IEC 62024-3:2026

High frequency inductive components - Electrical characteristics and measuring methods - Part 3: AC loss measured by sinusoidal wave of inductors for DC-to-DC converters

IEC 62024-3:2026 specifies test methods for AC losses of high-frequency inductive components for power supplies used in DC-to-DC converters and similar devices at currents close to actual operation and introduces the measurement principle, scope of application and matters to be noted for each method. This document is applicable to leaded and surface mount inductors with dimensions in accordance with IEC 62024-2.

General Information

• Status: Published
• Publication Date: 18-Jun-2026
• ICS: 29.100.10 - Magnetic components
• Technical Committee: TC 51 - Magnetic components, ferrite and magnetic powder materials
• Drafting Committee: WG 9 - TC 51/WG 9
• Current Stage: PPUB - Publication issued
• Start Date: 19-Jun-2026
• Completion Date: 17-Jul-2026

Standards Content (Sample)

IEC 62024-3 ®
Edition 1.0 2026-06
INTERNATIONAL
STANDARD
High frequency inductive components - Electrical characteristics and measuring
methods -
Part 3: AC loss measured by sinusoidal wave of inductors for DC-to-DC
converters
ICS 29.100.10  ISBN 978-2-8327-1325-9

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CONTENTS
FOREWORD . 2
INTRODUCTION . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Select measuring method . 5
5 Cross-power method . 5
5.1 General . 5
5.2 Measuring method . 6
5.2.1 Measuring circuit . 6
5.2.2 Measuring jig . 6
5.2.3 Practical notes . 7
6 Amplified vector network analyzer method . 8
6.1 General . 8
6.2 Measuring method . 8
6.2.1 Measuring method overview . 8
6.2.2 Measuring circuit . 8
6.2.3 Measuring jig . 10
6.2.4 Calibration . 11
6.2.5 Calculation method . 12
6.2.6 Practical notes . 14
Annex A (informative) Measuring accuracy . 15
A.1 Method for confirming measuring accuracy . 15
A.2 Case studies of AC loss measurements in different waveforms . 15
A.3 Measuring error due to bias T . 16
A.3.1 General. 16
A.3.2 Cross-power method . 16
A.3.3 Amplified vector network analyzer method . 16
Bibliography . 17

Figure 1 – Example of measuring circuit of cross-power method . 6
Figure 2 – Example of measuring jig of cross-power method . 7
Figure 3 – Measuring circuit of amplified vector network analyzer method . 8
Figure 4 – Measuring circuit of amplified vector network analyzer method . 10
Figure 5 – Measuring jig of amplified vector network analyzer method . 11
Figure 6 – Compensation jig of amplified vector network analyzer method . 12
Figure A.1 – AC loss difference with triangular wave (duty 50 %, frequency 10 kHz). 16

Table 1 – AC loss measuring method . 5

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
High frequency inductive components -
Electrical characteristics and measuring methods -
Part 3: AC loss measured by sinusoidal wave of
inductors for DC-to-DC converters

FOREWORD
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IEC 62024-3 has been prepared by IEC technical committee 51: Magnetic components, ferrite
and magnetic powder materials. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
51/1617/FDIS 51/1625/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/publications.
A list of all parts in the IEC 62024 series, published under the general title High frequency
inductive components - Electrical characteristics and measuring methods, 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
This document is intended for high-frequency inductive components used in DC-to-DC
converters.
Power saving of DC-to-DC converters is crucial owing to heat generation measures for
miniaturization and high-density mounting, longer battery life for mobile devices, and increased
power consumption in data centres with increased communication traffic. Under these
circumstances, the loss of high-frequency inductive components is an important characteristic
that determines the power saving of DC-to-DC converters. To measure the loss for possible
implementation in DC-to-DC converters, it is important to measure the AC loss at current values
close to the actual drive, but there was no measurement standard. AC loss measurements for
high-frequency inductive components are defined in IEC 62024-1, but the measured currents
are small and are not intended to be driven by DC-to-DC converters. IEC 62044-3 and
IEC 63300 address testing for large alternating current, but the applications are different
because they are for magnetic materials such as cores. Therefore, appropriate metrics for high-
frequency inductive components for DC-to-DC converter are crucial. This document introduces
a method for measuring the loss of high frequency inductive components when an alternating
current corresponding to the actual drive is applied.
This document is one of the IEC 62024 series of standards for high-frequency inductive parts.
This document specifies the test method and a measuring jig for accurately comparing AC
losses of high-frequency inductive components for DC-to-DC converters by sinusoidal wave
current. This document also presents measuring principles, application ranges, and attentions
of each method. Two different measurement methods with different ranges of measurement
frequencies are presented. AC losses are measured by setting the frequency, the magnitude of
the current, and the DC bias current.
The inductor current used in a DC-to-DC converter is a triangular wave, and the inductor loss
depends on the shape of the triangular wave in addition to the current, frequency, and DC bias
current. Therefore, the loss value measured by the measurement method using the sinusoidal
current in this document does not necessarily match the inductor loss of the DC-to-DC converter,
even if the same effective current is used. The measurement results are described in Annex A.
In the future, a separate standard defining the triangular current drive testing can be developed
for publication.
1 Scope
This part of IEC 62024 specifies test methods for AC losses of high-frequency inductive
components for power supplies used in DC-to-DC converters and similar devices at currents
close to actual operation and introduces the measurement principle, scope of application and
matters to be noted for each method. This document is applicable to leaded and surface mount
inductors with dimensions in accordance with IEC 62024-2.
2 Normative references
There are no normative references in this document.
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 Select measuring method
This document covers two methods for measuring AC losses of inductors at high currents: the
digitizing method using cross-power spectrum calculation, herein referred to as the cross-power
method, which is suitable for low frequencies, and the amplified vector network analyzer method,
using S-parameter which is suitable for high frequencies.
Table 1 shows the frequency range and impedance range for each measurement method. The
recommended connection method for the amplified network analyzer method varies depending
on the impedance range to be measured.
Table 1 – AC loss measuring method
Measuring method Connection method Frequency range Impedance range
Cross-power method - 10 kHz to 10 MHz 0,1 Ω to 10 kΩ
Amplified vector network analyzer Shunt through 100 kHz to 200 MHz 1 Ω to 100 Ω
method
Series through 100 kHz to 200 MHz 10 Ω to 10 kΩ

5 Cross-power method
5.1 General
The cross-power method is one of the multiplying methods. By sampling and detecting voltage
and current signals, performing FFT (Fast Fourier Transform) processing and calculating, it is
possible to measure the inductor loss accurately, including harmonic components generated by
the inductor nonlinearity. The cross-power method conforms to IEC 62044-3.
5.2 Measuring method
5.2.1 Measuring circuit
One way of measuring circuit is shown in Figure 1. The sinusoidal signal for measuring is
generated by measuring instruments (MI), amplified to the required AC current by an excitation
source (ES), and applied to the device under test (DUT). The AC voltage waveform gen
...