Dave Munguia from Pulse Electronics recently explained to us that when you’re working with gallium-nitride transistors and other wide-bandgap semiconductors, there are special challenges associated with inductors. Pulse Electronics addressed the issue in a paper they delivered at APEC 2019. Munguia says they picked five different constructions of inductors from the catalogs of different manufacturers. They did so thanks to a specialized machine they acquired that allows them to fully characterize the inductors at different frequencies, duty cycles, and so forth. Technicians excite the inductors with the actual waveforms that will be used in the final application when making measurements.
Munguia says they test the inductors not only at different frequencies but also at very low duty cycles. The results were interesting, he says. For some level of inductance, there are constructions that seem to work better than others, but once you exceed some level of inductance, a different construction works better. Munguia says the company still needs to do a lot of more work but has made a good start.
Munguia also says circuit designers working with GaN need to have several factors in mind when specifying an inductor. One, obviously, is the type of efficiency they’re looking for, the footprint they have in mind, and, also obviously, the inductance value. All in all, when suppliers like Pulse design inductors for specific applications, they end up doing a lot of engineering with the circuit designers.
For more information, got to www.pulseelectronics.com,