IEC 63093-9:2020

IEC 63093-9 ®
Edition 1.0 2020-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Ferrite cores – Guidelines on dimensions and the limits of
surface irregularities –
Part 9: Planar-cores
Noyaux ferrites – Lignes directrices relatives aux dimensions
et aux limites des irrégularités de surface –
Partie 9: Noyaux planaires
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IEC 63093-9 ®
Edition 1.0 2020-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Ferrite cores – Guidelines on dimensions and the limits of

surface irregularities –
Part 9: Planar-cores
Noyaux ferrites – Lignes directrices relatives aux dimensions

et aux limites des irrégularités de surface –

Partie 9: Noyaux planaires
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.100.10 ISBN 978-2-8322-8080-5

– 2 – IEC 63093-9:2020 © IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Primary dimensions . 7
4.1 Planar shapes and dimensions . 7
4.2 Dimensions and effective parameters of planar EL-core and mating PLT-core . 8
4.3 Dimensions and effective parameters of low-profile E-core and mating PLT-
core . 10
4.4 Dimensions and effective parameters of low-profile ER-core and mating
PLT-core . 12
5 Limits of surface irregularities . 15
5.1 General . 15
5.2 Examples of surface irregularities . 16
5.3 Chips and ragged edges . 17
5.3.1 General . 17
5.3.2 Chips and ragged edges on the mating surfaces . 17
5.3.3 Chips and ragged edges on other surfaces . 18
5.4 Cracks . 20
5.5 Flash . 20
5.6 Pull-outs . 20
5.7 Crystallites . 24
5.8 Pores . 24
Annex A (normative) Low-profile core design . 26
A.1 General design . 26
A.2 EL-core design . 26
A.3 ER-core design . 27
Annex B (informative) Reference values of allowable areas of chips . 29
Bibliography . 31

Figure 1 – Planar EL-core and mating PLT-core. 8
Figure 2 – Low-profile E-core and mating PLT-core . 10
Figure 3 – Low-profile ER-core and mating PLT-core . 12
Figure 4 – Examples of surface irregularities for planar EL-core . 16
Figure 5 – Examples of surface irregularities for low-profile E-core . 16
Figure 6 – Examples of surface irregularities for low-profile ER-core. 16
Figure 7 – Chip location for planar EL-core . 17
Figure 8 – Chip location for low-profile E-core . 17
Figure 9 – Chip location for low-profile ER-core . 17
Figure 10 – Cracks and pull-out location for planar EL-core . 20
Figure 11 – Cracks and pull-out location for low-profile E-core . 21
Figure 12 – Cracks and pull-out location for low-profile ER-core . 21
Figure 13 – Reference dimensions for EL-core . 21

Figure 14 – Reference dimensions for E-core . 22
Figure 15 – Reference dimensions for ER-core . 23
Figure 16 – Example of the location of a crystallite on planar EL-core . 24
Figure 17 – Example of the location of a crystallite on low-profile E-core . 24
Figure 18 – Example of the location of a crystallite on low-profile ER-core . 24
Figure 19 – Example of the location of a pore on planar EL-core . 25
Figure 20 – Example of the location of a pore on low-profile E-core . 25
Figure 21 – Example of the location of a pore on low-profile ER-core . 25

Table 1 – Dimensions of planar EL-core EL and mating PLT-core . 9
Table 2 – Effective parameter values and A values . 10
min
Table 3 – Dimensions of low-profile E-core and mating PLT-core . 11
Table 4 – Effective parameter values and A values . 12
min
Table 5 – Dimensions of low-profile ER-core and mating PLT-core . 13
Table 6 – Effective parameter values and A values . 14
min
Table 7 – Area and length reference for visual inspection . 19
Table 8 – Limits of cracks for planar EL-core . 22
Table 9 – Limits of cracks for low-profile E-core . 23
Table 10 – Limits of cracks for low-profile ER-core . 23
Table A.1 – Sizes and design ratios for ER-core . 28
Table B.1 – Allowable areas of chips for planar EL-core . 29
Table B.2 – Allowable areas of chips for low-profile E-core . 29
Table B.3 – Allowable areas of chips for low-profile ER-core. 30

– 4 – IEC 63093-9:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FERRITE CORES – GUIDELINES ON DIMENSIONS AND
THE LIMITS OF SURFACE IRREGULARITIES –

Part 9: Planar-cores
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
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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.
International Standard IEC 63093-9 has been prepared by IEC technical committee 51:
Magnetic components, ferrite and magnetic powder materials.
This first edition cancels and replaces the first edition of IEC 60424-5 published in 2009 and
first edition of IEC 62317-9 published in 2006 and its Amendment 1:2007. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
editions of IEC 60424-5 and IEC 62317-9:
a) IEC 63093-9 integrates IEC 60424-5 and IEC 62317-9;
b) Table 1, Table 2 and Table 3 in IEC 60424-5:2009 have been moved to Annex B;
c) some numbers are corrected in Table 4;
d) Table 6 is amended following IEC 60205.

