EMC measurements of components
description
Transcript of EMC measurements of components
EMC measurements of components
2
Summary
1. EMC problem examples
2. EM disturbance sources
3. EMC certification ?
4. EMC measurement for electronic systems
5. EMC measurement for integrated circuits
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EMC problem examples
A typical electromagnetic environment…
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http://www.emcs.org/acstrial/newsletters/fall04/63_67.pdf
EMC problem examples
Electromagnetic interference issues in medical devices
EMI types Reported cases Devices
Conducted interference
20 (1 death) Cardiac monitor, infusion device, defibrilator…
Radiated interference
55 (4 deaths) Pacemaker, ventilator, cardiac monitor
LF magnetic field
6 (1 death) Respirator, pacemaker
ESD 10 Respirator, infusion pump
Medical device EMI problems reported
by FDA between 1979 and 1993
405 suspected EMI problems reported by FDA between 1994 and 2005,
with 6 deaths, 170 injuries and 167 malfunctions. 72 % of cases concern
implantable devices.22 Apr 2023
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Electromagnetic interference issues in military systems
29th July 1967 : accident of the American aircraft carrier USS Forrestal. The accidental launching of a rocket blew gas tank and weapon stocks, killing 135 persons and causing damages which needed 7 month reparations. Investigations showed that a radar induced on plane wiring a sufficient parasitic voltage to trigger the launching of the rocket.
H.M.S. Sheffield catastrophe: “During the Falklands War, the British Ship H.M.S Sheffield sank after being hit by an Exocet missile. Despite the Sheffield having the most sophisticated antimissile defense system available, the system created EMI to radiocommunications to and among the contingent of Harrier jets assigned to the ship. While the Harriers took off, the missile defense was disengaged to allow communications with the jets and provided a window of opportunity for the Exocet missile.”
EMC problem examples
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Electromagnetic interference issues in automotive
Interference Technology – October 2011
Mercedez-Benz case: “During the early years of ABS, Mercedez-Benz automobiles equipped with ABS had severe braking problems along a certain stretch of the German autobahn. The brakes were affected by a near-by-near radio transmitter as drivers applied them on the curved section of highway. The near-term solution was to a erect a mesh screen along the roadway to attenuate the EMI. This enabled the brakes to function properly when drivers applied them…. Eventually, automobile ABS was qualified by EMI testing prior to procurement.”
EMC problem examples
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Electromagnetic interference issues in aviation
« Disturbances of flight instruments causing trajectory deviations appear when one or several passengers switch on electronic devices. » (Air et Cosmos, April 1993)
FAA Aviation Safety Reporting System has reported 12 cases of interference in aircraft due to personal electronic devices since 2002.
NASA publication 1374 (1986 – 1995)
EMC problem examples
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Electromagnetic interference issues in space aircraft
Vacuum cleaner incident: “During a Spacelab mission in 1985, the crew decided to use the middeck vacuum cleaner instead of the one in the lab. Switching the middeck vacuum on caused the voltage to drop and the Remote Acquisition Unit to shut off. In preflight EMI tests, the vacuum cleaner had not been tested and should not have been used in the lab. This case shows how careful and attentive one must when dealing with EMC.” [Nasa Publication 1374]
EMC problem examples
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Various disturbance sources that can affect electronic system operation
Natural sources Human activity
Intentional emission
Non intentional emissionElectrostatic discharge
EM disturbance sources
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Interferences from telecommunication systems
Fréquence (Hz)
100K 1M 10M 100M 1G 10G 100G
Radio AMRadio OC
CBTV VHF
Radio FM
RFID
TV UHF
ISM
GSMGPS
DCS
UMTS
Liaison satellite
IEEE 802.11
VHF30-300MHz
UHF300-3000MHz
SHF3-30GHz
EHF30-300GHz
HF3-30MHz
MF0.3-3MHz
Wimax
ZigBee
WiFi Gigabit
Liaison sous marine
Narrowband emission, modulated signals.
Regulation and planification of radioelectric spectrum controlled by ITU-R at international level, and by « Agence Nationale des Fréquences » (ANFR) at French level.
