1、BRITISH STANDARD BS EN 60444-4:1997 IEC 444-4: 1988 Incorporating Amendment No. 1 to BS 7681-4:1993 (renumbers the BS as BS EN 60444-4:1997) Measurement of quartz crystal unit parameters by zero phase technique in a ;-network Part 4: Method for the measurement of the load resonance frequency R R L ,
2、 load resonance resistance R Land the calculation of other derived values of quartz crystal units, up to 30 MHz The European Standard EN 60444-4:1997 has the status of a British Standard ICS 31.140BSEN 60444-4:1997 This British Standard, having been prepared under the directionof the Electronic Comp
3、onents Standards PolicyCommittee, was publishedunder the authorityofthe Standards Boardand comes into effect on 15 August 1993 BSI 04-1999 The following BSI references relate to the work on this standard: Committee reference ECL/11 Special announcement in BSINews, May 1993 ISBN 0 580 22503 8 Committ
4、ees responsible for this British Standard The preparation of this British Standard was entrusted by the Electronic Components Standards Policy Committee (ECL/-) to Technical Committee ECL/11, upon which the following bodies were represented: EEA (the Association of Electronics, Telecommunications an
5、d Business Equipment Industries) Electronic Components Industry Federation Institute of Physics Institution of Electrical Engineers Ministry of Defence National Supervising Inspectorate Amendments issued since publication Amd. No. Date Comments 9660 October 1997 BS renumbered as BS EN 60444-4:1997 a
6、nd new Annex ZA inserted Indicated by a sideline in the marginBSEN 60444-4:1997 BSI 04-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 1 Scope 3 2 Measuring circuit 3 3 Method of measurement 3 Appendix A Recommendations regarding the use of load capacit
7、ors 4 Annex ZA (normative) Normative references to international publicationswiththeir corresponding European publications 13 Figure A1 Typical load capacitor with carrier 7 Figure A2 Method of insertion of load capacitor into ;-network 8 Figure A3 Circuit diagram of ;-network including load capacit
8、or C L 9 Figure A4 Load capacitance inaccuracy as a function of frequency, foraloadcapacitance of 30 pF inclusive of calibration inaccuracy and residualinductance effects. (Worst case situation) 9 Figure A5 Relative measurement error of R Lversus crystal pulling sensitivityfor various frequencies at
9、 a load capacitance of 30 pF 10 Figure A6 Relative measurement error of R Lversus frequency, forvariousvalues of C L 10 Figure A7 Relative measurement error of C 1as a function of frequency 11 Figure A8 Relative measurement error of C 1as a function of C 1forvariousfrequency measurement errors C 0=
10、5 pF; C L1= 15 pF; C L2= 30 pF 11 Figure A9 Relative measurement error of C 1as a function of C 1forvariousvalues of quality factor Q C 0= 3 pF; C L1= 15 pF; C L2= 30 pF 12 List of references Inside back coverBSEN 60444-4:1997 ii BSI 04-1999 National foreword This Part of BS EN60444 has been prepare
11、d by Technical Committee EPL/49 (formerly ECL/11), and is the English language version of EN60444-4:1997, published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC444-4:1988, Measurement of quartz crystal unit parameters by zero phase technique in a
12、 -network Part 4: Method for the measurement of the load resonance frequency R L , load resonance resistance R Land the calculation of other derived values of quartz crystal units, up to 30 MHz, published by the International Electrotechnical Commission (IEC). Cross references Attention is drawn to
13、the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSIStandards Catalog
14、ue under the section entitled “International Standards Correspondence Index”, or using the “Find” 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 correc
15、t application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 14, an inside back cover and a back cover. This standard has been
16、updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60444-4 April 1997 ICS 31.140 Descriptors: Quartz crystal units, measurement of parameters, zero phase t
17、echnique in a pi-network, load resonance frequency and resistance, measuring circuit, method of measurement English version Measurement of quartz crystal unit parameters by zero phase technique in a pi-network Part 4: Method for the measurement of the load resonance frequency R R L , load resonance
18、resistance R Land the calculation of other derived values of quartz crystal units, up to30 MHz (IEC 444-4:1988) Mesure des paramtres des quartz pizolectriques par la technique de phase nulle dans le circuit en pi Partie 4: Mthode pour la mesure de la frquence de rsonance la charge R Let de larsistan
19、ce de rsonance la charge R Let pour le calcul des autres valeurs drives des quartz pizolectriques, jusqu 30 MHz (CEI 444-4:1988) Messung von Schwingquarz-Parametern nach dem Null-Phasenverfahren in einem Pi-Netzwerk Teil 4: Verfahren zur Messung der Lastresonanzfrequenz R L , des Lastresonanzwiderst
20、andes R Lund Berechnung anderer hergeleiteter Werte von Schwingquarzen bis 30 MHz (IEC 444-4:1988) This European Standard was approved by CENELEC on 1997-03-11. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Stand
