EMC Models

2 September 15 1.Models, what for ? 2.IC Models for EMC 3.Core Model 4.Package model 5.Test-bench models 6.Emission measurements/simulations 7.Immunity measurements/simulations 8.Conclusion Summary

3 September 15 IC DESIGNERS WANT TO PREDICT EMC BEFORE FABRICATION Models – What for ? Noise margin Switching Noise on Vdd IC designers want to predict power integrity and EMI during design cycle to avoid redesign EMC models and prediction tools have to be integrated to their design flows Short time-to-market Cost of redesign: several million €

4 September 15 © Siemens Automotive Toulouse Most of the time, EMC measurements are performed once the equipment is built. No improvements can be done at conception phase. Predict EMC performances  IC, board, equipment optimizations However, need of non-confidential IC models (black box models) Models – What for ? EQUIPMENT DESIGNERS WANT TO PREDICT EMC BEFORE FABRICATION

5 September 15 DESIGN Architectural Design Design Entry Design Architect FABRICATION EMC compliant EMC Simulations Compliance ? GO NO GO EMC VALIDATED BEFORE FABRICATION Design Guidelines Models Training Models – What for ?

6 September 15 Complexity Level Equipment Board Component Physical spice V, Z 10 6 R,L,C,I LEECS ICEM Dipoles 10 2 R,L,C,I 10 1 R,L,C,I 10 1 dipoles 10 0 V(f), 10 0 Z(f) x-highhighlowmedium Expo PowerSI 10 4 R,L,C,I EMC MODELS DEPENDS ON THE TARGETED COMPLEXITY, THE LEVEL OF CONFIDENTIALITY OF INFORMATION. Confidentiality IC models for EMC

7 September 15 IC models for EMC Core – I/O Model Package Model Test bench ModelTest board Model EMC Model for the circuit Electrical Simulation Simulated Emission spectrum GENERAL FLOW TO BUILD AN EMC MODEL AND PREDICT EMC PERFORMANCES IEC 62433

8 September 15 IC models for EMC THE IEC PROJECT IEC ICEM-CE Conducted RF emission IEC ICEM-RE Radiated RF emission IEC ICIM-CI Conducted RF immunity IEC ICIM-RI Radiated RF immunity

9 September 15 IC models for EMC THE IEC PROJECT Conducted mode Radiated mode Emission Immunity Intra-bloc ICEM-CE IEC ICEM-RE IEC ICIM-CI IEC ICIM-RI IEC Impulse immunity IEC Intra-bloc EMC IEC Standard available Draft of standard Research undergoing

10 September 15 IC models for EMC IEC – “ICEM Conducted Mode” Package IA PDN IT

11 September mA 3 A 32 bit processor 500 MHz 62.5 ns 2 ns 16 bit processor 16 MHz I time Core model INTERNAL ACTIVITY (IA) - CURRENT SOURCE EXTRACTION time I Extraction of internal current waveform 1st order assumption : model core activity by triangular waveform current source

12 September 15 Physical Transistor level (Spice) Huge simulation Limited to analog blocks Interpolated Transistor level Difficult adaptation to usual tools Limited to 1 M devices Simple, not limited Fast & accurate Gate level Activity (Verilog) Activity estimation from data sheet Very simple, not limited Immediate, not accurate Core model INTERNAL ACTIVITY (IA) – FROM PHYSICAL TO FIRST-ORDER ESTIMATION Equivalent Current generator Extraction In this course

13 September 15 Core model PASSIVE DISTRIBUTION NETWORK (PDN) Complex network of interconnections, vias and on-chip capacitances Coupling path for noise through the IC Require extraction of impedance between Vdd and Vss. Possible modeling by an equivalent passive model Equivalent passive model Substrate, interconnections metallization Capacitive behavior

14 September 15 Package model IC model Core model ICEM IN IC-EMC - DOUBLE LC SYSTEM IA Rvdd Cd Lvdd RvssLvss Cb LPackVdd LPackVss External VDD External VSS Secondary resonance Primary resonance Frequency Emission level Low L,C values => High resonant frequency ICEM-CE model (IEC ) PDN IA

15 September 15 [IBIS Ver] 2.1 [Date] March 17,2011 [File Name] dsPIC33FJ128GP706.ibs [File rev] 1.0 [Component] dsPIC33FJ128GP706 [manufacturer] MICROCHIP [Package] | R_pkg 19.05m 21.2m 16.9m L_pkg 3.025nH 2.61nH 3.44nH C_pkg 0.269pF 0.268pF 0.270pF … [IBIS Ver] 2.1 [Date] March 17,2011 [File Name] dsPIC33FJ128GP706.ibs [File rev] 1.0 [Component] dsPIC33FJ128GP706 [manufacturer] MICROCHIP [Package] | R_pkg 19.05m 21.2m 16.9m L_pkg 3.025nH 2.61nH 3.44nH C_pkg 0.269pF 0.268pF 0.270pF … Core Model ADDING IOS - IBIS: INPUT BUFFER I/O SPECIFICATION IBIS file  I/O switching noise prediction  I/O immunity prediction Very important for : Input driver I(V) characteristics Output driver I(V) characteristics

