EN IEC 60122-2:2025
(Main)Quartz crystal units of assessed quality - Part 2: Guidelines for the use
Quartz crystal units of assessed quality - Part 2: Guidelines for the use
IEC 60122-2:2025 has been compiled in response to a generally expressed desire on the part of both users and manufacturers for guidelines to the use of quartz crystal units for filters and oscillators so that the crystal units may be used to their best advantage. It draws attention to some of the more fundamental questions which will be considered by the user before it places its order for a unit for a new application, and in so doing will, it is hoped, help ensure against unsatisfactory performance, unfavourable cost and non-availability. It is not the function of this document to explain theory, nor to attempt to cover all the eventualities that can arise in practical circumstances. Lastly, it it is not considered as a substitute for close liaison between manufacturer and user. Standard specifications, such as those of the IEC of which these guidelines form a part, and national specifications or detail specifications issued by manufacturers, will define the available combinations of the resonant characteristics and the temperature characteristic. These specifications are compiled to include a wide range of quartz crystal units with standardized performances. It cannot be over-emphasized that it is the responsibility of the user , wherever possible, to select the quartz crystal units from these specifications, when available, even if it can lead to making small modifications to the circuit to enable the use of standard resonators. This applies particularly to the selection of the nominal frequency. This edition includes the following significant technical changes with respect to the previous edition: a) addition of SC cut type and related requirements; b) addition of ageing calculation and low level of drive requirements according to the general specification, c) update of the frequency temperature curve according to the common cut requirements; d) removal of infrequently used product types.
Schwingquarze mit bewerteter Qualität - Teil 2: Leitlinien zur Anwendung
Résonateurs à quartz sous assurance de la qualité - Partie 2: Lignes directrices pour l’utilisation
L’IEC 60122-2:2025 a été établie pour répondre à un désir généralement exprimé, tant par les utilisateurs que par les fabricants, de disposer de lignes directrices pour l’emploi des résonateurs à quartz destinés aux oscillateurs et aux filtres, afin qu’ils puissent être utilisés au mieux. Elle attire l’attention sur quelques-unes des questions fondamentales auxquelles l’utilisateur réfléchit avant de commander un résonateur pour une application nouvelle et il est à espérer, ce faisant, qu’il contribue à assurer un fonctionnement satisfaisant, un coût favorable et une disponibilité commerciale. Le présent document n’a pas pour but de développer des notions théoriques ni de couvrir tous les cas qui peuvent se poser en pratique; enfin, il ne saurait se substituer à une liaison étroite entre fabricant et utilisateur. Les spécifications de normes, telles que celles de l’IEC dont les présentes lignes directrices font partie, et les spécifications nationales ou les spécifications particulières publiées par les fabricants définissent les combinaisons possibles des caractéristiques de résonance et de température. Ces spécifications sont compilées pour inclure une large gamme de résonateurs à quartz avec des performances normalisées. Il faut toujours insister sur le fait qu’il incombe à l’utilisateur de choisir ses résonateurs à quartz, dans la mesure du possible, à l’aide de ces spécifications lorsqu’elles sont disponibles même si cela peut impliquer des modifications mineures du circuit pour permettre l’utilisation de résonateurs à quartz normaux. Ceci s’applique en particulier à la sélection de la fréquence nominale. Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente: a) ajout du type de coupe SC et des exigences correspondantes, b) ajout d’un calcul de vieillissement et de l’exigence d’un faible niveau d’excitation conformément à la spécification générale, c) mise à jour de la courbe température/fréquence en fonction des exigences des coupes courantes, d) suppression des types de produits rarement utilisés.
