GaN 1.5kW bidirectional 48-to-12V dc-dc demo board for automotive

Nominally 48 to 12V and back, it can produce 12 at 125A from 20 to 60V, or 48V at 29A from 12 to 15V. Peal efficiency is 97%.

“The design of this demonstration board is scalable. That is, two converters can be paralleled to achieve 3kW or three converters can be paralleled to achieve 4.5kW,” according to the company. “48V mild hybrid systems will require a 48V – 12V bidirectional converter with power ranging from 1.5kW to 6kW.”

On the 102 x 70 x 40mm board is a 250kHz two-phase design using four EPC2206 100V fets and controlled by a module that includes Microchip’s dsPIC33CK256MP503 16bit digital controller.

The company makes some claims against silicon-based converters, using a 3.5kW dc-dc as a comparison. As far as it is concerned, 800W/phase is possible with 250kHz GaN transistors, while only 600W/phase is possible at 100kHz with silicon mosfets.

“The efficiency of a four-phase GaN converter operating at 250 kHz is 1.5% higher than a five-phase silicon mosfet-based converter operating at 100kHz,” it said. “Overall, the dc-dc converter is three times faster, >35% smaller and lighter, and offers >1.5% higher efficiency compared to silicon mosfet solutions. AdditionallyGaN fets enables air cooling instead of water cooling.”

EPC9137 demonstration board is available from Digi-Key