Resonant wireless power systems use loosely-coupled, highly-resonant coils that are tuned to high frequencies (6.78 MHz or 13.56 MHz). The AirFuel Alliance has developed the standard for resonant wireless power applications. They address convenience-of-use issues such as source to device distance, device orientation on the source, multiple devices on a single source, higher power capability, simplicity of use, and imperfect placement.
Gallium nitride transistors can be used to improve the efficiency of DC-DC conversion. In this white paper we look at a new application that is being enabled by gallium nitride technology that has been difficult to implement using traditional silicon MOSFET power devices.
Photo-Voltaic (PV) inverter size and cost are dominated by thermal management and passive elements used for bulk energy storage and filtering. Using eGaN FETs to increase efficiency and/or increase switching frequency will reduce the size and cost of the system.
Even though the eGaN FET was designed and optimized as a power-switching device, it also exhibits good RF characteristics. EPC’s small 200 V eGaN FET was selected for RF evaluation and should be viewed as a starting point from which the RF characteristics of future eGaN FET part numbers can be optimized for even better RF performance at higher frequencies.
In this white paper eGaN FET technology is applied in a high frequency resonant converter. Previously, the advantages provided by eGaN FETs in hard switching isolated and non-isolated applications were addressed. This paper will demonstrate the ability of the eGaN FET to improve efficiency and output power density in a soft switching application, as compared to what is achievable with existing power MOSFET devices.
DC-DC converter designers can achieve higher power density at lower power levels by using forward converters with synchronous rectification and gallium nitride transistors. One very typical application is a 26 W, 48 V to 5 V , Power over Ethernet Powered Device (PoE-PD).
DC-DC converter designers can achieve low cost at low power densities by using flyback converters and enhancement mode gallium nitride transistors. To evaluate the performance of eGaN FETs in a flyback converter, two different converter designs were created and compared to MOSFET equivalent versions of the same design.
Improvements in buck converters over the past few years have been limited by the power MOSFET’s sedate switching speeds which, in this “hard-switched” topology, translates into lower power conversion frequencies (size and cost), lower efficiency (size and cost), and lower VIN/VOUT ratios (less efficient power management systems). In this paper we show that eGaN FETs unlock a new spectrum of performance that can be translated into significant power conversion system cost and performance improvements.