EN IEC 61967-4:2021
(Main)Integrated circuits - Measurement of electromagnetic emissions - Part 4: Measurement of conducted emissions - 1 Ω/150 Ω direct coupling method
Integrated circuits - Measurement of electromagnetic emissions - Part 4: Measurement of conducted emissions - 1 Ω/150 Ω direct coupling method
IEC 61967-4:2021 is available as IEC 61967-4:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 61967-4:2021 specifies a method to measure the conducted electromagnetic emission (EME) of integrated circuits by direct radio frequency (RF) current measurement with a 1 Ω resistive probe and RF voltage measurement using a 150 Ω coupling network. These methods ensure a high degree of reproducibility and correlation of EME measurement results. This edition includes the following significant technical changes with respect to the previous edition: - frequency range of 150 kHz to 1 GHz has been deleted from the title; - recommended frequency range for 1 Ω method has been reduced to 30 MHz; - Annex G with recommendations and guidelines for frequency range extension beyond 1 GHz has been added.
Integrierte Schaltungen - Messung von elektromagnetischen Aussendungen – Teil 4: Messung der leitungsgeführten Aussendungen - Messung mit direkter 1-Ohm-/150-Ohm-Kopplung
Circuits intégrés - Mesure des émissions électromagnétiques - Partie 4: Mesure des émissions conduites - Méthode par couplage direct 1 Ω/150 Ω
IEC 61967-4:2021 est disponible sous forme de IEC 61967-4:2021 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.L’IEC 61967-4:2021 spécifie une méthode de mesure de l’émission électromagnétique (EME) conduite des circuits intégrés par mesure directe des courants RF avec une sonde résistive de 1 Ω et mesure des tensions RF en utilisant un réseau de couplage de 150 Ω. Ces méthodes assurent un degré élevé de reproductibilité, ainsi que la corrélation des résultats des mesures EME. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: - la gamme de fréquences de 150 kHz à 1 GHz a été supprimée du titre; - la gamme de fréquences recommandée pour la méthode à 1 Ω a été réduite à 30 MHz; - l’Annexe G avec les recommandations et les lignes directrices pour l’extension de gamme de fréquences au-dessus de 1 GHz a été ajoutée.
Integrirana vezja - Meritve elektromagnetnega sevanja - 4. del: Meritve prevajanega sevanja, metoda neposrednega sklopa 1 ohm/150 ohmov (IEC 61967-4:2021)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2021
Nadomešča:
SIST EN 61967-4:2005
SIST EN 61967-4:2005/A1:2006
SIST EN 61967-4:2005/AC:2017
Integrirana vezja - Meritve elektromagnetnega sevanja - 4. del: Meritve prevajanega
sevanja, metoda neposrednega sklopa 1 ohm/150 ohmov (IEC 61967-4:2021)
Integrated circuits - Measurement of electromagnetic emissions - Part 4: Measurement
of conducted emissions, 1 ohm/150 ohm direct coupling method (IEC 61967-4:2021)
Integrierte Schaltungen - Messung von elektromagnetischen Aussendungen – Teil 4:
Messung der leitungsgeführten Aussendungen - Messung mit direkter 1-Ohm-/150-Ohm-
Kopplung (IEC 61967-4:2021)
Circuits intégrés - Mesure des émissions électromagnétiques - Partie 4 : Mesure des
émissions conduites - Méthode par couplage direct 1 ohm/150 ohm (IEC 61967-4:2021)
Ta slovenski standard je istoveten z: EN IEC 61967-4:2021
ICS:
