IEC 60938-2-1:2023

IEC 60938-2-1 ®
Edition 2.0 2023-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fixed inductors for electromagnetic interference suppression –
Part 2-1: Blank detail specification – Inductors for which safety tests are
required
Inductances fixes d'antiparasitage –
Partie 2-1: Spécification particulière-cadre – Inductances exigeant des essais de
sécurité
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IEC 60938-2-1 ®
Edition 2.0 2023-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fixed inductors for electromagnetic interference suppression –

Part 2-1: Blank detail specification – Inductors for which safety tests are

required
Inductances fixes d'antiparasitage –

Partie 2-1: Spécification particulière-cadre – Inductances exigeant des essais de

sécurité
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.100.10, 31.020 ISBN 978-2-8322-7932-8

– 2 – IEC 60938-2-1:2023 © IEC 2023
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 General information . 7
4.1 Methods of mounting. 7
4.2 Dimensions . 8
4.3 Ratings and characteristics . 8
4.4 Marking . 8
4.5 Ordering information . 8
4.6 Certified records of released lots . 9
4.7 Additional information (not for inspection purposes) . 9
4.8 Additional or increased severities or requirements to those specified in the
generic or sectional specification . 9
5 Inspection requirements . 9
5.1 Procedures . 9
5.2 Test schedules . 9
5.2.1 Initial approval . 9
5.2.2 Conformance tests . 9
5.2.3 Quality conformance inspection . 10
Annex A (normative) Declaration of design . 11
Annex B (informative) Quality conformance inspection . 12
Bibliography . 17

Table 1 – Dimensions related to case size . 8
Table 2 – Type designation related to values of inductance, rated current and DC
resistance . 8
Table 3 – Other characteristics . 9
Table 4 – Conformance tests (lot by lot) . 9
Table B.1 – Test schedule for quality conformance inspection . 12
Table B.2 – Test schedule for quality conformance inspection – periodical tests . 13

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIXED INDUCTORS FOR ELECTROMAGNETIC
INTERFERENCE SUPPRESSION –
Part 2-1: Blank detail specification –
Inductors for which safety tests are required

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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preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
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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
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60938-2-1 has been prepared by IEC technical committee 40: Capacitors and resistors for
electronic equipment. It is an International Standard.
This second edition cancels and replaces the first edition published in 1999. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) it combines IEC 60938-2-1:1999 and IEC 60938-2-2:1999 into one Blank detail specification
(BDS);
b) test schedule for quality conformance inspection is moved to an informative annex
(Annex B).
– 4 – IEC 60938-2-1:2023 © IEC 2023
The text of this International Standard is based on the following documents:
Draft Report on voting
40/3084/FDIS 40/3103/RVD
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 in the IEC 60938 series, published under the general title Fixed inductors for
electromagnetic interference suppression, can be found on the IEC website.
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, or
• revised.
INTRODUCTION
Blank detail specification
A blank detail specification is a supplementary document to the sectional specification and
contains requirements for style, layout and minimum content of detail specifications. Detail
specifications not complying with these requirements shall not be considered as being in
accordance with IEC specifications nor shall they so be described.
In the preparation of detail specifications, the content of 4.3 of the sectional specification shall
be taken into account.
The numbers between square brackets on the first page of the detail specification correspond
to the following information which shall be inserted in the position indicated.
Identification of the detail specification
[1] The "International Electrotechnical Commission" or the National Standards Organization
under whose authority the detail specification is drafted.
[2] The IEC or National Standards number of the detail specification, date of issue and any
further information required by the national system.
[3] The number and issue number of the IEC or national generic specification.
[4] The IEC number of the blank detail specification.
Identification of the inductor
[5] A short description of the type of inductor.
[6] Information on typical construction (when applicable).
[7] Outline drawing with main dimensions which are of importance for interchangeability
and/or reference to the national or international documents for outlines. Alternatively, this
drawing may be given in an annex to the detail specification.
[8] Application or group of applications covered and/or assessment level.
[9] Reference data on the most important properties, to allow comparison between the
various inductor types.
– 6 – IEC 60938-2-1:2023 © IEC 2023

[1] IEC 60938-2-1XX [2]
QC XXXXXXXXXXXX
ELECTRONIC COMPONENTS OF ASSESSED IEC 60938-2-1 [4]
QUALITY IN ACCORDANCE WITH: QC XXXXXX

