1、BRITISH STANDARD BS EN 60444-2:1997 IEC444-2: 1980 Incorporating Amendment No.1 to BS7681-2:1993 (renumbers the BS as BS EN60444-2:1997) Measurement of quartz crystal unit parameters by zero phase technique in a -network Part 2: Phase offset method for measurement of motional capacitance of quartz c
2、rystal units The European Standard EN60444-2:1997 has the status of a BritishStandard ICS 31.140BSEN60444-2:1997 This BritishStandard, having been prepared under the directionof the Electronic Components Standards PolicyCommittee, was publishedunder the authorityofthe Standards Boardand comes intoef
3、fecton 15September1993 BSI03-2000 The following BSI references relate to the work on this standard: Committee reference ECL/11 Special announcement in BSINews May1993 ISBN 0 580 22497 X Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted by the Elect
4、ronic Components Standards Policy Committee (ECL/-) to Technical Committee ECL/11, upon which the following bodies were represented: EEA (the Association of Electronics, Telecommunications and Business Equipment Industries) Electronic Components Industry Federation Institute of Physics Institution o
5、f Electrical Engineers Ministry of Defence National Supervising Inspectorate Amendments issued since publication Amd. No. Date Comments 9658 October 1997 BS renumbered as BS EN 60444-2:1997 and new AnnexZA insertedBSEN60444-2:1997 BSI 03-2000 i Contents Page Committees responsible Inside front cover
6、 National foreword ii Foreword 2 1 Scope 3 2 Principle of measurement 3 3 Measuring circuit 3 4 Method of measurement 3 5 Measurement errors 4 6 Other measuring methods 4 Appendix A 5 Annex ZA (normative) Normative references to international publications with their corresponding European publicatio
7、ns 9 Figure 1 Equivalent circuit of a quartz crystal unit 6 Figure 2 Measuring circuit 6 Figure 3 Phase and impedance characteristics of a quartz crystal unit in the vicinity of resonance 7 Figure 4 Deviation of C 1as a function of R rfor various error conditions 7 Figure 5 Deviation of C 1as a func
8、tion of measured phase angle error and different phase angles 8 Figure 6 The effect of parallel capacitance C 0on the measurement accuracy C 1versus measured phase angle 8 List of references Inside back coverBSEN60444-2:1997 ii BSI 03-2000 National foreword This Part of BS EN60444 has been prepared
9、by Technical Committee EPL/49 (formerly ECL/11), and is the English language version of EN60444-2:1997, published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC444-2:1980, Measurement of quartz crystal unit parameters by zero phase technique in a -
10、network Part2. Phase offset method for measurement of motional capacitance of quartz crystal units, published by the International Electrotechnical Commission (IEC). Cross references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative referen
11、ces to international publications with their corresponding European publications. The BritishStandards which implement these international or European publications may be found in the BSIStandards Catalogue under the section entitled “International Standards Correspondence Index”, or using the “Find
12、” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal
13、obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theENtitle page, pages2 to10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the a
14、mendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN60444-2 April1997 ICS 31.140 Descriptors: Quartz crystal units, measurement of parameters, zero phase technique in a pi-network, phase offset method, principle and circuit, motional capacitance English versi
15、on Measurement of quartz crystal unit parameters by zerophase technique in a pi-network Part 2: Phase offset method for measurement of motional capacitance of quartz crystal units (IEC444-2:1980) Mesure des paramtres des quartz pizolectriques par la technique de phase nulle dans le circuit en pi Par
16、tie2: Mthode de dcalage de phase pour la mesure de la capacit dynamique des quartz (CEI444-2:1980) Messung von Schwingquarz-Parametern nachdem Null-Phasenverfahren in einem Pi-Netzwerk Teil2: Messung der dynamischen Kapazittvon Schwingquarzen nach dem Phasenoffsetverfahren (IEC444-2:1980) This Europ
17、ean Standard was approved by CENELEC on1997-03-11. 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
18、concerning such national standards may be obtained on application to the Central Secretariat 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
19、into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Swe
20、den, Switzerland and UnitedKingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1997 CENELEC All rights of exploitation in any
21、 form and by any means reserved worldwide for CENELEC members. Ref. No.60444-2:1997 EEN60444-2:1997 BSI 03-2000 2 Foreword The text of the International Standard IEC444-2:1980, prepared by IEC TC49, Piezoelectric and dielectric devices for frequency control and selection, was submitted to the formal
22、 vote and was approved by CENELEC as EN60444-2 on1997-03-11 without any modification. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. Annexes designated “informative” are given for information only. In this standard, Annex ZA is normative and Appe
23、ndix A is informative. Annex ZA has been added by CENELEC. latest date by which the ENhas to be implemented at national level by publication of an identical national standard or by endorsement (dop)1997-12-01 latest date by which the national standards conflicting with the EN haveto be withdrawn (do
24、w)1997-12-01EN60444-2:1997 BSI 03-2000 3 1 Scope This standard describes a method of measuring the motional capacitance of quartz crystal units in the frequency range1MHz to125MHz with a total measurement error of the order of5%. The advantage of this method is that it uses only the measuring circui
25、t described in IEC Publication444 and therefore avoids the use of additional elements or instruments which could be sources of error. 2 Principle of measurement This method is based on the phase measurement at the resonance frequency and in its vicinity. The value of the motional capacitance (C 1in
26、Figure 1, page6) is calculated from the measured values of resonance frequency, two frequencies lying on both sides of the impedance curve with a given phase difference equal in magnitude and opposite in sign, and the resonance resistance. The resonance frequency and the resonance resistance are mea
27、sured as given in Clause6 of IECPublication444. 3 Measuring circuit The measuring circuit consists basically of a ;-network connected with coaxial cables to the associated measuring equipment (seeFigure 2, page 6). The associated measuring equipment is as follows: frequency synthesizer attenuators p
28、ower splitter phase meter 507 resistors. The -network and the associated measuring equipment shall meet all the requirements given in Clause5 of IEC Publication444. 4 Method of measurement 4.1 Initial calibration is carried out in accordance with Sub-clause6.1 of IEC Publication444. 4.2 The resonanc
29、e frequency f rand the resonance resistance R rof the crystal unit under test are measured as described in Sub-clause6.2 of IEC Publication444. 4.3 The frequency synthesizer is adjusted at the frequency f 1lower than the resonance frequency f rand then at the frequency f 2which is higher than f r .
