TITLE. Chip and Package-Level Wideband EMI Analysis for Mobile DRAM Devices. Jin-Sung Youn (Samsung Electronics)

Transcription

1 TITLE Chip and Package-Level Wideband EMI Analysis for Mobile DRAM Devices Jin-Sung Youn (Samsung Electronics) Image Jin-Sung Youn, Jieun Park, Jinwon Kim, Daehee Lee, Sangnam Jeong, Junho Lee, Hyo-Soon Kang, Chan-Seok Hwang, Jong-Bae Lee (Samsung Electronics)

2 Chip and Package-Level Wideband EMI Analysis for Mobile DRAM Devices Jin-Sung Youn (Samsung Electronics) Jin-Sung Youn, Jieun Park, Jinwon Kim, Daehee Lee, Sangnam Jeong, Junho Lee, Hyo-Soon Kang, Chan-Seok Hwang, Jong-Bae Lee (Samsung Electronics)

3 SPEAKERS Jin-Sung Youn Senior Engineer, Samsung Electronics He received the B.S. degree in Information and Telecommunication Electronics Engineering from Soongsil University, Korea, in 27. He received He received the M.S. and Ph.D. in Electrical and Electronic Engineering from Yonsei University, Korea, in 214. His doctoral dissertation concerned the high-speed and powerefficient 85-nm Si optoelectronic integrated receivers for optical interconnect applications. In 214, he joined the Samsung Electronics, Gyeonggi-do, Korea, where he is currently a Senior Engineer. His current research interests include the area of design methodology that include signal integrity (SI), power integrity (PI), electromagnetic interference (EMI), and electrostatic discharge (ESD).

4 Agenda Background Trends of in Mobile Devices EMI Source in Mobile Devices Wideband EMI Analysis Methodology EMI Simulation Flow Chip/Package-Level EMI Solution Correlation with Measurement Results Conclusion

5 Thickness [mm] Trends of Mobile Devices High performance/integration: multi cores, multi functions, huge data processing,... 8+components in a mobile device Higher connectivity: GSM, CDMA, UMTS, LTE, Bluetooth/WiFi, GPS, 5G(28GHz)... Thin and slim device Prediction Year 9.9mm 예 So A LG H Sa Source: 6.8mm Electromagnetic interference (EMI) becomes a critical issue! Source:

6 EMI Issues Evaluation of EMI Characteristics RF sensitivity degradation: cellular bands (2G/3G/LTE), Bluetooth/WiFi, GPS Malfunctions - Display/camera performance degradation - Ghost swipe in touch screen panel (TSP) Set-Level EMI Classify EM Noises & Find Root Causes NFS Chip Camera Module PMIC Component-Level EMI Camera Chip Memory Sensors (Gyro,Accelerometer) AP Far-Field TIS * TIS: Total Isotropic Sensitivity BT/WiFi Source: Modem microsd Card Near Field Near-field scan (NFS)-based EMI analysis is essential!

7 If Our Products Failed by EMI... Most of EMI evaluation and verification rely on testing... Requirement of additional cost and time to fix Effort (cost & time) can be reduced by adopting EMI simulation in the product design stage. Existing Process Product Design Fabrication EMI Test Pass Product Re-Design Fail Mass Production Signal Swing Level Slew Rate Control Operating Frequency Change Chip/PKG/System Revision Improved Process Product Design EMI Simulation Fabrication EMI Test Pass Product Re-Design Fail Mass Production EMI analysis methodologies are strongly required!

8 -65 Why We Need Wideband EMI Solution? Data rate of mobile DRAMs continuously increases... LPDDR2(8Mbps) LPDDR3(16Mbps) LPDDR4(32Mbps) LPDDR2 (8Mbps) LPDDR3 (16Mbps) LPDDR (32Mbps) [dbm] [dbm] [dbm] LTE/GSM LTE/GSM LTE/GSM GPS LTE/GSM /Glonoss BT/WiFi [Hz] 1G 2G 3G 4G 5G GPS LTE/GSM /Glonoss BT/WiFi [Hz] 1G 2G 3G 4G 5G GPS LTE/GSM /Glonoss BT/WiFi [Hz] 1G 2G 3G 4G 5G Radio-frequency interference (RFI) between memory and wireless antennas...