31.200 Integrirana vezja, Integrated circuits.
mikroelektronika Microelectronics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 61967-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2021
ICS 31.200 Supersedes EN 61967-4:2002 and all of its amendments
and corrigenda (if any)
English Version
Integrated circuits - Measurement of electromagnetic emissions
- Part 4: Measurement of conducted emissions - 1 Ω/150 Ω
direct coupling method
(IEC 61967-4:2021)
Circuits intégrés - Mesure des émissions Integrierte Schaltungen - Messung von
électromagnétiques - Partie 4: Mesure des émissions elektromagnetischen Aussendungen - Teil 4: Messung der
conduites - Méthode par couplage direct 1 Ω/150 Ω leitungsgeführten Aussendungen - Messung mit direkter 1-
(IEC 61967-4:2021) Ohm-/150-Ohm-Kopplung
(IEC 61967-4:2021)
This European Standard was approved by CENELEC on 2021-04-20. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
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Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61967-4:2021 E
European foreword
The text of document 47A/1101/CDV, future edition 2 of IEC 61967-4, prepared by SC 47A "Integrated
circuits" of IEC/TC 47 "Semiconductor devices" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN IEC 61967-4:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022-01-20
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-04-20
document have to be withdrawn
This document supersedes EN 61967-4:2002 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 61967-4:2021 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
CISPR 16-1-2 NOTE Harmonized as EN 55016-1-2
CISPR 25 NOTE Harmonized as EN 55025
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 61000-4-6 - Electromagnetic compatibility (EMC) - Part 4-6: EN 61000-4-6 -
Testing and measurement techniques -
Immunity to conducted disturbances, induced by
radio-frequency fields
IEC 61967-1 - Integrated circuits - Measurement of EN IEC 61967-1 -
electromagnetic emissions - Part 1: General
conditions and definitions
IEC 61967-4 ®
Edition 2.0 2021-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Integrated circuits – Measurement of electromagnetic emissions –
Part 4: Measurement of conducted emissions – 1 Ω/150 Ω direct coupling
method
Circuits intégrés – Mesure des émissions électromagnétiques –
Partie 4: Mesure des émissions conduites – Méthode par couplage direct
1 Ω/150 Ω
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.200 ISBN 978-2-8322-9568-7
– 2 – IEC 61967-4:2021 © IEC:2021
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 General . 7
4.1 Measurement basics . 7
4.2 RF current measurement . 9
4.3 RF voltage measurement at IC pins . 9
4.4 Assessment of the measurement technique . 9
5 Test conditions . 9
6 Test equipment . 10
6.1 RF measuring instrument . 10
6.2 RF current probe specification . 10
6.3 Test of the RF current probe capability . 11
6.4 Matching network specification . 11
7 Test setup . 12
7.1 General test configuration . 12
7.2 Printed circuit test board layout . 12
8 Test procedure . 13
9 Test report . 13
Annex A (informative) Probe verification procedure . 14
Annex B (informative) Classification of conducted emission levels . 18
B.1 Introductory remark . 18
B.2 General . 18
B.3 Definition of emission levels . 18
B.4 Presentation of results . 18
B.4.1 General . 18
B.4.2 Examples. 20
Annex C (informative) Example of reference levels for automotive applications. 22
C.1 Introductory remark . 22
C.2 General . 22
C.3 Reference levels . 22
C.3.1 General . 22
C.3.2 Measurements of conducted emissions, 1 Ω method . 23
C.3.3 Measurements of conducted emissions, 150 Ω method . 23
Annex D (informative) EMC requirements and how to use EMC IC measurement
techniques . 24
D.1 Introductory remark . 24
D.2 Using EMC measurement procedures . 24
D.3 Assessment of the IC influence to the EMC behaviour of the modules . 24
Annex E (informative) Example of a test setup consisting of an EMC main test board
and an EME IC test board . 26
E.1 Introductory remark . 26
E.2 EMC main test board . 26
E.3 EME IC test board. 28
IEC 61967-4:2021 © IEC:2021 – 3 –
E.3.1 General explanation of the test board . 28
E.3.2 How to build the test system . 28
E.3.3 PCB layout and component positioning . 30
Annex F (informative) 150 Ω direct coupling networks for common mode emission
measurements of differential mode data transfer ICs and similar circuits . 32
F.1 Basic direct coupling network . 32
F.2 Example of a common-mode coupling network alternative for LVDS or
RS485 or similar systems . 33
F.3 Example of a common-mode coupling network alternative for differential IC
outputs to resistive loads (e.g. airbag ignition driver) . 34
F.4 Example of a common-mode coupling network for CAN systems . 34
Annex G (informative) Measurement of conducted emissions in extended frequency
range . 35
G.1 General . 35
G.2 Guidelines . 35
G.2.1 Measurement network . 35
G.2.2 Network components . 36
G.2.3 Network layout . 38
G.2.4 Network verification . 38
G.2.5 Test board . 39
G.3 Application area . 41
Bibliography . 43
Figure 1 – Example of two emitting loops returning to the IC via common ground . 8
Figure 2 – Example of IC with two ground pins, a small I/O loop and two emitting loops . 8
Figure 3 – Construction of the 1 Ω RF current probe . 10
Figure 4 – Impedance matching network corresponding with IEC 61000-4-6 . 12