The text of this International Standard is based on the following documents:
CDV Report on voting
51/1308/CDV 51/1326/RVC
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 63093 series, published under the general title Ferrite cores –
Guidelines on dimensions and the limits of surface irregularities, 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 "http://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.
– 6 – IEC 63093-9:2020 © IEC 2020
INTRODUCTION
Today, DC-to-DC converter power supplies increasingly employ transformers and chokes, the
windings of which are made of multi-layer printed circuit boards or are constructed in the
motherboard, rather than the transformers wound by conventional copper wires. This
document specifies the optimum shapes and dimensions of cores for surface mounted devices
(SMDs) and of cores for which the windings are constructed in the motherboard. The
motherboard has slots cut out to accept the ferrite cores. This is called the total integration in
a multi-layer motherboard. The core shape specified in this document satisfies the demand for
lower profile as well as for smaller floor space.
The relations between the main dimensions of planar E-, ER- and EL-cores differ from those
of standard cores. For example, the width of planar-cores is larger while the total height is
much smaller. Also the thickness of the legs is in most cases smaller than compared to
standard cores. Therefore the concept of fixed reference dimensions to determine the length
of crack limits yields crack lengths which are not acceptable for this type of core. This
document follows another concept which relates the crack length to dimensions of the surface
on which the crack occurs.
Also the concept to determine the maximum area of chips based on the total mating surface
fails in the case of planar-cores. The outer legs of planar-cores are much thinner than those
of standard cores which makes overlapping and gluing much more difficult. A single chip of
maximum size on the outer leg can affect the functionality of the core set. Therefore this
document uses as a reference the mating surface on which the chip occurs.
Windings of planar-cores are often PCBs which are glued to the inner surfaces of the planar-
core. For this reason the inner surfaces of the planar-cores should have a better quality than
the inner surfaces of standard cores. This was taken into account by reducing the maximum
allowable area of pull-outs in the inner surfaces.

FERRITE CORES – GUIDELINES ON DIMENSIONS AND
THE LIMITS OF SURFACE IRREGULARITIES –

Part 9: Planar-cores
1 Scope
This part of IEC 63093 specifies the shapes and dimensions of ferrite cores for inductive
components (transformers and chokes), whose the coil is typically made of multi-layer boards
(or the coil is part of the motherboard), and the effective parameter values used in
calculations. This document gives guidelines on allowable limits of surface irregularities
applicable to planar-cores as well.
This document is considered as a sectional specification useful in the negotiation between
ferrite core suppliers and users about surface irregularities.
The general consideration upon which the design of this range of cores is based is given in
Annex A.
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 60205:2016, Calculation of the effective parameters of magnetic piece parts
IEC 60401-1, Terms and nomenclature for cores made of magnetically soft ferrites – Part 1:
Terms used for physical irregularities
IEC 60424-1, Ferrite cores – Guidelines on the limits of surface irregularities – Part 1:
General specification
3 Terms and definitions
For the purpose of this document, the terms and definitions given in IEC 60401-1 and
IEC 60424-1 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 Primary dimensions
4.1 Planar shapes and dimensions
The main shapes and dimensions shall be as given in the following figures and tables.
The main shapes, dimensions, and parameters for EL-cores are given in:

