1、BSI Standards PublicationMeasurement of quartz crystal unit parametersPart 6: Measurement of drive level dependence (DLD)BS EN 60444-6:2013National forewordThis British Standard is the UK implementation of EN 60444-6:2013. It is identical to IEC 60444-6:2013. It supersedes BS EN 60444-6:1997 which i
2、s withdrawn.The UK participation in its preparation was entrusted to Tech-nical Committee EPL/49, Piezoelectric devices for frequency con-trol and selection.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include a
3、ll the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013ISBN 978 0 580 64890 8ICS 31.140Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Stan
4、dard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2013.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 60444-6:2013EUROPEAN STANDARD EN 60444-6 NORME EUROPENNE EUROPISCHE NORM October 2013 CENELEC European Committ
5、ee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CE
6、NELEC members. Ref. No. EN 60444-6:2013 E ICS 31.140 Supersedes EN 60444-6:1997 English version Measurement of quartz crystal unit parameters - Part 6: Measurement of drive level dependence (DLD) (IEC 60444-6:2013) Mesure des paramtres des rsonateurs quartz - Partie 6: Mesure de la dpendance du nive
7、au dexcitation (DNE) (CEI 60444-6:2013) Messung von Schwingquarz-Parametern - Teil 6: Messung der Belastungsabhngigkeit (DLD) (IEC 60444-6:2013) This European Standard was approved by CENELEC on 2013-07-24. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate
8、 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 S
9、tandard 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
10、are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway,
11、 Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 60444-6:2013EN 60444-6:2013 - 2 - Foreword The text of document 49/1004/CDV, future edition 2 of IEC 60444-6, prepared by IEC/TC 49, “Piezoelectric, dielectric and electrostatic devices a
12、nd associated materials for frequency control, selection and detection“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 60444-6:2013. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical n
13、ational standard or by endorsement (dop) 2014-04-24 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2016-07-24 This document supersedes EN 60444-6:1997. EN 60444-6:2013 includes the following significant technical changes with respect to EN 60444-
14、6:1997: a) DLD measurement with oscillation circuit had the traditional method to detect the DLD abnormal modes at present time. Therefore, this method made the transition to the Annex B. b) High reliability crystal unit is needed to use for various applications at the present day, in order to upgra
15、de the inspection capabilities for DLD abnormal modes, the multi-level reference measurement method was introduced into this specification. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and/or CEN shall not be held respo
16、nsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 60444-6:2013 was approved by CENELEC as a European Standard without any modification. BS EN 60444-6:2013- 3 - EN 60444-6:2013 Annex ZA (normative) Normative references to international
17、 publications with their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the re
18、ferenced document (including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60444-1 - Measurement of quartz crystal unit parameters by zero phase techniqu
19、e in a pi-network - Part 1: Basic method for the measurement of resonance frequency and resonance resistance of quartz crystal units by zero phase technique in a pi-network EN 60444-1 - IEC 60444-5 - Measurement of quartz crystal unit parameters - Part 5: Methods for the determination of equivalent
20、electrical parameters using automatic network analyzer techniques and error correction EN 60444-5 - IEC 60444-8 - Measurement of quartz crystal unit parameters - Part 8: Test fixture for surface mounted quartz crystal units EN 60444-8 - BS EN 60444-6:2013 2 60444-6 IEC:2013 CONTENTS INTRODUCTION . 5
21、 1 Scope . 6 2 Normative references . 6 3 DLD effects 6 3.1 Reversible changes in frequency and resistance . 6 3.2 Irreversible changes in frequency and resistance 6 3.3 Causes of DLD effects . 7 4 Drive levels for DLD measurement . 7 5 Test methods 8 5.1 Method A (Fast standard measurement method)
22、. 8 5.1.1 Testing at two drive levels . 8 5.1.2 Testing according to specification 8 5.2 Method B (Multi-level reference measurement method) . 9 Annex A (normative) Relationship between electrical drive level and mechanical displacement of quartz crystal units 11 Annex B (normative) Method C: DLD me
23、asurement with oscillation circuit . 14 Bibliography 19 Figure 1 Maximum tolerable resistance ratio for the drive level dependence as a function of the resistances Rr2or Rr39 Figure B.1 Insertion of a quartz crystal unit in an oscillator 14 Figure B.2 Crystal unit loss resistance as a function of di
24、ssipated power . 15 Figure B.3 Behaviour of the Rrof a quartz crystal units 16 Figure B.4 Block diagram of circuit system . 16 Figure B.5 Installed Roscin scanned drive level range . 17 Figure B.6 Drive level behavior of a quartz crystal unit if Rosc = 70 is used as test limit in the “Annex B” test
25、. 17 Figure B.7 Principal schematic diagram of the go/no-go test circuit 18 BS EN 60444-6:201360444-6 IEC:2013 5 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
26、. 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
27、 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 dependen
