Ericsson - Digital Voltage Regulator Minimizes Space And Energy Usage

Industry first 40A PMBus-compliant point-of-load single-in-line voltage regulator
Designed for applications where board space is critical, the new device reduces footprint to less than 2.5cm2 (0.39in2)
Single-in-line BMR464 adds assembling flexibility to the recently announced surface-mount and through-hole mount BMR464 family
Built-in energy-optimization algorithms reduce energy consumption

The amount of functionality currently being placed on board-level designs is growing substantially with the migration from single-core to multi-core processors and advanced FPGAs, in addition to the increasing trend for system upgrades with new boards featuring additional features. These developments are prompting designers to assign board-allocation priorities to ‘core’ components such as microprocessors and limit the space available to ‘peripheral’ devices such as the voltage regulator.

The new BMR464-SIP (BMR4642002) meets these demands to save valuable board space for the core components as it enables vertical mounting – also known as single in-line packaging (SIP), which is often used for devices such as memory chips, voltage regulators and other control boards. This approach delivers a device footprint of less than 2.5cm2 (0.39in2), making the new device ideal for space-critical applications.

The new regulator can also easily be configured and monitored via the standard PMbus communication protocol and the company’s intuitive graphical user interface, making this the first PMBus-compliant 40A point-of-load SIP device available on the market, and offering designers the ability to fully optimize power management in high board-density applications.

The primary end-use applications are network routers, data storage and AdvancedTCA (Advanced Telecommunications Computing Architecture) boards, but the low height of the BMR4642002 also makes it suitable for many other applications when space is at a premium. The device’s measurements of 33.00 x 7.6 x 18.1mm make the product suitable for those high-density boards that require a small footprint and height below 20mm, guaranteeing a safe and comfortable fit when assembled in 1-inch rack systems.

In addition to the small footprint of 2.5cm2, a corresponding key feature of the 40A- and 132W-output regulator is a market-leading power density of almost 53W/cm2. The regulator accepts input voltages from 4.5V to 14V and has an output voltage range of 0.6V to 3.3V with typical efficiency of 97.2% at 5Vin, 3.3Vout and 50% load.

“The increasingly functionality being crammed on system boards these days has driven the development of products such as the BMR464-SIP,” said Patrick Le Fèvre, Marketing and Communication Director of Ericsson Power Modules. “We believe this industry first, a PMbus-compliant 40A/132W SIP voltage regulator with a footprint of only 2.5cm2, will help designers meet demands in space-critical applications that are featuring progressively higher board densities.”
The BMR464-SIP is based on Ericsson’s leading-edge digital-core controller combined with the latest MOSFET technology and built-in energy-optimization algorithms that not only contribute to significantly reducing energy consumption and power dissipation, but also deliver an impressive amount of features and level of flexibility.

The design concept underlying the company’s second-generation 3E POL devices makes it possible for systems designers to reduce energy consumption to the necessary minimum for system operation. Like the other BMR464, the new BMR464-SIP regulator offers unprecedented functionality enabling full monitoring and dynamic controlling of the power delivered to processors, FPGAs, ASICs and other components, ensuring minimum energy consumption under all operating conditions.

A synchronization feature allows several regulators to be locked to a common switching frequency to eliminate beat frequencies. This reduces EMI filtering complexity and the number of external components needed. Additionally, phase spreading reduces input capacitance requirements, and hence losses, because the peak current drawn from the input supply is spread over the whole switching cycle.
A current-sharing rail can be configured enabling 100% utilization of the output of each device and also, during periods of light loading, one or more phases can be disabled eliminating the associated current drain and switching losses. This process is handled automatically using a PMBus command. Efficiency is further enhanced with adaptive diode emulation that turns off the low-side MOSFET gate drive in the synchronous rectification circuit at low load currents.

The BMR464-SIP also features comprehensive circuit protection. Signaling is provided for remote control, power good, current sharing, voltage tracking, voltage margining and remote sense. Voltage setting is done via pin strapping or the PMBus.
The vertical-mount BMR464-SIP uses two through-hole connectors: one for low-power signals and the second for power. Each power pin (VIN, VOUT and GND) has been doubled, reducing power losses and improving thermal conduction.

Ericsson Power Modules was the first company to launch digitally controlled POL (point-of-load) regulators based on a digital core controller. Through close cooperation with board and systems designers, the company was the first to release a 21st century power architecture that can be fully integrated into the rest of the digital chain of processors and associated components.