[3] FIXED INDUCTORS FOR
ELECTROMAGNETIC INTERFERENCE
SUPPRESSION FOR WHICH SAFETY [5]
Outline drawing: (see Table 1) TESTS ARE REQUIRED
(. angle projection)
[7] [6]
(Other shapes are permitted within the dimensions
given)
[8]
NOTES [1] to [9] see page 4.
[9]
Information on the availability of components qualified
to this detail specification is given in the Register of
Approvals.
FIXED INDUCTORS FOR ELECTROMAGNETIC
INTERFERENCE SUPPRESSION –
Part 2-1: Blank detail specification –
Inductors for which safety tests are required

1 Scope
This part of IEC 60938-2 is applicable to the drafting of detail specifications for fixed inductors
for which safety tests are required for use in electronic equipment.
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 60938-2:2021, Fixed inductors for electromagnetic interference suppression – Part 2:
Sectional specification on power line chokes
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
4 General information
4.1 Methods of mounting
The recommended method of mounting for normal use shall be specified. It is mandatory to use
this method for the application of shock and vibration tests.
The method of mounting shall be given in the detail specification. This method shall be used for
the application of shock and vibration tests.
If the design of the inductor requires special mounting fixtures in its use, the detail specification
shall describe the mounting fixtures and they shall be used in the application of shock and
vibration tests. The specified heat sink shall be used in the application of the endurance test.

– 8 – IEC 60938-2-1:2023 © IEC 2023
4.2 Dimensions
Table 1 – Dimensions related to case size
Case size Dimensions
reference or
mm
type
L W H
When there is no case size reference, the dimensions should be given per type designation.
The dimensions should be given as maximum dimensions or as nominal dimensions with a tolerance.

4.3 Ratings and characteristics
• nominal inductance (L ) (see Table 2)
N
• tolerance on inductance
• rated current (I ) (see Table 2)
R
• DC resistance (R) (see Table 2)
• rated voltage
• rated temperature
• climatic category
• category of passive flammability (optional)
Table 2 – Type designation related to values of inductance,
rated current and DC resistance
Type designation related L I R
N R max
to values of inductance,
rated current and DC per line per line
resistance
mH A Ω
4.4 Marking
The marking of the inductor and the package shall be in accordance with the requirements
of 4.5 of IEC 60938-2:2021.
The details of the marking of the component and packaging shall be given in full in the detail
specification.
4.5 Ordering information
Orders for inductors covered by this specification shall contain, in clear or in coded form, the
following minimum information:
a) type designation;
b) nominal inductance;
c) rated current;
d) number and issue reference of the detail specification and style reference.

4.6 Certified records of released lots
Required/non required.
4.7 Additional information (not for inspection purposes)
4.8 Additional or increased severities or requirements to those specified in the
generic or sectional specification
Additions or increased requirements should be specified only when essential and listed in
Table 3.
Table 3 – Other characteristics
This table is to be used for defining characteristics
which are additional to or more severe than those
given in the sectional specification.

