1、 EIA STANDARD TP-107 Eye Pattern and Jitter Test Procedure for Electrical Connectors, Sockets, Cable Assemblies or Interconnection Systems EIA-364-107 May 2000 EIA-364-107 ANSI/EIA-364-107-2000 (R2013) Approved: March 10, 2000 Reaffirmed: January 15, 2013 NOTICE EIA Engineering Standards and Publica
2、tions are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for his particular nee
3、d. Existence of such Standards and Publications shall not in any respect preclude any member or nonmember of ECIA from manufacturing or selling products not conforming to such Standards and Publications, nor shall the existence of such Standards and Publications preclude their voluntary use by those
4、 other than ECIA members, whether the standard is to be used either domestically or internationally. Standards and Publications are adopted by ECIA in accordance with the American National Standards Institute (ANSI) patent policy. By such action, ECIA does not assume any liability to any patent owne
5、r, nor does it assume any obligation whatever to parties adopting the Standard or Publication. This EIA Standard is considered to have International Standardization implication, but the International Electrotechnical Commission activity has not progressed to the point where a valid comparison betwee
6、n the EIA Standard and the IEC document can be made. This Standard does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this Standard to establish appropriate safety and health practices and to dete
7、rmine the applicability of regulatory limitations before its use. (Created under Standards Proposal No. 4356 formulated under the cognizance of the CE-2.0 Committee on EIA National Connector and Socket Standards and reaffirmed under Standards Proposal No. 5253.07). Published by Electronic Components
8、 Industry Association 2013 Engineering Department 2214 Rock Hill Road, Suite 170 Herndon, VA 20170 PLEASE! DONT VIOLATE THE LAW! This document is copyrighted by the ECIA and may not be reproduced without permission. Organizations may obtain permission to reproduce a limited number of copies through
9、entering into a license agreement. For information, contact: IHS 15 Inverness Way East Englewood, CO 80112-5704 or call USA and Canada (1-877-413-5184), International (303-397-7956) i CONTENTS Clause Page 1 Introduction 1 1.1 Scope 1 1.2 Object . 1 1.3 Definitions 1 2 Test resources . 2 2.1 Equipmen
10、t 2 2.2 Fixture 2 3 Test specimen . 2 3.1 Description . 2 4 Test procedure 3 4.1 General . 3 4.2 Eye pattern 3 4.2.1 Method A, mask test . 3 4.2.2 Method B, eye opening test 4 4.3 Jitter 4 4.3.1 Method C, Pseudo-Random Bit Sequence (PRBS) test . 4 4.3.2 Method D, pulse test (single pattern) . 5 5 De
11、tails to be specified 5 6 Test documentation 6 Figure A.1 Single-ended terminations A-1 A.2 Differential (balanced) terminations A-2 B.1 Typical eye pattern response B-1 B.2 Eye pattern response showing eye height and eye width B-2 B.3 Eye pattern response with mask (no hits) . B-3 B.4 Eye pattern r
12、esponse showing hits inside mask . B-4 ii CONTENTS (continued) Clause Page Figure (cont.) B.5 DSO automatic method, showing vertical limits .B-5 B.6 DSO manual method, showing two vertical cursors .B-6 B.7 Method D, pulse test single test pattern, showing the pulse widthB-7 Annex A Normative . A-1 B
13、 Informative . B-1 EIA-364-107 Page 1 TEST PROCEDURE No. 107 EYE PATTERN AND JITTER TEST PROCEDURE FOR ELECTRICAL CONNECTORS, SOCKETS, CABLE, ASSEMBLIES OR INTERCONNECTION SYSTEMS (From EIA Standards Proposal No. 4356, formulated under the cognizance EIA CE-2.0 Committee on National Connector Standa
14、rds) 1 Introduction 1.1 Scope This procedure is applicable to electrical connectors, cable assemblies, or interconnection systems. 1.2 Object This standard describes methods for measuring an eye pattern response and jitter in the time domain. 1.3 Definitions 1.3.1 Eye pattern An oscilloscope display
15、 of synchronized pseudo-random digital data (signal amplitude versus time), showing the superposition of accumulated output waveforms. 1.3.2 Jitter The difference between the earliest and latest times at which a signal crosses a specified reference voltage level. 1.3.3 Bit period The time interval b
16、etween the successive like edges (rise to rise or fall to fall) of the clock signal. This is the reciprocal of the clock frequency. 1.3.4 Skew The difference in propagation delay between two signal paths. 1.3.5 Measurement system rise time. EIA-364-107 Page 2 Rise time measured with fixture in place
17、, without the specimen, and with filtering (or normalization). Rise time is typically measured from 10% to 90% levels. 2 Test resources 2.1 Equipment 2.1.1 High speed pattern generator with clock output capable of producing a signal with specified rise and fall times and data pattern. 2.1.2 Signal a
