IEC 62317-13:2008

IEC 62317-13
Edition 1.0 2008-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Ferrite cores – Dimensions –
Part 13: PQ-cores for use in power supply applications

Noyaux ferrites – Dimensions –
Partie 13: Noyaux PQ utilisés dans des applications d’alimentation électrique

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IEC 62317-13
Edition 1.0 2008-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Ferrite cores – Dimensions –
Part 13: PQ-cores for use in power supply applications

Noyaux ferrites – Dimensions –
Partie 13: Noyaux PQ utilisés dans des applications d’alimentation électrique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
P
CODE PRIX
ICS 29.100.10 ISBN 978-2-88910-668-4
– 2 – 62317-13 © IEC:2008
CONTENTS
FOREWORD.3
1 Scope.5
2 Normative references.5
3 Primary standards.5
3.1 Dimensions of PQ-cores .5
3.1.1 Principal dimensions .5
3.1.2 Effective parameter and A values .5
min
3.2 Dimensional limits for coil formers .6
3.3 Pin locations and base outlines.6
3.4 Pin diameter .6
4 Mounting .6
5 Main dimensions for coil formers.10
Annex A (informative) PQ-core design.12
Annex B (normative) An example of a gauge to check the dimensions of PQ-cores
meeting the IEC primary standard .13
Annex C (normative) Revised PQ-cores formulas in IEC 60205 Ed.3 Clause 3 .14

Figure 1 – Dimensions of PQ-cores .6
Figure 2 – Dimensions of low-profile PQI-cores .8
Figure 3 – Main dimensions of coil formers for PQ-cores .10
Figure 4 – Pin locations and base outlines viewed from the upper side of the board .11
Figure B.1 – Gauge dimensions.13
Figure C.1 – Dimensions, areas and mean lengths of flux path .14
Figure C.2 – Elemental radius and radius vector extends from F/2 to E/2 for the entire
circle.15

Table 1 – Dimensions of PQ-cores .7
Table 2 – Dimensions of low-profile PQI-cores .8
Table 3 – Effective parameter and A values for PQ-cores .9
min.
Table 4 – Effective parameter and A values for low-profile PQ-cores .9
min.
Table 5 – Main dimensions of coil formers for PQ-cores .10
Table B.1 – Gauge dimensions.13

62317-13 © IEC:2008 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FERRITE CORES –
DIMENSIONS –
Part 13: PQ-cores for use in power supply applications

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all
national electrotechnical committees (IEC National Committees). The object of the 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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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.
International Standard IEC 62317-13 has been prepared IEC technical committee 51: Magnetic
components and ferrite materials.
This bilingual version, published in 2008-09, corresponds to the English version.
The text of this standard is based on the following documents:
FDIS Report on voting
51/910/FDIS 51/925/RVD
Full information on the voting for the approval of this standard can be found in the report on voting
indicated in the above table.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

– 4 – 62317-13 © IEC:2008
A list of all parts of the IEC 62317 series, under the general title Ferrite cores – Dimensions, can
be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
62317-13 © IEC:2008 – 5 –
FERRITE CORES –
DIMENSIONS –
Part 13: PQ-cores for use in power supply applications

