POWER ELECTRONICS HANDBOOK
Power supply designers
take a hard look at soft magnetics The promise of high efficiency and small size
LELAND TESCHLER | EXECUTIVE EDITOR
brought by super-fast switching power supplies could be delayed by a lack of magnetic materials that are up to the task.
EYEBALL
the schedule for APEC, considered the premier technical conference for power electronics, and you’ll notice a number of sessions devoted to magnetics. The interest in magnetics stems from gallium-nitride and silicon-carbide semiconductors. These wide-bandgap semiconductors have “on”resistances and related losses that are one-tenth that of devices based on silicon which reduces both their inherent capacitance and resistor-capacitor time constant. The result is lower losses per switching cycle, a consequence that lets GaN and SiC-based switch-mode power supplies switch at much higher frequencies – sometimes on the order of hundreds of megahertz. Therein lies the reason for the APEC sessions on magnetics. Operation at these higher frequencies can drastically reduce the size of the magnetic components involved in energy storage, but it is tough to find magnetic materials that can operate at such frequencies without experiencing a lot of energy loss. So the quest is on to find better ones.
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DESIGN WORLD — EE NETWORK
Soft Magnetics — Power Electronics HB 02-19.indd 38
2 • 2019
Cores on inductors like these become more difficult to devise as the operating frequency rises. Researchers are now examining exotic candidate materials such as nano composites in an effort to handle power supply switching frequencies extending into the hundreds of megahertz.
eeworldonline.com | designworldonline.com
2/20/19 9:27 AM
