CE Analyst™ - Conducted Emissions Analysis software calculates interference induced on cables by active circuitry in electronic systems.

1. EMI Analyst™
EMI ANALYST™ Software Suite
I n t u i t i v e  A c c u r a t e  E f f e c t i v e
Conducted emissions analysis
overview

2. EMI Analyst™EMI Analyst™
EMI Analyst™ is a 4-in-1 EMI Analysis Tool
EMI Analyst™ calculates electromagnetic interference for cable-
connected circuits
• Conducted Emissions – CE Analyst™
– Audio and radio frequency noise emitted on cables
• Conducted Susceptibility – CS Analyst™
– Interference induced by noise on cabling
• Radiated Emissions – RE Analyst™
– Electric and magnetic fields emitted by cables
• Radiated Susceptibility – RS Analyst™
– Noise induced by electromagnetic fields on cables

3. EMI Analyst™EMI Analyst™
What does CE Analyst™ do?
Calculates RF current and voltage induced on cables and circuitry
by active circuits

4. EMI Analyst™EMI Analyst™
EMI Analyst™ Covers All Frequency Domain
Conducted Emissions (CE) Specifications
• All industries
– Consumer and Industrial
– Aviation
– Automotive
– Military and Space
• All frequency ranges
– Audio Frequency, 10 Hz – 150 kHz and up
– Radio Frequency, 10 kHz – 152 MHz and up

5. EMI Analyst™
Typical Audio Frequency CE Setup
• Military and Space
– CE101, MIL-STD-461G/F/E/D
– CE01, MIL-STD-461C
• Automotive
– CISPR 25
• Aviation
– DO-160G/F/E/D/C, Section 21
• Consumer and Industrial
– IEC EN 55011 and EN 55022

6. EMI Analyst™
Typical Radio Frequency CE Setup
• Military and Space
– CE102, MIL-STD-461G/F/E/D
– CE03, MIL-STD-461C/B/A
• Automotive
– CISPR 25
• Aviation
– DO-160G/F/E/D/C, Section 21
• Consumer and Industrial
– IEC EN 55011, EN 55022

7. EMI Analyst™EMI Analyst™
What Information is Needed?
Before you start the analysis, collect:
– Frequency range of the analysis
– CE test limit
– Active circuit waveforms
– EMI filter schematic
– Cabling configuration
– End circuit schematic

8. EMI Analyst™EMI Analyst™
Switch Mode Power Supply (SMPS)
For this example, MIL-STD-461F method CE102
Conducted Emissions Example
Block
Diagram
Circuit
Schematic
Switch Mode
Power
Converter
EMI Filter Cable Conductors
LISNs
and
DC Power
Supply
StrayC
4.7uH
1uF 3.3uF
0.1uF
0.1uF
10 uH
10 uH
330 nF
10 nF
10 nF
100 uH
PS
Power Converter EMI Filter Cable Conductors LISNs and DC PS
Frequency Range
10 kHz – 10 MHz
CE102 Limit
94 – 60 dBV
EMI Filter
Low pass, T-section
Cabling configuration
Shielded wire pair over
ground plane, conductive
fabric tape shield
End Circuit
LISN & Power Supply
Pass/Fail Criteria
Conducted emissions
must be less than CE limit

9. EMI Analyst™EMI Analyst™
Frequency Range
• Start & Stop frequencies
• Log or Linear scale
• Resolution
– Pts / Decade for Log Scale
– Hz for Linear Scale
• Example: MIL-STD-461F, CE102
– Range: 10 kHz – 10 MHz
– Scale: Log
– Resolution: 90 pts / decade
• 10 kHz – 150 kHz in 1 kHz steps
• 150 kHz – 10 MHz in 10 kHz steps

10. EMI Analyst™EMI Analyst™
CE102 SMPS Noise Source
• Switching power supply produces
– Differential mode current
– Common mode voltage
• EMI Analyst needs only circuit
waveforms from
– Datasheets
– Circuit analysis output
– Oscilloscope measurements

11. EMI Analyst™EMI Analyst™
SMPS Interference Noise Source
Input DM Current
Input CM Current
FET Switching
Voltage
Stray C

12. EMI Analyst™EMI Analyst™
Cabling Configuration
• 8 built-in templates
– 4 shielded, 4 unshielded
• Enter
– Physical dimensions
– Conductor and dielectric
materials
• Computes
– Characteristic impedance
– R, L, C values