Radio-navigation
EM disturbance sources
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Interferences from electronic systems
Parasitic noise generated by the activity (switching) of any electrical or electronic devices
The noise is usually impulse type broadband noise.
Example : Radiated emission from a 16 bit microcontroller (quartz freq = 8 MHz)
EM disturbance sources
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The EM environment according to ITU-R 372-8
Ambient field levels defined from EM survey in 70’s.
Recent surveys show a 20 – 40 dB increase in semi-enclosed environment.
Example: Survey of the average level of electric field in Canada during the 90’s in urban and suburban environment: between 1 and 20 V/m.
EM disturbance sources
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The EM environment
EM disturbance sources
Site Agence Nationale des Fréquences (www.anfr.fr) – outil Cartoradio.
Cha
mp
E
Etot = 4.35 V/m
Distance antenne – point de mesure = 60m
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EM disturbances can induce major failures in electronic systems.
The parasitic emission and susceptibility to EM disturbances must be tested to ensure electromagnetic compatibility of an electronic systems within a nominal environment.
Summary
But it is a tedious task because:
Diversity in terms of electronic devices
Numerous types of disturbances (LF, HF, pulsed, modulated), numerous EM environment
Various EM coupling possibilities (conducted, radiated, near-field…)
How defining generic tests to guarantee EMC for any electronic systems in any EM environment, with an industrial realism ?
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The EMC certification
The European directive 89/336/EEC (1996) and then 2004/108/EC (2004) requires that all « electrical apparatus » placed on the European market :
Do not produce electromagnetic interferences able to disturb radio or telecom equipments , and the normal operation of all equipments
Have a sufficient immunity level to electromagnetic interferences to prevent any degradation of the normal operation.
CE mark
All manufacturers of « electrical apparatus » must certify that the directive is supposed respected by delivering a declaration of conformity and placing a CE mark on the product.
Using harmonized standards adapted to the product to verify the supposition of conformity is recommended
EMC European Directive
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The EMC certification
R&TTE European Directive
The European directive 99/5/EC (1999) Radio & Telecommunications Terminal Equipment which is applied to all telecom and radio equipments emitting on the band 9 KHz – 3000 GHz replace the EMC directive. .
R&TTE requires that telecom and radio equipments placed on the European market: :
Comply to safety constraints given by the Low Voltage directive (73/23/EEC) (e.g. the limit of EM exposure for persons) and the EMC constraints given by the EMC directive 2004/108/EC.
Radio equipments use spectral resources dedicated for terrestrial and spatial communications without generating any interferences.
R&TTE mark:
Required for all equipments under the
R&TTE directive
Warning signal for class 2 equipments (special
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International European
International Electrotechnical Commission(IEC)
TC77Comité International Spécial des
Perturbations Radioélectriques(CISPR)
IEC 61000-X CISPR-XX
European Commitee for Electrotechnical Standardization (CENELEC)
European Telecommunication Standards Institute
(ETSI)
EN 300XXEN 50XXXEN 55XXXEN 6XXXX
Harmonized standards
The EMC certification
EMC normative bodies: the importance of EMC standards !
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Commercial harmonized standard (non exhaustive list !)
Basic standard(general and fundamental rules)
EN 61000-4-x(IEC61000-4-x)
EMC – Testing and measurement techniques
Generic standard(for equipments in a specific environment)
EN 61000-6-3 (IEC61000-6-3)
Generic Emission Standard, for residential, commercial and light industrial environment
EN 61000-6-1 (IEC61000-6-1)
Generic Immunity Standard, for residential, commercial and industrial environment
Product standard(for a specific product family)
EN 55022(CISPR22)
Information technology equipment (ITE)
EN 55014(CISPR14)
Household appliances, electric tools and similar apparatus
EN 55012(CISPR12)
Vehicles, boats and internal combustion engines
EN 330220 (ETSI 330 220)
Electromagnetic compatibility and radio spectrum matters (ERM); Short Range Devices (SRD); Radio equipment to be used in the 25 MHz to 1 000 MHz frequency range with power levels ranging up to 500 mW;
EN 330330(ETSI 300330-1)
Electromagnetic compatibility and radio spectrum matters (ERM); Short Range devices (SRD); Radio equipment to be used in the frequency range 9 KHz to 25 MHz and inductive loop systems in the frequency range 9 KHz to 30 MHz
The EMC certification
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Automotive, military, aerospace and railway industries have developed their own EMC standards.
