IEC 60444-6:2021

Measurement of quartz crystal unit parameters - Part 6: Measurement of drive level dependence (DLD)

IEC 60444-6:2021 applies to the measurements of drive level dependence (DLD) of quartz crystal units. Two test methods (A and C) and one referential method (B) are described. “Method A”, based on the p-network according to IEC 60444-5, can be used in the complete frequency range covered by this part of IEC 60444. “Reference Method B”, based on the p-network or reflection method according to IEC 60444-5 or IEC 60444-8 can be used in the complete frequency range covered by this part of IEC 60444. “Method C”, an oscillator method, is suitable for measurements of fundamental mode crystal units in larger quantities with fixed conditions.
NOTE The measurement methods specified in this document are not only applicable to AT-cut, but also to other crystal cuts and vibration modes, such as doubly rotated cuts (IT,SC) and to tuning fork crystal units (by using a high impedance test fixture). This edition includes the following significant technical changes with respect to the previous edition:
- some equations have been removed and corrected;
- it has been specified in the note of the Scope that the measurement methods specified in this document are not only applicable to AT-cut but also to other crystal cuts and vibration modes.

Mesure des paramètres des résonateurs à quartz - Partie 6: Mesure de la dépendance du niveau d’excitation (DNE)

L’IEC 60444-6:2021 s’applique aux mesures de la dépendance du niveau d’excitation (DNE) des résonateurs à quartz. Deux méthodes d’essai (A et C) et une méthode de référence (B) sont décrites. La méthode A, basée sur le réseau en p conformément à l’IEC 60444-5, peut être utilisée dans la plage de fréquences complète couverte par la présente partie de l’IEC 60444. La méthode de référence B, basée sur le réseau en p ou sur la méthode de réflexion conformément à l’IEC 60444-5 ou à l’IEC 60444-8, peut être utilisée dans la plage de fréquences complète couverte par la présente partie de l’IEC 60444. La méthode C, une méthode avec un oscillateur, est adaptée pour les mesures de résonateurs sur le mode fondamental en plus grandes quantités avec des conditions fixes. Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente:
- certaines équations ont été supprimées ou corrigées;
- il est spécifié dans la note du Domaine d’application que les méthodes de mesure spécifiées dans le présent document ne s’appliquent pas uniquement à la coupe AT, mais aussi à d’autres coupes de cristaux et à d’autres modes de vibration.

General Information

• Status: Published
• Publication Date: 31-Aug-2021
• ICS: 31.140 - Piezoelectric devices
• Technical Committee: TC 49 - Piezoelectric, dielectric and electrostatic devices and associated materials for frequency control, selection and detection
• Drafting Committee: WG 1 - TC 49/WG 1
• Current Stage: PPUB - Publication issued
• Start Date: 24-Sep-2021
• Completion Date: 01-Sep-2021

Relations

• Revises: IEC 60444-6:2013 - Measurement of quartz crystal unit parameters - Part 6: Measurement of drive level dependence (DLD)
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60444-6 ®
Edition 3.0 2021-09
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Measurement of quartz crystal unit parameters –
Part 6: Measurement of drive level dependence (DLD)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
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About the IEC
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International Standards for all electrical, electronic and related technologies.
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IEC 60444-6 ®
Edition 3.0 2021-09
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Measurement of quartz crystal unit parameters –
Part 6: Measurement of drive level dependence (DLD)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.140 ISBN 978-2-8322-4188-2

– 2 – IEC 60444-6:2021 RLV © IEC 2021
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references. 6
3 Terms and definitions . 6
4 DLD effects . 6
4.1 Reversible changes in frequency and resistance . 6
4.2 Irreversible changes in frequency and resistance . 7
4.3 Causes of DLD effects . 7
5 Drive levels for DLD measurement . 7
6 Test methods . 8
6.1 Method A (fast standard measurement method) . 8
6.1.1 Testing at two drive levels . 8
6.1.2 Testing according to specification . 9
6.2 Method B (Multi-level reference measurement method) . 10
Annexe A (normative) Relationship between electrical drive level and mechanical
displacement of quartz crystal units . 13
Annex B (normative) Method C: DLD measurement with oscillation circuit . 17
Bibliography . 22

γ
Figure 1 – Maximum tolerable resistance ratio for the drive level dependence as a
function of the resistances R or R . 10
12 13
Figure B.1 – Insertion of a quartz crystal unit in an oscillator . 17
Figure B.2 – Crystal unit loss resistance as a function of dissipated power . 18
Figure B.3 – Behaviour of the R of a quartz crystal unit . 19
r
Figure B.4 – Block diagram of circuit system . 19
Figure B.5 – Installed −R in scanned drive level range . 20
osc
Figure B.6 – Drive level behaviour of a quartz crystal unit if −R = 70 Ω is used as
osc
test limit in the Annex B test . 20
Figure B.7 – Principal schematic diagram of the go/no-go test circuit . 21

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MEASUREMENT OF QUARTZ CRYSTAL UNIT PARAMETERS –

Part 6: Measurement of drive level dependence (DLD)

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 IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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.
This redline version of the official IEC Standard allows the user to identify the changes made to
the previous edition IEC 60444-6:2013. A vertical bar appears in the margin wherever a change
has been made. Additions are in green text, deletions are in strikethrough red text.