– 8 – IEC 63093-9:2020 © IEC 2020
• Figure 1 – Planar EL-core- and mating PLT-core;
• Table 1 – Dimensions of planar EL-core and mating PLT-core;
• Table 2 – Effective parameter values and A values.
min
The main shape, dimensions, and parameters for low-profile E-cores are given in:
• Figure 2 – Low-profile E-core and mating PLT-core;
• Table 3 – Dimensions of low-profile E-core and mating PLT-core;
• Table 4 – Effective parameter values and A values.
min
The main shape, dimensions, and parameters for ER-cores are given in:
• Figure 3 – Low-profile ER-core and mating PLT-core;
• Table 5 – Dimensions of low-profile ER-core and mating PLT-core;
• Table 6 – Effective parameter values and A values.
min
A uniform dimensional nomenclature has been chosen in order to facilitate a comparison of
major physical attributes among the different core shapes.
4.2 Dimensions and effective parameters of planar EL-core and mating PLT-core
For the definitions of effective parameters and their calculations, reference shall be made to
IEC 60205.
Figure 1 – Planar EL-core and mating PLT-core

Table 1 – Dimensions of planar EL-core EL and mating PLT-core
Dimensions in millimetres
Size A B B C D E F F R
1 2 1 2 2
10,80 1,91 8,60 0,90 8,97 2,68 6,25
0,3
EL11 × 2,0     min.
11,20 2,11 9,00 1,10 9,37 2,88 6,55
max.
EL11 × 3,0     min. 10,80 2,91 8,60 1,90 8,97 2,68 6,25
0,3
max. 11,20 3,11 9,00 2,10 9,37 2,88 6,55
PLT11 × 1,0    min. 10,80 0,96 8,60

max. 11,20 1,06 9,00
EL13 × 2,2     min. 12,75 2,09 10,20 0,90 10,63 3,19 7,41
0,3
max. 13,25 2,29 10,60 1,10 11,03 3,39 7,71
EL13 × 3,2     min. 12,75 3,09 10,20 1,90 10,63 3,19 7,41
0,3
max. 13,25 3,29 10,60 2,10 11,03 3,39 7,71
PLT13 × 1,2    min. 12,75 1,14 10,20

max. 13,25 1,24 10,60
EL15,5 × 2,9   min. 15,20 2,82 12,15 1,40 12,67 3,82 8,81
0,3
max. 15,80 3,02 12,65 1,60 13,17 4,02 9,21
EL15,5 × 4,4   min. 15,20 4,32 12,15 2,90 12,67 3,82 8,81
0,3
max. 15,80 4,52 12,65 3,10 13,17 4,02 9,21
PLT15,5 × 1,4  min. 15,20 1,32 12,15

max. 15,80 1,52 12,65
EL18 × 3,7     min. 17,70 3,55 14,15 1,90 14,70 4,45 10,27
0,3
max. 18,30 3,75 14,65 2,10 15,30 4,65 10,67
EL18 × 5,7     min. 17,70 5,55 14,15 3,85 14,70 4,45 10,27
0,3
max. 18,30 5,75 14,65 4,15 15,30 4,65 10,67
PLT18 × 1,7    min. 17,70 1,55 14,15

max. 18,30 1,75 14,65
EL20 × 3,8     min. 19,65 3,73 15,70 1,90 16,37 4,91 11,43
0,5
max. 20,35 3,93 16,30 2,10 16,97 5,21 11,83
EL20 × 5,8     min. 19,65 5,68 15,70 3,85 16,37 4,91 11,43
0,5
max. 20,35 5,98 16,30 4,15 16,97 5,21 11,83
PLT20 × 1,8   min. 19,65 1,73 15,70

max. 20,35 1,93 16,30
EL22 × 4,0     min. 21,60 3,92 17,30 1,90 17,98 5,41 12,54
0,5
max. 22,40 4,12 17,90 2,10 18,68 5,71 13,04
EL22 × 6,0    min. 21,60 5,87 17,30 3,85 17,98 5,41 12,54
0,5
max. 22,40 6,17 17,90 4,15 18,68 5,71 13,04
PLT22 × 2,0   min. 21,60 1,92 17,30

max. 22,40 2,12 17,90
EL25 × 4,3    min. 24,55 4,19 19,65 1,90 20,48 6,17 14,29
0,5
max. 25,45 4,39 20,35 2,10 21,18 6,47 14,79
EL25 × 6,3    min. 24,55 6,14 19,65 3,85 20,48 6,17 14,29
0,5
max 25,45 6,44 20,35 4,15 21,18 6,47 14,79
PLT25 × 2,3    min. 24,55 2,19 19,65