18、nalyzer with external clock input capable of infinite persistence display. This is typically a digital sampling oscilloscope (DSO) with sampling head. It is preferred that the DSO have masking capability. NOTE Make sure not to exceed the maximum allowable input ratings of the oscilloscope input port
19、s. This will prevent costly damage and provide reliable measurements. Even signal excursions that are within the maximum allowable signal levels of the oscilloscope can result in unstable eye pattern responses. 2.2 Fixture 2.2.1 The test fixtures shall provide for proper signal(s) and ground pattern
20、(s) and, if required, proper termination of adjacent signal lines. 2.2.2 When measuring a differential response, make sure that the test fixtures and test cables are delay matched to minimize the skew. It is recommended that the skew of the test cables and fixtures be 5% of the bit period. 3 Test sp
21、ecimen 3.1 Description For 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. EIA-364-107 Page 3 3.1.3 Sockets A socket and test device or a socket and pluggable hea
22、der adapter. 4 Test procedure 4.1 General 4.1.1 Allow sufficient time for the equipment to warm-up and stabilize (according to the equipment manufacturers instructions). 4.1.2 If the specimen does not have a single-ended characteristic impedance of 50 or a differential impedance of 100 , impedance m
23、atching pads should be used. The required values are calculated using the equations in figures A.1 or A.2 of annex A. Use standard resistors having values nearest the values calculated from these equations. 4.1.3 Adjust the data generator for proper signal characteristics. These include rise time, a
24、mplitude, data rate, and encoding scheme. NOTE Rise time adjustments shall be made using hardware filters at the signal source and not using software filtering on the analyzer. 4.1.4 Trigger the oscilloscope on the data generator clock signal, making sure the clock signal does not exceed the normal
25、operating range of the clock input port. 4.1.5 Where possible, measure the eye pattern and/or jitter of the fixture and test cables without the specimen. Adjust the oscilloscope controls to display an eye pattern. The time base setting should be selected so that one unit interval (bit period) occupi
26、es at least 50% of the horizontal display. The vertical sensitivity should be selected so that the signal amplitude occupies 50% to 100% of the vertical display. See Annex B for examples. 4.2 Eye pattern 4.2.1 Method A, mask test 4.2.1.1 Set the oscilloscope to infinite persistence display mode and
27、set data acquisition to stop after the required number of waveforms. 4.2.1.2 Insert the specimen and initiate data acquisition to generate a preliminary eye pattern. 4.2.1.3 After the preliminary eye pattern data has been acquired, display or create the desired mask. Make sure the eye pattern and ma
28、sk are positioned with respect to each other and centered on the horizontal axis of the display). The mask should be placed (left to right) so that it best fits into the eye pattern. See Annex B.3 and B.4 for examples. EIA-364-107 Page 4 4.2.1.4 If available, enable the function on the DSO that coun
29、ts the number of data points that fall within the mask (referred to as “mask hits”). 4.2.1.5 Initiate data acquisition to generate a new eye pattern. 4.2.1.6 After the data acquisition is completed record the number of mask hits. If the automatic counting function (“hit counter”) is not available on
30、 the DSO, count and record the number of mask hits. 4.2.1.7 If required by the referencing document, make a hard copy of the oscilloscope display. 4.2.2 Method B, eye opening test 4.2.2.1 Set the oscilloscope to infinite persistence display mode and set data acquisition to stop after the required nu
31、mber of waveforms. 4.2.2.2 Insert specimen and initiate data acquisition to generate the eye pattern. 4.2.2.3 After the eye pattern has been acquired, measure and record the eye height at a time corresponding to 50% of the bit period (V 50% t). Measure and record the eye width at a voltage level cor
32、responding to 50% of the signal amplitude (t 50% V). 4.2.2.4 If required by the referencing document, make a hard copy of the oscilloscope display. 4.3 Jitter 4.3.1 Method C, Pseudo-Random Bit Sequence (PRBS) test, (multiple pattern) 4.3.1.1 Display the eye pattern per 4.2. 4.3.1.2 Center trace arou
33、nd the horizontal axis such that the entire eye pattern amplitude is visible on the display. 4.3.1.3 DSO, automatic method 4.3.1.3.1 If the oscilloscope contains automatic statistical measurement capability, its recommended to use the DSO functions to measure the jitter at the eye crossing point. 4.
