Summary of BMR481 48 V-TO-LOAD DIRECT CONVERSION DC/DC CONVERTERS
The BMR481 is a first-generation direct conversion DC/DC converter by Flex Power Modules designed for datacenter efficiency. It replaces traditional two-stage architectures with a single-stage solution, offering up to 92% efficiency and reducing board area by 50%. The main module supports up to five satellite modules to achieve 420A total current, featuring digital control via PMBus v1.3 and low output ripple.
Parts used in the BMR481 Project:
- Main unit
- Satellite modules
- Digital interface
- PMBus v1.3 interface
- Zero voltage/zero current switching components
Flex Power Modules’ converters are first generation direct conversion products
Flex Power Modules’ BMR481 DC/DC converter addresses the growing need for higher energy efficiency levels in datacenters and cloud computing infrastructures. This converter offers an input range of 40 V to 60 V targeting 48 V to 54 V nominal supplies and a programmable 0.5 V to 1.35 V output. The 12 mm x 27.7 mm footprint of the main module provides a maximum output current of 70 A and incorporates a digital interface for monitoring, configuration, and control purposes. This main unit can then be supported by up to five additional ‘satellite’ modules resulting in a total current rating that reaches 420 A.
The single-stage BMR481 provides an ideal alternative to the conventional two-stage intermediate bus converter (IBC) and point-of-load (POL) architecture which requires an extra conversion step, taking up more space and impacts operational performance. This groundbreaking direct conversion module presents engineers with a more streamlined and economical solution. The converter can achieve up to 92% efficiency from a 1 V output at 53 VIN which is 2% to 3% higher than what the equivalent IBC-based deployment can deliver. The BMR481 reduces board area by up to 50%. MTBF is more than 8.7 Mhrs for the main module.
Optimized efficiency is achieved by automatic enabling and disabling of phases/satellite modules depending on the required load, along with dynamic voltage adjustment to provide optimum supply rails to the connected ICs. Output ripple and noise is an extremely low 1 mVp-p (typical) due to the zero voltage/zero current switching employed. Load and line regulation are typically kept at 1 mV. At 53 V input and 0.5 V output, the full 70 A output current is available from the main module to over +75°C ambient temperature with 0.5 m/s airflow and over +90°C with 2 m/s airflow. Full digital control is implemented with a PMBus v1.3 interface compliant with PMBus or AVS/SVID. Isolation is rated at 1,500 VDC (functional).
Read more: BMR481 48 V-TO-LOAD DIRECT CONVERSION DC/DC CONVERTERS
- What is the primary function of the BMR481?
The BMR481 addresses the need for higher energy efficiency in datacenters and cloud computing infrastructures. - How does the BMR481 compare to conventional IBC and POL architectures?
It provides a streamlined, economical alternative that eliminates extra conversion steps and reduces board area by up to 50%. - What is the maximum output current achievable with this system?
The system reaches a total current rating of 420 A when the main unit is supported by up to five additional satellite modules. - Does the BMR481 support dynamic load management?
Yes, it achieves optimized efficiency by automatically enabling and disabling phases or satellite modules based on required load. - What is the typical output ripple and noise level?
Output ripple and noise are extremely low at 1 mVp-p due to zero voltage/zero current switching. - Can the BMR481 operate at high ambient temperatures?
Yes, it can deliver full 70 A output current over +75°C with 0.5 m/s airflow and over +90°C with 2 m/s airflow. - What digital interface protocol does the converter use?
Full digital control is implemented using a PMBus v1.3 interface compliant with PMBus or AVS/SVID standards.
