MasterGaN Reference Design from STMicroelectronics Demonstrates Heatsink-Free 250W Resonant Converter

by SSI BureauJune 4, 202120

STMicroelectronics has released the first reference design for its MasterGaN power packages, demonstrating how the new highly integrated devices increase power density, boost energy efficiency, simplify design, and accelerate time to market.

The EVLMG1-250WLLC reference design is a 250W resonant converter with a 100mm x 60mm board outline and 35mm maximum component height. It features the MasterGaN1, which contains one half-bridge STDRIVE gate driver optimally connected to two 650V normally-off GaN transistors with matched timing parameters, 150mΩ on-resistance (Rds(on)), and 10A maximum current rating. The logic inputs are compatible with signals from 3.3V to 15V.

MasterGaN1 is suitable for high-efficiency soft-switching topologies including resonant converters, active clamp flyback or forward converters and bridgeless totem-pole PFC (power-factor correction) in AC/DC power supplies, DC/DC converters, and DC/AC inverters up to 400W.

The primary side runs heatsink-free, leveraging the high efficiency of the GaN power transistors. In addition, GaN’s superior switching performance allows a higher operating frequency than ordinary silicon MOSFETs, permitting smaller magnetic components and capacitors for greater power density and reduced bill of materials.

Designed for a nominal 400V supply, the EVLMG1-250WLLC provides a 24V/10A output and achieves maximum efficiency above 94%. Benefiting from MasterGaN’s integrated safety features, the converter output is protected against short circuit and overcurrent. There is also brown-out protection and an input-voltage monitor that permits sequencing within an array of DC/DC converters and prevents a motor from starting under low-voltage conditions.

ST’s MasterGaN family comprises pin-compatible integrated half-bridge products including symmetrical and asymmetrical configurations, housed in a 9mm x 9mm low-profile GQFN package. Containing circuitry rated up to 650V, the packages have over 2mm creepage distance between high-voltage and low-voltage pads. MasterGaN modules are available in various power ratings, allowing engineers to scale their designs with minimal hardware changes.