max. 25,45 2,39 20,35
– 10 – IEC 63093-9:2020 © IEC 2020
Table 2 – Effective parameter values and A values
min
a
C C l A V A
min
1 2 e e e
Size Remarks
–1 –3 2 3 2
mm mm mm mm mm mm
–3
EL-EL11 × 4,0 0,826 45 49,923 × 10 13,7 16,5 226 15,9 The
combination
–3
EL-EL13 × 4,4 0,666 66 28,815 × 10 15,4 23,1 357 22,4
EL-EL refers
–3
EL-EL15,5 × 5,8 0,596 74 18,143 × 10 19,6 32,9 646 31,9
to two shorter
height EL-
–3
EL-EL18 × 7,3 0,538 30 12,162 × 10 23,8 44,3 1 050 43,0
cores for
size-
–3
EL-EL20 × 7,7 0,468 64 8,586 6 × 10 25,6 54,6 1 400 52,9
designation.
–3
EL-EL22 × 8,0 0,412 80 6,231 4 × 10 27,3 66,2 1 810 64,2 The
combination
–3
EL-EL25 × 8,6 0,350 34 4,094 2 × 10 30,0 85,6 2 570 83,0
EL-PLT refers
–3
EL-PLT11 × 4,0 0,826 45 49,943 × 10 13,7 16,5 226 15,9
to one taller
height EL
–3
EL-PLT13 × 4,4 0,666 66 28,815 × 10 15,4 23,1 357 22,4
core paired
–3
with one PLT-
EL-PLT15,5 × 5,8 0,569 74 18,143 × 10 19,6 32,9 646 31,9
core for each
–3
EL-PLT18 × 7,3 0,538 30 12,162 × 10 23,8 44,3 1 050 43,0
size-
designation.
–3
EL-PLT20 × 7,7 0,468 64 8,586 6 × 10 25,6 54,6 1 400 52,9
–3
EL-PLT22 × 8,0 0,412 80 6,231 4 × 10 27,3 66,2 1 810 64,2
–3
EL-PLT25 × 8,6 0,350 34 4,094 2 × 10 30,0 85,6 2 570 83,0
–3
EL-PLT11 × 3,0 0,701 76 42,170 × 10 11,7 16,6 194 15,9
–3
EL-PLT13 × 3,4 0,577 71 24,857 × 10 13,4 23,2 312 22,4
–3
EL-PLT15,5 × 4,3 0,502 96 15,212 × 10 16,6 33,1 550 31,9
–3
EL-PLT18 × 5,3 0,445 54 10,011 × 10 19,8 44,5 882 43,0
–3
EL-PLT20 × 5,7 0,392 32 7,167 9 × 10 21,6 54,9 1 180 52,9
–3
EL-PLT22 × 6,0 0,350 61 5,264 5 × 10 23,4 66,6 1 560 64,2
–3
EL-PLT25 × 6,6 0,302 22 3,515 6 × 10 26,0 86,0 2 230 83,0
a
See 4.2 of IEC 60205:2016 for the definition of A .
min
4.3 Dimensions and effective parameters of low-profile E-core and mating PLT-core
For the definitions of effective parameters and their calculations, reference shall be made to
IEC 60205.
Figure 2 – Low-profile E-core and mating PLT-core