Figure 5 – General test configuration . 12
Figure A.1 – Test circuit . 14
Figure A.2 – Insertion loss of the 1 Ω probe . 14
Figure A.3 – Layout of the verification test circuit . 15
Figure A.4 – Connection of the verification test circuit . 16
Figure A.5 – Minimum decoupling limit versus frequency . 16
Figure A.6 – Example of 1 Ω probe input impedance characteristic . 17
Figure B.1 – Emission level scheme. 19
Figure B.2 – Example of the maximum emission level G8f . 20
Figure C.1 – 1 Ω method − Examples of reference levels for conducted disturbances
from semiconductors (peak detector) . 23
Figure C.2 – 150 Ω method − Examples of reference levels for conducted disturbances
from semiconductors (peak detector) . 23
Figure E.1 – EMC main test board . 27
Figure E.2 – Jumper field . 27
Figure E.3 – EME IC test board (contact areas for the spring connector pins of the
main test board) . 28
Figure E.4 – Example of an EME IC test system . 29
Figure E.5 – Component side of the EME IC test board . 30
Figure E.6 – Bottom side of the EME IC test board . 31
– 4 – IEC 61967-4:2021 © IEC:2021
Figure F.1 – Basic direct coupling for common mode EMC measurements . 32
Figure F.2 – Measurement setup for the S21 measurement of the common-mode
coupling . 33
Figure F.3 – Using split load termination as coupling for measuring equipment . 33
Figure F.4 – Using split load termination as coupling for measuring equipment . 34
Figure F.5 – Example of an acceptable adaptation for special network requirements
(e.g. for CAN systems) . 34
Figure G.1 – Example of a 150 Ω measurement network . 36
Figure G.2 – Example of RF characteristic of network components . 37
Figure G.3 – Examples of S21 characteristic by simulation . 39
Figure G.4 – Examples of test board section . 40
Figure G.5 – Examples of unwanted cross coupling between measurement network
and traces on test PCB . 40
Figure G.6 – Examples of unwanted signal line cross coupling on S21 transfer
characteristic of RF measurement network . 40
Figure G.7 – Examples of test board with additional signal line connected to IC pin . 41
Figure G.8 – Examples of stub lines length effects on S21 transfer characteristic of
RF measurement network . 41
Table 1 – Specification of the RF current probe . 11
Table 2 – Characteristics of the impedance matching network . 12
Table B.1 – Emission levels . 21
Table D.1 – Examples in which the measurement procedure can be reduced . 24
Table D.2 – System- and module-related ambient parameters . 25
Table D.3 – Changes at the IC which influence the EMC. 25
Table G.1 – Draft selection table for conducted emission measurements at pins above
1 GHz . 42
IEC 61967-4:2021 © IEC:2021 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INTEGRATED CIRCUITS –
MEASUREMENT OF ELECTROMAGNETIC EMISSIONS –
Part 4: Measurement of conducted emissions –
1 Ω/150 Ω direct coupling method
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
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Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 61967-4 has been prepared by subcommittee 47A: Integrated circuits, of IEC technical
committee 47: Semiconductor devices. It is an International Standard.
This second edition cancels and replaces the first edition published in 2002 and
Amendment 1:2006. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) frequency range of 150 kHz to 1 GHz has been deleted from the title;
b) recommended frequency range for 1 Ω method has been reduced to 30 MHz;
c) Annex G with recommendations and guidelines for frequency range extension beyond
1 GHz has been added.
– 6 – IEC 61967-4:2021 © IEC:2021
The text of this International Standard is based on the following documents:
Draft Report on voting
47A/1101/CDV 47A/1107/RVC
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts of the IEC 61967 series, under the general title Integrated circuits –
Measurement of electromagnetic emissions can be found on the IEC website.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.
IEC 61967-4:2021 © IEC:2021 – 7 –
INTEGRATED CIRCUITS –
MEASUREMENT OF ELECTROMAGNETIC EMISSIONS –
Part 4: Measurement of conducted emissions –
1 Ω/150 Ω direct coupling method
1 Scope
This part of IEC 61967 specifies a method to measure the conducted electromagnetic emission
(EME) of integrated circuits by direct radio frequency (RF) current measurement with a
1 Ω resistive probe and RF voltage measurement using a 150 Ω coupling network. These
methods ensure a high degree of reproducibility and correlation of EME measurement results.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 61000-4-6, Electromagnetic compatibility (EMC) – Part 4-6: Testing and measurement
techniques – Immunity to conducted disturbances, induced by radio-frequency fields
IEC 61967-1, Integrated circuits – Measurement of electromagnetic emissions – Part 1: General
conditions and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions of IEC 61967-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 General
4.1 Measurement basics
The maximum tolerated emission level from an integrated circuit (IC) depends on the permitted
maximum emission level of the electronic system, which includes the IC, and also on the
immunity level of other parts of the electronic system itself (so called inherent EMC). The value
of this emission level is dependent on system and application specific (ambient) parameters.