1 Scope
This part of IEC 62317 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of PQ-cores and low-profile PQI-cores made of ferrite,
and the locations of their terminal pins on a 2,54 mm printed wiring grid in relation to the base
outlines of the cores.
The selection of core sizes for this standard is based on the philosophy of including those sizes
which are industrial standards, either by inclusion in a national standard, or by broad-based use
in industry. See IEC 62317-1 for more detail concerning the philosophy of selecting core sizes to
be included.
The general considerations that the design of this range of cores is based upon are given in
Annex A.
2 Normative references
The following referenced documents are indispensable for the application 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, Calculation of the effective parameters of magnetic piece parts
IEC 62317-1, Ferrite cores – Dimensions – Part 1: General specification
3 Primary standards
Compliance with the following requirements ensures mechanical interchangeability of complete
assemblies and wound coil formers.
3.1 Dimensions of PQ-cores
3.1.1 Principal dimensions
The principal dimensions of PQ-cores shall be as given in Table 1 and the low-profile PQ-cores
shall be as given in Table 2. See also Figures 1 and 2.
NOTE The dimensions of the cores may be checked by means of gauges. By way of example, a possible standard for
these gauges is given in Annex B. In order to facilitate production it may be necessary to use gauges having dimensions
differing from those given in Annex B, although no relaxation of the requirements for the dimensions of the cores given
in Table 1 and in Table 2 is permitted.
3.1.2 Effective parameter and A values
min
The effective parameter values for cores having the dimensions given in 3.1.1 are as shown in
Table 3 and Table 4.
– 6 – 62317-13 © IEC:2008
3.2 Dimensional limits for coil formers
The essential dimensions of coil formers suitable for use with a pair of PQ-cores shall be as given
in Table 5. See also Figure 3.
3.3 Pin locations and base outlines
These shall be as shown in Figure 4.
3.4 Pin diameter
Coil former terminations (pins) shall be accepted by a gauge having 1,2 mm holes on true
position.
4 Mounting
Due to their sizes and respective weights, it is recommended that the three largest cores
(PQ35/35, PQ40/40 and PQ 50/50) be fixed on the printed board with mounting assemblies at two
opposite sides of their coil formers.
Concerning low-profile PQ-cores, no mounting assemblies are defined. It is recommended that
the two cores be fixed by glue or adhesive tape.

C
B
L
D
X
X
IEC  478/08
NOTE Shape variation
Clamp recesses may be available at the outside wall of the outer legs, keeping “A” dimension in Table 1 when measured
within the recesses.
Figure 1 – Dimensions of PQ-cores
A
J
F
G
E
62317-13 © IEC:2008 – 7 –
Table 1 – Dimensions of PQ-cores
A B C D E F G J L
Size
mm mm mm mm mm mm mm mm mm
PQ 20/16   Min. 20,1  8,0 13,6  5,0 17,6  8,6 12,0
Nom.    4,8 10,5
Max. 20,9  8,2 14,4  5,3 18,4  9,0 13,0
PQ 20/20   Min. 20,1 10,0 13,6  7,0 17,6  8,6 12,0
Nom.    4,8 10,5
Max. 20,9 10,2 14,4  7,3 18,4  9,0 13,0
PQ 26/20   Min.  26,05   9,95  18,55  5,6  22,05 11,8 15,5
Nom.    7,3 13,9
Max.  26,95 10,2  19,45  5,9  22,95 12,2 16,5
PQ 26/25   Min.  26,05  12,25  18,55  7,9  22,05 11,8 15,5
Nom.    7,3 13,9
8,2  22,95 12,2 16,5
Max.  26,95 12,5  19,45
PQ 32/20   Min. 31,5  10,15 21,5  5,6 27,0 13,2 19,0
Nom.    6,2 15,1
Max. 32,5 10,4 22,5  5,9 28,0 13,7 20,0
PQ 32/30   Min. 31,5  15,05 21,5 10,5 27,0 13,2 19,0
Nom.    6,2 15,1
Max. 32,5 15,3 22,5 10,8 28,0 13,7 20,0
PQ 35/35   Min. 34,5  17,25 25,5  12,35 31,5 14,1 23,5
Nom.    7,3 16,4
Max. 35,7 17,5 26,5  12,65 32,5 14,6 24,5
PQ 40/40   Min. 39,6  19,75 27,4 14,6 36,4 14,6 28,0
Nom.    7,75 16,8
Max. 41,4 20,0 28,6 14,9 37,6 15,2 29,0
PQ 50/50   Min. 49,3  24,85 31,5 17,9 43,3  19,65 31,5
Nom.    10,0 22,0
18,2 44,7  20,35 32,5
Max. 50,7 25,1 32,5
– 8 – 62317-13 © IEC:2008
C
B
L
B
C 2
D
X
X
IEC  479/08
NOTE Shape variation
Clamp recesses may be available at the outside wall of the outer legs, keeping “A” dimension in Table 2 when measured
within the recesses.
Figure 2 – Dimensions of low-profile PQI-cores
Table 2 – Dimensions of low-profile PQI-cores
B C D E F G J L
A B1 2
Size
mm mm mm  mm Mm mm mm mm mm mm
PQI 16/7.8  Min. 16,1 5,3 2,25 10,9 2,9 14,1  6,8  9,6
Nom.     3,9 8,4
Max. 16,7 5,5 2,45 11,5 3,2 14,7  7,2 10,4
PQI 20/9   Min. 20,1 5,9 2,85 13,6 2,9 17,6  8,6 12,0
Nom.     4,8 10,5
Max. 20,9 6,1 3,05 14,4 3,2 18,4  9,0 12,5
PQI 26/12  Min.  26,05 7,2 4,10  18,55  2,95  22,05 11,8 15,5
Nom.     7,3 13,9
Max.  26,95 7,4 4,30  19,45  3,25  22,95 12,2 16,5