28、ce 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 destroy the resonator. Apart from this ef
29、fect, changes in frequency and resistance are observed at “low” drive levels in some crystal units, e.g. below 1 mW or 50 A 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 ri
30、pple 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 f
31、requency 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
32、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 60444-6:1995 is maintained. However, the more suitable definition for the users severe requirements was introduced. Also, the specifications based on
33、 the matters arranged in the Stanford meeting in June, 2011 are taken into consideration. BS EN 60444-6:2013 6 60444-6 IEC:2013 MEASUREMENT OF QUARTZ CRYSTAL UNIT PARAMETERS Part 6: Measurement of drive level dependence (DLD) 1 Scope This part of IEC 60444 applies to the measurements of drive level
34、dependence (DLD) of quartz crystal units. Two test methods (A and C) and one referential method (B) are described. “Method A”, based on the -network according to IEC 60444-1, can be used in the complete frequency range covered by this part of IEC 60444. “Reference Method B”, based on the -network or
35、 reflection method according to IEC 60444-1, 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. 2 Normat
36、ive references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) a
37、pplies. IEC 60444-1, Measurement of quartz crystal unit parameters by zero phase technique in a -network Part 1: Basic method for the measurement of resonance frequency and resonance resistance of quartz crystal units by zero phase technique in a -network IEC 60444-5, Measurement of quartz crystal u
38、nits parameters Part 5: Methods for the determination of equivalent electrical parameters using automatic network analyzer techniques and error correction IEC 60444-8, Measurement of quartz crystal unit parameters Part 8: Test fixture for surface mounted quartz crystal units 3 DLD effects 3.1 Revers
39、ible changes in frequency and resistance Reversible changes are changes in frequency and resistance occurring under the same drive levels after repeated measurements made alternatively at low and high levels, or after continuous or quasi-continuous measurements from the lowest to the highest level a
40、nd back, if these changes remain within the limits of the measurement accuracy. 3.2 Irreversible changes in frequency and resistance Irreversible changes are significant changes in frequency and/or resistance occurring at low level after an intermediate measurement at high level e.g. when a previous
41、ly high resistance at low level has changed in the repeated measurement to a low resistance. Especially, when the crystal unit has not been operated for several days, its resistance may have changed back to a high value when operated again at a lower level. Greater attention should be paid to the ir
42、reversible effect since it can significantly impair the performance of devices, which are operated only sporadically. BS EN 60444-6:201360444-6 IEC:2013 7 3.3 Causes of DLD effects Whereas the mostly reversible effects are due to excessive crystal drive level, the irreversible effects are due to pro
43、duction, especially to imperfect production techniques. Examples of causes are: Particles on the resonator surface (partly bound by oils, cleaning agents. solvents or bound electro-statically); Mechanical damage of the resonator (e.g. fissures due to excessively coarse lapping abrasive which may inc
44、rease in size); Gas and oil inclusions in the electrodes (e.g. due to a poor vacuum or an inadequate coating rate during evaporation); Poor contacting of the electrodes at the mounting (e.g. the conductive adhesive has an inadequate metal component, was insufficiently baked out or was overheated; al
45、so excessive contact resistance between the conductive adhesive and the electrodes or mounting); Mechanical stresses between mounting, electrodes and quartz element. 4 Drive levels for DLD measurement For the DLD measurement, a low and a high level of drive (and possibly further levels) are applied.
46、 The high level is the nominal drive level, which should be equal to the level in the application at its steady state. It should be noted that this level should be below the maximum applicable level that is derived in Annex A. If not specified, a standard value for the crystal current of 1 mA, corre
47、sponding to the velocity v max = 0,2 m/s for AT-cut crystal units, shall be used. The drive level in watts is then calculated with the mean value of the specified maximum and minimum resistances. The minimum drive level occurring at the start-up of an oscillator can be determined only in a few cases
48、 by active or passive measuring methods due to the noise limits of the measuring instruments for measurements according to IEC 60444-1, at approximately 1 nW or 10 A (depending on the equipment, the lowest power value can be reduced to 0,1 nW or 1 A). A velocity v max = 0,01 m/s, corresponding to 50
49、 A for AT-cut crystals, has proved to be practical value for -network measurements (see “Method A”). In the following, two methods and one referential method of DLD measurement are described. “Method A” is based on the -network method according to IEC 60444-1, which can be used in the complete frequency range covered by this standard. It allows the fast selection of drive level sensitive quartz crystal units by a sequence of three measurements. The allowed variation of the resonance resist