To characterise ICs, i.e. to provide typical EME values for a data sheet, a simple measurement
procedure and non-resonant measurement setup are required to guarantee a high degree of
reproducibility. Subclause 4.1 describes the basis of this test procedure.
– 8 – IEC 61967-4:2021 © IEC:2021
Figure 1 – Example of two emitting loops returning to the IC via common ground
The emission of an IC is generated by sufficiently fast changes of voltages and currents inside
the IC. These changes drive RF currents inside and outside the IC. The RF currents cause
conducted EME, which is mainly distributed via the IC pins conductor loops in the printed circuit
board (PCB) and the cabling. These loops are regarded as the emitting loop antennas. In
comparison to the dimension of these loops, the loops in the internal IC structure are considered
to be small.
The RF currents that accompany ICs action are different in amplitude, phase and spectral
content. Any RF current has its own loop that returns to the IC. All loops return mostly via the
ground or supply connection back to the IC. In Figure 1, this is shown for two loops returning
via ground. Loop 1 represents the supply wiring harness for the IC while loop 2 represents the
routing of an output signal. The common return path via ground is a suitable location to measure
the conducted EME as the measurement of the common RF sum current of the ground pin. This
test is named the “RF current measurement”.
If the IC under test has only one ground pin and all other pins are suspected to contribute
essentially to the EME, then the RF sum current is measured between the ground pin of the IC
under test and the ground (see i + i in Figure 1).
1 2
Figure 2 – Example of IC with two ground pins,
a small I/O loop and two emitting loops
If the IC under test has more than one ground pin or some of the pins are not suspected to
contribute much to the whole EME, then the IC under test gets its own ground plane as shown
in Figure 2. This ground plane is named “IC ground”. It is kept separately from the other ground,
that is named “RF-shield and peripheral ground”. The RF current is measured between the IC
ground and the peripheral ground.
ICs are often used in different configurations based on the application. For instance, a
microcontroller could be used as a single chip controller, with the I/O ports directly connected
to the external cabling system. In order to understand the influence of a single I/O pin on the
emission level of the IC, an additional measurement procedure, using the same equipment, is
provided. This measurement is named “single pin RF voltage measurement at IC pins” (see
also 4.3). In addition to the RF sum current measurement, the RF current measurement of a
IEC 61967-4:2021 © IEC:2021 – 9 –
single supply pin can be of interest in the analysis of an IC. This can also be attained with
application of the RF current measurement probe. For example, the RF current probe can be
applied to any of the multiple ground or supply pins in order to quantify the contribution of the
measured pin to the whole emission.
4.2 RF current measurement
In the test procedure, this measurement shall be made by measuring the voltage across the
1 Ω resistance of a RF current probe using a measurement receiver. The measurement shall
be made at the location shown in Figure 1 and Figure 2. The construction of the RF current
probe is specified in 6.2. The RF voltage level measured by the receiver is the voltage resulting
from all of RF currents returning to the IC through the probe impedance. The voltage
measurement can be converted to current by dividing the voltage by the probe impedance, if
the probe impedance is determined for the applicable frequency range e.g. in a verification
report.
NOTE 1 The probe impedance can be frequency dependant, caused by stray inductances of the probe, and thus
the usable frequency range can be limited.
NOTE 2 The probe impedance causes, depending on the IC current consumption, a voltage drop that can affect the
proper operation of the IC and limit the application of this method.
4.3 RF voltage measurement at IC pins
This measurement is used to identify the contribution of a single pin or a group of pins to the
EME of the IC under test. This measurement is only applied to those pins of the IC under test
that are intended to be connected directly to long (longer than 10 cm) PCB traces or wiring
harnesses (e.g. I/O, supply). These pins are loaded by a typical common mode impedance of
150 Ω, as specified in IEC 61000-4-6. In order to connect the measurement receiver, that has
an input-impedance of 50 Ω, the load has to be built as an impedance matching network. This
matching network is defined in 6.4.
Other I/O-pins of an IC may be loaded as specified in the general part of IEC 61967-1.
