1 / 21

Stephen Oliver, V•I Chip Inc. soliver@vicr , +1 978 749 3256

From the 380V DC Bus to sub-1V Processors: Efficient Power Conversion Solutions SC’07, Reno NV, 11-14-07. Stephen Oliver, V•I Chip Inc. soliver@vicr.com , +1 978 749 3256. Abstract.

brian-mccormick
Download Presentation

Stephen Oliver, V•I Chip Inc. soliver@vicr , +1 978 749 3256

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. From the 380V DC Bus to sub-1V Processors: Efficient Power Conversion SolutionsSC’07, Reno NV, 11-14-07 Stephen Oliver, V•I Chip Inc.soliver@vicr.com, +1 978 749 3256

  2. Abstract • Without a major architectural review, data centers may consume 100 Billion kWhr by 2011. i Additionally, inefficient power and cooling techniques may be the downfall of Moore’s law. ii • One efficiency improvement proposal iii is for the adoption of high voltage DC distribution to enable the AC – 384V stage to be bypassed and the downstream sub-systems (or blades) to be fed directly from the data center distribution busses. This paper represents a follow-on step and proposes high efficiency, high power density power conversion solutions from the HV bus down to processor and low-/medium- and high-power loads. • A baseline sub-system is established with a total load of 1320W: • 6x processors (1V, 120A) • 6x memory (1.5V, 50A) • Miscellaneous loads (12V, 12.5A) • Potential conversion steps considered are 380V-12V-1V and 380-48-1V with bus converter, synchronous buck converters and factorized power regulators with sine amplitude converters. • Efficiency, power density and annual electrical running cost comparisons are presented. • “Report to Congress on Server and Data Center Energy Efficiency” (p56), U.S. EPA ENERGY STAR Program, Andrew Fanara, August 2, 2007 • “The Invisible Crisis in the Data Center: The Economic meltdown of Moore’s Law”. Kenneth Brill, Uptime Institute, 2007 • “DC Power for Improved Datacenter Efficiency”, Ton (Ecos), Fortenbery (EPRI) & Tschudi (Lawrence Berkeley National Labs), January 2007.

  3. Rect., EMI& Inrush PFC Regulated HV DC-DC DC-DC‘Brick’ VRx CPU 380VDC AC 48V 12V 1.xV Backplane AC-DC ‘Silver Box’ VRx Memory 1.xV Motherboard ‘Original’ Traditional High Power System (IBA) • AC-48VDC ‘Silver Box’ + 48-12V DC-DC ‘Brick’ + VRM/VRDs to loads • As designed: • ‘High’ efficiency (~65%), ‘small’ size, ‘cost effective’ • Powered 1.5-2.5V processors, few concerns over energy costs • Over time: • AC-12VDC SMPS & VRM efficiencies / densities improved • IBA bus converters considered expensive and unnecessary • As a result, use of a 12V-only bus increased

  4. ‘Later’ Traditional High Power System (12V) • AC to 12V ‘silver box’ • 12V distribution • Synch Buck POLs to load voltages Rect., EMI& Inrush PFC Regulated HV DC-DC VRx CPU 380VDC AC 12V 1.xV AC-DC ‘Silver Box’ VRx Memory 1.xV Motherboard / Blade VRx CPU 1.xV VRx Memory 1.xV Motherboard / Blade

  5. 12V Bus Concerns • 12V bus is • Established • Proven • Multi-sourced • 12V Bus is also… • Inefficient • Distribution / connector losses • Low efficiency synch buck POLs (especially for sub-1V loads)due to duty-cycle limitations • Expensive • Large connectors, heavy bus bars, lots of copper, high electricity bills • Out of date • Only used in new systems due to incumbency and for legacy loads(e.g. 12V disk drives)

  6. Efficiency Improvements • Higher voltage bus (380VDC* and / or 48VDC) • Direct 48V-sub 1V conversion • Provide 12V for legacy / low power loads * “DC Power for Improved Datacenter Efficiency”, Ton (Ecos), Fortenbery (EPRI) & Tschudi (Lawrence Berkeley National Labs), January 2007.

  7. Revision #1: 380V to the Blade / Motherboard Rect., EMI& Inrush PFC 380VDC HV BCM VRx CPU AC 12V 1.xV • Silver Box  AC-“post-PFC” 380VDC • Reduces silver box size by >50% • 380V distribution direct to blade • Eliminates distribution loss in system(I2R loss at 380V is 0.1% of 12V loss) • Minimize connector size and cost • 380-12V conversion on the blade • Minimize 12V distribution distance AC-HVDC ‘Silver Box’ VRx Memory 1.xV Motherboard / Blade HV BCM VRx CPU 12V 1.xV VRx Memory 1.xV Motherboard / Blade

  8. HV DC-DC Conversion • Bus Converter Module (BCM) • Isolated, Unregulated • Voltage transformer / current multiplier • Sine Amplitude Converter Topology • ZVS, ZCS, >1Mhz switching frequency • 384:12V = 300W @ 95.5% • 384:48V = 330W @ 96.5% • 1.1 in2 package (>1000W / in3) • 1.28 x 0.87 x 0.26in • 0.5 oz / 15 g each U.S. and Foreign Patents and Patents Pending

