There has been a lot of hype and promises on wide-bandgap semiconductors, with misinformation at both ends of the spectrum. Rumors and speculation are muddying the waters, making it difficult to gain a solid perspective on the state of the art of Gallium Nitride (GaN) and Silicon Carbide (SiC) devices.
We recently attended the Applied Power Electronics Conference (APEC) held this year in Anaheim, California, where we were able to talk to four CEOs whose companies are at the forefront of the wide-bandgap revolution. We asked them about the current state of the art, not the promises of the next generation of products, nor the potential of the technology. We asked them about what they and their customers are doing now.
Navitas’ Gene Sheridan
In this video, Gene Sheridan, CEO of Navitas, talks about the company's GaN-based driver-on-substrate technology. The company’s GaNFast Power ICs AllGaN process uses GaN’s lateral structure to enable the monolithic integration of power FETs, drivers and logic into a single IC. This integration minimizes delays and eliminates parasitic inductances, reducing propagation delays down to 5 ns, with a dV/dt up to 200 V/ns.
Direct connection between the control IC’s digital PWM output and the GaNFast’s PWM input ensures a simple, minimal component count, rugged solution. Integration also eliminates gate overshoot and undershoot, while zero inductance on-chip insures no turn-off loss. This lack of ringing or overshoot makes tight control of deadtime easy in half-bridge circuits.
United SiC’s Chris Dries
United SiC’s approach is also a bit different from the wide-bandgap mainstream, being one of the only companies in the space offering epitaxial SiC devices. The company’s technology got a massive vote of support in the recently-announced strategic investment and long-term supply agreement from Analog Devices. In this video, Chris Dries, CEO of United Silicon Carbide, talks about the company's developments and products, as well as the major business partnership recently announced with Analog Devices.
At the show, the company released a range of SiC JFET die suitable for co-packaging with a controller IC with built-in low-voltage MOSFET to fabricate an extremely fast, cascode-based, 20-100 W Flyback product. Ranging from 650 V to 1700 V, these normally-on SiC JFETs enable simplified start-up implementation with zero standby dissipation and are ideal for the large Flyback AC-DC applications market.
Alex Lidow of EPC
Alex Lidow has been a wide-bandgap advocate since his days running International Rectifier, and his latest endeavor, Efficient Power Conversion, is at the forefront of GaN-based device development. In this video, EPC CEO Alex Lidow talks about the various design-ins at the show that underscore the advantages GaN-based devices can provide.
At APEC, the company unveiled the EPC2052, a 100 V GaN transistor with a maximum RDS(on) of 13.5mΩ, and a 74 A pulsed output current for high efficiency power conversion. Measuring 1.50mm x 1.50mm (2.25 mm2), operating in a 48V to 12V buck converter, the EPC2052 achieves greater than 97 percent efficiency at a 10 A output, while switching at 500 kHz and greater than 96 percent at a 10 A output while switching at 1 MHz.
GaN System’s Jim Witham
GaN Systems has been a leader in the wide-bandgap space, with a lot of available products and quite a few design-ins. In this video, GaN Systems' CEO Jim Witham explains several of the latest design-ins using their devices. These solutions include a low-current 3.5A, 8A, and 11A evaluation kit with EZDrive circuit, which eliminates the need for a discrete driver, half-bridge and bridgeless totem pole PFC reference designs utilizing uPI Semiconductor drivers and GaN Systems 100 V GaN E-HEMTs, and a high-performance Insulated Metal Substrate (IMS) half-bridge thermal mounting solution.
Other design-ins include a Half Bridge Daughter Card, with safety and protection features, fast loop response, and integrated chip functionality, which helps reduce component count. These solutions are suited for industrial and automotive markets and offer features not previously available with existing GaN Driver IC’s.
It is becoming more and more apparent, even to the naysayers, that wide-bandgap devices have arrived and are here to stay. In fact, the pressure from wide-bandgap is so strong that it is fomenting the development of better silicon-based devices in response. The important thing to remember is that even though GaN and SiC have “arrived,” wide-bandgap devices are still far from mature, and there is further growth and development ahead.