Friday, September 27, 2019
Power semiconductor devices with gallium nitride (GaN) and silicon carbide (SiC) are gradually replacing their silicon-based counterparts, largely because using GaN or SiC power transistors can lead to more straightforward and efficient energy storage solutions. The combined GaN and SiC market is projected to be valued at over US$3 billion by 2025 and will be substantially driven by renewables and electric vehicles. We live in a world where more and more data centers, electric vehicles, industrial engines are spreading. Everyone needs to improve their energy use.
Thanks to the use of gallium nitride it is, in fact, possible to build power supplies of higher efficiency than those based on silicon, capable of delivering a higher current using a lower number of components and thus considerably reducing the size of the loader.
We spoke with Paul Wiener, VP Strategic Marketing at GaN Systems, about the challenges and the future of GaN. GaN Systems offers various solutions in various industrial fields such as the automotive sector.
EE Times: GaN technology could be the clear and undisputed solution for today and tomorrow for various applications. How important is GaN, especially in comparison with other wide-bandgap materials. What do you expect from the evolution of the markets by using GaN technology?
Wiener: Power requirements are increasing in every market, global requirements for electricity are expected to increase from 25,000 TWh today to 38,000 TWh in 2050. At the sector level 8 million data centers in the world uses 2-3% of the world’s energy use and that share is expected to rise to more than 5%. Industrial motors consume 30% and that's growing, electric vehicles will become large consumers to 5% of global energy consumption by 2040. GaN reduces losses in all these systems.
GaN is important in driving innovation in power semiconductors. GaN is meeting new device requirements for more power and performance, greater efficiency, and smaller size.
GaN is delivering more favorable results compared to wideband gap semiconductors like SiC in terms of costs and materials availability, performance, design opportunities for low and mid-range voltage requirements.
Systems built with GaN have greater power density improvement than SiC. Benefits as a low gate charge, zero reverse recovery and flat output capacitance, all of which yield a high-quality switching performance. GaN prices can easily be projected to be competitive with silicon over time, especially since GaN is produced on silicon wafers.
We’re seeing the next power evolution now with GaN. Whereas several years ago GaN was in university research labs, today recognized companies like Denso, Sonnen, and Supermicro have described how GaN power semiconductors improve their systems. Many companies have leveraged the benefits of GaN in their production products. Also, the GaN ecosystem is much stronger. Drivers and magnetics, along with a much better understanding on how to use them — is clearly visible.
EE Times: What future challenges do you see affecting power solutions, and how do you plan to evolve your suite of products to meet those challenges?
Wiener: While GaN-powered devices are beginning to be commercialized, there’s so much more room for product innovation using those voltages. So, 100 V and 650 V GaN devices are serving the current and near future demands in power systems.
Also, there’s a continual need to be more efficient, smaller, and lower cost. This requires us to continually innovate our product design and packaging technologies. Additionally, the ecosystem will create the controllers and magnetics that will take advantage of the ever-increasing performance of GaN.
EE Times: How important is the thermal management for power applications? Could you mention an example?
Wiener: Thermal management is very important. High efficiency in higher-power systems is always a focus. Customers are looking to GaN to help them. For example, in a 20kW system with a silicon MOSFET-based system, 95% efficiency means that 1000 W is being wasted as heat instead of being utilized as power. With GaN, a 50% reduction in losses can be achieved, reducing the costs and area required to manage the heat.
We address this in a variety of methods. First, we have an embedded package for our chip which maximizes output power by efficiently drawing heat out of the device. We have also developed IMS (insulated metal substrate) systems for our devices to further manage thermals in higher power applications. And finally, for our highest current devices, including the recently released 150 A device, this part is sold as a die product so that power module companies can package it directly into their module products to maximize the thermal management.
EE Times: Electric vehicles are considered a green technology. How much is GaN Systems involved in this application and what you are doing to improve the technology, for example, improving the efficiency of batteries power management?
Wiener: GaN Systems is heavily involved in the automotive market both in electric vehicles and autonomous vehicles. Application areas include onboard battery charger (OBC), DC/DC Converter and Traction Inverter. In all these applications, customers are showing size and weight reductions in the 3-5X range and increase operating efficiencies several percentage points. Most interesting is that the system costs are typically not higher with GaN versus silicon. These improvements provide several benefits to the EV companies including longer range vehicles; smaller, lower cost batteries; and because the systems are smaller, perhaps air-cooled instead of water-cooled, optimized system placement within the vehicle is also a new design freedom.
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