Applications Standard references
Automotive ISO 7637, ISO 11452, CISPR 25, SAE J1113
Aerospace DO-160, ED-14
Military MIL-STD-461D, MIL-STD-462D, MIL-STD-461E
Railway EN 50121
Commercial harmonized standard (non exhaustive list !)
The EMC certification
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Case study 1
The EMC certification
You want to place on the European market a ventilator for domestic
installation. It is supplied by mains (220 V).
Which EMC standard(s) should you follow ? What tests should you
conduct for the EMC certification ?
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Application of EN55014-1 and 2:
“Electromagnetic compatibility –
Requirements for household appliances,
electric tools and similar apparatus” –
Part 1 = Emission, Part 2 = Immunity : Any domestic electric/electronic
equipments, toys, electric tool supplied
under 250 V (monophase) (motors, heat
elements, thermostats …)
Except light modules (EN55015), radio
receivers (EN55025), gaming machine
(EN55022).
The EMC certification
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Case study 1
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Case study 2
The EMC certification
Suggested emission tests:
Conducted emission 150 KHz – 30 / 300 MHz
Harmonic and flicker
Radiated emission 30 MHz – 1 GHz
Suggested immunity tests:ESD 4 KV contact / 8 KV air
EFT / burst 5/50 ns, 1 KV, 5 KHz repetition
Conducted immunity 150 KHz – 230 MHz, 3 V rms
Radiated immunity 80 – 1000 MHz, 3 V/m, modulation AM 1 KHz 80%
Surge 1 KV 1.2/50 µs pulse on power
Voltage dips and interruptions
40 % variations of the power supply, repeated 5×
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The EMC certification
You want to place on the European market a radio emitter/receiver for
remote control application in residential environment. The radio emitter
use the ISM band around 434 MHz. Its maximum radiated power is
limited to 500 mW. The emitter/receiver is an handheld device.
Which EMC standard(s) should you follow ? What tests should you
conduct for the EMC certification ?
Case study 2
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Case study 2
The EMC certification
The harmonized standard EN 300220: “Electromagnetic compatibility
and radio spectrum matters (ERM); Short Range devices (SRD); Radio
equipment to be used in the 25 MHz to 1000 MHz frequency range with
power levels ranging up to 500 mW” is adapted to short range devices : either with a Radio Frequency (RF) output connection and/or with an
integral antenna;
for alarms, identification, telecommand, telemetry, etc., applications;
with or without speech.
It covers fixed stations, mobile stations and portable stations, all types of
modulation.
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Case study 2
The EMC certification
List of suggested tests:
Frequency error or drift Does the carrier frequency remains stable?
Effective radiated power The radiated power must not exceed a max. level (< 500 mW)
Transient power The switching of the transmitter produces interferences in adjacent spectrum
Adjacent channel power The power transmitted in adjacent band must be limited.
Spurious emissions Parasitic emissions from the emitter and receiver between 9 KHz and ?? Must be limited.
Frequency stability under low voltage conditions
The emission from the transmitter must remain stable even in extreme low power conditions.
Duty cycle The manufacturer must indicate the duty cycle of the equipment
Blocking or desensitization Capability of the receiver to receive a wanted signal in presence of unwanted signal
Some ESD tests should be also done …
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Case study 3
The EMC certification
You are a semiconductor manufacturers and you want to sell your
integrated circuits in the European market. Your ICs are dedicated to
automotive applications.
Which EMC standard(s) should you follow ? What tests should you
conduct for the EMC certification ?
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Case study 3
The EMC certification
If your integrated circuits can not operate by themselves, you don’t
need EMC certification.
However, your customers will certainly push you to guarantee the low
emission and susceptibility of your devices, require measurements,
models, support….