  9. Revision #2: Direct 48V-to-load conversion Rect., EMI& Inrush PFC 380VDC HV BCM PRM VTM CPU AC 1.xV • Same 380V direct to blade • 380-48V conversion on the blade • 48-1.xV highest efficiency, smallest converter at the load • Minimize 12V on-blade distribution loss AC-HVDC ‘Silver Box’ 48V PRM VTM Memory 1.xV Motherboard / Blade HV BCM PRM VTM CPU 1.xV 48V PRM VTM Memory 1.xV Motherboard / Blade

  10. Direct 48V-to-Load Conversion Voltage Transformation Module (VTM) • Isolated, voltage transformer • Sine Amplitude Converter Topology • ZVS, ZCS, >1Mhz switching frequency • Performance • Up to 100A in 1.1in2 • >96% Efficient at 300W out • Input : Regulated 26-55V from PRM • Outputs : 0.8 - 55V, up to 100A (13 models) Pre-Regulator Module (PRM) • Non–isolated, regulator • ZVS Buck – Boost Topology • ZVS, >1MHz switching • Performance • 320W in 1.1in2 package • Power Density >1,100W/in3 • Efficiency = >97% at 320W out • Input : Unregulated 48V • Output : Regulated (26-55V) VTM • PRM + VTM = Isolated, regulated, voltage transformation direct to load US and Foreign Patents and Patents Pending

  11. Source Load Source Load Source Load 1uFhere 1,000uFhere Space-saving Powertrain – and no ‘Bulk’ • Direct 48V-to-load conversion with 2 V•I Chips • PRM can be located remotely • Increased space on motherboard / near load • Reduced power dissipation at load • Move POL Capacitance to input of VTM • Reduce capacitance by 1/k^2 • Additional space and cost savings

  12. Transient Response

  13. HV BCM PRM VTM 1.5V200A 380V 48V VF (48V) VTM Powertrain & Distribution Efficiency • High conversion efficiency and smallest footprint from 380V-load • Convert 380V to 1.5V, 200A • Total “380V-to-load” Efficiency = 85.2% • 96.5% x 97% x 91% • Total PCB power component footprint = 4.4 in2 ( 4 chip solution ) • With fewer caps, smaller filters, smaller heatsinks • Co-locate HV BCM & PRM, place only the VTM at the load= highest distribution efficiency (I2R) and least space taken at the load

  14. BCM VRx LowPowerLoads xV 12V Legacy, Low Power Loads Rect., EMI& Inrush PFC 380VDC HV BCM PRM VTM CPU AC 1.xV • Step down from 48V to create 12V for legacy / low power loads. • Simple unregulated DC-DC converter AC-HVDC ‘Silver Box’ 48V PRM VTM Memory 1.xV Motherboard / Blade Motherboard / Blade

  15. Systems Comparison • “System” • Blade / Motherboard Content: • 6 processors (1.0V, 120A ea.) • 6 memory (1.5V, 50A ea.) • Miscellaneous rails (12V, 150W total) • Infrastructure: • 30 blades / Motherboards • Board impedance 1.5mΩ • Rack distribution impedance 2.0mΩ • Operation: • Duty cycle = 65% • Air conditioning = 50% efficient • Electricity = $0.1028 per kWhr* • Systems: • [AC 12V] 1.xV (baseline) • [AC-384V] 12V 1.xV • [AC-384V] 48V 1.xV • [AC - 48V] 1.xV […] = silver box * Nevada industrial electricity price July ’07 ( http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_a.html )

  16. Efficiency Comparison: AC-Loads • In all cases, adoption of higher voltage improves efficiency • 380V in rack and 48V on blade / motherboard has highest efficiency • +8.7% pts over baseline • Improved efficiency 380V-Load means smaller PFC / EMI section. +8.7% pts

  17. Power Loss (per Blade / Motherboard) • Reduction of 173W per blade / motherboard vs. baseline 173 W

  18. Utility Savings ( per Year per Blade / Motherboard ) • 380V in rack and 48V on blade / motherboard has highest saving ($202 per year, per blade / motherboard) $202

  19. Conclusion • 12V-only distribution systems have limitations in high power computing applications • Lower load voltages and larger load domain power • Duty cycle limitation of synchronous buck conversion • Increased I2R distribution loss • Higher voltage (380V and / or 48V) distribution greatly reduces distribution loss • Direct 48-to-load conversion offers high efficiency and small size • Enable up to 8.7% pts efficiency improvement over 12V baseline • Significant running cost savings

  20. References • “Report to Congress on Server and Data Center Energy Efficiency” (p56), U.S. EPA ENERGY STAR Program, Andrew Fanara, August 2, 2007 • “The Invisible Crisis in the Data Center: The Economic meltdown of Moore’s Law”. Kenneth Brill, Uptime Institute, 2007 • “DC Power for Improved Datacenter Efficiency”, Ton (Ecos), Fortenbery (EPRI) & Tschudi (Lawrence Berkeley National Labs), January 2007 • “Datacenter Power Delivery Architectures : Efficiency and Annual Operating Costs”, Yeaman (V.I Chip), Digital Power Forum, September 2007

  21. Thank youQuestions & comments?Visit the V•I Chip booth (#832) for a live 380V-0.8V demo

More Related