How the power semiconductor market is evolving

“Why should an EV manufacturer choose GaN power semiconductors?” Matthew Beecham of Just-Auto.com spoke to Larry Spaziani, VP of Sales at GaN Systems to find out. The interview was originally printed here on June 29, 2021.

Could you give us some background on GaN Systems? 

GaN Systems is a leader in gallium nitride (GaN) power semiconductors with the most extensive range of transistors, including automotive-grade transistors that exceed AEC-Q101 performance requirements. We serve the major markets, including automotive, consumer electronics, data centre, renewable energy, and industrial sectors. GaN Systems is headquartered in Ottawa, Canada, with offices worldwide, including the Americas, Asia-Pacific, and EMEA.

Why should an EV manufacturer choose GaN power semiconductors and why now? 

Power is undergoing a revolution. Megatrends such as electrification, digital economy, and energy efficiency (in which automotive touches all three trends) are moving GaN to the forefront, enabling the creation of smaller, more efficient, more reliable, and lower cost power electronics. The tipping point is now, and most EV companies have realised that they must, in fact, design with GaN to be competitive in their field.

In EVs, GaN power semiconductors address significant challenges – the need for faster charging, extended range, reducing the size and weight of power electronics (by one-third), and lowering power system costs (by 10-20 percent). There are three areas in which GaN is critical: EV battery chargers, DC/DC converters, and traction inverters.

Using GaN power semiconductors results in On Board Chargers (OBCs) that are lighter and approximately one-third current size. It contributes to decreased vehicle weight (giving longer driving range) and opens up new design flexibility with OBC integration.  The next-generation EV designs that are happening now, for the most part, combine the DC to DC function in the same system as the OBC. DC to DC power conversion (400V to 12V or 48V) from the vehicle battery is needed to support accessory systems with low voltage needs such as heating, air conditioning, and power steering.

Power efficiency, system size, and weight are the sought-after benefits of technology for the drivetrain’s inverter that converts DC from the vehicle battery into the AC needed by the electric motor. The use of GaN power semiconductors in inverters expects to deliver efficiency improvements of more than 70 percent compared to today’s inverters using traditional semiconductors.  Increased efficiency accompanied by decreased power system size and weight will enable EVs to drive further even with current battery capabilities.

We are hearing a lot about autonomous vehicles. We understand that power semiconductors from GaN Systems can play a role in some of the sensors and wireless charging for those vehicles. What’s happening there? 

GaN Systems plays a role in wireless charging as well as LiDAR. LiDAR sensors are an essential element of AV systems, and in this application, only GaN will do. These sensors work by generating extremely short pulses of laser light, and only GaN devices are fast enough to drive the lasers to create accurate, cost-effective LiDAR systems. In 2019, we announced a partnership with Osram to develop the world’s highest power, 4-channel LiDAR laser/driver.

With autonomous vehicles, the charging must be “autonomous” as well, which means wireless charging. At these high power levels, 6 to 18kW, every efficiency point results in reducing heat by 120 Watts or so; think about how hot your 120W light bulbs get. Higher efficiency and lower losses translate into a need for GaN transistors. These systems employ the same magnetic resonance charging becoming popular in other segments because of the benefits of high efficiency, spatial freedom, and foreign object detection and rejection.

While we are seeing an acceleration of level 1 and 2 driving automation, there are delays in higher levels due to the lack of an established regulatory framework and the technical challenge of providing safety in all driving situations. Could you give us your thoughts on the threshold the industry now stands at between Level 2 and Level 3 autonomy?

While GaN and GaN Systems are not directly involved in the automation levels, we are, in a roundabout way, involved with how car companies manage automation data collection.  As the systems move from Levels 1 and 2 to Levels 3 and 4, even more sensors will be employed, creating an asymptotic growth of data to be managed. Some of the largest data centre expansion plans are EV companies creating data centres to collect the enormous data required to log autonomous cars. GaN in data centres provides benefits such as higher efficiency and significant carbon reduction.  We’ve modelled a 10-rack data centre using GaN, and the results are a $13K OPEX reduction per year and a 100 metric tons of CO2 reduction per year.   For these reasons, GaN is being rapidly adopted. 

In what ways can GaN technology help in the area of car audio?

The trend is for more of everything – power (with higher efficiency), sound, and speakers. GaN in Class-D audio systems, the architecture dominates consumer audio platforms, including in vehicles, are smaller, lighter, and provide better sound quality. GaN applications include the Class-D amplifier and switch-mode power supply. The high frequency, low Qg (gate charge), and zero reverse recovery inherent in GaN lead to distortion reduction. The resulting sound can be heard and felt by the listeners. For the power supply – using GaN means high efficiency, no heatsinks, and enables designers to reduce the size of magnetic components without compromising performance. 

To what extent is the current shortage of semiconductor chips helping you gain ground?  In what applications? 

First, due to some good planning and forecasting, we aren’t having shortage problems like many others in the industry. We planned for high growth and took actions to ensure the investments were in place to cover the high demand we are now seeing. That said, delays in availability and long lead times do open the door for companies to leapfrog projects and go to GaN much sooner. We’re seeing this kind of movement in the consumer and industrial segments. 

There appears to be more focus than ever on developing electric powertrain components. In terms of electrification, has the auto industry reached a turning point? 

Absolutely. The rapid development of power train components using wide bandgap technology (SiC and GaN) is a global trend.  Internal Combustion Engine (ICE) car companies have realised that they must move and move fast to create electric vehicles. We’re seeing companies revise their estimates and make bold statements about their EV position in the marketplace as soon as 2030, a far cry from the 2050 dates and deadlines promised in the past two to three years. The amount of development globally that we’re supporting is incredible – it’s everyone, everywhere. 

What are the other applications for GaN? 

We’ve covered most of it. For EVs, applications include battery chargers (OBC), DC/DC converters, and traction inverters. In AV, Lidar applications. Others include the Class-D 12V audio market. Our GaN transistors are already being used by companies such as Canoo (OBC), BrightLoop (DCDC converters), and Toyota (All GaN car), just to name a few. 

What’s next for GaN Systems?

As designs from major auto manufacturers focus on increased efficiency, power density, and reduced weight, you’ll be seeing our transistors in EVs in the near future.