prEN IEC 62024-2:2023

High frequency inductive components - Electrical characteristics and measuring methods - Part 2: Rated current of inductors for DC-to-DC converters

IEC 62024-2:2024 specifies the measuring methods of the rated DC limits for inductors as defined below. Standardized measuring methods for the determination of ratings enable users to accurately compare the current ratings given in various manufacturers' data books. This document is applicable to leaded and surface mount inductors with dimensions according to IEC 62025-1 and generally with rated current less than 125 A, although inductors with rated current greater than 125 A are available that fall within the dimension restrictions of this document (no larger than a 625 mm2 footprint). These inductors are typically used in DC‑to‑DC converters built on printed circuit boards (PCBs), for electronic and telecommunication equipment, and small size switching power supply units. The measuring methods are defined by the saturation and temperature rise limitations induced solely by direct current (DC). This edition includes the following significant technical changes with respect to the previous edition: a) extension of scope by increase of range of rated current from 22 A to 125 A; b) extension of scope by increase of footprint limitation from 12 mm × 12 mm to 625 mm2; c) addition of upper current limitation for Iclass B, Iclass C and Iclass D board to Table 1; d) revised application examples for Table 1; e) addition of wire size references for current ranges between 22 A ≤ I ≤ 125 A to Table 2; f) addition of crimp terminal references to Table 2; g) addition of thermal camera method.

Induktive Hochfrequenz-Bauelemente - Elektrische Eigenschaften und Messmethoden - Teil 2: Bemessungsstrom von Drosselspulen für DC/DC-Wandler

Composants inductifs à haute fréquence - Caractéristiques électriques et méthodes de mesure - Part 2: Courant assigné des bobines d'inductance pour les convertisseurs continu-continu

L'IEC 62024-2:2024 spécifie les méthodes de mesure des limites de courant continu assigné pour les bobines d'inductance, définies ci-après. Les méthodes de mesure normalisées pour la détermination des caractéristiques assignées permettent aux utilisateurs de comparer avec exactitude les caractéristiques assignées de courant indiquées dans les fiches de données des différents fabricants. Le présent document s'applique aux bobines d'inductance plombées et à montage en surface dont les dimensions sont conformes à l'IEC 62025-1 et dont le courant assigné est généralement inférieur à 125 A, même si des bobines d'inductance de courant assigné supérieur à 125 A sont disponibles et respectent les limites de dimensions du présent document (empreinte inférieure ou égale à 625 mm2). Ces bobines d'inductance sont habituellement utilisées dans des convertisseurs continu-continu montés sur des cartes à circuit imprimé (PCB, printed circuit boards), pour des équipements électroniques et de télécommunications, ainsi que pour les blocs d'alimentation à découpage de petite taille. Les méthodes de mesure sont définies par les limites de saturation et d'échauffement induites par le courant continu (DC) uniquement. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: a) le domaine d'application a été élargi en portant la plage du courant assigné de 22 A à 125 A; b) le domaine d'application a été élargi en portant les limites de l'empreinte de 12 mm × 12 mm à 625 mm2; c) une limite haute de courant a été ajoutée pour les cartes Iclasse B, Iclasse C et Iclasse D dans le Tableau 1; d) les exemples d'application ont été révisés pour le Tableau 1; e) des tailles de fils de référence ont été ajoutées pour les courants d'intensité 22 A ≤ I ≤ 125 A dans le Tableau 2; f) des bornes à sertir de référence ont été ajoutées dans le Tableau 2; g) la méthode par caméra thermique a été ajoutée.

