1、 ANSI/EIA-364-87A-2009 Approved: May 20, 2009EIA STANDARD TP-87A NANOSECOND EVENT DETECTIONTEST PROCEDURE FOR ELECTRICAL CONNECTORS, CONTACTS AND SOCKETS (Revision of EIA-364-87) EIA-364-87A EIA-364-87AMAY 2009 EIA Standards Electronic Components Association NOTICE EIA Engineering Standards and Publ
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7、mine the applicability of regulatory limitations before its use. (From Standards Proposal No. 5181 formulated under the cognizance of the CE-2.0 National Connector and Socket Standards Committee) Published by: ELECTRONIC COMPONENTS ASSOCIATION 2009 EIA Standards and Technology Department 2500 Wilson
8、 Boulevard Suite 310 Arlington, VA 22201 PRICE: Please call: Global Engineering Documents, USA and Canada (1-800-854-7179) http:/ All rights reserved Printed in U.S.A. PLEASE! DONT VIOLATE THE LAW! This document is copyrighted by the EIA and may not be reproduced without permission. Organizations ma
9、y obtain permission to reproduce a limited number of copiesthrough entering into a license agreement. For information, contact: Global Engineering Documents 15 Inverness Way East Englewood, CO 80112-5704 or call USA and Canada (1-800-854-7179), International (303-397-7956) CONTENTS Clause Page 1 Sco
10、pe . 1 1.1 Content 1 1.2 Description 1 1.3 Definition 1 2 Test conditions 1 3 Test Methods . 2 3.1 Method 1 . 2 3.2 Method 2 . 9 4 Details to be specified . 15 5 Test documentation . 15 Table 1 Test condition . 2 2 Pulse width tolerances 13 Figure 1 Equipment setup for amplitude sensitivity measurem
11、ent . 3 2 Series wired specimen example 4 3 TDR measurement trace of specimen circuit 5 4 Ten and 50 nanosecond fixturing 7 5 One nanosecond fixturing with nested 6 x 6 cm EMI loops . 8 6 Basic detector/test specimen arrangement 10 7 Typical pulse generator layout 12 8 Typical pulse generator layout
12、 12 9 Typical ac characterization plot 14 i (This page left blank) ii EIA-364-87A Page 1 TEST PROCEDURE No. 87A NANOSECOND EVENT DETECTION FOR ELECTRICAL CONNECTORS, CONTACTS AND SOCKETS (From EIA Standards Proposal No. 5181, formulated under the cognizance EIA CE-2.0 Committee on National Connector
13、 and Socket Standards, and previously published as EIA-364-87.) 1 Scope 1.1 Content The object of this procedure is to define methods for detecting events that can be as short as 1 nanosecond, see table 1. 1.2 Description 1.2.1 The methods as described herein are for detection of specimen failure ev
14、ents resulting from short duration large resistance fluctuations, or voltage variations that may result in improper triggering of high speed digital circuits. 1.2.2 Nanosecond duration event detection is considered necessary based on application susceptibilities to noise. This technique is not capab
15、le of measuring the duration of an event. 1.2.3 Low nanosecond event detection shall not be used as a substitute for the standard 1.0 microsecond requirement. This test was developed to detect different failure mechanisms then those used for he 1.0 microsecond minimum time duration. The number of co
16、ntacts being monitored in a series circuit will significantly limit the time events possible for detection of a specified event; see 3.1.3.1.2, Method 1 and 3.2.4.1, Method 2. 1.3 Definition An event shall be defined as a voltage increase of a given magnitude that lasts longer than a specified time
17、duration. 2 Test conditions 2.1 Test current shall be 100 mA 20 mA when the specimen is a maximum of 10 ohms, unless otherwise specified in the referencing document. 2.2 The resistance change necessary to produce an event shall be 10 ohms, unless otherwise specified in the referencing document. NOTE
18、 Subclauses 2.1 and 2.2 define the default voltage increase of 1.0 volt 0.2 volts necessary to produce an event. EIA-364-87A Page 2 Table 1 - Test conditions Application Test condition Minimum event duration, nanosecond(s) Test method 1 Test method 2 A 1.0 Yes No B 2.0 Yes YesC 5.0 Yes YesD 10.0 Yes
19、 Yes E 20.0 Yes YesF 50.0 Yes YesG As specified in the referencing document NOTE The application column indicates the method that may be used for the event duration indicated. Event durations of 1.0, 10.0 and 50.0 nanoseconds are preferred. 3 Test methods 3.1 Method 1 3.1.1 Equipment 3.1.1.1 Detecto
20、r The detector used shall be an AnaTech 64 EHD, 32 EHD or equivalent. The detector shall meet the following requirements: 3.1.1.1.1 Electromagnetic interference (EMI) Detector shall pass the European Community (EC) electrostatic discharge (ESD) requirement for computers (EN50 082-1:94, based on IEC
