Oct 22, 2018

From brick-like cell phones to heavyweight television sets, power supplies have a history of taking up an unsightly amount of space in electronics – and the need for higher power density has only continued to soar.

Innovation in silicon power supplies helped cut these old models down to a more manageable size, but those improvements have been mined to the limit. Silicon simply can’t run at the frequencies necessary to deliver more power without growing in size. That’s a critical factor for 5G wireless network rollout, for the future of robotics and for technology from renewable energy to data centers.

"Engineers have reached the limit – they can’t push more power in the space they have and they don’t want to increase the space their equipment needs," said Masoud Beheshti, a product manager at our company. "If the form factor can’t change, the only knob you can play with is power density."

GaN’s prime-time moment

For more than 60 years, silicon has been the basis of the electrical components that convert alternating current (AC) to direct current (DC) and change DC voltage to fit the needs of everything from mobile phones to industrial robots. And while the necessary components have been refined and optimized, physics has caught up with silicon.

But a new breed of power supply and conversion systems based on gallium-nitride (GaN) is solving the problem, generating less power waste and also less heat – which is critical since higher temperatures can increase operating costs, interfere with networking signals and lead to premature equipment failure.

GaN can process power at higher frequencies and with greater efficiency – it can deliver power with half the loss of a silicon component in as little as half the space. That improves power density, a critical concern for customers who need more power without giving up more space in their designs.

Higher frequency switching means that GaN can also convert wider ranges of power in a single step, reducing the need for additional power converters in complex devices. Because each power conversion introduces more waste, this advantage is critical for a growing number of high-voltage applications.

A 60-year technology doesn’t disappear overnight, but after years of research, real-world trials and reliability testing, GaN is more than ready to become the future of power density. Our company has put GaN devices through 20 million hours of accelerated reliability testing at higher temperatures and voltages than silicon. In that much time the GlobalFlyer jet – the world record holder for long-range flight – could make 259,740 trips around the globe.

"We made sure the GaN process, technology and devices are fully qualified and ready for mass production," Masoud said.

Our company is sharing these GaN qualification protocols with the Joint Electron Device Engineering Council standards body, and will steer its GaN qualification committee.

Where GaN will go next

GaN is already replacing silicon in key industries where improved power density is a premium feature. "Now that our company has mastered our GaN packaging and testing, customers have a new and reliable power converter option anywhere power density is a priority," said Arianna Rajabi, a product marketing engineer at our company.

These industries are among the best candidates for mainstream, mass-produced GaN power supplies:

Manufacturing: Today’s typical robot arms don’t actually contain all of the electronics needed to make the arm work. Power conversion and motor drive components are so large and inefficient that they are often located in separate cabinets, cabled over long distances to the arm itself. This reduces the productivity per cubic meter of industrial robots. GaN will make it easier to incorporate drive and power conversion inside the actual robot. That will streamline designs, reduce inefficient cabling and lower operating costs.

Data centers: Spurred by the insatiable demand for more digital services, the data center industry is in the middle of an overhaul to run directly from 48-volt DC power. Traditional silicon power conversion cannot efficiently go from 48 volts down to the low voltages required for most computing hardware in a single step. Creating intermediate steps reduces data-center power efficiency. GaN can step down from 48 volts to point-of-load before being delivered to servers and chips. This can reduce power distribution losses significantly and cuts conversion losses by 30 percent.

Wireless services: The move to blanket populations with comprehensive 5G cellular networks requires network operators to deploy higher-frequency equipment running on more power. Network operators don’t want to increase the size of cell tower equipment, so GaN’s power-density advantages will play a significant role.

Renewable energy: Renewable energy generation and storage also requires power conversion steps, so GaN’s efficiency advantages are key. Since renewable energy plans often use a smart grid approach that stores energy for later use – when wind turbines are still or solar panels aren’t being powered by the sun – being able to switch power in and out of large-scale batteries more efficiently is a great benefit. Our company and partners have demonstrated GaN’s ability to convert 10 kilowatts of renewable energy generation with 99 percent efficiency, a key benchmark for power utilities.

Over time, GaN will continue to expand into applications like consumer electronics, allowing for thinner flat-panel displays and reduced waste in rechargeable devices.

"If you just need a 3 percent or 4 percent efficiency improvement, you can get that other ways," Masoud said. "But if you need to double power density, GaN is your only option."