EMC DESIGN METHODOLOGY FOR LAYOUT OPTIMIZATION

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PROJECT N. 22409 - EMCLO
ESPRIT
E.S.D.
The European Initiative for the Spread of
Best Pratice in Design
PROJECT N. 22409-EMCLO

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PROJECT N. 22409 - EMCLO
EMCLO
EMC DESIGN METHODOLOGIES
FOR PCB LAYOUT
OPTIMIZATION

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PROJECT N. 22409 - EMCLO
EMCLO
• Type of the project: Demonstration project
• Duration: Nine months from May 96 to April 97 (two
months Magneti Marelli transfert site included)
• Project team:
» Magneti Marelli S.p.A prime contractor: end-user
» H.D.T Italia s.r.l partner: software tool vendor

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PROJECT N. 22409 - EMCLO
OBJECTIVE OF THE ACTION
• Show the viability of a prototype tool, named
PRESTO_CNT to perform:
» predictive analysis and screening of EMC problems on
PCB
» extraction, analysis, improvement of critical tracks
» experimental validation of the tool
• Integration with the design methodology inside
Magneti Marelli Electronic Division

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PROJECT N. 22409 - EMCLO
MAGNETI MARELLI - PRODUCTS
MICRO
MEMORY
ASICS
CONNECTOR

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PROJECT N. 22409 - EMCLO
PCB DESIGN METHODOLOGY
Current status
Specification Design Schematic Layout Protoytpe
Test EMC
LibrarySimulation Marelli
Rules

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PROJECT N. 22409 - EMCLO
Schematic & Layout
Analysis
Bench Testing
Debugging
Modification
OK
NO
YES
PRODUCT
EMC VERIFICATION METHODOLOGY
OK
Testing on car
Car environment
modification
OK
YES NO
YES
NO
STOP
CAR
STOP

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PROJECT N. 22409 - EMCLO
NEW EMC DESIGN METHODOLOGY
Goals
Reduce design recycles
Reduce layout recycles
Prediction of conducted noise susceptibility
Layout optimization

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PROJECT N. 22409 - EMCLO
• EMC Rules and EMC constraints defined in Pre-
layout phase
• Post-layout analysis using software simulation
environment
• Back-annotation to electrical scheme and/or layout of
improvements
• Upgrade of the constraints
NEW EMC DESIGN METHODOLOGY
Requirements

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PROJECT N. 22409 - EMCLO
NEW PCB DESIGN METHODOLOGY
Test EMC
Specification Design Schematic Layout Protoytpe
LibrarySimulation Marelli
Rules
Post - Layout
Verification
Library
EMC

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PROJECT N. 22409 - EMCLO
• CAD extractor linked to Cadence PCB DBase (Allegro).
• Link to equipment for EMC-models.
• WHAT-IF facility.
• EMC-filters to improve signal quality.
• Noise Sources to study the board susceptibility.
• Partial simulation of the board
MARELLI TOOL REQUIREMENTS

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PROJECT N. 22409 - EMCLO
• Display simplified view of the PCB layout
independently by the CAD system used in the PCB routing
• Choose the noise injection point
• Inject the noise source. The noise source can be both
user define or circuit dependent
• Define the noise model: sinusoidal (fixed or sweeped
frequency) or wideband e.g. pulse, fast transient
electrostatic discharge.
MARELLI REQUIREMENTS: continue

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PROJECT N. 22409 - EMCLO
Link to
equipment for
EMC-models
Physical &
Electrical
Library
FLOWMANAGER
Cad Extract
Field Solver
Simulator
Output
Reports
Graphic
Viewer
Allegro
database
PRESTO_CNT: FLOW
What-ifAnalysis

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PROJECT N. 22409 - EMCLO
PRESTO_CNT: FEATURES
• CAD Extract from PCB editor the physical and
electrical data.
• Field Solver algorithm to calculate Z0, TD for each TL,
L and C matrix for coupled lines.
• Link to Physical and Electrical Library to model the
components on the board.
• SPRINT™ simulator engine.
• SIGHTS™ graphical output or ASCII format.

