, the question of the dielectric strength of coils has become increasingly important in recent years when it comes to selecting the appropriate inductor.
What’s more: Continuous optimization of the production process and the material composition of molded inductors enable high permeability of the ferrite material to achieve the highest possible inductance values in the smallest possible package space. The power density per volume can therefore be raised continuously.
This entailed a steady increase in the proportion of iron powder or iron alloys relative to the insulation of the binder, resulting in the distance between individual grains becoming progressively smaller. If the insulation barrier between the individual metal particles is not high enough for the voltage applied in the application, a conductive path is created through the core material, caused by arcing between the individual metal particles. It may be observed in the application that the profile of the ripple current changes. Schematically, there is now a resistor parallel to the inductor.
The consequences: Self-heating of the coil rises dramatically due to the rising losses. These additional losses considerably reduce the inductor’s efficiency. The advantage of a DC/DC converter – to transmit voltage levels with high efficiency – is lost.
Suggested Items
TI Teams with NVIDIA to Bring Efficient Power Distribution to AI Infrastructure
05/26/2025 | Texas InstrumentsTexas Instruments technologies will help enable NVIDIA's future 800V high-voltage DC power-distribution systems for next-generation AI data centers.
Hitachi Energy Boosts Pennsylvania Investments to Over $70 million to Meet Surging Demand for Sustainable Grid Infrastructure
04/21/2025 | Hitachi EnergyHitachi Energy announced that it has increased its investments to more than $70 million USD in Pennsylvania. Originally announced in 2024 as part of a $155 million nationwide investment in U.S. manufacturing capacity.
Keysight Unveils 3kV High Voltage Wafer Test System for Power Semiconductors
10/10/2024 | BUSINESS WIREKeysight Technologies, Inc. introduces a 4881HV High Voltage Wafer Test System expanding its semiconductor test portfolio. The solution improves the productivity of power semiconductor manufacturers by enabling parametric tests up to 3kV supporting high and low-voltage in one-pass test.
STAr Sagittarius Series Intelligent Integrated Test System
08/12/2024 | PRNewswireSTAr Sagittarius Series, launched in 2001, is an intelligent test software designed for semiconductor parametric and reliability test and enables to integrate capacitance-voltage (CV) and current-voltage (IV) measurements into one single platform.
Knowles Extends Operating Life of Electronic Devices with New Arc Suppressor/Snubber Network Devices
08/08/2024 | PRNewswireKnowles Corporation, a market leader and global provider of advanced micro-acoustic microphones and speakers, audio solutions, and high-performance capacitors and RF products, announced the QAS Series, a new line of RC-type Arc Suppressor/Snubber components that extend the operating life of electronic and electro-mechanical devices.