– 4 – IEC 60444-6:2021 RLV © IEC 2021
IEC 60444-6 has been prepared by IEC technical committee 49: Piezoelectric, dielectric and
electrostatic devices and associated materials for frequency control, selection and detection. It
is an International Standard.
This third edition cancels and replaces the second edition published in 2013. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) some equations have been removed and corrected;
b) it has been specified in the note of the Scope that the measurement methods specified in
this document are not only applicable to AT-cut but also to other crystal cuts and vibration
modes.
The text of this International Standard is based on the following documents:
FDIS Report on voting
49/1374/FDIS 49/1377/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/standardsdev/publications.
A list of all parts in the IEC 60444 series, published under the general title Measurement of
quartz crystal unit parameters, 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.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

INTRODUCTION
The drive level (expressed as power/voltage across or current through the crystal unit) forces
the resonator to produce mechanical oscillations by way of piezoelectric effect. In this process,
the acceleration work is converted to kinetic and elastic energy and the power loss to heat. The
latter conversion is due to the inner and outer friction of the quartz resonator.
The frictional losses depend on the velocity of the vibrating masses and increase when the
oscillation is no longer linear or when critical velocities, elongations or strains, excursions or
accelerations are attained in the quartz resonator or at its surfaces and mounting points (see
Annex A). This causes changes in resistance and frequency, as well as further changes due to
the temperature dependence of these parameters.
At “high” drive levels (e.g. above 1 mW or 1 mA for AT-cut crystal units) changes are observed
by all crystal units and these also can result in irreversible amplitude and frequency changes.
Any further increase of the drive level may could destroy the resonator.
Apart from this effect, changes in frequency and resistance are observed at “low” drive levels
in some crystal units (e.g. below 1 mW μW or 50 μA for AT-cut crystal units). In this case, if the
loop gain is not sufficient, the start-up of the oscillation is difficult. In crystal filters, the
transducer attenuation and ripple will change.
Furthermore, the coupling between a specified mode of vibration and other modes (e.g. of the
resonator itself, the mounting and the back-fill gas) also depends on the level of drive.
Due to the differing temperature response of these modes, these couplings give rise to changes
of frequency and resistance of the specified mode within narrow temperature ranges. These
changes increase with increasing drive level. However, this effect will not be considered further
in this part of IEC 60444.
The first edition of IEC 60444-6 was published in 1995. However, it has not been revised until
today. In the meantime the demand for tighter specification and measurement of DLD has
increased.
In this new edition, the concept of DLD in IEC 60444-6:19952013 is maintained. However, the
more suitable contents for the user’s severe requirements have been introduced. Al
...

IEC 60444-6 ®
Edition 3.0 2021-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Measurement of quartz crystal unit parameters –
Part 6: Measurement of drive level dependence (DLD)

Mesure des paramètres des résonateurs à quartz –
Partie 6: Mesure de la dépendance du niveau d’excitation (DNE)

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
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About the IEC
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International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

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IEC 60444-6 ®
Edition 3.0 2021-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Measurement of quartz crystal unit parameters –

Part 6: Measurement of drive level dependence (DLD)

Mesure des paramètres des résonateurs à quartz –

Partie 6: Mesure de la dépendance du niveau d’excitation (DNE)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.140 ISBN 978-2-8322-1014-4

– 2 – IEC 60444-6:2021 © IEC 2021
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references. 6
3 Terms and definitions . 6
4 DLD effects . 6
4.1 Reversible changes in frequency and resistance . 6
4.2 Irreversible changes in frequency and resistance . 7
4.3 Causes of DLD effects . 7
5 Drive levels for DLD measurement . 7
6 Test methods . 8
6.1 Method A (fast standard measurement method) . 8
6.1.1 Testing at two drive levels . 8
6.1.2 Testing according to specification . 9
6.2 Method B (Multi-level reference measurement method) . 10
Annex A (normative) Relationship between electrical drive level and mechanical
displacement of quartz crystal units . 12
Annex B (normative) Method C: DLD measurement with oscillation circuit . 15
Bibliography . 20

γ
Figure 1 – Maximum tolerable resistance ratio for the drive level dependence as a
function of the resistances R or R . 9
12 13
Figure B.1 – Insertion of a quartz crystal unit in an oscillator . 15
Figure B.2 – Crystal unit loss resistance as a function of dissipated power . 16
Figure B.3 – Behaviour of the R of a quartz crystal unit . 17
r
Figure B.4 – Block diagram of circuit system . 17
Figure B.5 – Installed −R in scanned drive level range . 18
osc
Figure B.6 – Drive level behaviour of a quartz crystal unit if −R = 70 Ω is used as
osc
test limit in the Annex B test . 18
Figure B.7 – Principal schematic diagram of the go/no-go test circuit . 19

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MEASUREMENT OF QUARTZ CRYSTAL UNIT PARAMETERS –

Part 6: Measurement of drive level dependence (DLD)

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 IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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.
IEC 60444-6 has been prepared by IEC technical committee 49: Piezoelectric, dielectric and
electrostatic devices and associated materials for frequency control, selection and detection. It
is an International Standard.
This third edition cancels and replaces the second edition published in 2013. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) some equations have been removed and corrected;
b) it has been specified in the note of the Scope that the measurement methods specified in
this document are not only applicable to AT-cut but also to other crystal cuts and vibration
modes.
– 4 – IEC 60444-6:2021 © IEC 2021
The text of this International Standard is based on the following documents:
FDIS Report on voting
49/1374/FDIS 49/1377/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/standardsdev/publications.
A list of all parts in the IEC 60444 series, published under the general title Measurement of
quartz crystal unit parameters, 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.
IEC 60444-
...