EPC introduces a bi-directional converter for mild hybrid vehicles and battery backups

     EPC Power Conversion Corporation (EPC) has announced the launch of the EPC9137, a 1.5kW two-phase 48 V/12 V bi-directional converter with a small board area and an efficiency of 97%. The demo board is designed to be scalable - 3 kW in parallel with two converters, or 4.5 kW in parallel with three converters. The board uses four 100 V eGaN FETs (EPC2206) and is controlled by a module that includes a Microchip dsPIC33CK256MP503 16-bit digital controller.

     By 2025, one out of every 10 cars sold worldwide is expected to be a 48-V mild hybrid. The 48 V system improves fuel efficiency, delivers up to four times more power with the same size engine, and reduces CO2 emissions for the same system cost. These systems require a 48 V/12 V bi-directional converter with a power range of 1.5 kW to 6 kW. These systems are designed with a focus on small size, low cost and high reliability.

     EPC's eGaN FETs can achieve 97% efficiency at 250 kHz switching frequency and can achieve 800 W per phase, while silicon-based solutions can only achieve 600 W per phase because the latter has limited inductive current at a maximum switching frequency of 100 kHz. By using gallium nitride field-effect transistors, it is possible to reduce the number of phases in a 3.5kW converter from five to four, while simultaneously increasing efficiency. Four-phase gallium nitride based converters operating at 250 kHz are 1.5% more efficient than five-phase silicon MOSFET converters operating at 100 kHz.

     Overall, DC/DC converters based on gallium nitride devices are three times faster, more than 35% smaller in size and weight, and more than 1.5% more efficient than silicon MOSFET solutions. And the overall system cost is lower. In addition, the superior efficiency and thermal performance of gallium nitride FET enables air cooling rather than water cooling, and the miniaturized FET greatly reduces the heat emitted by the aluminum sheet, resulting in further system cost savings.

     Alex Lidow, CEO of EPC, said: "The eGaN FET offers fast switching, small size and high efficiency, which further reduces the size and weight of 48 V/12 V in-vehicle power system converters. Gallium nitride field-effect transistors demonstrate excellent reliability and are ideal for this very demanding application. The EPC9137 demo board best demonstrates the superior performance of gallium nitride field effect transistors by increasing frequency and improving efficiency, thereby reducing the size of the inductor, reducing phase and increasing power density.

     EPC is a leading supplier of power management devices based on enhanced Gallium nitride (eGaN) field effect transistors and integrated circuits that perform many times better than the best silicon power MOSFETs. Targeted applications include DC-DC converters, LiDAR, motor drives for electric transport, robotics and drones, and low-cost satellites. In addition, the company continues to expand its eGaN IC-based product range to provide customers with solutions that further save board space, energy and cost.