Automotive-qualified GaN power FETs work at higher temps than silicon counterparts

Transphorm Inc. announced that its third generation, JEDEC-qualified high voltage GaN platform has passed the Automotive Electronics Council’s AEC-Q101 stress tests for automotive-grade discrete semiconductors. This achievement marks the company’s second automotive-qualified product line. And, notably, its most reliable given the Gen III GaN platform’s ability to perform at 175°C during qualification testing.

Transphorm’s Gen III AEC-Q101 GaN FET, the TP65H035WSQA, offers a typical on-resistance of 35 mΩ in an industry standard TO-247 package. As with its predecessor—the 50 mΩ Gen II TPH3205WSBQA—the devices target AC to DC on-board chargers (OBCs), DC to DC converters and DC to AC inverter systems for plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEV).

Launched in June 2018, Transphorm’s Gen III devices came onto the market as the highest reliability, highest quality [Q+R] GaN FETs available. They offered lower electromagnetic interference along with increased noise immunity [threshold voltage at 4 V] and gate robustness [at ±20 V]. These advances produced quieter switching and higher performance at higher current levels with minimal external circuitry.

That commitment to Q+R influences Transphorm’s choice to conduct extended and accelerated standards testing, to include JEDEC and AEC-Q101. For this latest automotive qualification, the semiconductor manufacturer stressed the devices’ thermal limits to 25°C more than those of the standard AEC-Q101-qualified high voltage Silicon MOSFET counterparts.

Beyond proving the GaN platform’s robustness, the higher temperature testing demonstrates that Transphorm’s AEC-Q101 GaN FETs will give design engineers ample thermal headroom when developing any power system.

“Proving device quality and reliability is perhaps the most critical factor influencing customer confidence in high voltage GaN FETs—particularly in the automotive and electric vehicle markets,” said Philip Zuk, Vice President of Worldwide Technical Marketing, Transphorm. “To that end, we ensure that our GaN maintains its performance and reliability even in real-world conditions that may be far harsher than what mission profiles call for. As shown by the published reliability data, our JEDEC-qualified Gen III platform has a Field Failure FIT rate of 3, which is in line with that of Silicon Carbide. It’s this high-reliability level that allowed Transphorm to release a Gen III automotive FET at 175 degrees Celsius.”

The company’s second AEC-Q101 qualified device further validates Transphorm’s Q+R, as was also demonstrated in the January 2019 release of the industry’s first Field Reliability data and first Early Life Failure rate calculations–the source of the FIT rate referenced above.