1、BRITISH STANDARD Connectors for electronic equipment - Tests and measurements - Part 25-4: Test 25d - Propagation delay The European Standard EN 60512-25-4:2001 has the status of a British Standard ICs :31.220.10 BS EN 60512-25-4: 2001 IEC 60512-25-4: 2001 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS
2、 PERMITTED BY COPYRIGHT LAW BS EN 60512-25-4:2001 Amd. No. National foreword Date Comments 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
3、 19 November 2001 This British Standard is the official English language version of EN 60512-25-4:2001. It is identical with IEC 60512-25-4:2001 The UK participation in its preparation was entrusted by Technical Committee EPW48, Electromechanical components far electronic equipment, to Subcommittee
4、EPL/48/2, Connectors for electronic equipment, which has the responsibility to: - - aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related inte
5、rnational and European developments and promulgate them in the UK. - 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 27-1 has been renumber
6、ed 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 document may be found in th
7、e 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 British Standards are res
8、ponsible for their correct 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, the EN title page, pages 2 to 12, an inside back cover and a back cover. The BSI copyri
9、ght date displayed in this document indicates when the document was last issued. 8 BSI i9 November 2001 2 EUROPEAN STANDARD EN 6051 2-25-4 NORME EUROPENNE EUROPISCHE NORM October 2001 ICs 31.220.10 English version Connectors for electronic equipment - Tests and measurements Part 25-4: Test 25d - Pro
10、pagation delay (I EC 605 1 2-25-41 200 I ) Connecteurs pour quipements lectroniques - Essais et mesures Partie 25-4: Essai 25d - Retard de propagation (CE1 60512-25-4:2001) Steckverbinder fr elektronische Einrichtungen - Mess- und Prfverfahren Teil 25-4: Prfung 25d - Laufzeitverzgerung (IEC 6051 2-2
11、5-4:2001) This European Standard was approved by CENELEC on 2001-10-01. CENELEC members are bound to comply with the CENICENELEC 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 biblio
12、graphical 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 oficial versions (English, French, German). A version in any other language made by translation under the responsibility
13、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 Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxemb
14、ourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35,B - 1050
15、 Brussels O 2001 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60512-25-4:2001 E Page 2 EN 60512-25-4:2001 Foreword The text of document 488/1061/FDIS, future edition 1 of IEC 60512-25-4, prepared by SC 488, Connectors, of IEC T
16、C 48, Electromechanical components and mechanical structures for electronic equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60512-25-4 on 2001-10-01. The following dates were fixed: - latest date by which the EN has to be implemented at national level by p
17、ublication of an identical national standard or by endorsement - latest date by which the national standards conflicting with the EN have to be withdrawn Annexes designated “normative“ are part of the body of the standard. Annexes designated “informative“ are given for information only. In this stan
18、dard, annex A is normative and annex 6 is informative. (dop) 2002-07-01 (dow) 2004-10-01 Endorsement notice The text of the International Standard IEC60512-254:2001 was approved by CENELEC as a European Standard without any modification. O BSI 19 November 2001 Page 3 EN 60512-25-4:2001 CONTENTS Gene
19、ral . 4 1 . 1 Scope and object 4 1.2 Definitions 4 Test resources . 4 2.1 Equipment 4 2.2 Fixture 5 Method A, single-ended 5 Method B, differentially driven . 5 Test specimen . 6 3.1 Description . 6 3.1 . 1 Separable connectors . 6 3.1.2 Cable assembly 6 3.1.3 Sockets . 6 Test procedure 6 4.1 Probe
20、technique . 6 4.2 Insertion technique . 7 4.3 Reference fixture technique 7 Details to be specified . 7 Test documentation . 7 2.2.1 2.2.2 Annex A (normative) Diagrams and schematics of fixtures and equipment 9 Annex B (informative) Practical guidance . 12 Figure I . Rise time measurement points . 8
21、 Figure 2 . Propagation delay measurement points . 8 Figure A.1 . Technique diagrams . 9 Figure A.2 . Single-ended terminations . 10 Figure A.3 . Differential (balanced) terminations . 11 Table 1 . Recommended measurement system rise time (including fixture and filtering) 6 O BSI 19 November 2001 Pa
