TITLE Topic: Far-Field o Nam elementum EMI commodo Analysis mattis. Pellentesque Methodology and Verification on SSD Boards Topic: o malesuada blandit euismod. Seong-Jin Mun, (Samsung Electronics Inc.) Nam elementum commodo mattis. Pellentesque malesuada blandit euismod. Nam elementum commodo mattis. Pellentesque Image o Jin-Sung Youn (Samsung Electronics Inc.), Kyung-Nam Park (Samsung Electronics Inc.) Jieun malesuada Park (Samsung blandit euismod. Electronics Inc.), Daehee Lee (Samsung Electronics Inc.) Chan-Seok Hwang (Samsung Electronics Inc.), Jong-Bae Lee (Samsung Electronics Inc.) Topic: o Nam elementum commodo mattis. Pellentesque malesuada blandit euismod.
SPEAKERS Seong-Jin Mun Engineer, Samsung Electronics Inc. sungj.moon@samsung.com Received the B.S. degree from Department of Electronic Engineering, Sogang University, Seoul, Korea, in 2010. Since 2010, He has been an engineer with the Semiconductor Business, Samsung Electronics, Korea. His research interests are in the area of signal integrity (SI), power integrity (PI), electromagnetic interference (EMI), thermal integrity (TI) and package/board layout design verification.
Agenda Background o Trends of Data Storage o Necessity of EMI Simulation Methodology Far-Field EMI Simulation Methodology o Proposed EMI Simulation Flow o PCB-Level EMI Solution Correlation with Far-Field Measurement Results Relationship Between Board Design and Far-Field EMI Conclusion
Trends of Data Storage Hard Disk Drive (HDD) Solid-State Drive (SSD) o Higher Read/Write Rate, Faster Access Time, Lower Power Consumption HDD SSD Source: www.google.com Source: www.samsung.com SSD HDD Difference Media NAND FLASH Magnetic Platters Read/Write Speed Sequential [MB/s] 540 / 330 60 / 160 ⅹ9 / 2 Random [IOPS * ] 98000 / 70000 450/400 ⅹ217 / 175 Data Access Time [ms] 0.1 10~12 ⅹ100~120 Power Consumption Active(Idle) [W] 0.127(0.046) 1.75(0.8) ⅹ13 (ⅹ17 )
Emission(dB) EMI Problem in SSD Products SSD s speed and density is continuously increasing Far-Field EMI Measurement Setup Increasing Speed Increasing Density Digital Signal Spectrum Far Field Emission EMI(Electromagnetic Interference) becomes a critical issue! F knee Source: high-speed digital system design Overall Emission Spectrum (Speed x1) Overall Emission Spectrum (Speed x2) Source: www.google.com
Necessity of EMI Simulation Methodology Measurement-based EMI verification requires additional cost and time to debug EMI mechanisms and root causes of the radiated field need to analyze Existing Process Product Design Fabrication EMI Measurement Pass Product Re-Design Fail Mass Production F/W solution (Slew Rate Control) Operating Frequency Change SSC (Spread Spectrum Clock) Shielding Solution Design Revision Proposed Process Product Design EMI Simulation Fabrication PCB Design-Stage Improvement EMI Measurement Pass Product Re-Design Fail Mass Production
EMI Noises in SSD Products Composed of various devices o NAND, DRAM, CTRL, PMIC... o Operated with different speeds / voltages Data Path NAND Flash Memory Controller DRAM PMIC NAND Flash Memory o NAND interface, DRAM interface, Host interface Source: www.samsung.com Higher supply voltage, longer board routing Radiated Energy Regulation NAND 1st NAND 2nd NAND 3rd DRAM 1st NAND 4th DRAM 2nd SATA/ PCIe 1 >3 Frequency [GHz]
Proposed Far-Field EMI Simulation Flow Far-field EMI simulation methodology [Ref. APEMC2015, Benson Wei et. al.] Propose 3 items to enhance simulation accuracy and efficiency o EMI source extraction o Package and reference plane modeling o Huygens box optimization for N/F to F/F transform EMI Source Extraction Structure Modeling EM Solving Based on Huygens Principle 3m Huygens box Far-Field EMI Near-Field EMI Result SSD
