SiC and GaN Advances from Multiple Companies at PCIM

May 08, 2012 by Jeff Shepard

CISSOID, SemiSouth, Rohm, Powerex, Cree, Infineon Technologies, and GaN Systems were among the companies revealing developments in wide bandgap devices at this week’s PCIM event in Nuremberg. The announcements ranged from new discrete devices to modules and isolated gate drivers.

Targeting solar inverters, transportation and similar applications, CSSOID announced its Hades isolated gate driver optimized for use with SemiSouth normally-off SiC JFETs. The Hades reference design is based on CISSOID’s chipset including the Themis, Atlas and Rhea devices capable of operation over a temperature range of -55 to +225°C. In the near future, the company will introduce a reduced-cost version limited to a maximum temperature of 125°C with an expected operational life of at least 20 years. Driving SemiSouth’s SJEP120R100 SiC JFET, the test board was able to hard-switch 600V and 10A with turn-off and turn-on times of 14 ns and 24 ns, respectively.

Toward the back of the exhibition hall, SemiSouth announced two new devices, one rated for 650V/55mOhms and the second rated for 1,700V/1,400mΩ. The 650V SJDA065R055 device features a positive temperature coefficient and fast switching up to 150°C. These TO220-packaged devices are expected to find use in solar inverters, switching power supplies, PFC circuits, induction heating, UPS, motor drives and similar applications. Aimed at 3-phase power applications, the 1,700V SJDT170R1400 is being offered in a newly-developed SMD D2PAK-7L package in order to simplify PCB layout and optimize switching performance due to its lower inductance.

Near the entrance to the exhibit hall, Rohm announced mass production of a 1,200V/100A power module comprised entirely of SiC power elements. The new modules reduce losses by 85% compared ith conventional Si IGBT modules and can be switched at 100kHz or higher, more than 10X faster than comparable IGBT modules.

According to Rohm, development of full SiC modules has been impossible up to now due to unstable reliability at elevated temperatures. Rohm was able to overcome this limitation by developing unique screening methods and defect suppression technology that guarantees reliability, as well as a control system that prevents device deterioration at high temperatures making it possible for the company to mass produce SiC power modules.

This year Powerex was showing its second-generation full SiC modules. Originally introduced in 2010 as the QJD1210006/07 modules using SiC devices from Cree, the second-generation devices, the QJD1210010 (with a copper base place) and the QJD1210011 (with an AlSiC baseplate) are rated for 1,200V/100A.

Cree, which supplies the 20A SiC chips used in the Powerex modules, announced a new series of 50A devices including FETs rated for 1,200 and 1,700 V and three SiC Schottky devices. The new devices are available in die form for high-power modules for applications such as solar inverters, UPS and motor drives.

"Only Cree has the relentless innovation expertise across SiC materials technology wafer processing and deice design to make this kind of technology possible," stated Cengiz Balkas, vice president and general manager of Cree power and RF.

Also today at the PCIM Europe 2012 trade show, Infineon introduced the CoolSiC™ 1200V SiC JFET family. In order to ensure that the normally-on JFET technology is safe and easy to use, Infineon has developed a concept which is called Direct Drive Technology. In this concept, the JFET is combined with an external Low Voltage MOSFET and a dedicated Driver IC which ensures safe system start-up conditions as well as fast and controlled switching.

In the back of the main hall, GaN Systems announced the product roadmap for its GaN-on-SiC device technology. The company plans to roll out a range of diodes and transistors with voltage ranges from 150 to 1,200V, and currents from 2 to 300A. Integrated single chip half-bridge structures, full-bridge diode arrays, and GaNTetrode™ devices for power and RF applications are also compatible with the company’s unique island structure and are under development.