Companies team up to develop ultra-small intermediate bus converter

Flex Power Modules launched its BMR313 Intermediate Bus Converter (IBC) at the 2022 Open Compute Project global summit.

Developed with onsemi, the non-isolated and unregulated device provides a peak power rating of 3kW in an ultra-small package, only 23.4mm x 17.8mm x 7.65mm, yielding an excellent 908W/cm3 power density. The input voltage range is 40-60V, and the 4:1 input-to-output ratio provides an output of 10-15V. With 97.3% efficiency at 54V input, the continuous output power capability is 1kW, and the part is thermally optimised for cold wall mounting on the top side. It is provided in the industry-standard LGA footprint and pin-out.

The companies worked on the design to use the advantages of the FD6000, onsemi's latest generation intermediate bus digital controller. It supports integrated PMBusTM telemetry, which is needed in the product target application of data processing. The controller uses the company's resonant DC Transformer (DCX) topology, operating at higher than 1MHz for small size while preserving high efficiency. The controller is also flexible and may be used for future variants of the IBC range with higher and lower input-to-output conversion ratios.

"Our collaboration with onsemi in the development of the BMR313 has enabled us to achieve remarkable power density for demanding, space-constrained applications," comments Mikael Appelberg, CTO of Flex Power Modules. "onsemi provided excellent support, customising firmware to our specific requirements."

"We are extremely pleased with the level of innovation in energy efficiency and density achieved by combining Flex Power Modules' and onsemi's technical talent and technological capabilities," says Roberto Guerrero, general manager of the Cloud Power Solutions business unit at onsemi. "Flex Power Modules BMR313 and onsemi's FD6000 are setting a new standard in powering the cloud."