1、BRITISH STANDARD BS EN 60512-25-1: 2001 IEC 60512-25-1: 2001 Connectors for electronic equipment Tests and measurements Part 25-1: Test 25a Crosstalk ratio The European Standard EN 60512-25-1:2001 has the status of a British Standard ICS 31.220.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTE
2、D BY COPYRIGHT LAWBS EN 60512-25-1:2001 This British Standard, having been prepared under the direction of the Electrotechnical Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 16 November 2001 BSI 16 November 2001 ISBN 0 580 3
3、8668 6 National foreword This British Standard is the official English language version of EN 60512-25-1:2001. It is identical with IEC 60512-25-1:2001. The UK participation in its preparation was entrusted by Technical Committee EPL/48, Electromechanical components for electronic equipment, to Subc
4、ommittee EPL/48/2, Connectors for electronic equipment, which has the responsibility to: A list of organizations represented on this Subcommittee can be obtained on request to its secretary. From 1 January 1997, all IEC publications have the number 60000 added to the old number. For instance, IEC 27
5、-1 has been renumbered as IEC 60027-1. For a period of time during the change over from one numbering system to the other, publications may contain identifiers from both systems. Cross-references The British Standards which implement international or European publications referred to in this documen
6、t may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by 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 Brit
7、ish Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposa
8、ls for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 18, an inside back cover and a back cover. The BSI co
9、pyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 60512-25-1 NORME EUROPENNE EUROPISCHE NORM October 2001 CENELEC European Committee for Electrotechnical Standardization Comit Europen de
10、 Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2001 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60512-25-1:2001 E ICS 31.220.10 Engli
11、sh version Connectors for electronic equipment - Tests and measurements Part 25-1: Test 25a - Crosstalk ratio (IEC 60512-25-1:2001) Connecteurs pour quipements lectroniques - Essais et mesures Partie 25-1: Essai 25a - Taux de diaphonie (CEI 60512-25-1:2001) Steckverbinder fr elektronische Einrichtun
12、gen - Mess- und Prfverfahren Teil 25-1: Prfung 25a - bersprechen (IEC 60512-25-1:2001) This European Standard was approved by CENELEC on 2001-10-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the stat
13、us 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, French, German).
14、 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 electrotechnical committees of Austria, Belgium, Czech Republ
15、ic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Foreword The text of document 48B/1059/FDIS, future edition 1 of IEC 60512-25-1, prepared by SC 48B, Connectors, of IEC TC 48, Elect
16、romechanical components and mechanical structures for electronic equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60512-25-1 on 2001-10-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of
17、 an identical national standard or by endorsement (dop) 2002-07-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2004-10-01 Annexes designated “normative“ are part of the body of the standard. Annexes designated “informative“ are given for information
18、 only. In this standard, annex A is normative and annex B is informative. _ Endorsement notice The text of the International Standard IEC 60512-25-1:2001 was approved by CENELEC as a European Standard without any modification. _ Page 2 EN 60512251:2001 BSI 16 November 2001CONTENTS 1 General 4 1.1 Sc
19、ope and object 4 1.2 Definitions 4 2 Test resources.5 2.1 Equipment 5 2.1.1 Method A, time domain 5 2.1.2 Method B, frequency domain . 5 2.2 Fixture 5 2.2.1 Specimen conductor assignments . 6 2.2.2 Termination. 6 2.2.3 Crosstalk 6 2.2.4 Insertion technique fixture . 6 2.2.5 Reference fixture techniq
20、ue. 6 3 Test specimen . 7 3.1 Description . 7 3.1.1 Separable connectors . 7 3.1.2 Cable assembly. 7 3.1.3 Sockets. 7 4 Test procedure.7 4.1 Method A, time domain . 7 4.2 Method B, frequency domain. 9 5 Details to be specified.11 5.1 All tests .11 5.2 Time domain only.11 5.3 Frequency domain only 11
