Transphorm’s GaN used in AES’ power supplies for large passenger airplanes

Transphorm Inc of Goleta, near Santa Barbara, CA, USA — which designs and manufactures JEDEC- and AEC-Q101-qualified 650V gallium nitride (GaN) field-effect transistors (FETs) — says that its customer AES Aircraft Elektro/Elektronik System GmbH of Bremen, Germany has released its first 650V GaN-based power supplies.

Serving the aviation industry, AES provides products and services ranging from electrical engineering to certification and testing. Its latest switch-mode power supplies are used by large CS-25 airplane manufacturers (e.g. Airbus A318-A321, A330, A340, A380 and Boeing B767, B787 VIP aircraft) and use Transphorm’s GaN FETs to increase overall system efficiency by more than 10% compared with competing silicon-based power supply units (PSUs).

The two GaN-based switch-mode power supplies are the PS250X 500W system and the PS6120 1200W system (both currently shipping). Both support a 96–130VAC/360–800Hz input voltage with a 28VDC continuous power output at 15A for the 500W system and 42A for the 1200W system.

Further, AES certified the PS250X and PS6120 as DO-160 compliant — meeting the more than 25-point stringent standard of the Radio Technical Commission for Aeronautics (RTCA). This standard assesses system impact and performance under various external and internal conditions on aircraft — ranging from pressure and temperature to voltage spikes and RF emissions.

The flagship 500W PS250X is said to be the first passively cooled power supply at 420W and deploys Transphorm’s GaN in a single-phase CCM boost power factor correction (PFC) topology. It offers more than 92% overall system efficiency at full load, which is claimed to be more than 10% greater than its competition. The system also yields a more than 0.98 power factor and 200mVpp nominal at 115VAC/400Hz input at full load, all within an end product that weighs just 1.4kg (~3lbs).

The 1200W PS6120 deploys Transphorm’s GaN in a fan-cooled, three-phase CCM boost PFC topology. It offers more than 91.5% overall system efficiency at full load, which is 11.5% greater than its competition. The PS6120 also yields the same power factor and nominal ripple voltage at 115VAC/400Hz input at full load as the PS250X 500W PSU, all within an end product that weighs 4.0kg (~8.8lbs).

“The aviation industry is working toward reducing climate impact through any means possible,” says Dr Andreas Hammer, head of Competence Center Power, AES. “We sought out Transphorm’s GaN to replace previously used silicon MOSFETs so that we could provide a more efficient, lighter-weight power supply,” he adds. “These supplies have the potential to make a notable impact when considering each aircraft deploys several such PSUs. After only a year of redesign, we were able to offer our customers a better power solution, while also raising the performance bar within our own industry.”

Interested in the technology’s inherent higher switching frequency, AES reviewed GaN power switch converters from several GaN device manufacturers. It ultimately selected Transphorm’s 650V GaN technology due primarily to its ease of drivability and designability — specifically because Transphorm’s GaN FETs do not require custom drivers. As a result, system design is simplified while engineers can drive the switches using technology they are already familiar with (i.e. drivers and packages). Other factors affecting AES’ selection included Transphorm’s proven reliability (underscored by its GaN platform earning both a JEDEC qualification and AEC-Q101 qualification at 175°C).

“Our two-switch normally-off GaN devices come in standard packages and require minimal supporting circuitry to drive them, which reduces the overall system size, increases reliability, and simplifies design,” says Philip Zuk, VP of worldwide technical marketing & NA sales. “It’s crucial to us that our customers can come to market quickly with a product they have confidence in,” he adds.

Tags: Transphorm GaN-on-Si GaN HEMT Power electronics

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