The year 2021 was a transitional year in which the world decided to open its doors to GaN. In an interview with Power Electronics News during CES week, GaN industry experts confirmed that GaN is now proving its superiority over silicon.
The year 2021 was a transitional year in which the world decided to open its doors to gallium nitride (GaN). In an interview with Power Electronics News during CES week, Alex Lidow, CEO at EPC, said he’s convinced that GaN is now proving its supremacy over silicon. Fast chargers are currently a good consumer market for GaN, but as Lidow pointed out, the explosion of servers with rapid 48-V adoption ensures further adoption of GaN for DC/DC solutions.
“We also see rapid adoption of GaN in e-mobility applications — this is probably the news of the year, and I think it will be the story for scooters and drones that are starting to use GaN for obvious reasons such as smaller size, lighter, and more efficiency, so I think this year is a great opportunity,” said Lidow. “LiDAR has been around for several years; it’s not a new story. But what is new about LiDAR is that it is rapidly spreading horizontally into so many other markets, such as general robots and drones with collision-avoidance systems and even simple hoovers with collision-avoidance systems. Another developing market is for all the small electric motors in cars. I don’t think GaN will be adopted quickly in the traction inverter, but for applications like a fan motor, GaN makes a much quieter motor drive than MOSFETs. Also, there are seat motors, electric steering, and electric air conditioning where GaN has a place.”
GaN technology
Three megatrends are driving the evolution of power electronics: energy efficiency, electrification, and the digital economy (data everywhere). These changes need a shift in how power engineers construct their systems. As a result, there are prospects for growth all over the place. Data centers, 5G, industrial motors, micromobility, renewable energy, and electric cars are some of the less obvious high-growth fields.
In fast chargers and other consumer applications, GaN will continue to replace old silicon, and it will eventually take over in data centers and home solar energy and storage applications. On-board chargers and DC/DC converters in electric cars will increasingly use GaN technology. Stephen Oliver, vice president of corporate marketing and investor relations at Navitas Semiconductor, said in an interview with Power Electronics News during the opening of CES that he is convinced that GaN will eat into the market share of earlier SiC technology as GaN power levels climb and EV architects shift from “motor axles” to “in-wheel” drive.
At CES, Navitas will showcase its GaNFast power ICs, integrating GaN power and drive plus protection and control to deliver simple, small, fast, and efficient performance. According to Oliver, the company will also reveal how GaNFast technology has been supercharged with power-upgraded, thermally enhanced versions of the proven 650-/800-V GaNFast platform, now further upgraded to 700/800 V, to address the challenges of next-generation solar, data center, and EV fast-charging applications. In addition to the technologies and solutions on display, Navitas is also launching a competition to win a Tesla Model 3 Performance, worth over $60,000.
“As well as advancing GaN technology through higher powers and higher levels of integration and functionality, there are initiatives to support design as well as collaborations with strategic customers and partners,” said Oliver. “Recent announcements include a partnership with Anker for fast chargers; testimonials from Enphase [solar], Brusa [EVs], and Compuware [data centers]; and new application-focused design centers. Last month, we announced the opening of a new design center in Hangzhou, China, dedicated to bringing next-generation GaN power ICs and associated high-efficiency, high-power–density systems to enable data centers around the world to upgrade from silicon to GaN. This month, we opened the new Navitas EV Design Center in Shanghai, China. Each design center hosts a highly experienced team of world-class power system designers with comprehensive capabilities across electrical, thermal, and mechanical design; software development; and complete simulation and prototyping capabilities. Data center and EV customers will be supported worldwide by the new teams, from concept to prototype through to full qualification and mass production.”
At CES, GaN Systems is showing some of the industry’s GaN-based solutions in consumer electronics, including GaN chargers and GaN audio and in automotive. “GaN Systems is displaying the world’s smallest 65-W charger powering a laptop,” said Paul Wiener, vice president of strategic marketing at GaN Systems, in an interview with Power Electronics News. “We’re excited to show GaN chargers from well-known brands Dell, Philips, Harman, and several others.