34、3.1.3.2 When using manual measurement limits, insure that the vertical limits are as close together as possible, but a maximum of 20 mV apart; see figure B.5. 4.3.1.4 DSO, manual method EIA-364-107 Page 5 4.3.1.4.1 If the automatic measurement function is not available, position two vertical cursors
35、, one on each side of the eye cross transition; see figure B.6. 4.3.1.4.2 Read the jitter value from the delta (distance between) the cursor positions. 4.3.2 Method D, pulse test, (single pattern) 4.3.2.1 Set the generator for a DC balanced test pattern. This shall be a square wave or PRBS pattern a
36、t the specified frequency. 4.3.2.2 Set the oscilloscope to infinite persistence display mode, and adjust the vertical position to center the waveform vertically on the display, with half amplitude at center screen. 4.3.2.3 Adjust the generator to produce the specified test pattern. This pattern may
37、be chosen to simulate a long idle sequence, and is specific to the data pattern to be used in the application. It is typically a pattern of a logic “1” followed by twenty or more logic “0”s. For single ended measurements: measure the logic “1“ and logic “0“ levels, and adjust the generator if necess
38、ary to ensure the half amplitude of the waveform is still at center screen. For differential measurements: measure the logic “1“ and logic “0“ levels of both channels. Adjust the generator to minimize the offset in voltage or time between channels. If any voltage offset is present between channels,
39、the amount of offset shall be added to or subtracted from (as appropriate) the half-amplitude measurement point for the pulse width in 4.3.2.4. 4.3.2.4 Measure the width of the pulse that crosses the half-amplitude point (center screen), using cursors or oscilloscope measurement functions; see figur
40、e B.7. 4.3.2.5 Subtract the half-amplitude pulse width measured in 4.3.2.4 from the bit time (1 divided by the clock frequency of the generator) to obtain the jitter. 5 Details to be specified The following details shall be specified in the referencing document: 5.1 Signal rise time, amplitude, and
41、clock frequency 5.2 Data pattern; e.g., a (223-1) for PRBS or a 1+(20x0) for pulse pattern 5.3 Single-ended or differential 5.4 Termination value (and tolerances) 5.5 Signal/ground pattern, including the number and location of signal and grounds to be wired for this test EIA-364-107 Page 6 5.6 Speci
42、men environment impedance if other than 50 ohms for single-ended or 100 ohms for differential 5.7 Whether a hard copy of the oscilloscope display is required 5.8 Method A or B of evaluating eye pattern, (mask or eye opening) 5.7.1 Mask definition and position (if desired) relative to the eye pattern
43、 or clock. 5.7.2 Number of waveforms or samples to be acquired in generating the eye pattern 5.8 Method C (PRBS) 5.8.1 If the automatic (histogram) method is used, the height of the jitter box (vertical histogram limits) shall be specified. 5.8.2 Number of waveforms or samples to be acquired in gene
44、rating the eye pattern 5.9 Sampling rate of the DSO 6 Test documentation Documentation shall contain the details specified in clause 5, with any exceptions, and the following: 6.1 Title of test 6.2 Test equipment used, and date of last and next calibration 6.3 Test procedure and method 6.4 Fixture d
45、escription 6.6 The number of mask hits for Method A, see 4.2.1, or the eye opening for method B, see 4.2.2 6.7 Waveform plots (when required) 6.8 Jitter values when this test is requested 6.9 Observations 6.10 Name of operator and date of test EIA-364-107 Page A-1 Annex A Normative Minimum loss pad
46、equations: R1 = 50 1 - (Zo / 50) 0.5R1 = Zo 1 - (50 / Zo) 0.5R2 = Zo / 1 - (Zo / 50) 0.5R2 = 50 / 1 - (50 / Zo) 0.5Figure A.1 Single-ended terminations EIA-364-107 Page A-2 Minimum loss pad equations: R1 = Zo 1 - (100 / Zo) 0.5 / 2 R1 = 100 1 - (Zo / 100) 0.5 / 2 R2 = 100 / 1 - (100 / Zo) 0.5 R2 = Z
47、o / 1 - (Zo / 100) 0.5Figure A.2 - Differential (balanced) terminations EIA-364-107 Page B-1 B Informative B.1 Practical guidance, eye patterns B.1.1 An eye pattern is a measure of digital signal transmission quality. The eye pattern is typically measured using a data generator transmitting a non-re
48、turn to zero (NRZ) pseudo- random bit sequence (PRBS) and an oscilloscope having infinite persistence. To obtain an eye pattern on an oscilloscope, the sweep is triggered by the data clock signal, and the time base is set to display one bit period (also called the unit interval, which is equal to th
49、e period of one clock cycle). On each sweep of the oscilloscope, the bits of the random data are superimposed on the CRT display. The eye pattern shows the extent of distortion that can occur; see figure B.1. Figure B.1 - Typical eye pattern response B.1.2 Historically the eye pattern has been used as a qualitative measurement tool. Modern digital storage oscilloscopes permit the eye pattern to be used as a quantitative measurement tool. The open area in the center of an eye pattern pulse is an indicator of data transmission qual
