Fast Wireless Charging for Devices with Metal Cases

NuVolta Technologies Inc. has developed high efficiency fast wireless charging solutions for smart phones with metal cases. These solutions are based on NuVolta's integrated transmitter power management IC NU1000, incorporating a proprietary controlled magnetic resonance architecture at 6.78MHz. With a small opening on the metal cases, NuVolta's solutions can transfer fast charging compatible power with small receiver and transmitter coils, and at high system efficiency. In a typical application with a 25mm transmitter coil and a 25mm receiver coil, more than 10W can be transferred at about 70% efficiency through an aluminum plate with an opening as small as 15mm.

NU1000 is a power management IC integrating all key functional blocks to implement proprietary controlled magnetic resonance architecture in a power transmitter, including power MOSFETs, gate drivers, current sensing, and I2C interface. It is in 5mm x 5mm or 6mm x 6mm QFN packages, and can support an input voltage between 4.5V to 28V. This IC can be used for a wide range of applications, ranging from wearable devices with a fraction of a Watt to smart phones and laptop computers with tens of Watts.

“Fast charging through metal cases has been a big challenge for the wireless power industry. NuVolta team developed novel technologies to reduce power loss in systems with metal plates, and maintain good magnetic coupling between RX and TX coils, thus enabling efficient wireless charging through metal cases.” explained Dr. Hengchun Mao, CTO and a founder of the Silicon Valley startup. “With our controlled magnetic resonance architecture implemented in NUT1000, wireless charging works very well with complex system designs, including devices with metal cases or back covers. This gives designers of wearable and mobile devices more options for easy and flexible user charging experience. ”

“Many customers want fast wireless charging features on their phones, but it was simply impractical technically in the past.” said Michael Wang, CEO and a founder of the company. “Our designs have removed such technical barriers hindering the wide adoption of wireless chargers for consumer devices, and give end customers more choices in charging experiences".