Table 3 – Dimensions of low-profile E-core and mating PLT-core
Dimensions in millimetres
Size A B B C D E F
1 2
E14 × 3,5 × 5     min. 13,70 3,40 4,90 1,90 10,75 2,95
max. 14,30 3,60 5,10 2,10 11,25 3,05
PLT14 × 1,5 × 5   min. 13,70 1,40 4,90
max. 14,30 1,60 5,10
E18 × 4 × 10     min. 17,65 3,90 9,80 1,90 13,70 3,90
max. 18,35 4,10 10,20 2,10 14,30 4,10
PLT18 × 2 × 10   min. 17,65 1,90 9,80
max. 18,35 2,10 10,20
E22 × 6 × 16     min. 21,40 5,60 15,50 3,10 16,40 4,90
max 22,20 5,80 16,10 3,30 17,20 5,10
PLT22 × 2,5 × 16  min. 21,40 2,40 15,50
max. 22,20 2,60 16,10
E32 × 6 × 20     min. 31,10 6,20 19,90 2,95 24,90 6,20
max. 32,40 6,50 20,75 3,40 26,10 6,50
PLT32 × 3 × 20   min. 31,10 3,00 19,90
max. 32,40 3,35 20,75
E38 × 8 × 25     min. 37,30 8,10 24,85 4,30 30,20 7,40
max. 38,90 8,40 25,95 4,60 31,40 7,80
PLT38 × 4 × 25   min. 37,30 3,65 24,85
max. 38,90 3,95 25,95
E43 × 10 × 28    min. 42,30 9,35 27,30 5,25 34,70 7,90
max. 44,10 9,65 28,50 5,55 36,30 8,30
PLT43 × 4 × 28   min. 42,30 3,95 27,30
max. 44,10 4,25 28,50
E58 × 11 × 38    min. 57,20 10,35 37,30 6,35 50,00 7,90
max. 59,60 10,75 38,90 6,65 52,20 8,30
PLT58 × 4 × 38   min. 57,20 3,85 37,30
max. 59,60 4,25 38,90
E64 × 10 × 50    min. 62,70 10,05 49,70 4,95 52,50 10,00
max. 65,30 10,35 51,90 5,25 54,70 10,40
PLT64 × 5 × 50   min. 62,70 4,95 49,70
max. 65,30 5,25 51,90
E102 × 20 × 38   min. 100,0 20,10 36,50 12,90 85,00 13,70
max. 104,0 20,50 38,50 13,40 88,60 14,30
PLT102 × 7 × 38  min. 100,0 6,95 36,50
max 104,0 7,35 38,50
– 12 – IEC 63093-9:2020 © IEC 2020
Table 4 – Effective parameter values and A values
min
a
C C l A V A
min
1 2 e e e
Size Remarks
–1 –3 2 3 2
mm mm mm mm mm mm
–3
E-E14 1,380 8 92,055 × 10 20,7 15,0 311 15,0 Combination
–3
E-E
E-E18 0,607 08 15,177 × 10 24,3 40,0 971 40,0
–3
E-E22 0,410 81 5,200 1 × 10 32,5 79,0 2 560 79,0
–3
E-E32 0,324 85 2,525 5 × 10 41,8 129 5 370 127
–3
E-E38 0,276 13 1,443 9 × 10 52,8 191 10 100 185
–3
E-E43 0,274 13 1,219 7 × 10 61,6 225 13 800 215
–3
E-E58 0,269 43 0,893 10 × 10 81,3 302 24 500 278
–3
E-E64 0,153 67 0,295 56 × 10 79,9 520 41 500 518
–3
E-E102 0,273 88 0,506 86 × 10 148 540 80 000 525
–3
E-PLT14 1,114 2 74,277 × 10 16,7 15,0 251 15,0 Combination
–3
E-PLT18 0,507 08 12,677 × 10 20,3 40,0 811 40,0 E-PLT
–3
E-PLT22 0,329 80 4,174 6 × 10 26,1 79,0 2 060 79,0
–3
E-PLT32 0,275 28 2,138 6 × 10 35,4 129 4 560 127
–3
E-PLT38 0,229 08 1,195 0 × 10 43,9 192 8 420 185
–3
E-PLT43 0,225 10 0,996 95 × 10 50,8 226 11 500 214
–3
E-PLT58 0,225 00 0,740 83 × 10 68,3 304 20 800 278
–3
E-PLT64 0,134 18 0,258 30 × 10 70,0 519 36 200 518
–3
E-PLT102 0,225 76 0,418 68 × 10 122 539 65 600 525
NOTE Values ignore the effect of radii. These can have some influence on the outcome of the calculation. They
can be incorporated in the formulae as shown in IEC 60205.
a
See 4.2 of IEC 60205:2016 for the definition of A .
min
4.4 Dimensions and effective parameters of low-profile ER-core and mating PLT-core
For the definitions of effective parameters and their calculations, reference shall be made to
IEC 60205.
Figure 3 – Low-profile ER-core and mating PLT-core

Table 5 – Dimensions of low-profile ER-core and mating PLT-core
Dimensions in millimetres
Size A B B C D E F G
1 2
ER9,5 × 2,5 × 5   min. 9,15 2,375 4,80 1,60 7,50 3,25 7,00
max. 9,55 2,525 5,00 1,75 7,75 3,55 7,40
PLT9,5 × 1 × 5    min. 9,15 0,70 4,80

max. 9,55 0,85 5,00
ER11 × 2,5 × 6    min. 10,65 2,375 5,80 1,50 8,70 4,00 7,90
max. 11,00 2,525 6,00 1,65 9,00 4,25 8,30
PLT11 × 1 × 6    min. 10,65 0,80 5,80

