GaN demo board delivers 24V 250W

Called EVLMG1-250WLLC, it is designed to produce 24Vdc 10A from a nominal 400Vdc supply with maximum efficiency above 92%.

The main component is a MasterGaN1, an IC-like package containing a half-bridge driver and two normally-off 650V GaN transistors – the transistors have matched timing parameters and 150mΩ on-resistance. Its logic inputs are compatible with signals from 3.3V to 15V.

Physically open-frame and 100 x 60mm (35mm max component height), the PSU has a motherboard with the transformer, primary controller and two daughterboards: one with the MasterGaN1 on the primary side and the other on the secondary side with an SRK2001 synchronous rectifier controller and its silicon mosfets.

ST describes the PSU as a “heatsink-free 250W resonant converter”. The primary side does not need a heatsink, but the data brief shows a heatsink on the secondary side (figure 4 here) that does not seem to appear in the photo – Electronics Weekly has asked for clarification.

Protection is included against short-circuit, over-current and brown-out, and it has an input-voltage monitor for sequencing with other dc-dc converters or preventing a motor from starting under low-voltage conditions.

MasterGaN1 is intended for soft-switching topologies including resonant converters, active clamp fly-back or forward converters and bridgeless totem-pole power-factor correction in ac-dc power supplies, dc-dc converters and dc-ac inverters up to 400W.

The demo/evaluation board product page is here