High-stability 650W from quarter-brick converter

June 29, 2016 // By Graham Prophet
Ericsson’s third-generation BMR458 quarter-brick advanced bus converter delivers up to 650W for a range of Information and Communication Technologies (ICT) applications; it delivers a tightly regulated output voltage over the full operational input range of 40V to 60V.

Designed to meet the demands of high-end and high power applications based on intermediate bus conversion (IBC) and dynamic bus voltage (DBV) architectures, it has output current monitoring of ±1A for accurate system monitoring capability. The module is suitable for high-power applications that are powered by multi-cell batteries or rectifiers.


Features include the highest power delivery (650W) in the industry for a quarter-brick advanced bus converter, thereby reducing the number of required modules in very high power applications; and highly accurate current sharing. It is, Ericsson asserts, the only advanced bus converter available today to offer active- or droop-current sharing. Other key features including dynamic load compensation, snapshot parameter capture, and a PMBus v1.3 interface.


Key electrical characteristics of the module include efficiency of up to 96.6% at half load and 96.3% at full load; maximum current output of 54.2A; tightly regulated 12V output ( ±2 mV, typical) across the 40 to 60V input voltage range; output current monitoring of ±1A to enable highly accurate system monitoring capability; and a fast transient recovery time of 1 msec. Further specifications include: an MTBF of 8.2 million hours; and I/O functional isolation of 2250 Vdc, which meets the latest IEC/EN/UL60905 safety standard.


The module’s dynamic bus voltage capability is important for the most advanced power systems and enables the module’s output voltage to be adjusted to suit the load, thereby maximising overall system efficiency and reducing energy consumption. The module also delivers highly accurate current sharing with both active and droop options for paralleling up to more than six modules, delivering higher reliability and greater available power.


The BMR458’s dynamic load compensation (DLC) feature adjusts the control loop to meet the capacitance load. To help engineers further, the DLC feature can also be used in conjunction with the Ericsson Power Designer software tool, which has been developed for the initial development and prototyping of digital power systems,