max. 11,00 0,95 6,00
ER13 × 3 × 9     min. 12,5 2,775 8,45 1,625 10,9 4,85 8,75
max. 13,1 2,925 8,95 1,875 11,5 5,15 9,35
PLT13 × 1 × 9    min. 12,5 1,00 8,45

max. 13,1 1,20 8,95
ER14,5 × 3 × 7    min. 14,30 2,90 6,60 1,55 11,6 4,60 11,6
max. 14,70 3,00 6,80 1,75 12,0 4,80 12,0
PLT14,5 × 1 × 7  min. 14,30 1,20 6,60

max. 14,70 1,40 6,80
ER18 × 3 × 10    min. 17,65 3,05 9,5 1,50 15,3 6,05 13,5
max. 18,35 3,25 9,9 1,70 15,9 6,35 14,1
PLT18 × 1,5 × 10  min. 17,65 1,45 9,5

max. 18,35 1,65 9,9
ER20 × 6 × 14 min. 19,65 6,20 13,7 3,95 17,65 8,65 12,51
max. 20,35 6,40 14,3 4,25 18,35 8,95 13,21
PLT20 × 2 × 14 min. 19,65 2,25 13,7

max. 20,35 2,35 14,3
ER23 × 3,6 × 13  min. 22,75 3,50 12,25 1,50 19,8 7,8 17,5
max. 23,65 3,70 12,75 1,70 20,6 8,2 18,2
ER23 × 5 × 13   min. 22,75 5,00 12,25 3,00 19,8 7,8 17,5
max. 23,65 5,20 12,75 3,20 20,6 8,2 18,2
PLT23 × 2 × 13   min. 22,75 1,90 12,25
max. 23,65 2,10 12,75
ER25 × 8 × 18    min. 24,6 7,90 17,7 5,00 21,6 10,8 14,5
max. 25,4 8,10 18,3 5,30 22,4 11,2 14,9
PLT25 × 3 × 18   min. 24,6 2,75 17,7
max. 25,4 2,95 18,3
ER25 × 6 × 15    min. 24,5 5,40 14,5 3,00 21,3 9,20 18,3
max. 25,5 5,60 15,1 3,20 22,1 9,60 18,7
PLT25 × 2,4 × 15 min. 24,5 2,30 14,5
max. 25,5 2,50 15,1
ER25 × 6 × 18    min. 24,6 5,55 17,7 3,05 21,6 10,8 14,5
max. 25,4 5,65 18,3 3,35 22,4 11,2 14,9
PLT25 × 2 × 18   min. 24,6 2,35 17,7
max. 25,4 2,45 18,3
– 14 – IEC 63093-9:2020 © IEC 2020
Size A B B C D E F G
1 2
ER30 × 8 × 20    min. 29,6 7,85 19,7 5,10 25,6 10,8 19,05
max. 30,4 8,15 20,3 5,50 26,4 11,2 19,85
PLT30 × 3 × 20   min. 29,6 2,60 19,7
max. 30,4 2,80 20,3
ER32 × 5 × 21 min. 31,4 5,00 20,6 2,6 29,2 11,0 23,0
max. 32,6 5,20 21,4 2,8 30,2 11,4 24,2
PLT32 × 2 × 21 min. 31,4 2,3 20,6
max. 32,6 2,5 21,4
ER32 × 6 × 25    min. 31,65 5,84 25,0 2,65 26,8 12,15 26,8
max. 32,75 6,13 25,8 2,91 27,6 12,55 27,6
PLT32 × 3 × 25   min. 31,65 3,14 25,0
max. 32,75 3,34 25,8
ER35 × 10 × 26   min. 34,6 9,90 25,6 5,00 29,6 14,1 26,4
max. 35,4 10,1 26,4 5,30 30,4 14,7 27,5
PLT35 × 5 × 26   min. 34,6 4,75 25,6
max. 35,4 4,95 26,4
ER40 × 10 × 28   min. 39,6 9,90 27,6 5,00 34,6 14,6 31,5
max. 40,4 10,1 28,4 5,30 35,4 15,2 32,5
PLT40 × 5 × 28   min. 39,6 4,75 27,6
max. 40,4 4,95 28,4
Table 6 – Effective parameter values and A values
min
a
C C l A V A
min
1 2 e e e
Size Remarks
–1 –3 2 3 2
mm mm mm mm mm mm
–3
ER9,5 × 2,5 × 5 1,749 4 206,64 × 10 14,8 8,47 125 7,60 Combination
–3
ER11 × 2,5 × 6 1,310 6 111,23 × 10 15,4 11,8 182 10,3 ER-ER
–3
ER13 × 3 × 9 0,926 09 46,376 × 10 18,5 20,0 369 19,1
–3
ER14,5 × 3 × 7 1,133 5 64,620 × 10 19,9 17,5 349 17,3
–3
ER18 × 3 × 10 0,746 41 24,539 × 10 22,7 30,4 691 30,1
–3
ER20 × 6 × 14 0,578 88 9,741 4 × 10 34,4 59,4 2 040 55,4
–3
ER23 × 3,6 × 13 0,545 25 10,828 × 10 27,5 50,4 1 380 50,0
–3
ER23 × 5 × 13 0,660 31 13,059 × 10 33,4 50,6 1 690 50,0
–3
ER25 × 6 × 15 0,497 16 7,030 4 × 10 35,2 70,7 2 490 69,4
–3
ER25 × 6 × 18 0,374 11 4,070 1 × 10 34,4 91,9 3 160 86,4
–3
ER30 × 8 × 20 0,440 78 4,094 1 × 10 47,5 108 5 110 95,0
–3
ER32 × 5 × 21 0,400 06 3,985 5 × 10 40,2 100 4 030 98,5
–3
ER32 × 6 × 25 0,300 89 2,099 3 × 10 43,1 143 6 180 121
–3
ER35 × 10 × 27 0,274 12 1,372 5 × 10 54,7 200 10 900 163
–3
ER40 × 10 × 28 0,272 71 1,254 8 × 10 59,3 217 12 900 174

