Second-generation direct conversion DC-DC converter for data centres

Flex Power Modules offers the BMR482, its second generation of direct conversion isolated DC-DC converter. By converting directly from a 48V supply to the load voltage without an intermediate stage, the device offers increased efficiency in a compact package, allowing it to satisfy the higher power demands of today’s data centres and cloud computing.

The device can achieve up to 91.3% efficiency with a 0.8V output at 53Vin, which is 2-3% better than an equivalent solution based on an IBC and PoL. The single-stage converter also need up to 50% less board space than a conventional two-stage solution, assisting to decrease overall costs.

The new converter is offered as a ‘main unit’, measuring only 30mm x 12.7mm x 16.8mm, which incorporates a digital interface for monitoring, configuration and control, and can produce a maximum output current of 110A. If a higher output current is needed, up to five ‘satellite’ modules can be added, measuring 30mm x 12.7mm x 15.4mm each, to give a maximum total output current of 660A. These are automatically enabled and disabled by the main unit depending on the output current drawn, indicating efficiency is optimised over the complete current range dynamically.

Designed for server applications, it has an input range of 40-60V, allowing it to run with supplies nominally rated at 48V or 54V. It has a programmable 0.5-1.35V output voltage, and the main power train has 1500V isolation from input to output.

The device is compliant with the PMBus v1.3, AVSBus and Intel SVID interfaces, providing complete digital control. It is supported by the Flex Power Designer software tool, making power system design simpler and quicker.

Olle Hellgren, director product management and business development at Flex Power Modules, said: “Today’s data centres are testing the limits of conventional IBC/PoL architectures, with up to 3kW or 4kW required per board. The BMR482 solves this problem by converting directly from the 48V or 54V system bus voltage to the PoL voltage, which is typically less than 2V.”