A
J
F
G
E
A
62317-13 © IEC:2008 – 9 –
Table 3 – Effective parameter and A values for PQ-cores
min
a
C C A l V
A
min
1 2 e e e
Size
–1 -3 –3 2 3
mm mm
mm × 10 mm mm mm
PQ 20/16 0,580 53   9,034 6   64,3  37,3   2 400   59,3
PQ 20/20 0,709 95 11,129   63,8  45,3   2 890   59,3
PQ 26/20 0,361 41   2,932 5 123  44,5   5 490  113
PQ 26/25 0,437 38   3,569 9 123  53,7   6 590  113
PQ 32/20 0,313 14   2,001 2 157  49,0   7 670  142
PQ 32/30 0,440 40   2,833 3 155  68,5  10 600  142
PQ 35/35 0,465 38   2,718 8 171  79,7  13 600  161
PQ 40/40 0,491 97   2,602 7 189  93,0  17 600  174
PQ 50/50 0,342 34   1,032 6 332 113  37 600  314
a
See 2.2 of IEC 60205.
Table 4 – Effective parameter and A values for low-profile PQ-cores
min
a
C C A l V
A
min
1 2 e e e
Size
–1 –3 –3 3
mm mm mm
mm × 10 mm mm
PQI 16/7.8 0,466 78 11,185   41,7 19,5  814   37,4
PQI 20/9 0,345 95   5,238 7   66,0 22,8 1 510   59,3
PQI 26/12 0,224 03   1,814 3 123 27,7 3 420  110
a
See 2.2 of IEC 60205.
– 10 – 62317-13 © IEC:2008
5 Main dimensions for coil formers

H
q H
b
IEC  480/08
Figure 3 – Main dimensions of coil formers for PQ-cores
Table 5 – Main dimensions of coil formers for PQ-cores
D D D H H a b q
1 2 3 1 2
mm mm mm
Size
mm mm mm mm mm
Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Max. Max. Min.
PQ 20/16 17,05 17,45 10,85 11,05 9,05 9,25 9,6 9,95 8,55 9,2 23,35 23,35 6,1
PQ 20/20 17,05 17,45 10,85 11,05 9,05 9,25 13,6 13,95 12,55 13,2 23,35 23,35 6,1
PQ 26/20 21,35 21,85 14,15 14,45 12,25 12,55 10,8 11,15 9,75 10,4 26,95 29,65 6,1
PQ 26/25 21,35 21,85 14,15 14,45 12,25 12,55 15,4 15,75 14,35 15 26,95 29,65 6,1
PQ 32/20 26,35 26,85 15,85 16,15 13,85 14,15 10,8 11,15 9,65 10,3 32,35 34,35 6,6
PQ 32/30 26,35 26,85 15,85 16,15 13,85 14,15 20,35 20,95 19,2 20,1 32,35 34,35 6,6
PQ 35/35 30,85 31,35 16,65 17,05 14,75 15,05 24,05 24,7 22,9 23,95 35,55 39,45 7,1
PQ 40/40 35,75 36,25 17,35 17,65 15,45 15,75 28,55 29,05 27,4 28,2 40,45 42,45 6,1
PQ 50/50 42,65 43,15 22,95 23,45 20,55 21,05 34,75 35,25 33,5 34,3 51,25 51,25 9,6