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PROJECT N. 22409 - EMCLO
PRESTO_CNT FEATURES
• Starting point:
» One (eventually all) of the simulation levels
available in PRESTO:
– signal transmission
– trace crosstalk
– simultaneous switching noise
– trace supply distribution analysis
– trace radiated emission evaluation
– conducted noise transmission evaluation

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PROJECT N. 22409 - EMCLO
PRESTO_CNT environment
• The design is put in a steady state
• An external noise is injected in one or more nodes of
the design
• The conducted noise is evaluated at any node of the
electrical network, taking into account
simultaneously all the effects: concurent analysis of
all nets conducted Emissions & Conducted Noise
Susceptibility simulation is possible

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PROJECT N. 22409 - EMCLO
PRESTO_CNT environment
PRESTO_CNT offers the possibility to:
• display simplified view of the PCB layout independently by
the CAD system used in the PCB routing
• choose the noise injection point
• inject the noise source. The noise source can be both user
define or circuit dependent
• define the noise model: sinusoidal (fixed or sweeped
frequency) or wideband e.g. pulse, fast transient electrostatic
discharge.

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PROJECT N. 22409 - EMCLO
• the components: adding and placing them on the
scheme, deleting (not) existing components, modifing their
values. The components can be extracted from all libraries
(system and user libraries).
• the segments: adding and placing them on the layout,
deleting (not) existing segments, modifing their geometry.
PRESTO_CNT: WHAT-IF analysis
It is a powerful tool which allows the users to study the effects
of PCB modifications directly from the user interface.

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PROJECT N. 22409 - EMCLO

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PROJECT N. 22409 - EMCLO
A wide Physical & Electrical Library is provided. It contains:
• models of passive components (resistors,
capacitors, inductors, connectors, power and ground plane)
• models of digital components using Scattering
parameters in time domain, obtained by measurements,
static and dynamic transfer functions.
PRESTO_CNT model library

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PROJECT N. 22409 - EMCLO
• models of analog components using
Scattering parameters in time domain, obtained by
measurements, SPRINT primitives. This item has to
be studied to take into account the internal behaviour
of analog components with regard the susceptibility
to RF conducted noise. The result have to be verify
in terms of limits and errors.
EMC-model library

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PROJECT N. 22409 - EMCLO
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1
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-
+
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In 1
In 2
In 3
In 4
In 5
TEST/RESET
OUTPUT 5
OUTPUT 4
GROUND
I SET
V REF
V CC
OUTPUT 3
OUTPUT 2
OUTPUT 1
LM1946 - OFF CONDITION
The value for each
resistor is 100MEG
B1
AS3
+
-
Ink
OUTPUTk
GROUNDk
B2
B3
AS1AS2
1.00 2.00 3.00 4.00 5.00
TIME[nS]
-0.20
0.00
0.20
0.40
0.60
0.80
1.00
1.20
S [r]
PWL
EMC-model library: example

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PROJECT N. 22409 - EMCLO
• models of noise sources The model sources
could be injected in every nodes and the waveform
can be sinusoidal (fixed or sweeped frequency) or
wideband e.g. pulse, fast transient electrostatic
discharge.
EMC-model library

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PROJECT N. 22409 - EMCLO
EMC-model library
• Models of EMC-filters:
» Passive components (capacitors...) using
Scattering parameters in time domain, obtained
by measurements
» Murata EMC-filters: a complete library of filters
useful to reduce noise; the filters can be used to
simulate the effects of aimed actions.

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PROJECT N. 22409 - EMCLO
Validation: the simulations.
• An actual case is considered: the lights check PCB for lorry,
because:
– its behavior with RF-noise is known  it is possible to make
comparisons;
– there are both digital and analog devices  it is possible to verify the
models;
• The noise sources are used: 100 MHz and 900 MHz fixed
frequency sine noise source are used to simulate the RF-noise
injected (e.g. cellular telephone).
• The EMC-filters and the WHAT-IF analysis are used: in
order to provide the noise rejection.

