5 June 2018

Transphorm’s new Gen III GaN power conversion platform increases noise immunity and reduces switching noise

© Semiconductor Today Magazine / Juno PublishiPicture: Disco’s DAL7440 KABRA laser saw.

Transphorm Inc of Goleta, near Santa Barbara, CA, USA — which designs and manufactures JEDEC- and AEC-Q101-qualified high-voltage (HV) gallium nitride (GaN) field-effect transistors (FETs) for high-voltage power conversion applications — has announced availability of its third-generation (Gen III) 650V GaN FETs. Power transistors built on Gen III technology yield lower electromagnetic interference (EMI), increased gate noise immunity, and greater headroom in circuit applications, claims the firm.

The latest evolution of the platform stems from knowledge gained from working with customers on end-product designs now in production or soon to be released. Gen III devices being released include the TP65H050WS 50mΩ FET and TP65H035WS 35mΩ FET, both available now in standard TO-247 packages, priced at $8.86 and $11.55 respectively (in 1000-unit quantities). Optimal output ratings are for 1.5-5.0kW applications, depending on design criteria. Markets include broad industrial applications, data centers, merchant power supplies, and renewables.

Transphorm says that, since it has control over each critical stage of FET development, insight gained during customer development projects, along with Gen I and Gen II platforms, can be applied to the GaN-on-Si technology to increase the transistor’s quality, reliability and performance. Data is often gathered that also informs development techniques that can simplify design complexity, increase safety margin and/or positively affect power system performance, adds the firm.

Transphorm says research that led to Gen III produced both opportunities: increased benefits now inherent to the GaN technology itself and new design methods augmenting the FET’s performance. Further, the design and fabrication innovations enable it to reduce device price.

Also, incorporation of a new MOSFET along with other design modifications enable Gen III devices to deliver:

• an increased threshold voltage (noise immunity) to 4V from 2.1V for Gen II, eliminating the need for a negative gate drive; and
• a gate reliability rating of ±20V; an 11% increase versus Gen II.

As a result, switching is quieter, and the platform delivers performance improvement at higher current levels with simple external circuitry, says Transphorm.

Regarding learned design techniques, Transphorm published solutions for oscillation suppression in its app note 0009: ‘Recommended External Circuitry for Transphorm GaN FETs’. Example recommendations include the use of DC-link RC snubbers and switching-node RC snubbers that add further stability without adverse impact on efficiency. Notably, the solutions can benefit half-bridge and bridgeless totem-pole PFC topologies.

“It is important to us to evolve our GaN technology based on customer need and real-world experience,” says Philip Zuk, VP of technical marketing. “Our Gen III FETs exemplify what’s possible when we adhere to that basic philosophy,” he adds.

“We’ve brought forth a safer, more cost-effective high-voltage GaN FET,” says Dr Yifeng Wu, senior VP of engineering. “These transistors will be seen by customers as the new power semiconductors delivering invaluable efficiency, high power handling capability and other performance advantages with ease of use,” he believes.

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

Visit: www.transphormusa.com