650V GaN FET, low on-resistance, in TO-247 package

May 24, 2016 // By Graham Prophet
Gallium nitride device maker Transphorm recently introduced what it positions as the industry’s only fully-qualified 650V-rated FET, in 'conventional' packaging. It claims the lowest R(on) of any such device at 41mOhm; and ultra-low Qrr of 175 nC to increase power density and achieve higher efficiencies over a broad range of power levels.

Why TO-247? Transphorm acknowledges that to fully exploit the potential of GaN, there is an argument for more advanced packing [with lower inherent inductance]. However, the company says that to get designers working with GaN, the company has opted for a package that designer know and trust. There is a great deal of benefit to be gained from switching to GaN and moving from switching frequencies of, say, 10-20 kHz to 50 to 70 kHz, “It doesn't need to be 300 kHz [to see worthwhile gains]”. Transphorm sees a great deal of design activity around the adaptor market; external PSUs that operate in a tightly-regulated environment and where size and efficiency gains are always welcome. In this area, “It's all about cost,” a Transphorm spokesman commented, and “GaN will see a double-digit cost reduction each year out to 2020.”


The TPH3207WS GaN FET claims lowest on-resistance (41 mOhm) in a TO-247 package that reduces system volume as much as 50% without sacrificing efficiency. The device’s low Rds(on) and ultra-low Qrr (175 nC) bring the benefits of GaN to applications that previously relied on silicon, enabling engineers to achieve power-dense solutions with reduced component count and improved reliability in high-voltage power conversion applications.


The TPH3207 improves system reliability, performance and power density in an easy-to-handle cascode configuration. These advantages are being realized in hard-switched bridges and the continuous conduction mode (CCM) bridgeless totem-pole power factor correction (PFC) designs being used in on-board chargers, solar inverters, telecom power supplies and other power conversion applications. Transphorm’s GaN FET portfolio is also extended with the introduction of the TPH3208 family (130 mOhm) in industry-standard TO-220 and PQFN packages.


Transphorm emphasises its fully-qualified GaN technology; qualification and long-term reliability of all Transphorm devices, including extended tests for early infant mortality failure and long-term wear out failures, is unmatched by any GaN manufacturer. Its cascode configuration (EZ-GaN) can be easily driven with off-the-shelf