Examples of standards providing EMC measurement for ICs:
• IEC 61967: Integrated Circuits, Measurement of Electromagnetic
Emissions, 150 kHz to 1 GHz
• IEC 62132: Integrated circuits - Measurement of electromagnetic immunity,
150 kHz to 1 GHz
• ISO11452: Road vehicles - Electrical disturbances by narrowband
electromagnetic energy - Component test methods
• ISO 7637 or IEC61000-4-2/4/5 for ESD, pulse, surge testing.
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Why EMC standard measurement methods
Check EMC compliance of ICs, equipments and systems Comparison of EMC performances between different products,
different technologies, designs, PCB routings
Improve interaction between customers and providers (same
protocols, same set-up)
EMC measurement for electronic systems
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EMC measurement for electronic systems
Equipment / Device under test Coupling device
Coupling network
Antennas
Wave guide
Current clamp…
Acquisition system
Spectrum analyzer
EMI receiver
Oscilloscope
Emission measurements – General measurement set-up
Radiated or conducted coupling
50Ω adapted path
Control - Acquisition
Emission requirements verified ?
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EMC measurement for electronic systems
Emission measurements – Emission spectrum
Amplitude (dBµV)
Frequency (MHz)
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EMC measurement for electronic systems
Emblematic EMC equipment – Spectrum Analyzer (EMI receiver)
Frequency adjustment : Start, stop
, center
Amplitude adjustment : Level reference, dynamic.
Emission measurement requires high sensitivity and resolutionEmission measurement standards often recommend spectrum analyzer adjustment
RBW – frequency resolution, noise floor reduction
VBW – smooth display
50 Ohm input
X= frequency
Y= power (dBm, dBµV)
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EMC measurement for electronic systems
Emblematic EMC equipment – Spectrum Analyzer (EMI receiver)
Principle: based on super heterodyne receiver
tttt lorflorflorf cos2
1cos
2
1coscos
IN
fFrf
LO
fFlo
Input signal
Local oscillator
Output signalOUT
fFif Frf+Flo
ωif
MixerIF filter
OUT
fFif
IF filterA
No
RBWP = ½.A²+No.RBW
Detected power:
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Attenuator
DC blocking
Low pass filter
Gain IF
IF filter
Analog filter
Gain log
Video filter
Mixers
Local oscillator
Reference oscillator
Frequency sweep
Display
Envelope detector
Building blocks and adjustable elements:
Input signal
RBW VBWDetector
Attenuation
Fstart / Fstop
Fcenter / SpanPoint number
EMC measurement for electronic systems
Emblematic EMC equipment – Spectrum Analyzer (EMI receiver)
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Example: effect of RBW and VBW.Measurement of 100 MHz sinus.
Amplitude = 90 dBµV Amplitude = 20 dBµV
Sweep time :
RBW = 100 KHz 2.5 ms
RBW = 10 KHz 100 ms
Sweep time :
VBW = 30 KHz 100 ms
VBW = 1 KHz 980 ms
EMC measurement for electronic systems
Emblematic EMC equipment – Spectrum Analyzer (EMI receiver)
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Example: Influence of detector type (peak vs. quasi-peak vs. average).Measurement of radiated emission of a microcontroller.
EMC measurement for electronic systems
Emblematic EMC equipment – Spectrum Analyzer (EMI receiver)
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Device under testWide band
(calibrated) antenna
Power supply, DUT control
EMI receiver or spectrum analyzer)
Absorbents
R = 3 ou 10 m
1 m1 m
1 m
Faraday cage (with absorbents: semi-anechoic chamber)
(Siepel)
EN55022
EMC measurement for electronic systems
Radiated emission in (semi-)Anechoic chamber (30 MHz – 1 GHz)
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EMC measurement for electronic systems
E field EMI receiver
Rs =50 Ω
Optional pre-amplifier
Low loss 50 Ω cable
Bilog antenna
(or log-periodic, biconical, dipole…)
Vemi
Radiated emission in (semi-)Anechoic chamber (30 MHz – 1 GHz)
If far field and free space conditions ensured:
dBLossdBGainmdBAFmdBµVEdBµVVemi )/(/AF = Antenna factor
(from calibration)
The E field varies in 1/r with the distance r (the radiated power in 1/r²) possible extrapolation of field intensity.
