News: Microelectronics
11 May 2021
EPC launches scalable 1.5kW two-phase 48V/12V DC-DC demo board
Efficient Power Conversion Corp (EPC) of El Segundo, CA, USA – which makes enhancement-mode gallium nitride on silicon (eGaN) power field-effect transistors (FETs) and integrated circuits for power management applications – has announced the availability of the EPC9137 demonstration board, a 1.5kW, two-phase 48V–12V bidirectional converter that operates with 97% efficiency in a very small footprint.
The design is scalable; i.e. two converters can be paralleled to achieve 3kW or three converters can be paralleled to achieve 4.5kW. The board features four EPC2206 100V eGaN FETs and is controlled by a module that includes the Microchip dsPIC33CK256MP503 16-bit digital controller.
By 2025, one of every 10 vehicles sold worldwide is projected to be a 48V mild hybrid. 48V systems boost fuel efficiency, deliver four times the power without increasing engine size, and reduce carbon dioxide emissions without increasing system costs. These systems will require a 48V–12V bidirectional converter, with power ranging from 1.5kW to 6kW. The design priorities for these systems are size, cost and high reliability.
EPC’s eGaN FETs can operate with 97% efficiency at 250kHz switching frequency, enabling 800W/phase compared with silicon-based solutions, which are limited to 600W/phase due to the limitation on the inductor current at 100kHz maximum switching frequency. By using GaN FETs, it is possible to reduce the number of phases from five to four for a 3.5kW converter while increasing efficiency, says EPC. The efficiency of a four-phase GaN converter operating at 250kHz is 1.5% higher than a five-phase silicon MOSFET-based converter operating at 100kHz.
Overall, the DC-DC converter is three times faster, greater than 35% smaller and lighter, and offers greater than 1.5% higher efficiency compared with silicon MOSFET solutions. Also, the overall system cost is lower. Additionally, the efficiency and thermal performance of GaN FETs enables air cooling instead of water cooling, and the small size of the GaN FETs strongly reduces heat-dissipating aluminium housing for additional system cost saving.
“eGaN FETs provide the fast switching, small size and high efficiency needed to further reduce the size and weight of 48V–12V automotive power system converters,” says CEO Alex Lidow. “The demonstrated superior reliability of GaN FETs make them ideal for this very demanding application,” he reckons. “The EPC9137 is an ideal example of the capabilities of GaN FETs to increase frequency and efficiency to allow smaller inductance for less phases and higher power density.”
The EPC9137 demonstration board is priced at $510.72 and is available for immediate delivery from distributor Digi-Key Corp.