21、ard 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 Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, Fren
22、ch, 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 Central Secretariat has the same status as the official versions. CENELEC members are the national standards bodies of Austria, Belgium, Denmark, Fi
23、nland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische
24、Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1997 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC members Ref. No. EN 60444-4:1997 EEN60444-4:1997 BSI 04-1999 2 Foreword The text of the International Standard IEC444-4:1988, prepared
25、by IEC TC 49, Piezoelectric and dielectric devices for frequency control and selection, was submitted to the formal vote and was approved by CENELEC as EN 60444-4 on 1997-03-11 without any modification. The following dates were fixed: Annexes designated “normative” are part of the body of the standa
26、rd. Annexes designated “informative” are given for information only. In this standard, Annex ZA is normative and Appendix A is informative. Annex ZA has been added by CENELEC. latest date by which the EN has to be implemented at national level by publication of an identical national standard or by e
27、ndorsement (dop) 1997-12-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 1997-12-01EN60444-4:1997 BSI 04-1999 3 1 Scope This report specifies a simple method of measuring load resonance frequency R Land load resonance resistance R Lin the frequency r
28、ange up to30MHz. These measurements allow calculation of load resonance frequency offset %R L , frequency pulling range %R L1, L2and pulling sensitivity S as described in Amendment No. 1 to IEC Publication 122-1. The method uses the change in resonance frequency from R rto R L(i.e. %R L ) which occu
29、rs when a load capacitance C Lis inserted in series with the crystal unit. The accuracy is determined mainly by the precision of the frequency measurement and the calibration of the load capacitor. Measurement of load resonance frequency R Lwith different load capacitances may be used for the determ
30、ination of C 1and L 1as defined in IEC Publication302. It should be noted that when making measurements of the load resonance frequency of a quartz crystal unit, the accuracy obtainable is a function of the crystal unit design and the value of the load capacitance, as well as the method of measureme
31、nt. Useful information of general interest can be found in IEC Publication 122-2. 2 Measuring circuit 2.1 The measuring circuit consists of a zero phase ;-network system as described in IEC Publication444-1, in which a calibrated load capacitor can be inserted between the crystal unit terminals and
32、the contact plates of the ;-network, to obtain a specific load capacitance. The load capacitors shall be removable and interchangeable, so that the measurements at resonance or at load resonance with one or more values of load capacitance can be made in the same network, without disturbing the measu
33、rement system. 2.2 An outline description of a typical design for the load capacitor and the method of insertion into the ;-network together with measurement errors is given in Appendix A. 2.3 Load capacitor specification 2.3.1 The residual inductance of the load capacitors shall be less than1 10 9H
34、. 2.3.2 The tolerance on the specified nominal value should be equal to or better than 0.1pF at a frequency up to 1 MHz. 2.3.3 The cross-talk capacitance of the load capacitors shall be less than0.05pF. This can be measured as described in Appendix A. 2.3.4 The temperature coefficient at25C shall be
35、 less than30 10 6 /C. 3 Method of measurement 3.1 Initial adjustment The calibration and initial adjustment of the zero phase ;-network system is performed in accordance with IEC Publication 444-1, Clause6. 3.2 The reference resistor used in the system (see Sub-clause3.1) is removed from the network
36、, and the crystal unit, together with the appropriate load capacitor, substituted. The load resonance frequency R Lis measured at zero phase, and the load resonance resistance R Lis calculated from the values ofV Bsand V Asas described in IEC Publication 444-1, Sub-clause6.2. The load capacitors use
37、d for these measurements shall have the specified value within the tolerances in Sub-clause 2.3.2. (Standard values are given in IECPublication 122-1, Clause5). 3.3 From these measurements it is possible to calculate the values of %R L , %R L1, L2and S as defined in IECPublication 122-1, Amendment N
38、o. 1. 3.4 The motional capacitance C 1and motional inductance L 1can also be calculated using the formulae given in Sub-clause2.3.2 of IECPublication 302.EN60444-4:1997 4 BSI 04-1999 Appendix A Recommendations regarding the use of load capacitors A1 Load capacitor design A1.1 Mechanical features Any
39、 design that meets the requirements of Sub-clause2.3 is suitable. Load capacitors designed as set out below conform to these requirements. The capacitors are made by using two capacitive elements secured around their edges by soldering to the track of the fibre glass substrate as shown in Figure A1.