Visokofrekvenčne induktivne komponente - Električne karakteristike in merilne metode - 2. del: Naznačeni tok tuljav za presmernik DC/DC

General Information

• Status: Not Published
• Publication Date: 11-Nov-2024
• ICS: 29.100.10 - Magnetic components
• Technical Committee: CLC/SR 51 - Magnetic components and ferrite materials
• Drafting Committee: IEC/TC 51 - IEC_TC_51
• Current Stage: 4098 - Decision to drop project - Standstill maintained / released - Enquiry
• Start Date: 19-Jul-2024
• Completion Date: 23-Sep-2025
• Ref Project: oSIST prEN IEC 62024-2:2023 - High frequency inductive components - Electrical characteristics and measuring methods - Part 2: Rated current of inductors for DC-to-DC converters

Relations

• Revises: EN IEC 62024-2:2020 - High frequency inductive components - Electrical characteristics and measuring methods - Part 2: Rated current of inductors for DC-to-DC converters
• Effective Date: 26-Jul-2021

Standards Content (Sample)

SLOVENSKI STANDARD
01-junij-2023
Visokofrekvenčne induktivne komponente - Električne karakteristike in merilne
metode - 2. del: Naznačeni tok tuljav za presmernik DC/DC
High frequency inductive components - Electrical characteristics and measuring methods
- Part 2: Rated current of inductors for DC-to-DC converters
Induktive Hochfrequenz-Bauelemente - Elektrische Eigenschaften und Messmethoden -
Teil 2: Bemessungsstrom von Drosselspulen für DC/DC-Wandler
Composants inductifs à haute fréquence - Caractéristiques électriques et méthodes de
mesure - Partie 2: Courant assigné des bobines d'induction pour des convertisseurs
continu-continu
Ta slovenski standard je istoveten z: prEN IEC 62024-2:2023
ICS:
29.100.10 Magnetne komponente Magnetic components
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

51/1435/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 62024-2 ED3
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-04-21 2023-07-14
SUPERSEDES DOCUMENTS:
51/1409/CD, 51/1414/CC
IEC TC 51 : MAGNETIC COMPONENTS, FERRITE AND MAGNETIC POWDER MATERIALS
SECRETARIAT: SECRETARY:
Japan Mr Takeshi Abe
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

Other TC/SCs are requested to indicate their interest, if any,
in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for
Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of
• any relevant patent rights of which they are aware and to provide supporting documentation,
• any relevant “in some countries” clauses to be included should this proposal proceed. Recipients are reminded that
the enquiry stage is the final stage for submitting "in some countries" clauses. See AC/22/2007.

TITLE:
High frequency inductive components - Electrical characteristics and measuring methods - Part 2:
Rated current of inductors for DC-to-DC converters

PROPOSED STABILITY DATE: 2028
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
permission in writing from IEC.

IEC CDV 62024-2 © IEC 2023 2 51/1435/CDV

NOTE FROM TC/SC OFFICERS:
51/1435/CDV 3 IEC CDV 62024-2 © IEC 2023

1 CONTENTS
3 FOREWORD . 5
4 1 Scope . 7
5 2 Normative references . 7
6 3 Terms and definitions . 7
7 4 Standard atmospheric conditions . 7
8 4.1 Standard atmospheric conditions for testing . 7
9 4.2 Reference conditions . 8
10 5 Measuring method of DC saturation limited current . 8
11 5.1 General . 8
12 5.2 Test conditions . 8
13 5.3 Measuring circuit and calculation . 8
14 5.3.1 Measuring circuit . 8
15 5.3.2 Calculation . 9
16 5.4 Attachment jig of inductor . 9
17 5.5 Measuring method . 9
18 5.6 Quality conformance inspection . 10
19 6 Measuring method of temperature rise limited current. 10
20 6.1 General . 10
21 6.2 Test conditions . 10
22 6.3 Measuring jig . 10
23 6.3.1 General . 10
24 6.3.2 Printed-wiring board method . 11
25 6.3.3 Lead wire method . 18
26 6.4 Measuring method and calculation . 18
27 6.4.1 General . 18
28 6.4.2 Resistance substitution method . 19
29 6.4.3 Thermo-couple method . 20
30 6.4.4 Thermal Camera Method . 21
31 6.5 Quality conformance inspection . 22
32 7 Determination of rated current . 22
33 8 Information to be given in the detail specification . 22
34 8.1 General . 22
35 8.2 Measuring method of DC saturation limited current . 22
36 8.3 Measuring method of temperature rise limited current . 22
37 Annex A (informative) Example of recommended description on product specification
38 sheets and catalogues . 23
39 Bibliography . 24
41 Figure 1 – Inductance measuring circuit under application of DC saturation condition . 9
42 Figure 2 – Example of printed-wiring boards . 18
43 Figure 3 – Temperature rise measuring circuit by resistance substitution method . 19
44 Figure 4 – Temperature rise measuring circuit by thermo-couple method . 20
45 Figure 5 – Temperature rise measuring circuit by thermal camera method . 21
47 Table 1 – Width of circuits . 11