a
C C l A V A
min
1 2 e e e
Size Remarks
–1 –3 2 3 2
mm mm mm mm mm mm
–3
ER9,5 × 2,5 × 5 / 1,394 3 168,95 × 10 11,5 8,25 95,0 7,60 Combination
PLT9,5 × 1 × 5
ER-PLT
–3
ER11 × 2,5 × 6 / 1,082 4 94,686 × 10 12,4 11,4 141 10,3
PLT11 × 1 × 6
–3
ER13 × 3 × 9 / 0,760 78 38,520 × 10 15,0 19,8 297 19,1
PLT13 × 1 × 9
–3
ER14,5 × 3 × 7/ 0,947 19 54,097 × 10 16,6 17,5 290 17,3
PLT14,5 × 1 × 7
–3
ER18 × 3 × 10 / 0,643 27 21,212 × 10 19,5 30,3 592 30,1
PLT18 × 1,5 × 10
–3
ER20 × 6 × 14 / 0,433 67 7,153 7 × 10 26,3 60,6 1 590 55,4
PLT20 × 2 × 14
–3
ER23 × 3,6 × 13 / 0,480 86 9,557 1 × 10 24,2 50,3 1 220 50,0
PLT23 × 2 × 13
–3
ER23 × 5 × 13 / 0,539 38 10,699 × 10 27,2 50,4 1 370 50,0
PLT23 × 2 × 13
–3
ER25 × 6 × 15 / 0,413 16 5,888 5 × 10 29,0 70,2 2 030 69,4
PLT25 × 2,4 × 15
–3
ER25 × 6 × 18 / 0,309 27 3,412 1 × 10 28,0 90,6 2 540 86,4
PLT25 × 2 × 18
–3
ER30 × 8 × 20 / 0,345 32 3,210 0 × 10 37,1 108 4 000 95,0
PLT30 × 3 × 20
–3
ER32 × 5 × 21 / 34,8 100 3 490 98,5
0,346 04 3,444 8 × 10
PLT32 × 2 × 21
–3
ER32 × 6 × 25 / 0,255 65 1,731 3 × 10 37,7 148 5 570 121
PLT32 × 3 × 25
–3
ER35 × 10 × 26 / 0,214 13 1,022 2 × 10 44,9 209 9 400 163
PLT35 × 5 × 26
–3
ER40 × 10 × 28 / 0,216 83 0,950 50 × 10 49,5 228 11 300 174
PLT40 × 5 × 28
NOTE Values ignore the effect of radii. These can have some influence on the outcome of the calculation. They
can be incorporated in the formulae as shown in IEC 60205.
a
See 4.2 of IEC 60205:2016 for the definition of A .
min
5 Limits of surface irregularities
5.1 General
Surface irregularities are defined in IEC 60424-1.