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Measured power Pemi
50107 Semiemi RwithdBµVVdBmP
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EMC measurement for electronic systems
Example of emission measurementsConducted emission on power supply (FCC certification) – Peak detector
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EMC measurement for electronic systems
Example of emission measurements
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Radiated emission at 3 meters (FCC certification) – Peak detector
EMC measurement for electronic systems
Does EMC certification cancel the interference risks?
Let’s consider a radio receiver (such as a mobile phone). We suppose that it operates at 900 MHz, its antenna has an antenna factor of 29 dB/m, and its receiving floor is -90 dBm. It is placed at 1 m of a “noisy” electronic equipment with a CE Mark.
Could you have a risk of interferences ?
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Equipment / Device under test
Coupling deviceCoupling
network
Antennas
Wave guide
Clamp…
Radiated or conducted coupling
Disturbance generation
Harmonic signal
Transients
Burst
50Ω adapted path
Failure detectionInjected level Extraction
Immunity requirements verified ?
EMC measurement for electronic systems
Immunity measurements – General measurement set-up
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EMC measurement for electronic systems
Immunity measurements – General test procedure for harmonic disturbance
Start
F = Fmin
P = Pmin
Increase P
Wait dwell time
Failure or P = Pmax ?
Save F and PF = Fmax ?
End
Increase FWithout EMI
With EMI Failure
Detection mask
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EMC measurement for electronic systems
Device under testWide band
(calibrated) antenna
Power supply, DUT control
Absorbents
R = 3 ou 10 m
1 m1 m
1 m
Faraday cage (with absorbents: semi-anechoic chamber)
(Siepel)
Radiated immunity in (semi-)Anechoic chamber (30 MHz – 1 GHz)
Power amplifier ( > 100 W)
Signal synthesizer
Field monitoring
Typical max. RI level:
Commercial product: 3 – 10 V/m
Automotive (ISO-11452-2): 25 – 200 V/m
Military (MIL-STD461E): 20 – 200 V/m
Aeronautics (DO160-D): 8 – 800 V/m
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Injection clamp
Induced RF current
Bus, cable
Microcontroler
DUT
Failure ?
Measurement clamp
Directional coupler
Signal synthesizer
RF disturbance
LoadLISN
Induced current measurement
Interface circuit
Faraday cage
Usually, the max. current is between 50 mA and 300 mA.
EMC measurement for electronic systems
Immunity measurements – Bulk current injection (BCI)
Power amplifier
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EMC measurement for electronic systems
Immunity measurements – Pulse, ESD, bursts, surge…Pulse waveforms and severity levels defined by standards such as IEC61000-4-x or ISO7637
Ideal ESD waveform at 4 KV (IEC61000-4-2) (level 2)
Tr = 0.8 ns
I30 = 8 A
I60 = 4 A
Ipeak = 15 A
Ideal Fast transient / burst (IEC61000-4-4) (level 2)
Vpeak = 1 KV (on 50 Ω)
Vpeak = 1 KV (on 50 Ω)
Tr = 5 ns Repetition rate = 5 – 100 KHz
Td= 50 ns
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EMC measurement for integrated circuits
Why taking into account EMC for ICs ?
K. Armstrong, Advanced PCB design and layout for EMC
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EMC measurement for integrated circuits
Why testing EMC for ICs ?
Integrated circuits are often the main cause of disturbances in electronic equipment.
In recent years, there has been a strong demand for simple, reliable and standardized measurement methods focusing only on integrated circuits that electronic system designers could use to:
Obtain quantitative measure of emission/immunity from ICs establishing a
uniform testing environment Qualify the low emission and high immunity performance of circuit. Optimize circuit placement, routing, filtering and decoupling components Evaluate the impact of IC redesign, technology improvement or package
modification.