9 Voltage Voltage Package-on-Package (PoP) EMI Sources EMI Sources in Mobile DRAM Devices On-Chip radiation: direct emission (by on-chip interconnection) from chip surface Off-Chip radiation: signal conductors and power plane from package TOP Package (Memory) Bottom Package (AP) DRAM#4 DRAM#3 DRAM#2 DRAM#1 On-Chip EM Radiation DRAM Cell VDD I/O Signal I/O Signal GND Off-Chip EM Radiation (Power Plane) Off-Chip EM Radiation (Signal Path) Signal Path Power Plane DQ(Ch1.) DQ(Ch2.) Time Time Crosstalk Noise Timing delay/skew Jitter Impedance mismatch VDDQ(Ch1.) VDDQ(Ch2.) Simultaneous Switching Noise (SSN) Plane coupling PWR/GND Impedance

10 EMI Simulation Flow Various circuit/em simulation tools are available for EMI simulation. How to increase accuracy of EMI simulation...? Source:

11 Input Stimulus EMI Source Extraction Memory read operation at 1.6 Gbps Block diagram Memory I/O buffer Power distributed network (PDN) Memory/AP package models Input stimulus Verify by package direct probing & logic analyzer Periodic pattern (832bits) t oggle t oggle t oggle 416bit 32bit 32bit 32bit. 12bit 16bit 4bit *Toggle: Non-Toggle:...

12 Voltage [V] EMI Source Extraction - I/O Buffer Model SPICE model provides better accuracy with long simulation time. IBIS Model Static and dynamic curves describing electrical behavior of the I/O Used for fast extraction of basic parameters SPICE Model Rising Waveforms IBIS Model PMOS Power Clamp Diodes IN OUT IN OUT NMOS GND Clamp Cap C comp Falling Waveforms Pullup Pulldown IBIS SPICE Knee Overshoot Ringback Time [ns] Waveform differences btw SPICE and IBIS Models High-frequency components * IBIS: I/O Buffer Information Specification SPICE model is needed to achieve wideband EMI solution.

13 DQ DQ2 DQ4 DQ6 DQ8 DQ1 DQ12 DQ14 DQ DQ2 DQ4 DQ6 DQ8 DQ1 DQ12 DQ14 DQ DQ2 DQ4 DQ6 DQ8 DQ1 DQ12 DQ14 Magnitude [db] Magnitude [db] Magnitude [db] EMI Source Extraction - Power Distributed Network (PDN) PDN based on R-network can be used for simple and fast simulation. RC Network is extracted from layout Accurate PDN effect can be included in our simulation. R Network Power Plane SPICE Model.subckt DRAM in out vdd vss nmos out in vss vss pmos out in vdd vdd cdecap vdd vss 1p.ends Time Domain No significant difference! R Network RC Network Ground Plane RC Network Power Plane Ground Plane SPICE Model.subckt DRAM in out vdd vss nmos out in vss vss pmos out in vdd vdd cdecap vdd vss 1p.ends Frequency Domain ~13dB difference@2 nd harmonic MHz 16MHz 24MHz R Network RC Network

14 Package model setting using SIwave Chip/Package Modeling Full Package Model Layer/DIE Stack-up Source Attachment Chip Metal DRAM#N Dielectric Solderball Bondwire DRAM#1 Copper Dielectric Simple Model JEDEC 4-Point Sig. GND Copper Dielectric Interposer Model (for Testing) Frequency-Independent Source (FFT Dataset File)

15 Simulation is done using SIwave Frequency range Near-Field Simulation 7MHz~1GHz (51points) 15MHz~18MHz (51points) 23MHz~25MHz (51points) [Simulation Results at 8MHz] Hx Probe Hy Probe Hz Probe Extract the maximum value btw Hx and Hy probes at each frequency

16 Correlation (1): Simulation vs. Measurement Memory read operation (16Mbps) for each byte Near-field scan measurement up to 3 rd harmonic (8MHz, 16MHz, 24MHz) Error between measurement and simulation is less than 3dB Simulation is well matched with measurement!! Byte Byte1 Byte2 Byte3 EM Field EM Field [dbm] Sim. Meas. [dbm] Sim. Meas. [dbm] Sim. Meas. [dbm] Sim. Meas. Byte (Ch1.) Byte (Ch2.) [MHz] [MHz] [MHz] [MHz] [MHz] [MHz] [MHz] [MHz] Sim. Sim. Sim. Sim. Meas. Meas. Meas. Meas.

17 H-Field [dbm] H-Field [A/m] H-Field [A/m] Correlation (2): Simulation vs. Measurement Memory read operation (16Mbps) with all byte simultaneously Near-field scan (NFS) measurement up to ~2.4GHz Correlation between measurement and simulation is about 89.4% EM Field EM Field All Byte [dbm] Frequency [MHz] Frequency [MHz] Frequency [MHz] Simulation Measurement [MHz]

18 Conclusion Wideband EMI Analysis Methodology for Mobile DRAM Devices Chip/Package-Level EMI Solution and its Detail Analysis Strategies I/O and Power Distribution Network Models Chip/Package Modeling Correlation with Near-Field Scan Measurement Results Wideband spectrum (~2.4 GHz) with correlation factor of 89.4 %

19 Thank you! Jin-Sung Youn QUESTIONS?