Bus converter ideal for Network-Attached-Storage apps


Bus converter ideal for Network-Attached-Storage apps

Ericsson has launched what is presented as the first digitally-controlled Advanced Bus Converter specifically aimed at powering Redundant Array of Independent Disks (RAID) and Network Attached Storage (NAS) hard-disk applications that operate with high capacitive loads up to 15 millifarads (mF). Based on the Ericsson 3E* FRIDA II platform, the BMR456 High-Cap' series (BMR4560004/018) guarantees stable and accurate 12V bus voltage over the full input-voltage range. RAID and NAS applications developed for datacenters are designed for high performance and reliability and require very stable and smooth bus voltages without disturbances, such as voltage glitches or delays that result from power sources operating with current-mode limitations. Designers will commonly use large arrays of capacitors, often resulting in an average value of 12 to 15 mF, to secure that the bus voltages delivered to hard disks and other sub-assemblies are exempt from noise. Developing these types of products can be a significant challenge, but the BMR456 High-Cap' converter makes full use of the flexibility offered by digital control in addition to its Ericsson Energy and Performance Optimizer firmware, and embeds a voltage-mode-control algorithm that maintains a tight output voltage between 11.88V and 12.12V and accurately controls the 20 millisecond ramp-up time. "Designing a product of this nature in a traditional way would require significant hardware modifications and could mean many months work," said Patrick Le Fèvre, Marketing and Communication Director, Ericsson Power Modules. "However, the flexibility offered by the FRIDA II platform and its Ericsson Energy and Performance Optimizer firmware has made this possible in significantly less time, thereby reducing time-to-market for our customers. The BMR456 High-Cap Advanced Bus Converter is an excellent representation of the benefits offered by digital power and the unprecedented level of flexibility offered to board and systems designers." Designed for 12V bus applications that might only require 6V in standby mode, controlled via PMBus commands, the output voltage can also be adjusted to as little as 4V, even powering 5V board-level subsystems in idle mode, delivering significant headroom to board designers. The BMR4560004/018 has an output power of 420W and a flat efficiency of 96% from low to high load, guaranteeing the lowest power dissipation at any point of load and contributing to reduced energy consumption and total-cost-of-ownership for end customers. Designed to be fully integrated and optimized in the energy optimization chain, the converter includes a USER_STORE memory block, which can be used by system designers to store their own customized configuration files to profile BMR456 High-Cap behavior to match certain conditions. The BMR4560004/018 meets the insulation requirements of EN60950, sustains an I/O isolation voltage of 2250 VDC, and also offers an extensive set of capabilities and features such as: remote sensing; PMBus-configurable protection (over-temperature, over-current and over-voltage); configurable start/stop; precision delay ramp-up; voltage margining; configurable fault response; power good; and extensive power management programmability. Ericsson Power Modules