Stage 1: EMI Source Extraction Read operation at 460 Mbps (NAND to Controller Interface) Input Stimulus NAND Controller Block diagram 0 1 0 1 0 1 0 DQS o NAND Flash I/O buffer 1 0 1 0 1 0 1 DQSB o Controller I/O buffer o Board model (S-parameter) Input Stimulus 0 1 0 1 0 0 1 0 0 1 1 0 1 1 IO0 IO7 SSD Board o I/O Buffer : PRBS 2 7-1 o Strobe and clock signals Periodic pattern RE REB Input Stimulus 0 1 0 1 0 1 0 1 0 1 0 1 0 1 5% duty cycle distortion : To include power noise
Far-Field Radiated Energy [db] Stage 2: Structure Modeling (1) EM simulation with package and board together o Impractical solution due to simulation time and hardware resources Propose virtual package model with metal plane Both results shows similar simulation results <PKG> <Virtual PKG model> Real PKG Model Virtual PKG Model 100 200 300 400 500 600 700 800 900 1000 Frequency [MHz]
Far-Field Radiated Energy [db] Stage 2: Structure Modeling (2) Propose the merged reference plane o Power and ground plane are modeled in connection to the one plane Represents return path through the capacitor of the die o Simulation result is similar to the measurement GND GND reference PWR GND+Power reference Measurement GND reference GND+Power reference 1st 2nd 3rd
Stage 3: EM Solving Based on Huygens Principle Proposed near- to far-field transform method based on Huygens principle o Radiated energy simulation at 3-m distance from micro-unit SSD board N/F Simulation 2.5D EM solver F/F Simulation 3D EM solver 3m Huygens Box Attach I/O current as EMI source Maximum electric field calculation at 3-m sphere surface How to optimize Huygens box size?
Stage 3: EM Solving Based on Huygens Principle Huygens box size optimization o Proper box size is necessary to minimize error for near- to-far field transform o The radiated field is saturated from 10mm box size
Far-Field EMI at 3-m Distance [dbu(v/m)] Correlation with Far-Field Measurement Results NAND read operation (460Mbps) Good agreement up to 1GHz between simulation and measurement 920 Measurement (Vertical) 460 690 230 Measurement (Vertical) Measurement (Horizontal) Simulation Measurement (Horizontal) 30 300 Frequency [MHz] 1000
Far-Field EMI at 3-m Distance [dbu(v/m)] Far-Field EMI at 3-m Distance [dbu(v/m)] Case Analysis (1) Investigate on relationship between board design and far-field EMI o Routing scheme, Signaling scheme, Number of layer, Number of channel Outer Layer vs. Inner Layer Pseudo Diff. vs. Fully Diff. Pseudo differential Fully differential Outer routing Inner routing 2nd 3rd 4th 1st 2nd 3rd
Far-Field EMI at 3-m Distance [dbu(v/m)] Far-Field EMI at 3-m Distance [dbu(v/m)] Case Analysis (2) Investigate on relationship between board design and far-field EMI o Routing scheme, Signaling scheme, Number of layer, Number of channel vs. Add Layer 2-channel vs. 1-channel 10 Layer 12 Layer 8 Channel 4 Channel 1st 2nd 3rd 2nd 3rd
Conclusion Far-field EMI analysis methodology for commercial SSD products o EMI source extraction o PCB structure modeling o EM solving method based on huygens principle Good correlation between simulation and measurement Investigation of the relationship between board designs and the radiated energy o Routing scheme, signaling scheme, number of layer and number of channel EMI analysis in the design stage prior to the manufacturing process
Thank you! Seong-Jin Mun sungj.moon@samsung.com QUESTIONS?