EMC Models

2 19 Apr 2023

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 19 Apr 2023

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 19 Apr 2023

© 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 19 Apr 2023

DESIGN

Architectural Design

Design EntryDesign Architect

FABRICATION

EMC compliant

EMC SimulationsCompliance ?

GO

NO GO

EMC VALIDATED BEFORE FABRICATION

Design Guidelines

Models

Training

Models – What for ?

6 19 Apr 2023

Complexity

Level

Equipment

Board

Component

Physicalspice

V, Z

106 R,L,C,ILEECS

ICEM

Dipoles

102 R,L,C,I

101 R,L,C,I

101 dipoles

100 V(f), 100 Z(f)

x-highhighlow medium

Expo PowerSI

104 R,L,C,I

EMC MODELS DEPENDS ON THE TARGETED COMPLEXITY, THE LEVEL OF CONFIDENTIALITY OF INFORMATION.

Confidentiality

IC models for EMC

7 19 Apr 2023

IC models for EMC

Core – I/O Model

Package ModelTest bench Model Test 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 19 Apr 2023

IC models for EMC

THE IEC 62433 PROJECT

IEC 62433-2 ICEM-CE

Conducted RF emission

IEC 62433-3 ICEM-RE

Radiated RF emission

IEC 62433-4 ICIM-CI

Conducted RF immunity

IEC 62433-5 ICIM-RI

Radiated RF immunity

9 19 Apr 2023

IC models for EMC

THE IEC 62433 PROJECT

Conducted mode Radiated mode

Emission

Immunity

Intra-bloc

ICEM-CE

IEC 62433 - 2

ICEM-RE IEC 62433-3

ICIM-CI

IEC 62433-4

ICIM-RI

IEC 62433-5

Impulse immunity IEC 62433-6

Intra-bloc EMC IEC 62433-7

Standard available

Draft of standard

Research undergoing

10 19 Apr 2023

IC models for EMC

IEC 62433-2 – “ICEM Conducted Mode”

IAPDN

(including package)

IA

IA

PDNof PCB

IC model

IA = Internal Activity

PDN = Power Distribution Network

IT = Internal Terminal

ET = External Terminal

PDN(including package)

PDN(including package)

IBCIBC

IBCIBC

IT

IT

IT

IT

IT IT

IT IT

IT IT

IT IT

IT IT

IT IT

IT IT

IT IT

ET

ET

ET

ET

ET ET

ET ET

ET ET

ET ET

ICEM-CE Block A

ICEM-CE Block B

ICEM-CE Block C

Example : Digital core

Example : Analog core

Example : I/O buffers

Package

IA

PDN

IT

11 19 Apr 2023

100 mA

3 A

32 bit processor500 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

IAPDN

(including package)

IA

IA

PDNof PCB

IC model

IA = Internal Activity

PDN = Power Distribution Network

IT = Internal Terminal

ET = External Terminal

PDN(including package)

PDN(including package)

IBCIBC

IBCIBC

IT

IT

IT

IT

IT IT

IT IT

IT IT

IT IT

IT IT

IT IT

IT IT

IT IT

ET

ET

ET

ET

ET ET

ET ET

ET ET

ET ET

ICEM-CE Block A

ICEM-CE Block B

ICEM-CE Block C

Example : Digital core

Example : Analog core

Example : I/O buffers

12 19 Apr 2023

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)

time (ns)0

20040060080010001200

0 20 40 60 80 100 120 140

Activity

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

generatorExtraction

In this course

IAPDN

(including package)

IA

IA

PDNof PCB

IC model

IA = Internal Activity

PDN = Power Distribution Network

IT = Internal Terminal

ET = External Terminal

PDN(including package)

PDN(including package)

IBCIBC

IBCIBC

IT

IT

IT

IT

IT IT

IT IT

IT IT

IT IT

IT IT

IT IT

IT IT

IT IT

ET

ET

ET

ET

ET ET

ET ET

ET ET

ET ET

ICEM-CE Block A

ICEM-CE Block B

ICEM-CE Block C

Example : Digital core

Example : Analog core

Example : I/O buffers

13 19 Apr 2023

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 19 Apr 2023

Package model IC model

Core model

ICEM IN IC-EMC - DOUBLE LC SYSTEM

IA

Rvdd

Cd

Lvdd

Rvss Lvss

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 62433-2)

