Power conversion demonstration board

EPC is making available the EPC9149, a 1 kW-capable 48 V input to 12 V output LLC converter that operates as a DC transformer with a conversion ratio of 4:1.

This demonstration board features the 100V EPC2218 and 40 V EPC2024 GaNFETs.

The board is the size of DOSA-standard ⅛th brick format, measuring 58.4mm by 22.9mm, which is considerably smaller than alternative silicon-based solutions that are generally sized in the ¼th brick format, or twice as large, for 1 kW of output power. The total thickness of the converter without heatsink is only 10 mm. To make it simple for a power supply designer to easily replicate this design, all supporting materials for this board including schematic, bills of materials, and Gerber files are available on the EPC website.

The high-power density, 1226 W/in3, is achieved thanks to EPC GaN FET technology. eGaN FETs enable high switching frequency, in this case 1 MHz, and they are very small, ⅓ of the size of silicon MOSFETs with similar on resistance.

The EPC9149 board features four 100 V rated EPC2218 eGaN FETs for the primary rectification, and eight 40 V rated EPC2024 eGaN FETs for the secondary synchronous rectification. The board also features a 4 mm x 4 mm Microchip dsPIC33CKMP102T-I/M6 for flexibility, configuration, communications, and programmability.

This demonstration board can operate from an input voltage between 36 V and 60 V and delivers up to 83.3 A load current. The peak efficiency from 48 V to 12 V is 98% and the full load efficiency, at 12 V when delivering 1 kW, is 97%.The highest temperature in steady state operation at maximum load with 400 LFM airflow is 88°C, which relates to a maximum junction temperature of 95°C.