Digital point-of-load regulator employs embedded dynamic loop compensation

June 25, 2014 // By Graham Prophet
With output uprated to 50A, this regulator offers high power density of 32.61W/cm3 (534W/in3) and 25% more output current compared to previous version and in the same footprint. Dynamic Loop Compensation improves stability: paralleling of seven modules with phase-spreading delivers 350A, while ripple-and-noise is reduced to the lowest possible level.

Ericsson's 3E series BMR464-50A is a third-generation digital point-of-load (POL) regulator that features Dynamic Loop Compensation (DLC) and also extends output current up by 25% to 50A from the 40A offered by the BMR464-40A, yet it comes in a fully compatible footprint. The product also features a full set of PMBus commands enabling systems architects to fully monitor and dynamically control the energy delivered to strategic components, such as processors, FPGAs and ASICs, down to a very low and highly economical level.

Embedding the latest Dynamic Loop Compensation technology, the BMR464-50A runs the DLC algorithm as default following the enabling of the output. However, three more settings are also available via the PMBus for systems architects to choose the most appropriate method for the application with the DLC algorithm run every second or every minute or simply disabled. In addition to standard methods, designers can also use the Loop Compensation Tool featured in the Ericsson Power Designer software to set their own loop compensation profile to match the requirements of specific applications.

The BMR464-50A powertrain uses the latest MOSFET technology to deliver up to 97.2% efficiency at a 3.3V output with a 5V input. With an input voltage range of 4.5V to 14.0V, the BMR464-50A complies with most intermediate bus voltages (5V to 12V) that are commonly used in the industry and provides an adjustable output voltage from 0.6V to 3.3V with the factory default set at 1.2V. Output voltage can be adjusted to any value through simple PMBus commands or via a 1% tolerance pin-strap resistor offering 28 different levels of output voltages.

When higher power or a star-point current distribution is required, the BMR464-50A can also be paralleled with up to seven devices delivering a total current of 350A. When in parallel, the modules can be synchronised with the use of phase-spreading reducing noise and peak current. Phase-spreading can be simply simulated and programmed via the tools embedded