“In audio, we’re showing our Gen2 amplifier reference design, the Syng Alpha Cell speaker, named one of Time’s 100 Best Inventions of 2021; Orchard Audio’s all-in-one Starkrimson Streamer Ultra; and a revolutionary Class-D audio amplifier with controller chip from Axign,” he added. “In automotive, we’re showing GaN implementations in a DC/DC converter, on-board charger, traction inverter, and complementary automotive power modules.”
Applications
According to Navitas, in addition to ultra-fast chargers for laptops and mobile devices, there are significant opportunities for next-generation GaN semiconductors to “Electrify Our World” by saving energy in data centers, delivering high-efficiency solar inverters and accelerating EV adoption.
Fast chargers are an excellent illustration of GaN’s effective adoption, which has resulted in tremendous market penetration. According to Navitas, GaN ICs provide the extremely portable, high-power–density, low-weight, and high-performance solutions expected by current portable electronics. “There are many reasons why GaN is here to stay and will become more prevalent across a growing number of sectors,” said Oliver. “GaN runs up to 20× faster, enables up to 3× more power, and delivers 3× faster charging while halving application size and weight. This not only has benefits in terms of performance, form factor, and weight, but it means that GaN can make a significant contribution to sustainability and the reduction of carbon emissions.
“In data centers, for example, we estimate that GaN ICs can reduce electricity use by up to 10%, an improvement that, if applied across all data centers, could save >15 TWh or $1.9 billion in annual electricity costs,” he added. “When it comes to renewables, GaN semiconductors increase the efficiency of photovoltaic inverters and energy storage systems to reduce the cost per watt of solar power, which, in turn, will accelerate adoption. While deploying GaN in electric vehicles, GaN allows EV manufacturers to address the key issues of charging time, energy savings, price, and range. We believe our technologies will accelerate EV adoption by up to three years to deliver an additional 20% reduction in road-sector CO2 emissions.”
According to Wiener, the principles of semiconductor economics are playing out: “Higher volumes drive increased process knowledge and higher performance and drive down cost. We’re seeing some of it today, allowing GaN to displace other transistor technologies in both lower- and higher-power applications where silicon MOSFETs, IGBTs, and SiC have a position today.”
For GaN systems, the most noticeable has to be GaN chargers. “They’ve been covered extensively in many consumer electronics publications, but most importantly, you’re seeing the big companies from Apple to Dell debut GaN chargers,” said Wiener. “The strongest argument is that GaN is the best technology to meet the power electronics industry’s efficiency, size, and cost needs. GaN performance is 13× better than silicon and 6× better than silicon carbide [SiC].”
In addition to fast chargers, Lidow sees e-mobility (EVs) as a growing market, as mentioned earlier, and in focusing on the green issue, he pointed out that the biggest question is not whether EVs are 100% green but how green our electricity grid will be. “In terms of energy efficiency, there’s a 4:1 ratio of energy efficiency to move something with an electric motor compared with an internal combustion engine, and if the electricity grid is coal-fired, it will have a possible negative impact,” he said. “I think that’s where we need to turn our attention. The electric car is coming; we need to clean up the grid by investing in renewables. For solar, it’s crucial to find the right peak operating point, and GaN finds its right place with DC/DC power-point trackers but also in inverters where the situation sees GaN and SiC. There are large installations with central inverters and those are still SiC-based, and then there are small inverters that are finding their way into solar applications.”
The next generation of power devices must incorporate technologies that meet performance, efficiency, and value requirements, and GaN has emerged as a vital component. However, when evaluating GaN solutions, the question emerges as to what the best solution is for RF applications: GaN-on-Si, GaN-on-SiC, or GaN-on-GaN.
According to Lidow, the default substrate for GaN is silicon or SiC. For the latter, there are many applications in the RF field. “I don’t see GaN-on-GaN succeeding for several reasons,” he said. “Silicon carbide is much more thermally conductive than GaN. The second thing is that the electron mobility in GaN is much higher than silicon carbide, but only in a lateral device. And this is because of the two-dimensional electron gas. So if you switch to a vertical device, you lose that advantage. And it’s more or less the same that gallium nitride crystals are in a much more primitive state of development.
“Moreover, GaN-on-Si is produced just like silicon, so there is no need to invest so much,” he concluded. “You have a lot of investment when you want to have GaN-on-GaN because it is a very different production process. So why this huge capital investment when it doesn’t have a comparative advantage over silicon carbide?”