PDN

IA

15 19 Apr 2023

[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 16.9mL_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 16.9mL_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 fileIBIS file

I/O switching noise prediction I/O immunity prediction

Very important for :

Input driver I(V) characteristics

Input driver I(V) characteristics

Output driver I(V) characteristics

Output driver I(V) characteristics

Core Model

16 19 Apr 2023

IC PIN DECLARATION - MODELS

17 19 Apr 2023

Core Model

MODEL DETAILS

Core Model

18 19 Apr 2023

ADDING IOS – SIGNAL TRANSPORT

19 19 Apr 2023

Package Model

CASE STUDY – DSPIC 33F

z11-dspic-vdd_10-vss_9.zz11-dspic-vdd_10-vss_9.z

On-chip decap Package

inductance

20 19 Apr 2023

1 To receiver

DUT

Emission measurement/simulation

CONDUCTED/RADIATED EMISSION PREDICTION

Time Domain Simulation

FFT of Vanalyzer(t)

EMC model

Measurements

Core Model

Elec. package Model

BoardModel

IC Model

Spectrum analyzer

Compare spectrums

Simulations Measurements

21 19 Apr 2023

ICEM-CE CASE STUDY – DSPIC 33F

Emission measurement/simulation

Core only

22 19 Apr 2023

ICEM-CE CASE STUDY – DSPIC 33F

Emission measurement/simulation

Core + 16 ADDR 20dB more noise

than core

23 19 Apr 2023

Emission measurement/simulation

ICEM-RE – CURRENT DIPOLE THEORY

chip

Vdd

Vss

I(vdd)

I(vss)

P

H1

H2

i

iHPH

r P

H

IL

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 19 Apr 2023

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

VssX1 VssA

VssX2VssR2

Vss2

Vdd2

Vss1

Vdd1

VssR1 VddR1

H[x,y,z] of I(f)

ICEM-RE – SIMULATION/MEASUREMENT

25 19 Apr 2023

Emission measurement/simulation

ICEM-RE – RADIATING DIPOLES

IA

PDN

IT

IT

26 19 Apr 2023

Passive elements

IB Active elements

Residual disturbances

Behavioural output

PDN RF

Disturbances

Vin, Iin

Vr, Ir

Vo, Io IEC 62433-4

IC models for EMC

IEC 62433-4 – “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 19 Apr 2023

IC models for EMC

IEC 62433-4 – “ICIM CONDUCED IMMUNITY”

Package

IB

PDN

Package PDN

Package PDN Silicon die

IC PDN Internal Behavio

ur

IB

External pins

ICIM – immunity modelPackage

Monitoring of the failure

PDN = Passive Distribution Network

detection

RF disturbance Coupling

path

Close to ICEM-CEClose to ICEM

Add Diodes (camp, back-to-back, ESD, EOS)

New!

28 19 Apr 2023

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 62433-4 – “ICIM CONDUCED IMMUNITY”

29 19 Apr 2023

Susceptibility measurement/simulation

SUSCEPTIBILITY PREDICTION MODEL

Functional model

outputinput

clock

Vdd

Vss

Resonance

I/O

Supply network Z(f)

Time

Amplitude

Disturbance model

IC model

From ICEMFrom

IBISCoupling path model

ICIM – CE immunity model

Reuse of standard non-confidential models (ICEM, IBIS)

Susceptibility peaks linked with supply network anti-resonances

30 19 Apr 2023

Susceptibility measurement/simulation

SUSCEPTIBILITY SIMULATION FLOW

Aggressed IC Model (ICEM)

Package and IO model (IBIS)

RFI and coupling path model (Z(f))

Set RFI frequencyIC-EMC

Increase V aggressor

Time domain simulation

WinSPICE

Criterion analysis

Extract forward power

IC-EMC

Increase RFI frequency

Susceptibility threshold simulation

31 19 Apr 2023

Test bench model

DPI capacitance

C=1nF

L=0.5nH

R=15mΩ

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 CellDPI injection

DUT

TEM

K=1%C=20fF

Near-field scanDUT

K=6%

L=4nHR=1Ω

32 19 Apr 2023

Susceptibility case study

DPI ON A 330 OHM LOAD

Immunity > Dpi330ohm

33 19 Apr 2023

• 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