Core Model 16 September 15 IC PIN DECLARATION - MODELS

17 September 15 Core Model MODEL DETAILS

Core Model 18 September 15 ADDING IOS – SIGNAL TRANSPORT

19 September 15 Package Model CASE STUDY – DSPIC 33F z11-dspic-vdd_10-vss_9.z On-chip decap Package inductance

20 September 15 11 To receiver DUT Emission measurement/simulation CONDUCTED/RADIATED EMISSION PREDICTION Time Domain Simulation FFT of V analyzer (t) EMC model Measurements Core Model Elec. package Model Board Model IC Model Spectrum analyzer Compare spectrums Simulations Measurements

21 September 15 ICEM-CE CASE STUDY – DSPIC 33F Emission measurement/simulation Core only

22 September 15 ICEM-CE CASE STUDY – DSPIC 33F Emission measurement/simulation Core + 16 ADDR 20dB more noise than core

23 September 15 Emission measurement/simulation ICEM-RE – CURRENT DIPOLE THEORY chip Vdd Vss I(vdd) I(vss) P H1 H2  Package is the main contributor of the radiated emission of an IC  Magnetic field emission is generated by the flowing of parasitic current through package pins Magnetic near field scan of a 16 bit microcontroller

24 September 15 Scan Simulations Core Model Elec. package Model Analog Time Domain Simulation Fourier Transform of I(t) Compare scans Scan Measurements Spectrum analyser H[x,y] at given f, given z Positionning [x,y] Emission measurement/simulation Geometrical package model H[x,y,z] of I(f) ICEM-RE – SIMULATION/MEASUREMENT

25 September 15 Emission measurement/simulation ICEM-RE – RADIATING DIPOLES IA PDN IT

26 September 15 IC models for EMC IEC – “ICIM CONDUCED IMMUNITY” The package and die impedance act as a coupling path for RF interference (Vin, Iin) to the active blocks, Filtering effect and/or distortion through the PDN and produce (Vr,Ir). The IB block describes how the circuit reacts to internal perturbations, and can be represented as (Vout,Iout) for monitoring the failure

27 September 15 IC models for EMC IEC – “ICIM CONDUCED IMMUNITY” Package IB PDN Package PDN Silicon die IC PDN Internal Behaviour IB External pins ICIM – immunity model Package Monitoring of the failure PDN = Passive Distribution Network detection RF disturbance Coupling path Close to ICEM-CE Close to ICEM Add Diodes (camp, back-to- back, ESD, EOS) New!

28 September 15 Functionnal model Coupling path model RF generator model Susceptibility criterion +Internal Behavior (IB) +Behaviour of sensitive & non-linear parts +DUT power supply +DUT input structure model +Passive Decoupling Network (PDN) +Perturbation source +Extraction of power injection Injection model +Injection device model +PCB model Power limit Voltage threshold Overcurrent SNR degradation LSB degradation …. IC models for EMC IEC – “ICIM CONDUCED IMMUNITY”

29 September 15 Susceptibility measurement/simulation SUSCEPTIBILITY PREDICTION MODEL Functional model output input clock Vdd Vss Resonance I/O Supply network Z(f) Time Amplitude Disturbance model IC model From ICEM From IBIS Coupling path model  ICIM – CE immunity model  Reuse of standard non-confidential models (ICEM, IBIS)  Susceptibility peaks linked with supply network anti-resonances

30 September 15 Susceptibility measurement/simulation SUSCEPTIBILITY SIMULATION FLOW Aggressed IC Model ( ICEM ) Package and IO model ( IBIS ) RFI and coupling path model ( Z(f) ) Set RFI frequency IC-EMC Increase V aggressor Time domain simulation WinSPICE Criterion analysis Extract forward power IC-EMC Increase RFI frequency Susceptibility threshold simulation

31 September 15 Test bench model DPI capacitance  Electrical model extracted by S parameter measurements and electromagnetic simulations  Test bench models should be generic  Limited frequency range due to influence of parasitic elements, apparition of high order propagation mode TEST BENCH MODEL TEM Cell DPI injection Near-field scan

32 September 15 Susceptibility case study DPI ON A 330 OHM LOAD Immunity > Dpi330ohm

33 September 15 EMC models can help earn/save money Macro-models of ICs include core, I/O and package modeling The core model is based on current evaluation and on-chip capacitance The package model is based on RLC Good prediction of emission and susceptibility up to 2 GHz Soon, requirements up to 3-10 GHz Conclusion