LONDON – Efficient Power Conversion Corp. (El Segundo, Calif.), a 2007 gallium nitride power transistor startup, has announced that wireless charging startup WiTricity Corp. has demonstrated wireless charging using gallium nitride FETs.
Efficient Power Conversion (EPC), the 2007 startup founded by Alex Lidow, previously of International Rectifier, claimed that the switching speed of EPC's eGAN FETs increases the efficiency of resonant wireless power transfer compared to silicon MOSFETs. GaN transistors are superior for the proposed 6.78-MHz carrier frequency for resonant transfer.
The resonant aspect of WiTricity's technology means it is capable of transferring power at distance enabling a wide range of consumer, medical, industrial and automotive applications.
Many wireless charging products now in the market use traditional magnetic induction coils with operating frequencies between 100-300 kHz, and Class E, F and S amplifier converter topologies Recently, organizations such as the Consumer Electronics Association and A4WP (Alliance for Wireless Power) have called for 6.78-MHz to be adopted as a higher frequency standard for wireless charging systems. At higher frequencies silicon-based power MOSFETs approach the limit of their switching capability.
This wireless power demonstration system jointly developed by EPC and WiTricity is a class-D power system operating at 6.78 MHz, and capable of delivering up to 15 W to a load. The purpose of this demonstration system is to simplify the evaluation process of the wireless power technology. The system includes all the critical components in a single system that can be easily connected to demonstrate the powering of a device with wireless energy transfer.
EPC, founded in 2007, is included in version 13.0 of the Silicon 60 list of emerging startups published by EE Times. EPC entered the Silicon 60 at version 10.0 in April 2010.