Company: Flex Power Modules
Category: Power Product of the Year
For power conversion, power density is critical. In telecom and data centre applications, the trend is to deliver better performance and functionality in smaller spaces. Flex Power Modules has developed the BMR491 series – the industry’s highest power density digital DC/DC isolated converter with built-in digital interfaces.
There are three variants of the BMR491. The newest version delivers 2450 W peak power for periods of up to one second, with a continuous output power rating of up to 1540 W, thus making it the industry’s highest power density digital DC/DC isolated converter. It has a typical efficiency of up to 97.5% at 48Vin / 50% load, with output current of up to 205 A at a nominal 12 V output.
Pioneering performance and features
The BMR491 is the company’s sixth-generation quarter-brick isolated DC/DC converter. The first generation BMR453 had a maximum power output of 300 W, and this has increased by more than a factor of eight to the BMR491’s peak output of 2450 W. It also supports paralleling through droop load sharing, enabling multiple converters to be used together to achieve even higher power.
The BMR491 helps system designers to dramatically cut time to market by taking advantage of built-in functionality and software tools such as Flex Power Designer.
Compared to previous designs and incumbent solutions, the mechanical design of the BMR491 has been optimized in such a way that the total build height is now available to be used for ferrites, a technology that has evolved from the BMR490 where an ‘open deck’ baseplate concept was introduced.
An advanced thermal design is also employed with the goal to allow higher continuous power by transporting heat away from the main heat generating devices to the baseplate and pins with a very low thermal resistance. An example of this is the extra baseplate that can be found on the rear side of the BMR491.
Additionally, the BMR491 employs the very latest state-of-the-art transistor packaging which reduces power losses even though fewer transistors are used than before.
Innovative proprietary technology
The BMR491 incorporates Flex Power Modules’ proprietary Hybrid Regulated Ratio (HRR) technology. HRR converters combine the advantages of two existing approaches to power conversion: a fixed-ratio converter with unregulated output, or a fixed-output version with full regulation. Depending on the input voltage, a HRR converter will switch between these two modes.
By adding the benefits of regulation to fixed-ratio DC/DC conversion, the HRR technology enables greater power delivery, and efficiency, under common operating conditions. It also improves resilience to voltage transients, and enables a wide input voltage range.
The BMR491 also incorporates enhanced thermal conduction techniques, based on patented technology from Flex Power Modules, which enables it to achieve superior heat transfer through the baseplate compared to competitors’ products.
Reliability is still king
Reliability is a key benefit provided by the converters which offer advanced over-voltage, over-temperature and short-circuit protection. The mean time between failures (MTBF) of the latest BMR491 exceeds seven million hours. Its operating temperature range is from -40Â°C to +125Â°C, and it complies with IEC/EN/UL 62368-1 safety standards. Input to output isolation is 1500 V.
The BMR491 is provided in a low-profile quarter-brick format, measuring 58.4 x 36.8 x 14 mm (2.30 x 1.45 x 0.55 in) with baseplate. It is also available with an integrated heatsink, with a height profile of 19 mm.
The level of peak power demand delivered by the BMR491 is a prerequisite for telecom and data centres – for example it is often required during the burst mode operation of processors such as Intel’s Ice Lake family of CPUs.
Greater power density is a trend set to continue. In telecommunications, a typical 4G base station remote radio unit might require 300 W input power, while a 5G equivalent would need somewhere between 1100 W and 1500 W. For data centres, greater use of AI, Machine Learning, Autonomous Vehicles and Cloud Computing is spurring demand for higher power system efficiency and power density to keep things as cool and as compact as possible. Overall, the BMR491 can meet this kind of high-power density requirements without power designers needing to compromise on efficiency, features or simplicity of design.