D
D
a
D
62317-13 © IEC:2008 – 11 –
PQ 20/16
PQ 26/20
PQ 32/20
PQ 20/20
PQ 26/25
PQ 32/30
PQ 35/35
PQ 40/40
2,54 mm grids
PQ 50/50
IEC  481/08
Figure 4 – Pin locations and base outlines viewed from the upper side of the board

– 12 – 62317-13 © IEC:2008
Annex A
(informative)
PQ-core design
A.1 General
The design of PQ-cores standardized by the IEC is based on the following considerations:
a) minimize design “q” (l /A × l /A ) with a uniform cross-section area of each magnetic path;
e e w w
where
l is the average length of turns;
w
A is the available winding cross-section;
w
one useful way to consider ferrite core design is by evaluating the design factor “q”. Minimize
“q” results in the highest inductance and lowest copper losses in the transformer or inductor.
PQ-core dimensions in IEC 62317-13 are based on this type of design philosophy;
b) get more transmission power from the transformer assembly or real estate compared with
similar size cores;
c) be able to take out innermost wire without crossing other wires;
There are no base plates on the sides of the centre pole area. The innermost wire in the coil
can be taken out directly, making it easier to support the specified withstand voltage of
transformers;
d) the outside legs cover the coil former more than E-cores;
PQ-cores cover the coil former more than 40 %, resulting in a good magnetic shielding effect.

62317-13 © IEC:2008 – 13 –
Annex B
(normative)
An example of a gauge to check the dimensions of
PQ-cores meeting the IEC primary standard
B.1 General
The gauges shall be in accordance with Figure B.1 and Table B.1.

b
c
d
IEC  482/08
Figure B.1 – Gauge dimensions
Table B.1 – Gauge dimensions
a b c d e f
Size mm mm mm mm mm mm
Min. Max. Min. Max. Min. Max. Min. Min. Max. Min. Max.
PQ 16 16,705 16,715 7,5 7,6 11,505 11,515 2,90 14,085 14,095 7,205 7,215
PQ 20 20,905 20,915 12,2 12,3 14,405 14,415 5,00 17,585 17,595 9,005 9,015
PQ 26 26,955 26,965 14,5 14,6 19,455 19,465 5,60 22,035 22,045 12,205 12,215
PQ 32 32,505 32,515 17,3 17,4 22,505 22,515 5,60 26,985 26,995 13,705 13,715
PQ 35 35,705 35,715 19,5 19,6 26,505 26,515 12,35 31,485 31,495 14,605 14,615
PQ 40 41,405 41,415 22,0 22,1 28,605 28,615 14,60 36,385 36,395 15,205 15,215
PQ 50 50,705 50,715 27,1 27,2 32,505 32,515 17,90 43,285 43,295 20,355 20,365

B.2 Procedure and requirements
To check the winding space, the gauge shall be fully inserted into the core without forcing; when
fully inserted, the gauge shall meet the mating surface of the outer legs of a core under test.
f
e
a
– 14 – 62317-13 © IEC:2008
Annex C
(normative)
Revised PQ-cores formulas in IEC 60205, Ed.3, Clause 3

C.1 Pair of PQ-cores
NOTE 1 This calculation ignores the effect of spring recesses.
NOTE 2 PQ+PLT (Plate)-cores use PQ core formulas.

’
”
A A l
8 4
7 l
α
l
β 3
l
max
’
”
l
l
A
L
A /2
l
h
D
C
B
IEC  483/08
Figure C.1 – Dimensions, areas and mean lengths of flux path

Area of outer leg:
βE 1
A = C(A − G) − + GI
2 2
where
G
⎛ ⎞
β = arccos
⎜ ⎟
E
⎝ ⎠
I = E sin β
Mean length of flux path at outer leg:
l = 2D
A
l
min
J
G
F
E
”
l
’
l
62317-13 © IEC:2008 – 15 –
Core factors associated with l :
For l , A the elemental radius dr shown in Figure C.2 is elemental length of the flux path in the
2 2
integral below. The radius vector extends from F/2 to E/2 for the entire circle. The effective length
l for the section is multiplied by f. The area is the physical area multiplied by K.
2i
r
dr
IEC  484/08
Figure C.2 – Elemental radius and radius vector extends from F
...