IEC CDV 62024-2 © IEC 2023 4 51/1435/CDV

48 Table 2 – Wire size of circuits . 18
51/1435/CDV 5 IEC CDV 62024-2 © IEC 2023

50 INTERNATIONAL ELECTROTECHNICAL COMMISSION
51 ____________
53 HIGH FREQUENCY INDUCTIVE COMPONENTS –
54 ELECTRICAL CHARACTERISTICS AND MEASURING METHODS –
56 Part 2: Rated current of inductors for DC-to-DC converters
58 FOREWORD
59 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
60 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
61 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
62 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
63 Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)“). Their
64 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
65 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
66 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
67 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
68 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
69 consensus of opinion on the relevant subjects since each technical committee has representation from all
70 interested IEC National Committees.
71 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
72 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
73 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
74 misinterpretation by any end user.
75 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
76 transparently to the maximum extent possible in their national and regional publications. Any divergence between
77 any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
78 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
79 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
80 services carried out by independent certification bodies.
81 6) All users should ensure that they have the latest edition of this publication.
82 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
83 members of its technical committees and IEC National Committees for any personal injury, property damage or
84 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
85 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
86 Publications.
87 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
88 indispensable for the correct application of this publication.
89 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
90 rights. IEC shall not be held responsible for identifying any or all such patent rights.
91 IEC 62024-2 has been prepared by IEC technical committee 51: Magnetic components, ferrite
92 and magnetic powder materials.
93 This third edition cancels and replaces the second edition published in 2020. This edition
94 constitutes a technical revision.
95 This edition includes the following significant technical changes with respect to the previous
96 edition:
97 a) extension of scope by increase of range of rated current from 22 A to 125 A;
98 b) extension of scope by increase of footprint limitation from 12 mm X 12 mm to 625 mm ;
99 c) addition of upper current limitation for I , I and I board to Table 1;
CLASS B CLASS C CLASS D
100 d) revised application examples for Table 1;
101 e) addition of wire size references for current ranges between 22 A ≤ I ≤ 125 A to Table 2;
102 f) addition of crimp terminal references to Table 2;
103 g) addition of thermal camera method.

IEC CDV 62024-2 © IEC 2023 6 51/1435/CDV

104 The text of this international standard is based on the following documents:
FDIS Report on voting
51/xxxx/FDIS 51/xxxx/RVD
106 Full information on the voting for its approval can be found in the report on voting indicated in
107 the above table.
108 The language used for the development of this International Standard is English.
109 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
110 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
111 at https://www.iec.ch/members_experts/refdocs. The main document types developed by IEC
112 are described in greater detail at https://www.iec.ch/standardsdev/publications.
113 A list of all parts of IEC 62024 series, published under the general title High frequency inductive
114 components – Electrical characteristics and measuring methods can be found on the IEC
115 website.
116 The committee has decided that the contents of this document will remain unchanged until the
117 stability date indicated on the IEC website under webstore.iec.ch in the data related to the
118 specific document. At this date, the document will be
119 • reconfirmed,
120 • withdrawn,
121 • replaced by a revised edition, or
122 • amended.
51/1435/CDV 7 IEC CDV 62024-2 © IEC 2023