4.4 Assessment of the measurement technique
The above techniques have the following properties:
– high measurement reproducibility, because few parameters influence the result;
– capability to compare different IC configurations (e.g. packages);
– single pin EME measurements of the various I/O pins are dependent on their importance for
the emission in a specific application;
– assessment of the EME contribution of the IC using current sum measurement;
– simple verification of the measurement impedance using insertion loss measurement;
– measurement is also possible at very low frequencies.
With these characteristics, it is possible to measure the EME of ICs with a high degree of
reproducibility and therefore this technique offers a good method for comparison.
Annex D gives an example of how the measurement techniques can be used for the assessment
of ICs.
5 Test conditions
All test conditions required in this document are specified in IEC 61967-1.
– 10 – IEC 61967-4:2021 © IEC:2021
6 Test equipment
6.1 RF measuring instrument
The measurement equipment shall fulfil the requirements described in IEC 61967-1.
6.2 RF current probe specification
Figure 3 shows the basic construction of the 1 Ω RF current probe.
Figure 3 – Construction of the 1 Ω RF current probe
Table 1 presents a detailed specification of the RF current probe.
To prevent the measurement equipment from being damaged by DC voltage, the use of a DC
block is recommended. This shall have an attenuation of <0,5 dB at the lowest frequency to be
measured.
IEC 61967-4:2021 © IEC:2021 – 11 –
Table 1 – Specification of the RF current probe
Frequency range DC to 30 MHz
The applicable frequency range of the used probe shall be
evaluated e.g. in a S-parameter measurement and
documented in the test report.
Current probes available on the market have proved to be
usable e.g. only up to 30 MHz. Therefore bandwidth and
impedance over frequency of the used probe shall be verified
and documented in a diagram. The same applies to on-board
probes with SMD components.
In future, for enhanced RF probes, the usable frequency range
may change.
a)
Measurement resistor
RF resistor (low inductance) 1 Ω (±1 %).
The measurement resistor can also consist of resistors in
parallel, which increases the maximum permissible current
through the probe (e.g. 2 Ω//2 Ω) and reduce the stray
inductance.
Matching resistor 49 Ω (±1 %)
Maximum current < 0,5 A
Output impedance Z
40 Ω to 60 Ω
o
Insertion loss in verification circuit 34 dB ± 2 dB
Decoupling in verification circuit See Figure A.1 and Figure A.5.
Cable connection Flexible, double shielded coaxial cable with 50 Ω ± 2 Ω line
impedance. The RF connector shall be mounted with low
reflection. The insertion loss includes the cable and the probe.
Changes to the cable length will result in additional attenuation
to be considered with the measurement results.
Construction Coaxial probe or comparable construction, which can be
connected to a 4 mm coaxial socket. The measurement
resistor shall be as close as possible to the probe tip. It shall
be built in such a way that no mechanical damage is possible.
The connection of the probe cable shall be coaxial; the probe
tips should be replaceable, but nevertheless firmly connected
to the cable.
a)
The series impedance caused by the parasitic inductance should be lower than the resistor in the used
measurement range.
6.3 Test of the RF current probe capability
The current probe shall be functionally verified in a test circuit shown and described in detail in
Annex A.
6.4 Matching network specification
Based on IEC 61000-4-6, a cabling network can be represented in most cases by an antenna
with an impedance of about 150 Ω. In order to get accurate measurement results over the full
frequency range, a termination network of 145 Ω ± 20 Ω shall be used. Usual measurement
equipment provides an input impedance of 50 Ω so that the matching network shall match the
signal line impedance to the equipment impedance. The circuitry is shown in Figure 4, and the
characteristics of the impedance matching network used are shown in Table 2. Additional
information of matching networks for differential pin measurements are provided in Annex F
and recommendations.
– 12 – IEC 61967-4:2021 © IEC:2021
Figure 4 – Impedance matching network corresponding with IEC 61000-4-6
Table 2 – Characteristics of the impedance matching network
Frequency range 150 kHz – 1 GHz
Input impedance with 50 Ω termination Z 145 Ω ± 20 Ω
i
0,258 6 (−11,75 dB ± 2 dB)
Insertion loss within a 50 Ω system
Voltage ratio V / V 0,173 8 (−15,20 dB ± 2 dB)
out in
7 Test setup
7.1 General test configuration
A general test configuration is shown in Figure 5. This general test configuration can be built
up in the form of a special test configuration (an example is described in Clause E.2) or in any
other configuration, e.g. also in a real application.
Figure 5 – General test configuration
7.2 Printed circuit test board layout
In order to obtain a high degree of reproducibility of measurement results and be able to make
a valid comparison between different printed circuit test boards, the following guidance is given.
