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Future Component Characterization
for
EMI Analysis
- INCASES Engineering GmbH O. Rethmeier
Copyright INCASES Engineering GmbH
W. Rissiek
Motivation
Modern designs use components that are
characterized through





increasing package density
increasing package dimension
increasing clock rates
faster transition times
high power consumption
 Increasing signal integrity problems
 High thermal radiation
 Strong electromagnetic fields in the neighborhood
of the IC
 Package can be as effective as antennas
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Radiation Effects
Differential Mode
 Current Loops (e.g. Signal Loops / Bypass

Loops)
EDM  IDM A 

 E  A m2
DM

 
Common Mode
 Differential mode - Common
mode
coupling


(Potential
the Supply
ICM  IDM Shift
but in
often
ECM System)
EDM

 Radiation through cables and packages
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Requirements
EMI Analysis and SI Analysis requires a
 complete
 clear
 consistant
provision of all data and parameters of the
design (including component characterization).
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Component Characterization
 Mechanical characterization
 highly complex internal structure
 often no geometrical information
available
 Electrical characterisation
 e.g. IBIS
 Thermal characterization
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Complexity of Design
 In general, a
 numerical EMI analysis of the complete design is
not possible
– memory
– computation time
 Partitioning of the problem uses
 a prior knowledge of an expert approach
(more ‘classification’ data)
 simplified assumptions
(less detailed simulation models)
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Essential Component
Characteristics for EMI-Analysis (I)
Geometrical parameter
 Package type (e.g. QFP, BGA, PGA,...)
 Package dimensions (length, width, height,...)
 Pin pitch of the component
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Essential Component
Characteristics for EMI-Analysis
(II)
Electrical Parameter









Technology
Supply-voltages
Analog, mixed analog / digital
Noise margin
Input- / output behavior
Band width of signal pins
Max. / min. voltage res. currents
Transfer time
Frequency
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Details on Electrical Parameter
Buffer Specific Quantities: Voltages and Currents
Parameter
Symbol Unit Buffer
Voltage
positive power supply
Vcc
V
negative power supply
Vss/GND V
min. voltage low-level
VOLmin
V
max. voltage low-level
VLmax
V
min. voltage high-level
VHmin
V
max. voltage high-level
VOHmax
V
Threshold voltage
VIt
V
Ref.-voltage low/high Def. td VmDR
V
Ref.-voltage high/low Def. td VmDF
V
max. current low-level
max. current high-level
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IOLmax
IOHmax
I/O
I/O
O
I/O
I/O
O
I
I/O
I/O
Currents
A
O
A
O
Application
Source
Analysis/Evaluationdatasheet
Analysis/Evaluationdatasheet
Analysis
datasheet
Analysis/Evaluationdatasheet
Analysis/Evaluationdatasheet
Analysis
datasheet
Evaluation
datasheet
Evaluation
datasheet
Evaluation
datasheet
Analysis
Analysis
datasheet
datasheet
Details on Electrical Parameter
Buffer Specific Quantities: Time and Clock Frequencies
Parameter
Symbol Unit Buffer
max. Fall time low/high
max. Fall time high/low
typical Fall time low/high
typical Fall time high/low
special delay time low/high of
an output load circuit
special delay time high/low of
an output load circuit
t TIRmax
tTIFmax
tTOR
tTOF
Times
s
I
s
I
s
O
s
O
Application
Source
Evaluation
Evaluation
Analysis
Analysis
datasheet
datasheet
model
model
tOmDR
s
O
Evaluation
model
tOmDF
s
O
Evaluation
model
Analysis
Analysis
Analysis
datasheet
datasheet
Spec
Clock Frequencies
min. work frequency
max. work frequency
typical work frequency
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fWmin
fWmax
fWtyp
Hz
Hz
Hz
I/O
I/O
I/O
Details on Electrical Parameter
Buffer Specific Quantities:
Voltages
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Details on Electrical Parameter
Buffer Specific Quantities: Resistance, Capacitance
Parameter
Symbol Unit Buffer
Application
Source
I
O
O
Analysis
Analysis
Analysis
model
model
model
Capacitance
F
I
F
O
Analysis
Analysis
model
model
Resistance
Input resistance
Output resistance low/high
Output resistance high/low
Input capacitance
Output capacitance
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Ri
ROLH
ROHL
CI
CO
W
W
W
Details on Electrical Parameter
Derived Quantities
Derived Quantities
Explanation
Buffer specific Characteristics
Band width
fOB of a signal at output (fPmin/typ/max, tTOR/F)
fIB of a buffer at input (tTIR/Fmax)
(static) Noise margin
high-level SH = VOHmin - VIH min
low-level SL = VILmax - VOLmax
VILmax, VIHtop - VHmin
Classification of radiated / internal noise
characteristics from driver parameter into low,
medium, high
Classification of sensitivity from the receiver
parameter into low, medium, high
Classification using all parameter into low, medium,
high
Noise potential
Sensitivity
Activity
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Details on Electrical Parameter
Derived Quantities
Derived Quantities
Explanation
Component specific Characteristics
Noise potential
parameter
Sensitivity
parameter
Activity
parameter
Classification of the component using all
into low, medium, high
Classification of the component using all
into low, medium, high
Classification of the component using all
into low, medium,high
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Details on Electrical Parameter
Buffer Classification
Signal Class Explanation
BUS
Bus-inputs and outputs; e.g.at bus driver, controller, etc.
CLOCK
All clock inputs and outputs; e.g. at flip-flop, counters,
processor, etc.
CTRL
Control inputs like Reset, RAS, CAS, WE, OE, DIR, etc.
DATA
Data inputs and outputs like gates, memory components, etc.
SUPPLY
Supply pins of all components
HYPOTHETIC
Pins that cannot be assigned to other classes
DEFAULT

DEFAULT BUS,CLOCK,CTRL,DATA,SUPPLY,
HYPOTHETIC
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Summary
EMI - Analysis of PCB’s requires
 behavioral buffer models like IBIS
 additional ‘classification’ parameters for an expert
approach
 specific geometrical package information
Extension of current standardization
required!
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