BMR313 intermediate bus converter

The 1kW continuous non-isolated and unregulated intermediate bus converter, called BMR313, has a fixed 4:1 ratio, taking in 40 – 60V outputting 10 – 15V.

Efficiency is 97.3% at 54Vin, and the part is thermally optimised to take waste heat to the top face for heatsinking.

Exact dimensions are 23.4 x 17.8 x 7.65mm (so 300W/cm3 continuously), and the footprint and pinout is industry-standard LGA.


Flex “worked with Onsemi in the design of the BMR313 to leverage the advantages of the FD6000, its latest generation intermediate bus digital controller,” according to Flex. “The controller uses Onsemi’s DCX resonant dc transformer topology, operating at higher than 1MHz. Onsemi provided excellent support, customizing firmware to our specific requirements.”

FD6000 supports PMBus telemetry, implemented in the dc-dc converter as the product is aimed at data processing.

The official launch of the BMR313 is next week at the Open Compute Project global summit in San Jose.