22、ge 4 EN 60512-25-42001 CONNECTORS FOR ELECTRONIC EQUIPMENT - TESTS AND MEASUREMENTS - Part 25-4: Test 256 - Propagation delay 1 General 1.1 Scope and object This part of IEC 60512 applies to electrical connectors, sockets, cable assemblies or inter- connection systems. This standard describes a meth
23、od for measuring the time it takes for a digital signal to propagate from one specified point to a second specified point. 1.2 Definitions For the purpose of this part of IEC 6051 2, the following definitions apply. 1.2.1 measurement system rise time rise time measured with the fixture in place, wit
24、hout the specimen, and with filtering (or normalization). Rise time is typically measured from 10 % to 90 % levels; see figure 1 1.2.2 specimen environment impedance impedance presented to the signal conductors by the fixture. This impedance is a result of transmission lines, termination resistors,
25、attached receivers or signal sources, and fixture parasitics 1.2.3 propagation delay time required for a signal to travel between two specified points of an interconnect system; see figure 2 2 Test resources 2.1 Equipment 2.1 .I Pulse generator and oscilloscope, time domain reflectometer (TDR) or ot
26、her suitable equipment with a measurement system rise time less than or equal to the measured propagation delay. 2.1.2 Probes Probes, where applicable, shall have suitable rise time performance and circuit loading characteristics (resistance and capacitance). O BSI 19 November 2001 Page 5 EN 60512-2
27、5-42001 2.2 Fixture Unless otherwise specified in the reference document, the specimen environment impedance shall match the impedance of the test equipment. Typically, this will be 50 I2 for single-ended measurements and 100 SR2 for differential. 2.2.1 Method A, single-ended The fixture shall allow
28、 one signal line to be driven at a time. The driven line shall be terminated according to one of the methods of figure A.2 with the specimen environment impedance. Unless otherwise specified, a 1:l signal-to-ground ratio shall be used with each end having all grounds commoned. Each line adjacent to
29、the driven line(s) shall also be terminated in the specimen environment impedance at both near and far ends. 2.2.1 .I Probe technique The fixture shall be designed to allow the signal to be probed at the two points between which the delay is to be measured; see figure A.la. 2.2.1.2 Insertion techniq
30、ue The fixture shall be designed to allow measurement of propagation delay with and without the specimen; see figure A.lb. 2.2.1.3 Reference fixture technique Two fixtures shall be designed that include the same fixture electrical length and character- istics of environment transmission line. The “s
31、pecimen fixture” includes the specimen. The “reference fixture” does not include the specimen. The fixture electrical length does not include the specimen length; see figure A. 1 c. 2.2.2 Method 6, differentially driven The fixture shall allow one signal pair to be driven at a time. The driven line
32、shall be terminated according to one of the methods of figure A.3 with the specimen environment impedance. Unless otherwise specified, a 2:l signal-to-ground ratio shall be used. Each line adjacent to the driven line(s) shall also be terminated in the specimen environment impedance at both near and
33、far ends. 2.2.2.1 Probe technique The fixture shall be designed to allow the signal pair to be probed at the points between which the delay is to be measured; see figure A.1a. 2.2.2.2 Insertion technique The fixture shall be designed to allow measurement of propagation delay with and without the spe
34、cimen; see figure A.l b. 2.2.2.3 Reference fixture technique Two fixtures shall be designed that include the same fixture electrical length and characteristics of the environment transmission line. The “specimen fixture” includes the specimen. The “reference fixture” does not include the specimen. T
35、he fixture electrical length does not include the specimen length; see figure A.lc. O BSI 19 November 2001 Page 6 I EN 60512-25-4:2001 Measured (expected) propagation delay of the specimen PS 100 - 500 500 - 1 O00 I O00 3 Test specimen Measurement system rise time PS 1 O0 500 1 O00 3.1 Description F
