10 November 2021
Transphorm’s SuperGaN Gen IV multi-kW-class power FET gains AEC-Q101 qualification
Transphorm Inc of Goleta, near Santa Barbara, CA, USA — which designs and manufactures JEDEC- and AEC-Q101-qualified gallium nitride (GaN) field-effect transistors (FETs) for high-voltage power conversion applications — says that its flagship SuperGaN Gen IV 35mΩ device has completed the Automotive Electronics Council’s AEC-Q101 stress tests for automotive-grade discrete semiconductors, representing the firm’s third automotive-qualified product line.
As with its Gen III predecessor, the Gen IV TP65H035G4WSQA device is qualified to 175°C. This junction temperature is 25°C higher than what silicon MOSFETs qualify at and is a temperature rating yet to be achieved by any other GaN solution, some of which are only qualified to 125°C, says Transphorm.
“With each generation of its GaN platform, Transphorm has increased device performance, increased power density, increased manufacturability, all while bringing the device price down closer to that of silicon devices,” comments Richard Eden, senior principal analyst at Omdia. “The automotive market is beginning to see increased interest in the benefits of GaN technology and Transphorm, having a strong AEC-Q101-qualified GaN portfolio, can fuel that adoption,” he adds. “Omdia believes that the early adoption of GaN transistors within the multi-billion-dollar automotive market could pass $100m by 2025.”
High-voltage GaN solutions positively address several electric vehicle (EV) issues. For example, GaN delivers higher power conversion efficiency from the EV battery to its drive train, enabling the use of either a smaller battery for the same range or the same size battery for extended range, reducing range anxiety.
Additionally, GaN FETs operate at higher frequencies, resulting in higher power density as well as smaller and lighter systems. These advantages benefit on-board chargers (OBCs), DC-to-DC converters, and main traction inverters while also contributing to larger battery range and faster charging. These three highlighted critical systems make battery electric vehicles (BEVs) not only drive but function properly, and GaN plays a part in all.
The AEC-Q101-qualified TP65H035G4WSQA FET delivers a typical on-resistance of 35mΩ in an industry-standard, thermally superior TO-247 package — a package configuration that is not available in any version of e-mode (enhancement-mode) GaN, it is claimed. Via its patented SuperGaN technology, the device also offers:
- A flatter and higher efficiency curve with an improved figure of merit (RON*QOSS) that shows 27-38% reduction in power loss over silicon carbide (SiC) in a similar TO-247 package-based comparison.
- Reduced package inductance, resulting in softer switching, which helps to reduce electromagnetic interference (EMI).
- Increased noise immunity (threshold voltage at 4V), eliminating sporadic turn-on due to gate transients to which other GaN technologies with threshold voltages less than 2V are susceptible in higher-power systems.
- The industry’s most robust gate at ±20V, it is claimed.
These advantages produce quieter switching and higher performance at higher current levels with minimal external circuitry compared with what other GaN devices such as e-mode require to maximize power density, reliability and system cost.
“We view GaN power semiconductors as a major differentiator in our automotive electric powertrain solutions,” says Joachim Fetzer, chief technology and innovation officer at Marelli — a global independent suppliers to the automotive sector as well as a strategic Transphorm partner. “We partnered with and have invested in Transphorm as we see their commitment to quality, reliability and manufacturing is unmatched by any other GaN supplier today,” he adds. “The automotive qualification of their SuperGaN Gen IV device is just one more proof point. It stands as a cost-effective, high-performing solution for our applications — allowing us to gain a competitive edge not just in performance and efficiency but in overall system advantages. With Transphorm, we aim to deliver more reliable electric power at a reasonable cost to our customers.”
Transphorm’s AEC-Q101 qualified TP65H035G4WSQA FET will be available in early December. The device is based on its JEDEC-qualified predecessor, the TP65H035G4WS, which is currently available from distributors Digi-Key and Mouser.