30、At frequencies f 1and f 2the phase shifts with respect to f rare equal in magnitude, but opposite in sign (seeFigure 3, page7). 4.4 The measured values of f r , f 1 , f 2and R rare used in the formulae(1) and(2) for calculation of motional capacitance: In the case when the phase angle = 45 , the for
31、mula for calculating C 1is: (1) (2)EN60444-2:1997 4 BSI 03-2000 5 Measurement errors There are several sources of measurement errors. The main source of error is the error in the measurement of resonance resistance R r . The relative error for the value of motional capacitance is: the magnitude of e
32、rror as a function of the measured value of resonance resistance and the relative error of resistance measurement is given in the graph of Figure 4, page7. The error in phase measurement, at the frequencies f 1and f 2giving an equivalent phase offset (absolutevalue), is highest when these errors hav
33、e opposite signs. The error is: The value of % is the mean algebraic value of phase errors at the frequencies f 1and f 2taking into account the error sign. For the case when equals45 the error is: Figure 5, page 8, gives the relative error of motional capacitance measurement for three different valu
34、es of phase angle. The error which results from the presence of parallel capacitance C 0for different phase offsets is given by the formula: and is shown in Figure 6, page 8. 6 Other measuring methods Other methods of measurement, such as the load capacitance method specified in IEC Publication302,
35、may be used. The method specified in IEC Publication302 can also be used with the zero phase technique specified in IEC Publication444, providing that particular care is taken with regard to the construction of the ;-network and to the methods of insertion of the capacitance into this network. These
36、 precautions especially apply at higher frequencies. In cases of doubt, the phase offset method as defined in this publication should be used as a reference method. (3) For the value (4) (5) (6)EN60444-2:1997 BSI 03-2000 5 Appendix A Quartz crystal units can be represented by an equivalent circuit s
37、hown in Figure 1, page6 (seeIECPublication302, Sub-clause1.1). In the vicinity of the series resonance frequency, the influence of parallel capacitance C 0can be disregarded. NOTEFor more precise measurements C 0should be included. The influence of C 0can be assessed by examining the figure of merit
38、M = Q/r (seeIEC Publication302, page21). Figure 6, page 8, shows the relationship between the phase angle offset, the figure of merit and the percentage fractional error in the measurement of C 1to be expected. The equation for the impedance is: Equalizing real and imaginary parts of equation (A2) y
39、ields: Substitution of frequencies f 1 , f 2and f r(seeFigure 3, page 7) in equation (A3) yields the following equations: From equations (A3), (A4), (A5) and (A6) it is possible to obtain equations in the form: where 1 = 2 By solving equations (A7), the equation for motional capacitance C 1becomes:
40、where R 1 = R r . (A1) (A2) (A3) a) where (A4) b) where (A5) c) where (A6) (A7) (A8)EN60444-2:1997 6 BSI 03-2000 As the crystal unit is measured in a ;-network and is loaded with257, one obtains: Approximating: (A9) Figure 1 Equivalent circuit of a quartz crystal unit NOTEThe30dB attenuator in chann
41、el A may be desirable with certain phase and voltage meters. Figure 2 Measuring circuitEN60444-2:1997 BSI 03-2000 7 Figure 3 Phase and impedance characteristics of a quartz crystal unit in the vicinity of resonance Figure 4 Deviation of C 1as a function of R rfor various error conditionsEN60444-2:19
42、97 8 BSI 03-2000 Figure 5 Deviation of C 1as a function of measured phase angle error and different phase angles Figure 6 The effect of parallel capacitance C 0on the measurement accuracy of C 1versus measured phase angleEN60444-2:1997 BSI 03-2000 9 Annex ZA(normative) Normative references to intern
43、ational publications with their corresponding European publications This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated r
44、eferences, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). NOTEWhen the international pub
45、lication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Date IEC302 1969 Standard definitions and methods of measurement for piezoelectric vibrators operating over the frequency rangeupto30MHz 10 blankBSEN60444-2:1997 BSI 03-20
46、00 List of references Seenational foreword.BS EN 60444-2:1997 IEC444-2: 1980 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the internationa
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