21、801-2, ed 2:91). The performance criteria is “1) normal performance within the specification limits;“ i.e., no channel is allowed to trip. Air discharge voltages shall include 2, 4, 8 and 15 kilovolts. Contact discharge voltages shall include 2, 4, 6 and 8 kilovolts. Detector inputs shall be protect
22、ed with coaxial shorts. 3.1.1.1.2 DC current Each channel shall supply 100 milliamperes 20 milliamperes when the specimen is a maximum of 10 ohms resistance. 3.1.1.1.3 Input impedance 3.1.1.1.3.1 Direct current (dc) Detector source resistance (impedance) shall be 50 ohms when the specimen resistance
23、 is between zero and 10 ohms. EIA-364-87A Page 3 3.1.1.1.3.2 RF input impedance A Time Domain Reflectometer (TDR) or Network Analyzer Time Domain Reflectometer (NATDR) shall be used to measure the reflection in percent of a (simulated) 0.5 nanosecond risetime step when the specimen direct current re
24、sistance is 10 ohms and the detector current is 100 milliamperes. (The 10 ohm specimen resistance is put on the bias port for NATDR.) An acceptable detector shall reflect less than 30% amplitude. 3.1.1.1.4 Amplitude sensitivity Amplitude required to trip the detector with a 1 nanosecond duration pul
25、se shall be no more than 120% of the direct current trip amplitude. One nanosecond pulse duration shall be measured at 90% of the pulse amplitude, and the rise and fall times shall be less than 0.5 nanosecond. Pulse low level shall be zero volts. These shall be measured with a 1 gigahertz bandwidth
26、oscilloscope and a pulse generator; see figure 1. Figure 1 - Equipment setup for amplitude sensitivity measurement 3.1.1.1.5 Accuracy It shall be possible to adjust the detector to trip at 10 ohms 1 ohm for all channels in use, unless otherwise specified in the referencing document. 3.1.2 Test setup
27、 Recommended equipment is as shown in figure 4. A short flexible ground strap directs ground loop currents away from the specimen. The RG-223 coaxial cable is well shielded whereas the short 50 ohm miniature coaxial cable is flexible. Each EMI loop is connected to a detector channel and is used as a
28、 control. EIA-364-87A Page 4 3.1.3 Specimen and EMI loop preparation Specimen circuit shall have a resistance less than 4 ohms. 3.1.3.1 Specimen wiring 3.1.3.1.1 A contact or series wired contacts; see figure 2, note A, shall be wired from the center conductor to the braid of miniature 50 ohm coaxia
29、l cable; see figure 4, note C. NOTES A Series wired contacts, see 3.1.3.1.1. B Contacts skipped to reduce crosstalk, see 3.1.3.2.2. C The circuit with maximum capacitance to fixture, see 3.1.3.3.1.2 and 3.1.3.3.2.2 D The very short miniature coaxial cable ground, see 3.1.3.2.1. Figure 2 - Series wir
30、ed specimen example EIA-364-87A Page 5 3.1.3.1.2 The specimen, as wired to the miniature coaxial cable for testing, shall be capable of passing short duration pulses. A time domain reflectometer (TDR) shall be used to measure the transition time of a fast risetime step (28.9ns will be detected. NOTE
31、 Requirement is that point 2 - point 1 25 mm wide, see 3.1.4.3. F. Strain relief coaxial cable at these locations. G. Physical support for patch panel. H. RG-223 double braid coaxial cable. Figure 4 - Ten and 50 nanosecond fixturing EIA-364-87A Page 8 3.1.3.3.2 One nanosecond 3.1.3.3.2.1 Three contr
32、ol channels shall be provided, consisting of 3 nested, mutually perpendicular loops, see figure 5. Each loop shall have a nominal area of 36 square cm (e.g., 6 cm x 6 cm). These loops shall be suspended over the specimen(s). 3.1.3.3.2.2 Find the series wired circuit with the greatest capacitance to
33、the fixturing metal, measured without any coaxial cable attached. Instead of connecting this to a miniature coaxial cable, connect it to the center of one of the control channel loops, opposite the coaxial cable connection. A separate specimen may be required if specimen has only one contact . Figur
34、e 5 - One nanosecond fixturing with nested 6 x 6 cm EMI loops 3.1.4 Procedure 3.1.4.1 Prepare specimens and the fall time shall be measured per 3.1.3.1.2 using TDR. If this requirement cannot be met, fewer contacts in series or better fixture wiring may be required. 3.1.4.2 The EMI loop(s) shall be
35、placed in accordance with 3.1.3.3 over the specimen and connected to the specimen circuit with greatest capacitance. EIA-364-87A Page 9 3.1.4.3 The equipment shall be assembled as indicated in figure 4 (or 5 for one nanosecond). The 50 ohm miniature coaxial cable and especially the ground strap, see
