Impact of GaN technology on EMI
While attending DesignCon several months ago, I had the chance to hear an interesting keynote presentation by Alex Lidow, CEO of Efficient Power Conversion, Inc., speaking on the upcoming development in gallium nitride (GaN) technology for high-power switching devices.
I also had the fortune of meeting Steve Sandler, author of the book, Power Integrity—Measuring, Optimising, and Troubleshooting Power Related Parameters in Electronic Systems, who was associated with measuring the picosecond edge speeds of these devices (see his article in the References section).
Because of the fast switching speeds and related higher efficiencies of these new power switches, we’ll expect to see them primarily applied to switch-mode power supplies and RF power amplifiers. They may broadly replace existing MOSFETs and have lower “on” resistance, less parasitic capacitance, are smaller, and faster. I’m already noticing new products using these devices. Other applications include telecom DC-DC, wireless power, LiDAR, and class D audio. Obviously, any semiconductor device that switches in a few picoseconds is likely to generate large amounts of EMI. In order to evaluate these GaN devices, Sandler arranged for me to test some evaluation boards. The one I chose to characterise was a half-bridge 1MHz DC-to-DC buck converter from Efficient Power Conversion (EPC9101, figure 1). Refer to the References section for additional information on this demo board, plus several others.