– 16 – IEC 63093-9:2020 © IEC 2020
5.2 Examples of surface irregularities
Figure 4 shows different examples of surface irregularities for a planar EL-core.

Figure 4 – Examples of surface irregularities for planar EL-core
Figure 5 shows different examples of surface irregularities for a low-profile E-core.

Figure 5 – Examples of surface irregularities for low-profile E-core
Figure 6 shows different examples of surface irregularities for a low-profile ER-core.

Figure 6 – Examples of surface irregularities for low-profile ER-core

5.3 Chips and ragged edges
5.3.1 General
Chips and ragged edges are shown in Figure 7, Figure 8 and Figure 9.
5.3.2 Chips and ragged edges on the mating surfaces

Figure 7 – Chip location for planar EL-core

Figure 8 – Chip location for low-profile E-core

Figure 9 – Chip location for low-profile ER-core
The areas of the chips located on the mating surfaces (C1 and C1’ irregularities in Figure 7,
Figure 8 and Figure 9) shall not exceed the following limits:
– the cumulative area of the chips shall be less than 4 % of the relevant mating surface. The
mating surface of each outer leg and centre post is considered separately. The minimum
area is taken as 0,5 mm to be distinguishable to the naked eye;
– the total length of the ragged edges shall be less than 25 % of the perimeter of the
relevant mating surface.
– 18 – IEC 63093-9:2020 © IEC 2020
5.3.3 Chips and ragged edges on other surfaces
For chips and ragged edges located on the surfaces:
– the allowable chipping areas are doubled as compared to the limits for the whole mating
surfaces;
– the total length of the ragged edges shall be less than 25 % of the perimeter of the smaller
adjoining surface;
– chips and ragged edges are not acceptable on the inner edges of the wire slot area
(C2 irregularity in Figure 8 and Figure 9).
Area and length reference for visual inspection are given in Table 7. Reference values of
allowable areas of chips are given in Annex B.

Table 7 – Area and length reference for visual inspection

– 20 – IEC 63093-9:2020 © IEC 2020
5.4 Cracks
Different cracks are shown in Figure 10, Figure 11 and Figure 12. In principle three different
types of cracks can be distinguished.
a) Cracks which are parallel to the magnetic flux path (S1, S2, S5, S5’, S5’’). These cracks
are magnetically not critical. The maximum length of a single crack is 33 % (1/3) of the
dimension of the relevant surface which is parallel to the crack. In the case of multiple
cracks the maximum cumulative length doubles.
b) Cracks which are perpendicular to the magnetic flux path (S3, S3’, S3’’, S4, S4’). These
cracks are magnetically critical. They can reduce the relative cross-section of the
magnetic flux or add an additional air gap into the magnetic circuit. The maximum total
length of cracks is 20 % (1/5) of the dimension of the relevant surface which is parallel to
the crack.
c) Cracks which go from one edge to another edge (S6). These cracks can cause chipping
during the operation in the circuit. The loose particles can cause malfunctions in the circuit.
Therefore this type of crack is not acceptable in any case.
The reference dimensions are given in Figure 13, Figure 14 and Figure 15.
The limits for cracks are given in Table 8, Table 9 and Table 10.
5.5 Flash
There shall be no flash extending from the core into the wire slot.
5.6 Pull-outs
The pull-outs are applicable only for the inner surface where the PCB is seated (as shown in
Figure 10, Figure 11 and Figure 12).
For planar EL-cores, low-profile E-cores and low-profile ER-cores, the cumulative area of pull-
outs of the core shall be less than 20 % of the total respective surface area.

Figure 10 – Cracks and pull-out location for planar EL-core

Figure 11 – Cracks and pull-out location for low-profile E-core

Figure 12 – Cracks and pull-out location for low-profile ER-core

Figure 13 – Reference dimensions for EL-core

– 22 – IEC 63093-9:2020 © IEC 2020
Table 8 – Limits of cracks for planar EL-core
a b
Type Reference dimension Limits for single crack Limits for multiple cracks
S1 F 33 % (1/3) of reference dim. 66 % (2/3) of reference dim.
S2 (A-E)/2 33 % (1/3) of reference dim. 66 % (2/3) of reference dim.
S3 F 20 % (1/5) of reference dim. 20 % (1/5) of reference dim.
S3’ F 20 % (1/5) of reference dim. 20 % (1/5) of reference dim.
S3’’ C 20 % (1
...