Vicor proposes factorised power modules to meet Google power thinking

March 11, 2016 // By Graham Prophet
Vicor has announced its latest generation of 48V Direct-to-PoL (Point-of-Load) power components, to supply high-current devices such as CPUs, GPUs, ASICs and DDR memory directly from a 48V distribution bus with, the company says, power density, conversion efficiency and low power system distribution loss.

Embodying advances in power conversion engines, control systems and modular power technology, these 48V modules are being introduced following the Open Compute Project (“OCP”) Summit 2016 at which Google announced its initiative to promote 48V server and distribution infrastructure as a standard for data centres. Patrizio Vinciarelli, President and CEO of Vicor, commented: “By developing its 48V server infrastructure, Google pioneered green data centres. And by promoting an open 48V rack standard, Google is now enabling a reduction in the global cloud electricity footprint.”


Although the benefits of a higher distribution bus voltage, particularly 48V, which requires no special safety precautions, are well known, Vicor says, (smaller cables and bus bars, lower distribution losses, smaller storage capacitors), conventional power conversion approaches have not been able to efficiently, or compactly, transform power from a 48V bus into the low voltages (e.g., 3.3V, 1.8V and 0.8V) and high currents (e.g. 95 Amps) required by contemporary CPUs or GPUs. As a result, CPU power conversion has customarily relied on 12V distribution. A 12V bus, however, must carry four times the current carried by a 48V bus, and, because distribution losses are a function of the square of the current, the power lost in a 12V bus can be as much as 16 times the loss in a 48V bus. By providing efficiencies from a 48V bus that are better than 12V legacy solutions, in a fraction of the space, Vicor’s 48V Direct-to-PoL product families enable system designers to implement “green” distributed system solutions featuring high conversion efficiency, high power density and low distribution loss.


Vicor’s latest generation 48V Direct-to-PoL modules include the Cool-Power PI3751-02 Buck-Boost, Pre-Regulator Module (“PRM”) and the VTM48Kp020x Current Multiplier Module (“VTM”). The PRM receives its input from a 48V distributed bus (Vin up to 55V) and drives a controlled “factorised” bus voltage to the VTM; the VTM generates an output voltage that is 1/24th of the voltage