Navitas Semiconductor, a major supplier of gallium nitride (GaN) power devices, showcased its latest products at CES 2023 in Las Vegas. These GaN-based devices range from 20-W mobile phone chargers to 2-kW data center power supplies and 20-kW electric vehicle (EV) chargers to megawatt-scale grid-connected products.
At CES 2023, Navitas garnered some GaN attention with demonstrations from its senior executives and GaN technology partners. The company was also able to highlight its theme of “Electrifying Our World”, while various prizes were announced for booth visitors. Navitas, which means energy in Latin, has come a long way since its founding on a trailer in the parking lot of the Hughes Research Laboratories (HRL) in Malibu, California.
It was founded in 2013 by former International Rectifier (HRL) executives Gene Sheridan and Dan Kinzer. The following year, investment firm MalibuIQ licensed GaN power electronics technology from HRL, which has done extensive work in maturing GaN devices for military RF and mmWave applications.
In July 2015, Navitas raised $15.1 million in equity funding. It also moved from the trailer to El Segundo, California, and eventually established its headquarters in Torrance, California. The company currently employs approximately 200 people; approximately half of them are in the United States, with the remainder in various locations in Asia and Europe.
GaN Design Challenges
The CES 2023 exhibit halls are a great place to gauge the design progress GaN semiconductors have made over the past few years. The lack of high-performance circuits to drive GaN transistors quickly and cost-effectively has been a key limit to the potential of GaN semiconductors, according to Navitas co-founder and chief technology officer Dan Kinzer.
Navitas has found a solution to this design challenge by monolithically integrating GaN drive and logic circuitry with GaN power FETs. This monolithic integration enables high frequency power conversion and enables the miniaturization of passive components such as transformers, EMI filters and output capacitors. This, in turn, has enabled solutions that could charge older and slower silicon devices at half the size and weight 3 times faster.
Stephen Oliver, Navitas Semiconductor’s vice president of corporate marketing, expanded on this key design premise for GaN devices when he spoke with EDN at the company’s booth. GaN has been an important material to help make fast and efficient semiconductors, but it has one big problem: gates, he said. It’s very fragile and will break if you apply too much voltage to it. So when you have a switch with a vulnerable gate, you have to protect it a lot. This takes up more space and design cost.
Plus, Oliver warns, you still have a chance of getting voltage spikes. So, you have to slow down and even consider going back to silicon. “It was a dead end.” However, the integration of GaN switches, GaN drivers, GaN regulators, GaN ESD protection diodes, level shifting, bootstrapping, undervoltage lockout, and current sensing has resulted in powerful GaN ICs.
Thermal management is another stumbling block for GaN semiconductors. “The benefit of GaN is that it has much lower resistance than silicon, which allows you to develop very small chips,” Oliver said. “The bad thing is that a smaller chip has less surface area, so it has less thermal resistance to the outside world.” Therefore, design engineers must ensure that GaN devices don’t generate too much heat. “What we did with the initial platform was use a standard QFN package size,” Oliver added.
Power Disruption for GaN
To overcome design challenges associated with GaN, Navitas also takes a platform-level or system-level approach. “It’s a new technology, so if you’re giving a product that runs at 2 MHz to a power system designer who’s used to 50 kHz, they’re going to need a little help,” Oliver said. “We created a design platform built around the method of operation so that engineers could review necessary details like the bill of materials.”
Navitas entered the GaN space at a time when this Wide Bandgap (WBG) technology was already crossing the bridge from academia to commercial use cases. Fast-forward to 2023, and the GaN specialist is confident of continuing to deliver GaN solutions that can replace silicon in power electronics, while working with TSMC on wafers and Amkor on packaging.
Figure 3 After mobile chargers and data center power supplies, EVs are one of the next frontiers for GaN power devices. Source: Navitas Semiconductor
Just a few years ago, people were asking when GaN would come. And now, when GaN is already here, it might be a bit late to join the GaN party. Navitas is one of the few experts in GaN devices and is now part of this disruption in the power electronics market. 2023 may be about market penetration, and Navitas appears to be part of this GaN race for fortune.