Modules Support Architecture Highlighted by Google at OpenPOWER Summit
Vicor Corporation today announced an expansion of its family of 48V Direct-to-PoL (Point-of-Load) power modules. Optimized for system loads (CPUs, GPUs, ASICs, and DDR memory) requiring operating voltages below 1.25 Volts at load currents up to hundreds of Amperes, these new modules enable power systems with higher density and conversion efficiency than alternative solutions. Combining best-in-class power density, efficiency, and thermal and electrical performance afforded by Vicor's Sine Amplitude Converter (SAC) technology in a rugged, thin 13mm x 23mm ChiP, these new modules are ideally suited for use in a broad range of 48 Volt power systems applications.
Efficient, dense, cost-effective, and reliable power distribution is a critical element in data centers and other applications. It is axiomatic that higher distribution bus voltage reduces distribution bus loss. However, overall system power loss is comprised of both distribution bus loss and the losses in the power converters that power CPUs and other loads. Because conventional approaches to power conversion exhibit decreasing efficiency and power density as bus voltage increases, conventional distributed power system design has required trading off bus voltage, and bus losses, against power converter loss and size.
So, while the "sweet spot" for distributed power is at 48V, given lower distribution losses, smaller storage capacitors, smaller cables and bus bars, and no special safety precautions, conventional distributed power systems have historically relied on a lower voltage bus (e.g., 12V) and its associated higher losses. 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 eliminate the tradeoff between bus voltage and system efficiency and density, enabling system designers to implement "green" distributed system solutions featuring high conversion efficiency, high power density, and low distribution loss.
Vicor's 48V Direct-to-PoL product family is comprised of non-isolated Buck-Boost Pre-Regulator Modules (PRMs) and Voltage Transformation Modules (VTMs). When configured in a "Factorized Power Architecture," a PRM (e.g., a Vicor Cool-Power P3751-02 Buck-Boost PRM) receives its input from a 48V distributed bus and delivers a controlled, "factorized" voltage to the input of a VTM. The output voltage of the VTM is the factorized voltage multiplied by a fixed conversion ratio (K) and the output current of the VTM is 1/K times the VTM input current. Current multiplication at the Point-of-Load delivers higher efficiency, density, and bandwidth, all of which are distinguishing attributes of Factorized Power.
Vicor announced its latest generation 48V Direct-to-PoL product family at the Open Compute Project Summit 2016 in March of this year, coincident with Google's announcement of its adoption of a 48V server and distribution infrastructure for green data centers. Vicor's PRM/VTM solutions have been designed into advanced CPU/GPU motherboards, including advanced applications incorporating next generation POWER CPU products.
Two new VTM current multiplier modules are being introduced during OpenPOWER Summit 2016: a K=1/48 unit, whose secondary-side voltage is one-forty-eighth (1/48) of its primary-side voltage, delivering up to 135 Amps of current at a density up to 1948 Amps/In3, and a K=1/40 unit, whose secondary-side voltage is one-fortieth (1/40) of its primary-side voltage, delivering up to 130 Amps of current at a density up to 1354 Amps/In3. Devices can be operated in parallel to address higher current GPU processors of 250A or more. VTMs feature typical conversion efficiency exceeding 94% and true bidirectional power transfer capability.
Each VTM features very low output impedance, allowing users to remove bulk capacitors from the Point-of-Load. Furthermore, only the high current VTM needs to be close to the CPU; the PRM can be located remotely. And, whereas conventional buck regulator solutions require a multiplicity of phases to handle the full transient current demanded by a CPU operating in 'turbo' or 'boost' mode, a single VTM, having a peak current capability that is only thermally limited, delivers up to twice its rated continuous current for milliseconds at a time, thereby accommodating transient CPU/GPU operating modes without sacrificing system power density and cost. In applications that require telemetry and PMBus digital control (e.g., some CPU, GPU, ASIC and DDR4 memory applications) Vicor's PI3020 Digital Control and Telemetry device may be used with a VTM/PRM pair.
