COVER STORY ADVERTISEMENT FEATURE


AND THEN FILTER IT: FOR MODERN ENGINEERS


Figure 2 – High IP-rated EMC filter


IP-Rated Filters for Harsh Environments Dust, moisture, vibration, and heat are all enemies of consistent filter performance. High IP-rated filters (e.g., IP54, IP65, IP67) are essential in rail, marine, or outdoor applications. These robust enclosures protect the filter components


without compromising EMC performance.


Water Cooling for High Power Density Traditional air cooling is often insufficient for high-power inverters, EV chargers, or industrial drives. In these scenarios, water- cooled filters and chokes can keep systems compact and efficient while maintaining performance under thermal stress.


Filters for Long Cable Runs Cables can act as unintentional antennas, picking up or radiating EMI. Specialised filters for long cable runs help attenuate common- and differential-mode noise close to the source or load while also addressing potential reflections and impedance mismatches.


power electronics is transforming the landscape of EMC design. These wide bandgap devices offer faster switching speeds, higher efficiency, and reduced losses compared to traditional silicon, essential for next-generation power supplies, inverters, and EV chargers. However, these benefits come with a trade-


off: higher di/dt and dv/dt switching rates, significantly increasing the potential for electromagnetic emissions. Key implications for EMC design include:


• More aggressive conducted and radiated noise, particularly in the MHz range. • Optimised PCB layout, minimising loop areas and parasitic capacitances. • Filters with higher frequency attenuation capability often require advanced materials and compact, low-inductance configurations. • Increased importance of shielding, grounding, and impedance control across the entire system. Designers working with GaN and SiC must


often adopt a more holistic EMC strategy, combining high-speed layout techniques with appropriately specified input/output filters. In many cases, pre-compliance testing and simulation become essential tools for validating designs early and avoiding costly redesigns down the line.


PARTNERING UP: WHEN TO CALL IN THE EXPERTS While in-house teams can often manage standard filtering needs, working with specialist EMC filter manufacturers benefits specific applications. These companies bring product expertise and


• Custom filter solutions tailored to high IP, thermal, or footprint constraints


• Simulation support and datasheets with real- world performance metrics


• Consultation on placement, grounding, and integration with other EMC mitigation measures This is especially useful for companies


operating in highly regulated sectors, such as rail, medical, and energy, where compliance and reliability are business-critical.


CONCLUSION: MAKE NOISE, BUT MAKE IT COMPLIANT EMI isn’t going away; faster switching, denser electronics, and more interconnected devices mean it’s becoming more challenging. But with the right strategy – combining intelligent filter design, accurate simulation, and practical implementation – noise becomes something you can control, not fear. Whether you’re designing a drive system for a wind turbine, an EV charger, or a safety-critical rail component, EMC filtering is no longer an afterthought. It’s vital to deliver reliable, market- ready products that meet both performance expectations and regulatory demands.


Figure 4 – REO DC Power Supplies


So go ahead — bring the noise. Just make Figure 3 – EMC results for long cables


Wide Bandgap Devices and EMC: The GaN and SiC Effect The growing adoption of Gallium Nitride (GaN) and Silicon Carbide (SiC) semiconductors in


a deep understanding of the standards and real-world installation scenarios. A good filter partner can offer:


• Pre-certified filters aligned with EN standards


sure you know how to filter it. REO UK


T: 01588 673411 E: marketing@reo.co.uk www.reo.co.uk


APRIL 2025 DESIGN SOLUTIONS 13


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