24 July 2020
OPPO adopts Navitas’ GaNFast power ICs
Navitas Semiconductor Inc of El Segundo, CA, USA says that phone manufacturer OPPO has adopted its gallium nitride (GaNFast) power ICs to enable what’s claimed to be the world’s smallest, thinnest and lightest 50W fast charger. Measuring only 82mm x 39mm x 10.5mm (34cc) and as light as 60g, it is the first fast charger that is as thin as the phone itself.
The Mini provides the full 50W via OPPO’s SuperVOOC fast-charging protocol, or the USB-C Programmable Power Supply (PPS) specification. The device has the flexibility to charge smartphones, tablets and many types of laptop. It’s also the same size as the popular Asian ‘Wang Wang’ brand rice cookie – which has led many to refer to it as the ‘cookie’ charger.
The 50W Mini SuperVOOC charger was launched on 15 July by OPPO’s chief charging technology scientist Jialiang (Jeff) Zhang. “Using gallium nitride devices to drive transformers to very high frequencies has been the dream of all technical workers for many years,” he says. “GaN devices will trigger a technological revolution in the field of power supplies.”
GaN runs up to 20x faster than silicon and enables 3x more power, which translates to up to 3x faster charging in half the size and weight. GaNFast power ICs monolithically integrate GaN power, GaN analog and GaN logic circuits on the same chip, to enable faster, reliable, efficient operation, says Navitas.
For the 50W Mini, the high-speed performance of GaNFast power ICs opened the door to a new circuit topology – the ‘pulsed’ active-clamp flyback (ACF), which can tolerate a very wide input voltage range while maintaining a steady output to charge the phone battery. This allows the designer to remove the electrolytic ‘bulk capacitor’ from the system, which can take up 40% of the total volume. In addition, running 16x faster than traditional chargers meant that a traditional 50kHz ‘wire-wound’ transformer with over 20mm height can be replaced with a new high-speed 800kHz, 8mm planar transformer for an extremely low-profile and lightweight form-factor.
The new topology also allows OPPO’s proprietary ‘direct-charge’ approach to reduce wear-out mechanisms and extend phone battery life.
“The 50W Mini is a great example of a next-generation fast charger, where new materials, new architectures and new component technology combine to create a revolution in power electronics,” says Stephen Oliver, Navitas’ VP marketing & investor relations. “We’re at the point where GaN fast chargers have stepped far beyond boutique accessories and are now addressing high-volume, cost-effective and extremely high-performance markets.”