13. EMI Analyst™
Cabling Configuration
• Shielded Wire Pair Over Ground
Plane for this example
– #18 AWG wires
– Twisted, shielded pair
– 5 cm above aluminum ground plane
per MIL-STD-461F
– Fabric tape shield. Properties are
defined on Transfer Impedance
form

14. EMI Analyst™
Conductive Fabric Tape Shield
• Laird 86203 Nickel/Copper Black
Fabric Tape
Metalized Fabric
Conductive Adhesive
Release Paper

15. EMI Analyst™
Conductive Fabric Tape Properties
• Conductive Layer
– Nickel over Copper-plated polyester fabric
• Adhesive Layer
– Acrylic, conductive
Metalized Fabric
Conductive Adhesive
Release Paper
0.13 mm
Metalized Fabric
Conductive Adhesive
Non-Conductive Surface
I
V
RX-Y = 0.06 Ω / sq.
ASTM F390
Metalized Fabric
Conductive Adhesive
Metal Plate
Metal Plate
VI
1 square-inch area
MIL-STD-202 Method 303, 5 psi
RZ = 0.04 Ω / sq.-in.
= 25.8 µΩ / sq.-m

16. EMI Analyst™
Fabric Resistivity and Adhesive Resistivity
• Thickness of metalized fabric is not specified
– Fabric + Adhesive = 0.13 mm
– Assume fabric is 0.065 mm (half)
• Surface Resistivity
– 𝑅 𝑆 =
𝜌
𝑡
Ω
𝑠𝑞𝑢𝑎𝑟𝑒
– 𝜌 𝑓𝑎𝑏𝑟𝑖𝑐 = 𝑡𝑅 𝑆 = 0.065 𝑚𝑚 𝑥 0.06
Ω
𝑠𝑞𝑢𝑎𝑟𝑒
=
3.9 𝑥 10−6
Ω − 𝑚
– 𝜌𝑐𝑢 = 1.68 𝑥 10−8
Ω − 𝑚
– 𝜌 𝑟 𝑓𝑎𝑏𝑟𝑖𝑐
𝜌 𝑓𝑎𝑏𝑟𝑖𝑐
𝜌 𝑐𝑢
=232.14
• Adhesive Resistivity
– 𝜌 𝑎𝑑ℎ𝑒𝑠𝑖𝑣𝑒 = 25.8
Ω
𝑠𝑞.−𝑚
,
assuming metallized fabric is much more
conductive than adhesive

17. EMI Analyst™EMI Analyst™
End Circuits
• Schematic capture
– Ladder network
– Passive components (R, L, C,
and magnetically coupled)
• Left-End of cable
– EMI filter for PS circuit
• Right-End of cable
– LISN circuit

18. EMI Analyst™EMI Analyst™
Left-End Circuit: EMI Filter
Input Power Filter Schematic
EMI Analyst™ Filter Schematic
10uF
1uF
1uF
25 uH
25 uH
330 nF
10 nF
10 nF
100 uH

19. EMI Analyst™EMI Analyst™
Right-End Circuit: LISN and DC Power Supply
LISN schematic
EMI Analyst™ LISN schematic
and power supply impedance

20. EMI Analyst™EMI Analyst™
Analysis Results
CE102 Voltage at LISNs
CM and DM Cable Current
View current and voltage at all points in the circuit
and anywhere along the length of the cable.

21. EMI Analyst™EMI Analyst™
Analysis Results – Animated
• Cable Input Impedance, 10 kHz
to 10 MHz
– Wire1-to-Shield (blue)
– Shield-to-Ground (orange)
– Wire1-to-Wire2 (green)
• Animate any cable current,
voltage, or impedance over
frequency or cable length
Click graph to play

22. EMI Analyst™EMI Analyst™
Analysis Results – 3D
• View cable current, voltage,
or impedance versus
frequency and position on
cable
– Rotate – Click + drag
– Zoom – Ctrl + drag
– Move – Shift + drag
Shown: Common Mode Current

23. EMI Analyst™EMI Analyst™
Summary
• The preceding example computes conducted emissions produced by a switching power
supply and compares results to the MIL-STD-461F, CE102 limit.
• Conducted emissions are one of four applications in the EMI Analyst Suite
– CE Analyst™
– RE Analyst™
– CS Analyst™
– RS Analyst™
• Recommended links:
– https://www.emisoftware.com/blogs/emi-analysis-tool-emi-analyst-overview/
– https://www.emisoftware.com/blogs/what-else-can-emi-analyst-do/
– https://www.emisoftware.com/blogs/right-blend-electromagnetic-interference-analysis/
– https://www.emisoftware.com/blogs/6-qualities-to-look-for-in-emi-software/