21、 5.4 Additional recommended fixture specifications by the referencing document.11 6 Test documentation.12 Annex A (normative) Diagrams and schematics of fixtures and equipment 14 Annex B (informative) Practical guidance18 Figure 1 Waveform .13 Figure A.1 Technique diagrams 14 Figure A.2 Single-ended
22、 terminations .15 Figure A.3 Differential (balanced) terminations16 Figure A.4 Far-end crosstalk, balanced terminations.17 Table 1 Recommended measurement system rise time (including fixture and filtering) . 8 Page 3 EN 60512251:2001 BSI 16 November 2001CONNECTORS FOR ELECTRONIC EQUIPMENT TESTS AND
23、MEASUREMENTS Part 25-1: Test 25a Crosstalk ratio 1 General 1.1 Scope and object This part of IEC 60512 applies to interconnect assemblies, such as electrical connectors, sockets and cable assemblies. This standard describes test procedures for measuring the magnitude of the electric and magnetic cou
24、pling between driven and quiet lines of an interconnect assembly. Both time domain (method A) and frequency domain methods (method B) for single-ended and differential transmission are described. Insertion and reference fixture techniques are also described. 1.2 Definitions For the purpose of this p
25、art of IEC 60512, the following definitions apply. 1.2.1 drive signal a step waveform (in the time domain) or a sinusoidal waveform (in the frequency domain) 1.2.2 crosstalk ratio ratio of the signal coupled (induced) into the quiet signal conductor or conductor pair to the magnitude of the signal i
26、n the driven conductor or conductor pair. Both signals have the same units of either voltage or current, and the ratio may be expressed in per cent or decibels (dB) 1.2.3 near end crosstalk ratio (NEXT) crosstalk ratio calculated on the quiet line at or in proximity to the sending (signal source) en
27、d of the driven line. This is the ratio of the near end quiet line signal amplitude to the near end driven line signal amplitude 1.2.4 far end crosstalk ratio (FEXT) crosstalk ratio calculated on the quiet line at or in proximity to the receiving (destination) end of the driven line. This is the rat
28、io of the far end quiet line signal amplitude to the near end driven line signal amplitude 1.2.5 measurement system rise time rise time measured with fixture in place, without the specimen, and with filtering (or normal- ization). Rise time is typically measured from 10 % to 90 % levels Page 4 EN 60
29、512251:2001 BSI 16 November 20011.2.6 specimen environment impedance impedance presented to the specimen signal conductors by the fixture. This impedance is a result of transmission lines, termination resistors, attached receivers or signal sources, and fixture parasitics 1.2.7 step amplitude voltag
30、e difference between the 0 % and 100 % levels, ignoring overshoot and undershoot, as indicated in figure 1 1.2.8 isolation standard reference fixture without a test sample and with identical crosstalk characteristics as the test fixture. This fixture may or may not be part of the test board 2 Test r
31、esources 2.1 Equipment 2.1.1 Method A, time domain 2.1.1.1 A step generator is used on the driven line and an oscilloscope monitors the quiet line. In a differential application, both shall be able to process differential signals. Typically, this means complementary outputs with provision for amplit
32、ude and skew adjustment, and dual inputs with a display of the difference and sum. Filtering or normalization shall be available for varying the rise time. A time domain reflectometer (TDR) is usually used. NOTE The test professional should be aware of limitations of any mathematical operation(s) pe
33、rformed by an instrument, (e.g. normalization or software filtering). 2.1.1.2 Probes Probes, when used, shall have suitable rise time performance and circuit loading charac- teristics (resistance and capacitance). 2.1.2 Method B, frequency domain A network analyzer is preferred. When greater dynamic
34、 range is desired, a signal generator and spectrum analyzer or a vector network analyzer (for measurement with full 2-port calibration) may alternatively be used. If necessary, additional equipment to increase the measurement sensitivity (e.g. broadband output amplifiers or low-noise preamplifiers)
35、may be used. A multi-port network analyzer with appropriate software or baluns may be used for differential measurements. 2.2 Fixture Unless otherwise specified in the referencing document, the specimen environment impedance shall match the impedance of the test equipment. Typically, this will be 50
