by Tim Brookes
Gallium Nitride (GaN) chargers were everywhere at CES 2020. This modern alternative to silicon means smaller, more efficient chargers and power bricks are on the way. Here’s how it works.
The Advantages of a Gallium Nitride Charger
GaN chargers are physically smaller than current chargers. This is because gallium nitride chargers don’t require as many components as silicon chargers. The material is able to conduct far higher voltages over time than silicon.
GaN chargers are not only more efficient at transferring current, but this also means less energy is lost to heat. So, more energy goes to whatever you’re trying to charge. When components are more efficient at passing energy to your devices, you generally require less of them.
As a result, GaN power bricks and chargers will be noticeably smaller when the technology becomes more widespread. There are other benefits, too, such as a higher switching frequency that enables faster wireless power transfer, and bigger “air gaps” between the charger and device.
At present, GaN semiconductors generally cost more than the silicon kind. However, due to improved efficiency, there’s a reduced reliance on additional materials, like heatsinks, filters, and circuit elements. One manufacturer estimates cost savings of 10 to 20 percent in this area. This could improve even further once the economic benefit of large-scale production kicks in.
You might even save a bit of money on your power bill since more efficient chargers mean less wasted energy. Don’t expect to see a huge change with relatively low-power devices, like laptops and smartphones, though.
What Is Gallium Nitride?
Gallium nitride is a semiconductor material that rose to prominence in the 1990s through the manufacture of LEDs. GaN was used to create the first white LEDs, blue lasers, and full color LED displays you could see in daylight. In Blu-ray DVD players, GaN produces the blue light that reads the data from the DVD.
It appears GaN will soon replace silicon in many areas. Silicon manufacturers have worked tirelessly for decades to improve silicon-based transistors. According to Moore’s Law (named after the co-founder of Fairchild Semiconductor and, later, the CEO of Intel, Gordon Moore), the number of transistors in an integrated silicon circuit doubles about every two years.
This observation was made in 1965, and it largely rang true for the last 50 years. In 2010, though, semiconductor advancement slowed below this pace for the first time. Many analysts (and Moore himself) predict Moore’s Law will be obsolete by 2025.
Production of GaN transistors ramped up in 2006. Improved manufacturing processes mean GaN transistors can be manufactured in the same facilities as the silicon type. This keeps costs down and encourages more silicon manufacturers to use GaN to produce transistors instead.
Why Is Gallium Nitride Superior to Silicon?
The benefits of GaN compared to silicon boil down to power efficiency. As GaN Systems, a manufacturer that specializes in gallium nitride, explained:
“All semiconductor materials have what is called a bandgap. This is an energy range in a solid where no electrons can exist. Simply put, a bandgap is related to how well a solid material can conduct electricity. Gallium nitride has a 3.4 eV bandgap, compared to silicon’s 1.12 eV bandgap. Gallium nitride’s wider bandgap means it can sustain higher voltages and higher temperatures than silicon.”
Efficient Power Conversion Corporation, another GaN manufacturer, stated that GaN is capable of conducting electrons 1,000 times more efficiently than silicon, and with lower manufacturing costs, to boot.
A higher bandgap efficiency means the current can pass through a GaN chip faster than a silicon one. This could result in faster processing capabilities in the future. Simply put, chips made of GaN will be faster, smaller, more power-efficient, and (eventually) cheaper than those made of silicon.
Where You Can Buy a GaN Charger Today