gesponsertMagnetic components for high power densitye More power, less space: Magnetics becomes a system-level design issue

Higher switching frequencies make magnetic components smaller, but they also increase the demands on losses, thermal management and EMC. Elytone addresses these requirements with proven product designs and custom engineering for power supplies, e-mobility, energy storage and AI infrastructure.

More power, less space: This requirement now runs through almost every area of power electronics. Space is limited in a server power supply, just as it is in a DC/DC converter in a vehicle or a compact industrial drive. At the same time, systems are expected to become more efficient, generate less heat and meet stricter electromagnetic compatibility requirements.

Higher switching frequencies are therefore an important part of the answer. They allow magnetic components to become smaller and increase power density. But this reduction in size does not come for free. What may initially look like a smaller transformer on the data sheet can quickly affect the entire power design.

This is exactly the area Elytone works in. The Taiwanese company has been developing and manufacturing electronic components for more than 45 years and focuses particularly on magnetic components for power electronics. These include transformers, inductors, chokes and other components for power conversion and EMC.

Alongside proven product designs, Elytone offers custom development and engineering support for applications where standard solutions are not sufficient.

Higher frequency saves space, but also increases losses

When the operating frequency of a converter increases, its magnetic components can become smaller. This is one reason why the development of SiC and GaN power semiconductors is also changing magnetics. Faster-switching power devices allow higher frequencies – and therefore more compact passive components.

Elytone sees a clear trend toward high-frequency designs and planar transformers. Conventional wire-wound transformers reach their limits especially where low profiles and high power density are required. Planar structures and PCB windings can reduce volume and allow the geometry to fit the available space more closely.

But that does not solve the whole problem. Core and copper losses still have to be controlled, while skin and proximity effects increasingly influence the windings. Simply scaling down an existing transformer is therefore not enough. Core material, geometry, conductor layout and operating frequency have to work together.

At that point, a component issue becomes a system issue. A transformer may work electrically at the required frequency and still reach its thermal limits under real operating conditions. Losses that were relatively easy to remove from a larger component are now concentrated in a much smaller volume.

More power in less space makes heat part of the design

AI servers, charging infrastructure, battery systems and industrial power supplies are expected to handle more power without becoming proportionally larger. For magnetics, this increases more than just the electrical load. The path by which heat leaves the component also becomes part of the design.

Elytone refers to thermal paths that have to be considered during development. Depending on the application, this can include integration with heat sinks, potting materials or the customer’s cooling system.

That means looking beyond the transformer itself. How the component is mounted on the PCB, which materials surround it and where the heat can actually go all affect the thermal balance. Even relatively small additional losses can matter in a compact converter – and in a data center, the same effect is multiplied across a large number of power supplies.

Faster switching also makes EMC more difficult

Another challenge is electromagnetic compatibility. As devices become more compact, power and signal paths move closer together. At the same time, higher frequencies place greater demands on EMC design.

Custom chokes and filters are therefore another part of Elytone’s development work alongside transformers. Common-mode chokes face much the same challenge as other components: they have to become smaller while still providing sufficient noise suppression.

According to Elytone, European customers in particular place high demands on EMC, efficiency, thermal stability and long-term reliability.

These targets cannot be optimized independently. A winding design that reduces losses can also change parasitic characteristics; a smaller component may save space while making heat removal more difficult. In the end, the converter as a whole has to work – electrically, thermally, in terms of EMC and at a cost that fits the application.

Standard parts are not always enough for production-ready designs

Elytone therefore works with two approaches. For applications whose requirements can be met with existing and proven designs, the company can draw on established product platforms. Where space constraints, switching frequency, thermal budgets or EMC requirements go beyond those designs, custom engineering comes into play.

Depending on the project, cooperation can range from adapting an existing design to developing a completely new solution. Elytone aims to become involved as early as possible, from the initial concept and electrical and mechanical design through to prototypes and later volume production.

This does not mean that every power supply needs a completely new transformer. If an existing design meets the requirements, there is little technical or economic reason to develop a custom version. The tighter the design constraints become, however, the more difficult that choice becomes.

Custom magnetics then often does not start with a part number. First come the operating conditions of the converter: input and output, power level, topology, switching frequency, insulation requirements, height, temperature and acceptable losses. The final component design follows from these requirements.

AI servers and e-mobility share the same basic requirement

Elytone currently sees switching power supplies and DC/DC converters as important growth areas. Demand for high-frequency transformers is growing particularly strongly, according to the company.

The applications behind this could hardly be more different. On one side are AI servers, data centers and energy storage systems. On the other are e-mobility and charging infrastructure. Industrial drives, automation and other power supply applications add to the list.

From a technical point of view, however, many of them come down to the same requirement: more power in less volume, preferably without additional losses or thermal problems.

Elytone is therefore already working with architectures around 800 V HVDC power distribution for AI data centers. At the same time, the company is following developments in solid-state transformers and higher voltage levels in e-mobility.

SiC and GaN also change the components around the switch

For the coming years, Elytone sees three closely connected directions: higher frequencies, higher power levels and greater use of planar magnetic components.

One important driver is the growing adoption of SiC and GaN. Wide-bandgap semiconductors enable higher switching frequencies. The magnetics have to be able to follow.

Otherwise, the problem simply moves somewhere else.

Transformers, inductors and EMC components also have to be adapted. For Elytone, this mainly means development work on core materials, winding structures and geometries. AC losses have to be reduced, while higher power levels also increase the demands on insulation and thermal management.

A faster switch alone does not make a more compact converter. Only when the other components can handle the new operating conditions can the potential increase in power density actually be transferred to the system.

European customers bring their own set of requirements

Europe is not a new market for Elytone. The company wants to become involved earlier in development projects, particularly in e-mobility, industrial automation, renewable energy and energy storage.

European customers, Elytone says, often combine high technical requirements with strong cost pressure. Efficiency, thermal performance, EMC and long-term reliability have to be right, while the product still has to make economic sense. That is another reason not to leave magnetics until late in a project: if a design turns out to be too hot, too expensive or problematic in EMC testing, changes become more difficult once topology and components are fixed.

Elytone does not see growing demand for energy storage as a European issue alone. As renewable energy expands and the power requirements of data centers increase, so does the need for systems that store, convert and distribute energy.

In the end, the transformer does not just get smaller

The development of modern power electronics can easily be told as a story of smaller and smaller components. Higher switching frequencies allow smaller transformers, planar designs reduce height, and better semiconductors reduce losses.

The design does not become simpler because of that.

As frequency and power density increase, the individual design decisions become more closely connected. Core material and winding design affect losses. Losses determine the thermal design. Geometry and switching behavior affect EMC. And in the end, all of this has to become a component that can be manufactured reliably.

The magnetic component gets smaller. Its role in the design decisions does not.

This is why magnetics in many modern power architectures can no longer be treated as something that is simply selected near the end of the design process. (sb)

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