The characteristics of eGaN FETs and ICs, such as low output capacitance, low input capacitance, low parasitic inductances, and their small size in the demonstration kits show that GaN FETs and ICs can be used for increasing efficiency in highly resonant, AirFuel Alliance-compatible wireless power transfer systems, says the company.

The EPC9127 wireless power kit includes a 10W, class 2 amplifier, category 3 receiver device and the EPC9128 kit consists of a 16W, class 3 amplifier and two receiver devices (categories 3 and 4). They join the company’s EPC9120, 33W class 4 and the EPC9121 multi-mode kit capable of operating to either an AirFuel Class 2 standard with a category 3 device or a Qi (A6)/PMA standard with a compatible receiving device to provide a range of wireless power demonstration kits.

With the introduction of these demonstration kits, the company covers a range of the AirFuel resonant technology standard. The popularity of resonant wireless power transfer is increasing rapidly, explains the company, with end applications evolving quickly from mobile phone battery charging, to powering large surface areas where handheld tablets, laptops, and computers (and, soon TV sets, lamps, and other electrically powered appliances) simultaneously, anywhere on the surface.

The demonstration kits simplify the evaluation process of using eGaN FETs and ICs for efficient wireless power transfer. The kits, operating at 6.78MHz (the lowest ISM band) use the high frequency switching capability of EPC gallium nitride (GaN) transistors to facilitate wireless power systems. Efficiency is about 87 per cent from input to the amplifier to the output of the receiver (end-to-end). Future improvements in architecture and GaN IC technology could see this reach 95 per cent, says the company.

The EPC9127 wireless power system consists of a source board (transmitter or power amplifier) EPC9510, a Class 2 AirFuel Alliance-compliant source coil (transmit coil) and a category 3 AirFuel Alliance-compliant receiving device, the EPC9513. The EPC9128 wireless power system consists of four boards, a source board (transmitter or power amplifier) EPC9509, a Class 3 AirFuel Alliance-compliant source coil (transmit coil), a Category 3 AirFuel Alliance-compliant receiving device EPC9513 and a Category 4 AirFuel Alliance-compliant receiving device, EPC9515.

The source (amplifier) boards included in these kits are efficient zero voltage switching (ZVS), Class-D amplifiers configured in an optional half-bridge topology (for single-ended configuration) or default full-bridge topology (for differential configuration). They include the gate driver(s), oscillator, and feedback controller for the pre-regulator. This allows for compliance testing operating to the AirFuel standard over a wide load range, says the company. The amplifier boards are available separately as EPC9509 and EPC9510 for evaluation in existing customer systems.

The receiving device boards include the Category 3 EPC9513 (5.0V, 5.0W) and Category 4 EPC9515 (5.0V, 10W). They are also available separately for customers which have their own source boards or for those who want to design wireless power systems powering multiple devices simultaneously.

The boards allow customers to bring various wirelessly powered consumer electronic products quickly to market, says EPC. With the range of efficient receivers that can be used to power anything from lamps to laptops to tablets, while remaining compatible with cell phone charging.