36、 for single-ended measurements and 100 for differential. Page 5 EN 60512251:2001 BSI 16 November 20012.2.1 Specimen conductor assignments For each measurement, the driven and quiet lines shall be fixtured as indicated in the reference document. In the special case where the drive signal is different
37、ial and not balanced, the common mode energy shall be terminated. Adjacent signal lines to these should likewise be terminated if possible (electrically long adjacent signal lines may resonate, adding error to the results). Unless otherwise specified, a 1:1 signal-to-ground ratio (one differential p
38、air to one ground if differential measurements are performed) shall be used with each end having all grounds commoned. For an example, see figure A.4. 2.2.2 Termination The far end of the driven lines and both ends of the quiet line shall be terminated in the specimen environment impedance specified
39、 using one of the methods in figures A.2 and A.3. Care should be taken to minimize the reactances of the resistive terminations over the range of test frequencies. NOTE The fixture geometry and materials may impact the measurements due to the fixture parasitics. Usually, the products intended use di
40、ctates the most meaningful way to fixture it. 2.2.3 Crosstalk It is not usually possible to separate fixture crosstalk from that of the specimen. Also, where ground currents are combined in a fixture conductor, common impedance coupling will occur that will add to the actual crosstalk. The reference
41、 document should specify the fixture so that its crosstalk contribution is minimized and termination impedances are duplicated. When this is not specified, these contributions should be small compared to the actual specimen crosstalk. NOTE Since the test board footprint or cable assembly termination
42、 technique can significantly impact the crosstalk, it is recommended that an isolation standard (for measuring fixture crosstalk) be included in the fixture. 2.2.4 Insertion technique fixture The fixture shall be designed to allow measurement of crosstalk with and without the specimen, see figure A.
43、1. If baluns are used for a balanced measurement, or minimum loss pads used for impedance matching, see figures A.2 and A.3, these are included in the fixture. 2.2.5 Reference fixture technique In this technique, a separate fixture that combines both near end and far end is used for the fixture cros
44、stalk measurement. This fixture shall be a duplicate of the specimen fixture, only without the specimen. Traces, if used, shall include fixture connectors, vias, bends and corners. If baluns are used for a balanced measurement, or minimum loss pads used for impedance matching, see figures A.2 and A.
45、3, these are included in the fixture. Page 6 EN 60512251:2001 BSI 16 November 20013 Test specimen 3.1 Description For this test procedure, the test specimen shall have more than one signal line and shall be as follows. 3.1.1 Separable connectors A mated connector pair. 3.1.2 Cable assembly Assembled
46、 connectors and cables, and mating connectors. 3.1.3 Sockets A socket and test device or a socket and pluggable header adapter. 4 Test procedure The far end of the driven lines and both ends of the quiet line(s) shall be terminated in the specimen environment impedance specified using one of the met
47、hods in figures A.2 and A.3. For increased accuracy, it may be necessary to terminate the adjacent signal lines. 4.1 Method A, time domain 4.1.1 Place the specimen a minimum of 5 cm from any objects that would affect measured results. 4.1.2 Reference measurement and fixture crosstalk Crosstalk is a
48、function of drive step rise time and amplitude in the specimen. The drive step rise time is increased by the fixture. Thus the measurement system rise time will be greater than the rise time produced by the test equipment and shall be measured. Rise time shall be measured from 10 % to 90 % levels. F
49、ixture crosstalk adds to the specimen crosstalk. The fixture includes minimum loss pads, if used. If the reference document precisely describes the fixture so that its crosstalk contribution is known, then the fixture crosstalk measurement is optional. These results are a magnitude versus time plot. Measure the measurement system rise time, drive amplitude and fixture crosstalk with one of the following techniques. 4.1.2.1 Insertion technique 4.1.2.1.1 Assemble the fixture so that the near end is connec