Kvarčna kristalna enota določene kakovosti - 2. del: Smernice za uporabo (IEC 60122-2:2025)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2025
Kvarčna kristalna enota določene kakovosti - 2. del: Smernice za uporabo (IEC
60122-2:2025)
Quartz crystal units of assessed quality - Part 2: Guidelines for the use (IEC 60122-
2:2025)
Schwingquarze mit bewerteter Qualität - Teil 2: Leitlinien zur Anwendung (IEC 60122-
2:2025)
Résonateurs à quartz sous assurance de la qualité - Partie 2: Lignes directrices pour
l’utilisation (IEC 60122-2:2025)
Ta slovenski standard je istoveten z: EN IEC 60122-2:2025
ICS:
31.140 Piezoelektrične naprave Piezoelectric devices
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 60122-2
NORME EUROPÉENNE
EUROPÄISCHE NORM August 2025
ICS 31.140
English Version
Quartz crystal units of assessed quality - Part 2: Guidelines for
the use
(IEC 60122-2:2025)
Résonateurs à quartz sous assurance de la qualité - Partie Schwingquarze mit bewerteter Qualität - Teil 2: Leitlinien
2: Lignes directrices pour l'utilisation zur Anwendung
(IEC 60122-2:2025) (IEC 60122-2:2025)
This European Standard was approved by CENELEC on 2025-08-01. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60122-2:2025 E
European foreword
The text of document 49/1506/FDIS, future edition 3 of IEC 60122-2, prepared by TC 49
"Piezoelectric, dielectric and electrostatic devices and associated materials for frequency control,
selection and detection" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 60122-2:2025.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-08-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-08-31
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60122-2:2025 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
IEC 60068 (series) NOTE Approved as EN 60068 (series)
IEC 60444 (series) NOTE Approved as EN 60444 (series)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60122-1 2002 Quartz crystal units of assessed quality - EN 60122-1 2002
Part 1: Generic specification
+ A1 2017 + A1 2018
IEC 60122-2 ®
Edition 3.0 2025-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Quartz crystal units of assessed quality –
Part 2: Guidelines for the use
Résonateurs à quartz sous assurance de la qualité –
Partie 2: Lignes directrices pour l’utilisation
ICS 31.140 ISBN 978-2-8327-0529-2
IEC 60122-2:2025-06(en-fr)
IEC 60122-2:2025 © IEC 2025
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Quartz crystal unit as an electronic component . 5
4.1 General . 5
4.2 Modes of vibration . 6
4.3 The equivalent electrical circuit of a quartz crystal unit . 7
4.4 Crystal resistance . 9
4.5 Frequency versus temperature characteristics . 10
4.6 Q factor . 13
4.7 Level of drive and drive level dependency . 14
4.7.1 Level of drive . 14
4.7.2 High level of drive . 14
4.7.3 Low level of drive . 14
4.7.4 Drive level dependency . 14
4.8 Specifying frequency tolerance and operating temperature range . 15
4.9 Load capacitance and frequency pulling . 16
4.10 Unwanted responses . 20
4.11 Effects of ageing . 22
4.12 Crystal unit enclosures . 25
4.13 Start-up time . 25
4.14 Mechanical reliability . 26
5 Application guidelines . 26
5.1 Oscillator circuits and oscillation condition . 26
5.1.1 Factors affecting the frequency . 26
5.1.2 Types of oscillators . 27
5.1.3 Series resonance oscillators . 27
5.2 Oscillators, practical considerations . 29
5.2.1 General. 29
5.2.2 Crystal unit resistance . 29
5.2.3 Unwanted responses . 29
5.2.4 Drive level . 30
5.2.5 Frequency stability . 30
5.3 Use in filter applications . 30
6 Factors affecting cost and availability of quartz crystal units . 30
6.1 Overview . 30
6.2 Crystal unit frequency . 31
6.3 Crystal unit enclosures . 31
6.4 Frequency tolerances . 31
6.5 AT-cut temperature coefficient cost aspects . 31
6.6 Ageing . 32
6.7 Environmental factors . 33
6.8 General testing considerations . 33
IEC 60122-2:2025 © IEC 2025
7 Technical data to accompany the order form . 33
7.1 Check list of crystal unit parameters to be specified in article sheet . 33
7.2 Requirements . 34
Bibliography . 36
Figure 1 – Designation of the most commonly used crystal cuts . 6
Figure 2 – Equivalent circuit of a quartz crystal unit . 8
Figure 3 – Reactance/frequency variation characteristic in the vicinity of resonance . 10
Figure 4 – Theoretical frequency/temperature curves of some common crystal cuts . 11
Figure 5 – Frequency/temperature curves generalized (AT-cut) . 12
Figure 6 – Frequency/temperature curves generalized (SC-cut) . 13
Figure 7 – Theoretical reactance/frequency of quartz crystal resonators. 17
Figure 8 – Fractional load resonance frequency offset (D ), fractional pulling range
L
(D ) and pulling sensitivity of a quartz crystal unit . 19
L1,L2
Figure 9 – Pulling sensitivity (S) versus C /C for various values of load
0 1
capacitance C . 19
L
Figure 10 – Five examples of unwanted crystal responses measured over the spectrum
adjacent to the main response . 22
Figure 11 – Typical ageing curves . 24
Figure 12 – Series resonance oscillator . 27
Figure 13 – Positive reactance oscillator . 28
Figure 14 – The crystal unit operates as an inductance in the phase shifting network . 28
Figure 15 – Crystal unit with a series connected load capacitance . 29
Figure 16 – AT cut crystal units-frequency tolerance/temperature range difficulty
aspect . 32
Table 1 – Modes of vibration as a function of frequency . 7
Table 2 – Time acceleration factors for E = 0,38 eV . 24
a
Table 3 – Checklist . 34
IEC 60122-2:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Quartz crystal units of assessed quality -
Part 2: Guidelines for the use
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,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any I
...
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