40、 The capacitive elements consist of a ceramic substrate with a thin layer of base plating using a chrome-nickel-gold alloy. This assembly is then electroplated with a copper layer0.3 mm thick on each side. The final coating is of gold plating5 4m thick. The construction is illustrated in Figure A1.
41、The two sections of the load capacitor are approximately equal each having the value 2 C L , where C Lis the desired load capacitance. The capacitance value may be adjusted by erosion of the edges to meet the specified limits of the load capacitor specification given in Sub-clause2.3.2. A1.2 Inserti
42、on into -network Figure A2 illustrates how the load capacitor is inserted into the ;-network so as to interpose a capacitor between each of the network contacts and the terminals of the crystal unit. The electrical circuit arrangement when the crystal and load capacitor are in position, is shown in
43、Figure A3. Provision should be made so that the load capacitor is held in a vertical position in the ;-network. A1.3 Calibration and measurement of load capacitors A1.3.1 Calibration of the load capacitor shall be carried out at a frequency of 1 kHz using an appropriate capacitance meter allowing th
44、e measurement of one-port capacitors (with one lead of which is earthed). The procedure is as follows: A1.3.2 Measure the capacitance of the test fixture C iof the capacitance meter without the load capacitor inserted. A1.3.3 Insert the load capacitor and measure the two sections of it. The resultin
45、g capacitance values areC RAand C RB . A1.3.4 The actual value of the load capacitance C Lis calculated from the relation: A1.3.5 Cross-talk capacitance measurement The cross-talk capacitance C ccan be calculated from the measurement of the cross-talk attenuation of the load capacitor. The relation
46、between the cross-talk attenuation and the cross-talk capacitance is given by the equation: The cross-talk attenuation of the capacitor can be measured in a similar way to that described in IECPublication 444-1, Sub-clause5.1 using the following equation: where V Bo-totalis he B channel voltage meas
47、ured with the load capacitor inserted andV Bo-networkis that measured with the network only, V Bsis the voltage measured with the shorting blank inserted in place of the load capacitor. (1) (2) (3)EN60444-4:1997 BSI 04-1999 5 A2 Measurement errors A2.1 General The standard method for measurement of
48、the motional capacitance C 1and motional inductance L 1is given in IEC Publication 444-2. However, the ;-network in conjunction with the load capacitor described above can also be used to measure the motional capacitance C 1and inductance L 1 . A2.2 Main sources of measurement errors The main source
49、s of measuring errors are: crystal holder capacitances C AHand C BH ; residual stray capacitances; residual contact resistances; accuracy of load capacitance value calibration; accuracy of frequency and resistance measurement in the ;-network using the zero-phase method. The load capacitance inaccuracy due to calibration uncertainty and frequency dependence is shown in Figure A4. The main reason is the residual inductance L rof the load capacitor which results in a slight increase of C Lwith frequency. Th