36、 figure 4, note E, shall be kept as short as practical. Additionally, the miniature coaxial cable ground connection to connector shell and/or metal fixturing shall be as short as possible and perpendicular to nearby specimen conductors, see 3.1.3.2.1 and figure 2. 3.1.4.4 Turn on detector. Unless ot
37、herwise specified, the detector shall be set to deliver 100 milliamperes 20 milliamperes and set to trip at 10 ohms above the initial resistance. Reset all channels. If the referencing document specifies using a current less than 80 milliamperes or a threshold resistance less than 10 ohms, it may be
38、 necessary to add additional shielding, i.e., shielded room, box, etc. 3.1.4.5 Disconnect each specimen from the detector by unmating the coaxial connectors. Confirm that the indicator trips when disconnected as a functional check. 3.1.4.6 The desired environmental stress shall be applied to the con
39、nector-under-test. The test shall be broken up into equal length time periods. At the end of each, the status of each channel shall be polled. Any events detected during a polling period that also registers an event on a control channel shall be considered EMI induced (not a connector failure). 3.1.
40、4.7 At the end of testing, the failure indications at different polling times shall be analyzed for patterns suggesting EMI, such as simultaneous events in different channels. 3.2 Method 2 3.2.1 Equipment 3.2.1.1 Direct current power supply capable of supplying currents up to 100 milliamperes with a
41、n accuracy of 10% when the specimen is 10 ohms maximum. 3.2.1.2 Detector(s) compatible for detecting events as specified. 3.2.1.3 Pulse generator compatible to the speed characteristics as specified. 3.2.1.4 Digital scope with a minimum bandwidth of 1.0 GHz. 3.2.2 Basic theory of operation 3.2.2.1 F
42、igure 6 indicates the basic detector/test specimen arrangement EIA-364-87A Page 10 Figure 6 - Basic detector/test specimen arrangement 3.2.2.2 A constant dc signal is maintained through the contacts under test. The resistance across the test specimen will be the sum of the resistances of the contact
43、s wired in series for the test. This resistance will be in the order of milliohms. The resistor has a magnitude significantly higher than the specimen resistance. This results in the detector input voltage in being low. 3.2.2.3 Thus any increase in the contact resistance will cause the detector inpu
44、t to increase. If this voltage increase exceeds the detector threshold and is maintained for a given time period, the detector will trigger. 3.2.2.4 The time period that the detector input voltage must exceed the threshold level is dependent upon the detection circuit design and the transmission lin
45、e attenuations. With the use of the proper components and careful circuit layout, the detector is designed to operate when the threshold level has exceeded the specified time period. 3.2.2.5 The detector system may be interfaced with a computer system to log the number of events that may occur along
46、 with other pertinent information. In this instance, automatic reset capability should be employed. 3.2.2.6 A discrete detection circuit, suitable logic analyzer or storage oscilloscope could be used as the “detector” for this type of testing. 3.2.3 Typical discrete circuit considerations 3.2.3.1 Th
47、e following subclauses are a list of precautions to be taken when using an ECL detector circuit for monitoring logic events. 3.2.3.2 Similar techniques should be used with other types of detection, i.e., GaAs FETs, fast CMOS, oscilloscope input circuits, etc., in order to minimize false triggering (
48、noise) and input circuit frequency response. EIA-364-87A Page 11 3.2.3.3 The first consideration is the response and sensitivity of the test circuit used. For this purpose, the set, rest, or clock input of an ECL flip flop are the possible choices for low nanosecond event detection. 3.2.3.4 To incre
49、ase noise immunity and decrease false triggering, the VEE of the ECL logic is set to -5.2 volts. 3.2.3.5 Transmission lines shall be kept as short as possible to reduce losses. 3.2.3.6 A 100 ma current shall be used to power the contacts under test. This level is used since lower values will reduce sensitivity and increase false triggering. 3.2.3.7 An “Event” shall be defined as a change in ECL logic. The level of an event that will trigger the monitor can be controlled by varying the voltage at the low end of the contacts (V ref). Increasing V ref wi