5 Inspection requirements
5.1 Procedures
For qualification approval, the procedure shall be in accordance with 5.1 of IEC 60938-2:2021.
5.2 Test schedules
5.2.1 Initial approval
See IEC 60938-2:2021, Annex A and Annex B for sampling plan and test schedule.
5.2.2 Conformance tests
5.2.2.1 Conformance tests (lot-by-lot)
See Table 4.
Table 4 – Conformance tests (lot by lot)
Subclause number and D Conditions of test Sample size Requirements
test or
of IEC 60938 2:2021 and of IEC 60938 2:2021 and
ND
Clause 4 of this document Clause 4 of this document
a
5.6 Inductance ND Within specified tolerance
100 %
5.3 Visual examination Legible marking and as
specified in 4.4 of this
specification
5.5 Voltage test No permanent breakdown or
flashover
a
Can be carried out as end-of-line testing.
Key:
D destructive
ND non destructive
– 10 – IEC 60938-2-1:2023 © IEC 2023
5.2.2.2 Re-qualification
Re-qualification tests according to 5.2.1 can be required by the certification body when a change
of the declared design as given in Annex A is intended.
The certification body shall be informed about the intended change(s) and shall decide whether
re-qualification tests have to be performed.
As a maximum, a complete re-qualification according to 5.2.1 can be necessary.
5.2.3 Quality conformance inspection
Annex B gives an example of a test schedule for quality conformance inspection (see Table B.1
and Table B.2).
Annex A
(normative)
Declaration of design
(Confidential to the manufacturer and the certification body)
The purpose of this description is to register essential data and the basic design of the inductors
for which approval is sought. The completed form shall be submitted to the relevant certification
body prior to any approval testings; its circulation to other parties is left to the decision of the
manufacturer.
For identification of materials in item 6 below the declaration of manufacturer names is not
required, if
• materials or components comply with a recognized standard, or
• the material or component is identified by a recognized unique type reference.
Changes of the declared design are permitted only after notifying the certification body in
writing. In this case the certification body will decide on necessary steps to be taken. As a
maximum, a complete re-qualification can be required.
Registration number: (to be allocated by the certification body)
1 Applicant:
2 Manufacturer:
3 Manufacturing site:
4 Type designation:
5 Circuit diagram:
6 Identification of materials
6.1 Encapsulation (if applicable)
6.2 Insulation sleeve (if applicable)
6.3 Core
6.4 Wire
6.5 Others
7 Constructional details:
Location Date Signature
– 12 – IEC 60938-2-1:2023 © IEC 2023
Annex B
(informative)
Quality conformance inspection
Table B.1 and Table B.2 give an example of a test schedule for quality conformance inspection
It includes sampling, periodicity, severities and requirements. The formation of inspection lots
is described in 5.1 of the sectional specification.
Table B.1 – Test schedule for quality conformance inspection
Subclause number and test D Conditions of test IL AQL Performance requirements
of IEC 60938-2:2021 and of IEC 60938-2:2021 and
or
Clause 4 of this document Clause 4 of this document
ND
GROUP A INSPECTION
(lot-by-lot)
ND S-4 2,5 % As in 5.3.1
Subgroup A1
Legible marking and as
5.3 Visual examination specified in 4.4 of this
specification
4.5 Marking See Table 1 of this
specification
5.3.1 Dimensions (gauging)
Subgroup A2 ND II 1,0 %
5.7 DC line resistance See 4.3 of this specification

5.6 Inductance Within specified tolerance

5.5 Voltage test
See Table 2 of this
4.3 Insulation resistance specification
(test A only)
GROUP B INSPECTION
(lot-by-lot)
Subgroup B1 D S-3 2,5 %
5.16 Solderability Method: .
Specify ageing if none
or
other than 16 h 155 °C
dry heat
5.16.4 Final inspection Visual examination Good tinning as evidenced by
free flowing of the solder with
wetting of the terminations, or

solder shall flow within 3 s, as

applicable
Key:
D destructive
ND non-destructive
IL inspection level, selected from IEC 61193-2
AQL acceptable quality level, selected from IEC 61193-2

Table B.2 – Test schedule for quality conformance inspection – periodical tests
Subclause number and D Conditions of test Sample size and Performance requirements
test or of IEC 60938-2:2021 and
acceptance criterion
of IEC 60938-2:2021 and ND Clause 4 of this document
Clause 4 of this
document
a
p c
n
GROUP C INSPECTION
(periodic)
Subgroup C1A D 6 5/3/1/1 0/0/0/0

5.3.2 Dimensions Table 1 of this specification
(detail)
5.3.2 Creepage distances For method and severity Table 1 of this specification
and clearances see detail specification
and 5.3.2 of
IEC 60938-2:2021
For method and severity:
5.12 Robustness of
terminations see detail specification
No visible damage
5.15 Resistance to See detail specification

soldering heat for the method (1A or 1B)

For method 1A:
(if applicable)
Immersion time: 10 s,
unless otherwise
specified in the detail
specification
5.24 Component sol-
No visible damage
vent resistance
See 4.3 of this specification
(if applicable) Visual examination