36、or this test procedure, the test specimen shall be as follows. 3.1.1 Separable connectors A mated connector pair. 3.1.2 Cable assembly Assembled connectors and cables, and mated connectors. 3.1.3 Sockets A socket and test device or a socket and pluggable header adaptor. 4 Test procedure Unless other
37、wise specified, the measurement system rise time shall be less than or equal to the measured delay. The measurement system rise times specified in table 1 are recom- mended. The three techniques below apply to single-ended and differential measurements. For differential measurements, it is necessary
38、 to determine if any phase andlor amplitude errors exist between the probelchannels and to provide necessary compensation for these errors so that each step arrives at the specimen simultaneously. Two measurements shall be performed as described in 4.2 or 4.3 and the time difference recorded; see fi
39、gure 2 and figure A.1. Unless otherwise specified, for all three techniques the delay shall be measured at both the 10 % and 50 % amplitudes. Place the specimen a minimum of 5 cm from any object that would affect measured results. NOTE 1 The test professional should be aware of limitations of any ma
40、thematical operation(s) performed by an instrument (e.g. normalization or software filtering). NOTE 2 Specimen induced skew should not be compensated. When skew is observed, a waveform plot should be provided. NOTE 3 The input and output step amplitudes may not be equal, due to attenuation in the de
41、vice under test. When this occurs, the output step 10 Yo and 90 % levels are referenced from maximum output voltage, regardless of what voltage was put in. 4.1 Probe technique Measure the time difference between the input and output voltages. This is the propagation delay. O BSI 19 November 200 1 Pa
42、ge 7 EN 60512-25-42001 4.2 Insertion technique Measure the time difference of the output voltage with and without the specimen. This is the propagation delay. 4.3 Reference fixture technique Measure the time difference between the “reference fixture” and the “specimen fixture”. This is the propagati
43、on delay. 5 Details to be specified The following details shall be specified in the reference document. 5.1 Measurement system rise time, if other than specified in table 1 5.2 Termination value (and tolerances). 5.3 Signallground pattern, including the number and location of signal and grounds to b
44、e wired for this test. It is recommended that the specimen locations represent the maximum and minimum delays. 5.4 Points between which the delay shall be measured. 5.5 differential. Specimen environment impedance if other than 50 SZ for single-ended and 100 Cl for 6 Test documentation Documentation
45、 shall contain the details specified in clause 5, with any exceptions, and the following. 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 Title of test. Test equipment, and date of last and next calibration. Test procedure and method. Fixture description. Measurement system rise time (including fixture and filt
46、ering, 10 % to 90 %). Measured propagation delay(s). Waveform plots (when required); see clause 4, note 2. Observations. Name of operator and date of test. O BSI 19 November 2001 Page 8 EN 60512-25-4:2001 Input rise time 90 yo V, 100 Vin Input waveform L 10 % 5, Output rise time IEC f193nf Output wa
47、veform Components Kn input voltage Vaut output voltage Figure 1 - Rise time measurement points Input waveform Output waveform 100 % y“ 1 100 % v, td (50 %) + 50 IEC 1190/01 Components R, resistor 1 Ri resistor 2 Z, characteristic impedance i, source voltage Minimum loss pad equations: R1 = 50 I - (Z
48、, / 5O)Ov5 R* = z, / I - (z, 50)iO. Ri = Z, I - (50 I Z,)o5 R2 = 50 / I - (50 / Z,)o5 Figure A.2 - Single-ended terminations O BSI 19 November 2001 Page 11 EN 60512-25-4:2001 a) VO + O Test 1 soecimen - R, = Z, I R, = 242 b) 50 n receivers zo = loo c) O R2 f 4 Z“ .= 100 or 50 Cl receivers 2, 100 IEC
49、 1191/01 Components RI resistor 1 RI resistor 2 Z, characteristic impedance V, source voltage Minimum loss pad equations: R, = 100 I - (z, IOO). I 2 R2 = Z, I I - (Z, I 100)o5 R = z, I - (100 I Z,)IO. 2 R2 = 100 I I - (100 I Z,)o,5 Figure A.3 - Differential (balanced) terminations O BSI 19 November 2001 Page 12 EN 60512-25-4:2001 Annex 6 (informative) Practical guidance Near perfect resistive terminations of the signal lines may not be possible at high frequencies due to parasitic reactances in both signal and ground conductors. These reactances will h
