How GaN chargers work
They’re smaller, lighter and quicker, but what’s their secret?
GaN CHARGERS ARE cool. Not in the informal statement of approval sense, but they’re quite literally cool. By using gallium nitride (GaN for short) instead of silicon for their transformers, GaN chargers generate less heat when charging. This means the components can be packed closer together in the unit, making them smaller and easier to carry around. And with less energy being lost to heat, the power is more efficiently transferred into the device that you’re charging. They can also carry a greater voltage than silicon too. The end result? Faster charging.
Gallium nitride itself isn’t a new discovery. It’s been used in blue light– emitting diodes (LEDs) since the Nineties, and later provided the breakthrough that made the first white LEDs possible. It’s also used for solar cell arrays on satellites, and the blue lasers used in Blu–ray players. But it’s the potential of gallium nitride semiconductors in chargers and power supply units we’re interested in here, and in this area, it’s fairly new.
Back in the day, a charger was a very simple device. It transferred mains power to a battery–powered device, constantly charging the battery. Yet as mobile technology advanced, it was realized that this was a very poor way of powering up. Receiving a constant power supply in this way, even when the battery was full, caused degradation over time. A degraded battery holds less power, meaning you got shorter and shorter use from your mobile device before it needed charging again.
The next generation of chargers work much smarter, and with greater efficiency. A silicon–based chip inside the device monitors the battery capacity and notes how full it currently is, adjusting the power going into the cell accordingly. A fast charger might fill your battery up to around 80% full as quickly as possible, but slows down greatly for the last 20%, reducing wear and tear on the battery and prolonging its life.
TRAVEL FRIENDLY
For the emerging GaN charger generation, a gallium nitride semiconductor chip replaces the silicon–based one. As stated, GaN chips are more energy efficient than silicon chips. When a regular charger is plugged into the mains, it gets warm to the touch. Not so GaN chargers, which lose much less energy as heat. This means heat–dissipating components such as heatsinks aren’t needed. Passive components that reduce the flow of electricity through a circuit are in less demand too.
With the transistors giving off less heat you can place them closer together, and incorporate several outlets into the same charging device too. This means you can charge multiple devices at once, with the charger providing enough power to do so. And with GaN chargers of around 65W appearing, they have enough power to charge a laptop.
This is obviously great news for holidaymakers and business travellers. Where before you might need to carry separate chargers for your MacBook, iPad, iPhone and Apple Watch, now a single charger might cover all your equipment. And that charger might actually be
smaller and lighter than the ones you’re used to as well. It’s also likely to last longer before failing. With less heat generated by the charging process there’s less strain on the charger, meaning it’s less susceptible to wear and tear.
But is there a drawback in using gallium nitride instead of silicon for charging products? At the moment, there is: cost. A gallium nitride semiconductor as used in GaN chargers are more expensive than silicon semiconductors. As a result, a gallium nitride–based charger is considerably more expensive than a silicon–based model. Yet this isn’t likely to be the case for long. As GaN chargers become more popular, gallium nitride semiconductors are likely to come down in price due to economies of scale. Better still, as GaN chargers produce much less heat than silicon chargers, they need fewer components such as heatsinks, passive inductive and capacitive circuit elements and more. This, of course, will bring down the price. Semiconductor manufacturers GaN Systems predict an eventual saving of 10–20% for products that use gallium nitride semiconductors.
GOING, GOING, GAN
GaN chargers are not yet widespread, but you can already buy one if you wish. Third–party manufacturer Belkin, for example, has a powerful 108W four–port GaN charger for just under $90. With two USB–C and two USB–A ports, you’ll be able to power a laptop and three additional devices. Amazon has a competitively priced two–port 65W charger for a little under $20. This charger has a 45W USB–C port and an 18W USB–A port; just the thing for laptops, tablets and phones. For a little under $40, MINIX has a 66W three–port GaN charger (two USB–C and one USB–A), which comes with UK, US and European plugs, so it’s ideal for travellers.
With gallium nitride chargers, the future for mobile devices looks very cool indeed.