While there is a growing cadre of start-ups developing GaN power devices, this year’s PCIM Europe was notable for the number of major semiconductor makers introducing and showing GaN products. Major GaN developments were revealed by International Rectifier Corp. (IR), ON Semiconductor, Inc., Panasonic Industrial Devices Semiconductor Division and RF Micro Devices, Inc. (RFMD). All these major suppliers were showing high-voltage GaN power switches in various configurations and packages. And in each case, the devices are offered as ‘normally-off’ switches.
Of the major power semiconductor makers, IR has been offering GaN devices in production for the longest time. IR was not only showing their "GaNpowIR" devices being used in a commercial audio amplifier, they shared their product roadmap for the next couple of years with PowerPulse. That roadmap starts with the 5×7.65 LGA packaged 100V, 35mOhm GaN half bridge device being used in the audio amplifier. At this year's PCIM, IR was showing its new 135mOhm and 70mOhm GaN cascade devices both in a 6x8mm QFN package and rated for 600V. Next year, the company plans to increase the complexity of its GaN offering with a 600V Cascode half-bridge including an integrated driver IC all in a 8x9mm QFN package.
Both RFMD and Panasonic were showing GaN switches that are currently available for sampling and are scheduled to enter production by the fourth quarter of this year. RFMD was showing two GaN devices and three evaluation boards (EVBs). The devices included the RFJS3006F a 650V normally-off source-switched FET (SSFET) that is RFMD's version of a Cascode structure. It is rated for 30A and 45 mOhms in a TO247 package. RMFD's RFJS1506Q SSFET is a 15A, 85 mOhm device offered in a 8x8mm PQFN package. RFMD also was showing three EVBs, a 1kW synchronous boost converter using the PQFN-packaged GaN device; plus a 2.4kW boost converter and a 3kW bridgeless totem-pole PFC design both using the TO247 GaN device.
Panasonic was showing a single device, but with a roadmap for three additional devices in the same family scheduled for near-term introduction. The first device in Panasonic's GaN offering is rated for 600V and 15A with an on-resistance of 71 mOhms in a TO-220D package. All the Panasonic GaN devices feature the company's proprietary "gate injection transistor" (GIT) structure that is a single-chip, Normally OFF device structure, but is not a Cascode. It features stable Vth over the entire temperature range, allows switching up to 1MHz+ and provides a "zero reverse recovery" characteristics. These initial devices are currently in sampling with production scheduled for the fourth-quarter of this year.
Panasonic was also showing four EVBs including a 1kW boost circuit operating at 500kHz, a 1.2kW bridgeless totem-pole PFC section operating at 100kHz, a full-bridge LLC resonant dc-dc converter rated for 1kW switching at 1MHz and a second full-bridge LLC resonant dc-dc converter rated for 1kw and operating at 350kHz. The company also showed laboratory samples of three additional GaN devices, all rated for 600V. A 10A, 147 mOhm device and a 30A, 34 mOhm device both in a TO-220D package and a 15A, 56 mOhm device in a 8x8mm QFN package. Those three devices are expected to enter production in 2015.
Aiming further in the future, ON Semiconductor was showing its comprehensive program started in 2013 to bring GaN-based 650V products to the market in 2016. ON has established a GaN Pilot line leveraging existing silicon manufacturing facilities in Oudenaarde, Belgium. The company has established a 650V GaN D-HEMT platform development program with engineering and production masksets with current/Ron scalability from 1Ohm (2A) down to 38mOhm (50A). And the company is actively engaged with numerous European GaN development programs as well as several R&D partnerships with major power electronic system OEMs. The result of these development activities is expected to be the announcement of GaN-based power modules in 2016.