5.15 Final measurements
DC line resistance
Subgroup C1B D 6 9/6/4/1 0/0/0/0

5.25 Solvent resistance Legible marking
of the marking
(if applicable)
5.17 Rapid change of
θ = Lower category
A
temperature
temperature
θ = Upper category
B
temperature
Five cycles
Duration t = . h,
No visible damage
Visual examination
5.13 Vibration
For mounting method,
see detail specification
Frequency range:
from . Hz to . Hz
Total number of sweep
cycles: .
No visible damage
5.13.2 Intermediate Visual examination

inspection
5.14 Shock
For mounting method,
see detail specification
Number of shocks: .
Acceleration: . m/s
Duration of pulse: . ms
No visible damage
Visual examination
See 4.3 of this specification
DC line resistance
– 14 – IEC 60938-2-1:2023 © IEC 2023
Subclause number and D Conditions of test Sample size and Performance requirements
test or acceptance criterion of IEC 60938-2:2021 and
of IEC 60938-2:2021 and ND Clause 4 of this document
Clause 4 of this
document
a
p c
n
Subgroup C1 D 4 14/9/4/2 0/0/0/0

5.6 Inductance For reference
5.18 Container sealing Test Qc or Qd as No leakage
(if required in the prescribed in the detail
detail specification) specification

5.19 Climatic sequence
5.19.2 Dry heat Temperature: upper

category temperature
Duration: 16 h
5.19.3 Damp heat, cyclic,
test Db, first cycle
5.19.4 Cold Temperature: lower

category temperature
Duration: 2 h
5.19.5 Low air pressure Air pressure 8,0 kPa

(if required in the unless otherwise stated

detail specification) in the detail specification
Duration: 1 h
Visual examination
No permanent breakdown,
flashover, harmful
deformation of the case
Recovery: 1 h to 26 h
5.19.6 Damp heat, cyclic,
test Db, remaining
cycles
No visible damage
Visual examination
5.19.7 Final
Legible marking
measurements
See 4.3 of this specification
DC line resistance
Within –5 %/+10 % of value
Inductance
measured in group 0
No breakdown or flashover
Voltage proof
Voltage: 66 % of voltage
applied in group 0
≥50 % of values in 5.4
Insulation resistance
Subclause number and D Conditions of test Sample size and Performance requirements
test or acceptance criterion of IEC 60938-2:2021 and
of IEC 60938-2:2021 and ND Clause 4 of this document
Clause 4 of this
document
a
p c
n
Subgroup C2 D 12 8/5/4/2 0/0/0/0

5.6 Inductance For reference
5.20 Damp heat, steady Recovery: 1 h to 26 h
state
5.20 Final measurements Visual examination  No visible damage
Legible marking
DC line resistance See 4.3 of this specification

Inductance Within –5 %/+10 % of value
measured in group 0
Voltage proof No breakdown or flashover
Voltage: 66 % of voltage
applied in group 0
A polarizing voltage shall
be applied if specified in
the detail specification
≥50 % of values as measured
Insulation resistance
in 5.4
D
Subgroup C3A 3 8/4/2/1 0/0/0/0

5.9 Temperature rise Duration: until thermal

(inductors with equilibrium has been

reached
mass > 5 g only)
5.9.2 Test conditions Current: rated current

Ambient temperature:
rated temperature
As in 5.9.3
5.9.3 Final measurements Internal temperature

Duration: 1 000 h
5.11.1 Endurance, current
(inductors with Current: 1,1 × rated
mass ≤5 g only) current
Recovery: 1 h to 26 h
Subgroup C3B (inductors D 3 10/6/4/2 0/0/0/0
with more than one
winding
only)
3 impulses, full wave
Crest voltage: see 5.10.1
5.10 Impulse voltage
Duration: 1 000 h
Voltage and temperature,
5.11.2 Endurance, voltage
see 5.11.2
between line terminations
Subgroup C3
5.11.3 Final measurements Recovery: 1 h to 26 h

Visual examination No visible damage
Legible marking
DC line resistance As for group 0

Voltage proof No breakdown or flashover
Voltage: 66 % of voltage
applied in group 0
Insulation resistance See 5.11.3

Inductance Within –5 %/+10 % of value
measured in group 0
– 16 – IEC 60938-2-1:2023 © IEC 2023
Subclause number and D Conditions of test Sample size and Performance requirements
test or acceptance criterion of IEC 60938-2:2021 and
of IEC 60938-2:2021 and ND Clause 4 of this document
Clause 4 of this
document
a
p c
n
b
Subgroup 4 D 12 0
S
...