The test board should be built using PCB material of epoxy type (thickness 0,6 mm to 3 mm,
dielectric constant about 4,7). The top side and the bottom side are covered with a minimal
35 µm copper layer.
IEC 61967-4:2021 © IEC:2021 – 13 –
The bottom layer should be used as ground plane.
If peripheral ground and IC ground are used for the 1 Ω method, these two grounds are isolated
by an isolation gap. This isolation gap should be between 0,5 mm and 0,6 mm. If needed, the
IC ground shall be located underneath the DUT. The maximum size of this area should not
exceed the size of the package minimum footprint by more than 3 mm on each side.
To obtain the necessary accuracy for higher frequencies, parasitic coupling capacitance
between IC ground and peripheral ground shall be controlled. This parasitic coupling
capacitance between IC ground and peripheral ground shall be lower than 30 pF.
The IC ground is solely connected to the peripheral ground via the 1 Ω probe. In case of external
RF current probe, a socket should be used. The shield of the RF current probe tip should be
connected to the RF peripheral ground by the socket, while the IC ground or the IC ground pin
is connected to the current probe tip. The connection between the IC ground and the probe tip
shall be as short as possible. In any case, the trace length shall not exceed 15 mm. The trace
should be connected to the IC ground at the shortest distance to the centre point of the DUT.
If the above-mentioned guidelines are not applicable, the transfer characteristic of modified
design shall be determined and documented in the test report.
The DUT and all components needed to operate the DUT should be mounted onto the top side
of the test board. As much wiring as possible should be routed in the top layer. The DUT should
be placed in the centre of the PCB, while the needed matching networks should be placed
around this centre. The wiring between the IC pins and the matching network should be
designed to have a line impedance of 150 Ω. In case the 150 Ω line impedance is difficult to
implement, the line shall be of the maximum reasonable impedance but short enough, in order
to comply with the requirements of Table 2.
The wiring of the outputs of the matching networks should be designed to have a line impedance
of 50 Ω. An example of a PCB layout can be found in Annex E.
The supply shall be connected with a single wire directly to the capacitor C5. C5 could be a
surface mount device, of electrolytic type and having a value of at least 10 µF. The capacitor
C5 shall be positioned near the probe socket.
The test board may have any rectangular or circular shape.
Additional information and guidelines for extended frequency applications are described in
Annex G.
8 Test procedure
The requirements for the test procedure are described in IEC 61967-1.
9 Test report
The requirements for the test report are described in IEC 61967-1.
Emission measurement results may be presented using classification or reference levels. An
example of a classification scheme for emission levels is presented in Annex B. In addition,
Annex C shows how this classification scheme may be applied to set up reference levels for
ICs used in the automotive industry.
– 14 – IEC 61967-4:2021 © IEC:2021
Annex A
(informative)
Probe verification procedure
The test circuit shown in Figure A.1 is recommended for the probe verification. It consists of a
PCB laid out using microstrip techniques (see Figure A.3). The PCB has an input port to which
the RF generator is connected. The RF current probe to be verified is connected to the output
port. The RF current probe output is connected to a test receiver (see Figure A.4). This
verification procedure measures the isolation provided by the test circuit in a 50 Ω system
(see also CISPR 16-1-2 [1] ) and the insertion loss of the RF current probe.
Two separate measurements are recommended. The first measurement is performed with the
test circuit configured as shown in Figure A.1, circuit diagram A. Note that clamp A is not
inserted. While sweeping the RF generator over the required frequency range, measure the
voltage appearing at the output of the RF current probe.
Figure A.1 – Test circuit
The second measurement is performed identically to the first one but with clamp A installed to
shunt the RF generator to the probe input as shown in Figure A.1, circuit diagram B. This
measurement results in the RF current probe insertion loss which indicates its sensitivity.
Figure A.2 shows a result of such a measurement.
Figure A.2 – Insertion loss of the 1 Ω probe
___________
Numbers in square brackets refer to the Bibliography.
IEC 61967-4:2021 © IEC:2021 – 15 –
The calculated difference of both measurements is called the “decoupling”. The decoupling
should be above the limit shown in Figure A.5. The decoupling is equal to the measurement
dynamics in relation to the signal source. The decoupling does include the quality
characteristics, the sensitivity and the shielding of the probe.
Dimensions in millimetres
Key
1 coupling area
2 reference ground
Figure A.3 – Layout of
...
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