Efficient Power Conversion Corp (EPC) of El Segundo, CA, USA, which makes enhancement-mode gallium nitride on silicon (eGaN) power field-effect transistors (FETs) for power management applications, has announced the availability of a complete Class 4 wireless power charging kit, the EPC9120, capable of transmitting up to 33W while operating at 6.78MHz – the lowest industrial, scientific & medical (ISM) band.
The purpose of the demonstration kit is to simplify the evaluation process of using eGaN FETs for highly efficient wireless power transfer. The EPC9120 utilizes the high-frequency switching capability of EPC’s GaN transistors to facilitate wireless power systems with full power efficiency of 80-90% under various operating conditions.
The EPC9120 wireless power system consists of four boards:
- source board (transmitter or power amplifier) EPC9512;
- Class 4 Air Fuel-compliant source coil (transmit coil);
- Category 4 AirFuel-compliant device coil with rectifier and DC smoothing capacitor; and
- Category 3 AirFuel-compliant device coil with rectifier and DC smoothing capacitor.
The popularity of highly resonant wireless power transfer is increasing rapidly, particularly for applications targeting portable device charging, says EPC. The end applications are varied and evolving quickly, from cell-phone charging to handheld tablets and laptop computers. Delivering up to 33W supports all of these applications.
Source (amplifier) board
The source board is a highly efficient zero voltage switching (ZVS) Class-D amplifier configured in an optional half-bridge topology (for single-ended configuration) or default full-bridge topology (for differential configuration), and includes the gate driver(s), oscillator and feedback controller for the pre-regulator. This allows for compliance testing operating to the AirFuel Class 4 standard over a wide load range.
This amplifier board is available separately as EPC9512 for evaluation in existing customer systems.
Source (transmit) and device (receiving) coils
The source coil, as well as the device coil, are AirFuel compliant and have been pre-tuned to operate at 6.78MHz. The source coil is Class 4- and the device coils are Category 3- and Category 4-compliant.
EPC9120 wireless power transfer demonstration systems are priced at $907.20 each. The EPC9512 amplifier board can also be purchased separately and is priced at $390 each. Both are available for immediate delivery from distributor Digi-Key.