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PROJECT N. 22409 - EMCLO
+
-
U1/3
R51R75
R69
R7
C20C1C2
R75
C34
C60
P1_8
P3_2
P3_8
P3_1
Component List
U1 LM1946
C1 4.7 nF
C2 4.7 nF
C20 4.7 nF
C34 100 nF
C60 1 nF
R7 0.1 W
R51 560 W
R57 33 K W
R69 8.06 K W
R75 560 W
UN1CAPACITOR798PB0UN1CONN11B228PA0
UN1CAPACITOR50PA0
UN1CAPACITOR785PA0 UN1CAPACITOR927PB0
UN1CAPACITOR798PA0

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PROJECT N. 22409 - EMCLO
half-stiff coax. cable
felxible coax. cable
Power splitter
HP8648C
added ground plane
TR321
HP54120 DSO
TDR
• Soldered ground plane to
define a unique ground
contact point
• Multiple connection
measurement setup is
provided to perform all
measurements

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PROJECT N. 22409 - EMCLO
10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00 50.00 TIME[nS]
-600.00
-400.00
-200.00
0.00
200.00
400.00
600.00V [mV]
P1_8 meas.
P1_8 simul.
Measurement/simulation comparison:
the 100 MHz noise.

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PROJECT N. 22409 - EMCLO
Measurement/simulation comparison:
the 900 MHz noise.
25.00 25.50 26.00 26.50 27.00 27.50 28.00 28.50 29.00 29.50 30.00 TIME[nS]
-200.00
-150.00
-100.00
-50.00
0.00
50.00
100.00
150.00
200.00V [mV]
U1_6 meas.
U1_6 simul.
U1_5 simul. U1_5 meas.

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PROJECT N. 22409 - EMCLO
10.00 14.00 18.00 22.00 26.00 30.00 34.00 38.00 42.00 46.00 50.00
TIME[nS]
-40.00
-35.00
-30.00
-25.00
-20.00
-15.00
-10.00
-5.00
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
V [mV]
U1_6 without C FILTER
U1_5 without C FILTER
U1_6 with C FILTER U1_5 with C FILTER
With/without CFILTER comparison:
the 100 MHz noise.

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PROJECT N. 22409 - EMCLO
25.00 25.50 26.00 26.50 27.00 27.50 28.00 28.50 29.00 29.50 30.00 TIME[nS]
-150.00
-120.00
-90.00
-60.00
-30.00
0.00
30.00
60.00
90.00
120.00
150.00V [mV] U1_6 with C FILTERU1_5 with C FILTER
U1_6 without C FILTER
U1_5 without C FILTER
With/without CFILTER comparison:
the 900 MHz noise.

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PROJECT N. 22409 - EMCLO
25.00 25.50 26.00 26.50 27.00 27.50 28.00 28.50 29.00 29.50 30.00 TIME[nS]
-60.00
-50.00
-40.00
-30.00
-20.00
-10.00
0.00
10.00
20.00
30.00
40.00
50.00
60.00
V DIFF [mV]
Without Filters
With Filters
With/without EMC-filter comparison:
the 900 MHz noise.

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PROJECT N. 22409 - EMCLO
MAIN RESULTS
• User friendly environment: the user can easily
optimize the behavior of PCB for reducing susceptibility to
conducted noise.
• Viability of the prototype tool.
• EMC model library: wide range of models fitted to
conducted noise analysis.
• PRESTO_CNT prototype tool validated on an
actual case: good comparison between measurements
and simulations.

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PROJECT N. 22409 - EMCLO
BENEFITS
• Improvement of the design and analysis of ECUs
• Optimization of components value and layout
• Product control at each development phase
• Reduction of time to market: the EMC effects can
be taken into account during the design phase.

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PROJECT N. 22409 - EMCLO
CONCLUSIONS - continue
Project Benefits
• User&Tool vendor good collaboration
• Increase Magneti Marelli experience in use of
Design Tool and new Methods
• Increase HDT Italia knowledge in Automotive
market sector
• Viability of PRESTO_CNT focused on customer
needs

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CONCLUSIONS - continue
Project Limits
• Modeling Methodology to be improved to take into
account the analog components susceptibility
• EMC Library to be extended in analog components

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PROJECT N. 22409 - EMCLO
CONCLUSIONS - continue
Project Evolution
• To solve analog Modeling to take into account the
analog components susceptibility
• Software Modeling Enviroment to guide the user
in model creation