125 HIGH FREQUENCY INDUCTIVE COMPONENTS –
126 ELECTRICAL CHARACTERISTICS AND MEASURING METHODS –
128 Part 2: Rated current of inductors for DC-to-DC converters
129 1 Scope
130 This part of IEC 62024 specifies the measuring methods of the rated direct current limits for
131 small inductors as defined below.
132 Standardized measuring methods for the determination of ratings enable users to accurately
133 compare the current ratings given in various manufacturers’ data books.
134 This document is applicable to leaded and surface mount inductors with dimensions according
135 to IEC 62025-1 and generally with rated current less than 125 A, although inductors with rated
136 current greater than 125 A are available that fall within the dimension restrictions of this
137 document (no larger than a 625 mm footprint). These inductors are typically used in DC-to-DC
138 converters built on PCBs, for electronic and telecommunication equipment, and small size
139 switching power supply units.
140 The measuring methods are defined by the saturation and temperature rise limitations induced
141 solely by direct current.
142 2 Normative references
143 The following documents are referred to in the text in such a way that some or all of their content
144 constitutes requirements of this document. For dated references, only the edition cited applies.
145 For undated references, the latest edition of the referenced document (including any
146 amendments) applies.
147 IEC 60068-1:2013, Environmental testing – Part 1: General and guidance
148 3 Terms and definitions
149 For the purposes of this document, the following terms and definitions apply.
150 ISO and IEC maintain terminological databases for use in standardization at the following
151 addresses:
152 • IEC Electropedia: available at http://www.electropedia.org/
153 • ISO Online browsing platform: available at http://www.iso.org/obp
154 3.1
155 DC saturation limited current
156 allowable value of DC current for which the decrease of the inductance is within the specified
157 value
158 3.2
159 temperature rise limited current
160 allowable value of DC current for which the self-generation heat of the inductor results in
161 temperature rise within the specified value
162 4 Standard atmospheric conditions
163 4.1 Standard atmospheric conditions for testing
164 Standard atmospheric conditions for testing shall be as follows (see 4.3 of IEC 60068-1:2013):
165 – temperature: 15 °C to 35 °C;
166 – relative humidity: 25 % to 75 %;
167 – air pressure: 86 kPa to 106 kPa.

IEC CDV 62024-2 © IEC 2023 8 51/1435/CDV

168 In the event of dispute or where required, the measurements shall be repeated using the referee
169 temperatures and such other conditions as given in 4.2.
170 4.2 Reference conditions
171 For reference purposes, one of the standard atmospheric conditions for referee tests taken from
172 4.2 of IEC 60068-1:2013 shall be selected and shall be as follows:
173 – temperature: 20 °C ± 2 °C;
174 – relative humidity: 60 % to 70 %;
175 – air pressure: 86 kPa to 106 kPa.
176 5 Measuring method of DC saturation limited current
177 5.1 General
178 When alternating current in which DC current is superimposed is supplied to an inductor, the
179 inductance of the inductor decreases according to the DC current value.
180 In a typical application, the saturation current results from the peak current of the superposition
181 of AC on DC current. In this document, the saturation current is measured as DC current
182 offsetting a small signal AC current.
183 NOTE It is not practical to set a standard for AC saturation limited current, because there is an unlimited number
184 of different ways to apply AC current in an application. Therefore, manufacturers and users have generally defined
185 DC saturation limited current as a common point of reference. This document does the same.
186 5.2 Test conditions
187 Unless otherwise specified in the detail specification, the test conditions shall be in accordance
188 with Clause 4.
189 NOTE The variation of the value of DC saturation limited current, as a function of temperature, is dependent on the
190 magnetic material and the structure of the magnetic core of the inductor. However, measurement of DC saturating
191 currents at elevated temperatures is generally not practical for inspection purposes. Therefore, the measurement at
192 room temperature as provided by this document is generally applied for specification purposes. De-rating curves
193 indicating variation of DC saturation limited current as a function of maximum operating temperature of the inductor
194 can be generated. These curves can be used to correlate the DC saturation limited current at room temperature to
195 the DC saturation limited current at typical operating temperatures. In some cases, it will become necessary for the
196 manufacturer and user to agree on an additional specification at a high temperature such as 85 °C, 105 °C or 125 °C.
197 5.3 Measuring circuit and calculation
198 5.3.1 Measuring circuit
199 The measuring circuit is as shown in Figure 1.
51/1435/CDV 9 IEC CDV 62024-2 © IEC 2023