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EMC measurement for integrated circuits
Why testing EMC for ICs ? Based on pre existing standards, such as:
CISPR 25 – Radio disturbance characteristics for the protection of receivers used
on board vehicles, boats and on devices – Limits and methods of measurements
IEC 61000-4 – Electromagnetic Compatibility (EMC) – Part 4: Testing and
measurement techniques
ISO 11452 part 1 to 7, Road vehicles – Electrical disturbances by narrow band
radiated electromagnetic energy – Component test methods
Measurement methods for EMC of Ics proposed by IEC:
IEC 61967:Integrated circuits -Measurement of electromagnetic
emissions, 150 kHz to 1 GHz.
IEC 62132: Integrated circuits - Measurement of electromagnetic
immunity, 150 kHz to 1 GHz.
IEC 62215: Integrated circuits – Measurement of impulse immunity
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International standards for IC emission measurement methods
IEC 61967-2
(TEM : 1GHz)
IEC 61967-2
(GTEM 18 GHz)
IEC 61967-5
(WBFC, 1 GHz)
IEC 61967-8
(IC-Stripline, 3/6 GHz)
IEC 61967-3
(Near field scan, 1/5GHz)
IEC 61967-6
(Magnetic field probe, 1GHz)
IEC 61967-4
(1/150 ohm, 1 GHz)
IEC 61967-7
(Mode stirred chamber, 1 GHz)
Appareil de mesure 50
ohms Câble coaxial Z0=50Ω
Appareil de mesure 50Ω Conducted method
Radiated method TEM Cell improvemnt
Investigation method
EMC measurement for integrated circuits
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EMC measurement for integrated circuits
IC Conducted emission
Osc
illat
or
Digital Core
I/O
Driver
VddCore
Vdd osc
PCB line
Load
Load
Integrated circuit
Icore(t)
Iosc(t)
VE/S(t)
Vdriver(t)
Two noise sources: internal activity (power supply noise) and I/O
switching (Simultaneous Switching Noise, I/O line excitation)
Characterization of transient current and voltage induced by ICs.
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EMC measurement for integrated circuits
« Local » ground
IC Conducted emission - IEC 61967-4 –1 ohm / 150 ohms method
ICPCB
Decoupling
RF current Conducted emission is produced
by RF current induced by IC
activity.
The current induced voltage
bounces along power distribution
network and radiated emission.
The « 1 ohm » method aims at measuring the RF current flowing from circuit Vss pin(s) to the ground reference.
2RF
A
IV
Vdd
« Global » ground
Spectrum analyzer
1 Ω
49 Ω
IRF
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IC Conducted emission - IEC 61967-4 –1 ohm / 150 ohms method
I/O buffer
RF current
RF current
External load
I/O switching is a major contributor to conducted emission.
They induced voltage fluctuation along power supply and I/O
lines.
The « 150 ohms » method aims at measuring the RF voltage induced at one or several IC output.
Vdd
PCB
Decoupling
51 Ω
120 Ω 6.8 nFSpectrum analyzer
150 Ω matching network
)150(
17.0
KHzabove
VV RFA
VRF VA
EMC measurement for integrated circuits
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IC current extraction from 1 Ω probe measurement
dsPIC33F: measurement in time domain and frequency of the voltage
across the 1 Ω probe proportional to the IC current.
EMC measurement for integrated circuits
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IC Radiated emission - IEC 61967-2 – TEM cell
TEM cell (SAE J1752/3)
IC under test
Emission spectrum
Spectrum analyzer
Pre-ampli 20-30 dB
Test board
Relation between the voltage measured by the spectrum analyzer and the radiated emission from the circuit
50 ohm
EMC measurement for integrated circuits
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TEM cell – EM field inside the waveguide
septum
Aperture for DUT
Port1 Port2
50 Ω 50 Ω
y
z
y
x
Tapered transition
Tapered transition
E
H
O Field repartition:
Quasi homogeneous field
R.J. Spiegel, and al.,“A Method for Calculating Electric and Magnetic Fields in TEM Cells at ELF”, IEEE Trans. on EMC, Nov. 1987
o TEM propagation
mode up to 1 GHz
o |E/H| = 377 Ω
W = 15 cm, T = 9 cm, Wsept = 10 cm, V = 1 V, y = 8 cmWsept
T
W
EMC measurement for integrated circuits
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TEM cell – Field coupling with a DUT
Example: coupling with a 50Ω microstrip line
Dimensions of the microstrip: W = 2.5 mm, L = 75 mm, h = 1.6 mm, epsr = 4.5
septumPort150 Ω load
50 Ω load
Port2 VNANear end Far
end Appearance of non TEM propag. mode
+ 20 dB/dec.
EMC measurement for integrated circuits
The magnetic field coupling
depends of the orientation of
the line in the TEM cell.
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International standards for IC susceptibility measurement methods
IEC 62132-3
(BCI, 1 GHz)
IEC 62132-4
(DPI : 1 GHz)
IEC 62132-2
(TEM - GTEM : 1 / 18GHz)
IEC 62132-8
(IC-Stripline, 3/6 GHz)
IEC 62132-5
(WBFC, 1 GHz)
IEC 62132-6
(LIHA, 10GHz)
IEC 62132-9
(Near-field scan, 1/5 GHz)
IEC 62132-7
(Mode stirred chamber, 1 GHz)
Conducted methods Radiated methods
TEM cell improvement
Investigation method
EMC measurement for integrated circuits
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Victim circuit
Electronic equipment
Cables
PCB
Radiated disturbances
Induced conducted disturbances
Vs
Zs
Zc, Td ZL
Equivalent Thevenin generator of RF
disturbancesCables, PCB lines
Input impedance of victim circuit
Conducted immunity
Applying conducted disturbances directly to IC pin ?
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EMC measurement for integrated circuits
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Conducted immunity - IEC 62132-4 – Direct Power Injection (DPI)
DPI Capacitor ( 1 – 10 nF)
Decoupling network
Chip under test
Pforw Prefl
Directional coupler
Signal Synthesizer
Amplifier
Failure detection
• Oscilloscope• Acquisition card
Susceptibility threshold
> 400 Ω
Test on 1 pin
Individual test of each sensitive IC pin.
EMC measurement for integrated circuits
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Conducted immunity - IEC 62132-4 – Direct Power Injection (DPI)
0
5
10
15
20
25
30
35
1 10 100 1000
Forw
ard
pow
er (d
Bm)
Frequency (MHz)
Forward power limit
Example : DPI test on the power supply of an RF device
Simple, repeatable, low power measurement
IC prequalification test
EMC measurement for integrated circuits
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Conducted immunity - IEC 62132-4 – Direct Power Injection (DPI)
EMC measurement for integrated circuits
Class Fwd Power (dBm - RMS)
Voltage (V) (across 50 Ω)
I/O type – protection level
1 30 - 37 10 - 22 Low filtering, pin connected to long cable harness (power circuit)
2 20 – 27 3 – 7 Short connections, low filtering (signal conditioning, communication line driver)
3 10 - 17 1 - 2 No direct connection with the environment
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Case study – Starcore EMC testing The Starcore is 16-bit micro-controller used in automotive industry:
• 16 bit MPU with 16 MHz external quartz, on-chip PLL providing internal 133 MHz operating clock
• 128 Kb RAM, 3 general purpose ports (A, B, C, 8 bits), 4 analog inputs 12 bits, CAN interface
Prepare an EMC test plan: conducted emission (1 /150 Ω) and susceptibility test (DPI)
EMC measurement for integrated circuits
SIGNAL Description
VDD Positive supply
VSS Logic Ground
VDD_OSC Oscillator supply
VSS_OSC Oscillator ground
PA[0..7] Data port A (programmable drive)
PB[0..7] Data port B (programmable drive)
PC[0..7] Data port C (programmable drive) external 66MHz data/address
ADC In[0..3] 4 analog inputs (12 bit resolution)
CAN Tx CAN interface (high power, 1MHz)
CAN Rx CAN interface (high power, 1MHz)
XTL_1, XTL_2 Quartz oscillator 16MHz
CAPA PLL external capacitance
RESET Reset microcontroller22 Apr 2023