202 Key
203 Components
204 R source resistor R = R
s s
205 R range resistor R = R
r r
206 V voltmeter
207 V voltmeter
208 E    RMS voltage value measured by voltmeter V
209      RMS voltage value measured by voltmeter V
E 2
210 E     RMS voltage value of source
s
211 C DC current blocking capacitor
212 Supplies
213 f frequency of source
s
214 I supplied current to range resistor
r
215 I supplied current to specimen
x
216 I = I
x r
217 Figure 1 – Inductance measuring circuit under application of
218 DC saturation condition
219 5.3.2 Calculation
220 Voltages E and E shall be measured when frequency f and voltage E of the signal generator
1 2 s s
221 are supplied in accordance with the detail specification, and an initial value of the inductance
222 shall be calculated by the following formulae.
E −E
223 ZR
xr
IE
r 2
224 𝑍𝑍 = |𝑍𝑍 |cos𝜃𝜃 +𝑗𝑗|𝑍𝑍 |sin𝜃𝜃
𝑥𝑥 𝑥𝑥 𝑥𝑥
225 Z R+ jX
xx x
XX
xx
L
x
ωπ2 f
s
227 where
228 R is the resistance of the specimen;
x
229 X is the reactance of the specimen;
x
230 Z is the impedance of the specimen;
x
231 L is the equivalent series inductance of the specimen;
x
232 E is the applied voltage to the specimen;
233 E is the applied voltage to the range resistor (= I R );
2 r r
234 θ is the phase angle of the complex impedance
.
235 5.4 Attachment jig of inductor
236 The attachment jig of the specimen shall be specified in a detail specification (see Clause 8) .
237 5.5 Measuring method
238 a) A short compensation shall be done before measurement.
239 b) The specimen shall be connected to the circuit shown in Figure 1, by using the attachment
240 jig specified in 5.4.
241 c) When the specimen is connected by soldering, it shall be left until it becomes cool enough.
==
=
==
IEC CDV 62024-2 © IEC 2023 10 51/1435/CDV

242 d) Voltages E and E shall be measured when frequency f and voltage E of the signal
1 2 s s
243 generator are supplied in accordance with the detail specification, and an initial value of the
244 inductance shall be calculated by the formulae of 5.3.2.
245 e) The value of the DC current that is superimposed on the specimen shall be modulated and
246 the inductance value shall be measured.
247 f) The decrease from the initial value of the inductance shall be calculated. DC saturation
248 limited current shall be determined by measuring the DC current when the decrease in
249 inductance matches the specified value in the detail specification.
250 g) The decrease in inductance that is specified in the detail specification should be 10 % or
251 30 %.
252 NOTE 10 % is one of the design points typical for sharp-saturating inductors, and 30 % is one of the design points
253 typical for soft-saturating inductors. See Annex A.
254 5.6 Quality conformance inspection
255 The DC current specified in the detail specification shall be supplied to a specimen in
256 accordance with the methods specified in 5.3 to 5.5, and then inductance shall be measured.
257 The decrease in inductance shall be within the specified value.
258 6 Measuring method of temperature rise limited current
259 6.1 General
260 When DC current is supplied to an inductor, the inductor generates heat by itself according to
261 the supplied DC current value because of its DC current resistance.
262 NOTE 1 Temperature rise results from self-heating of the inductor. The sources of heating are DC copper losses,
263 AC copper losses and AC core losses. This document defines the tempera
...