1、 EIA STANDARD TP-102 Rise Time Degradation Test Procedure for Electrical Connectors, Sockets, CableAssemblies or Interconnection Systems EIA-364-102December 1998 ELECTRONIC COMPONENTS, ASSEMBLIES see figure 1. The formula used to calculate risetime degradation for gaussian signals from 10% to 90% is
2、 as follows:Rise time degradation = square root (measured rise time)2- (measurement system rise time)21.3.2 Measurement system rise timeRise time measured with fixture in place, without the specimen, and with filtering (ornormalization). Rise time is typically measured from 10% to 90% levels; see fi
3、gure 1.1.3.3 Specimen environment impedanceThe impedance presented to the signal conductors by the fixture. This impedance is a result oftransmission lines, termination resistors, attached receivers and signal sources, and fixtureparasitics.EIA-364-102Page 221.3.4 Rise timeThe time required for a vo
4、ltage step to occur, measured between its initial value and final value,typically from 10% to 90% levels.1.3.5 Termination (electronics usage)An impedance connected to the end of a transmission line, typically to minimize reflected energyon the line.2 Test resources2.1 EquipmentPulse generator and o
5、scilloscope, time domain reflectometer (TDR) or other suitable equipmentwith a measurement system rise time less than or equal to 70% of the measured rise time.2.2 MaterialWhen the fixture is a printed circuit board, the reference trace and the test trace should be madeon the same printed circuit bo
6、ard to reduce any difference in PCB fabrication processes,dielectric material variations, etc.2.3. FixtureUnless otherwise specified in the referencing document the specimen environment impedanceshall match the impedance of the test equipment. Typically this will be 50 ohms for single-endedmeasureme
7、nts and 100 ohms for differential.2.3.1 Method A, single-endedThe fixture shall allow one signal line to be driven at a time. The driven line shall be terminatedaccording to one of the methods of figure A.2 with the specimen environment impedance.Unless otherwise specified a 1:1 signal to ground rat
8、io shall be used with each end having allgrounds commoned. Each line adjacent to the driven line shall also be terminated in its specimenenvironment impedance at both near and far ends.2.3.1.1 Insertion techniqueThe fixture shall be designed to allow measurement of rise time with and without the spe
9、cimen;see figure A.1.a.EIA-364-102Page 32.3.1.2 Reference fixture techniqueTwo fixtures shall be designed to have the same fixture electrical length and characteristics ofenvironment transmission line. The “specimen fixture” includes the specimen. The “referencefixture” does not include the specimen
10、. The fixture electrical length does not include thespecimen length; see figure A.1.b.2.3.2 Method B, differentially drivenThe fixture shall allow one signal pair to be driven at a time. The driven line shall be terminatedaccording to one of the methods of figure A.3 with the specimen environment im
11、pedance.Unless otherwise specified a 2:1 signal to ground ratio shall be used. Each line adjacent to thedriven line shall also be terminated in the specimen environment impedance at both near and farends.2.3.2.1 Insertion techniqueThe fixture shall be designed to allow measurement of rise time with
12、and without the specimen;see figure A.1.a.2.3.2.2 Reference fixture techniqueTwo fixtures shall be designed to have the same fixture electrical length and characteristics ofenvironment transmission line. The “specimen fixture” includes the specimen. The “referencefixture” does not include the specim
13、en. The fixture electrical length does not include thespecimen length; see figure A.1.b.3 Test Specimen3.1 DescriptionFor this test procedure the test specimen shall be as follows:3.1.1 Separable connectorsA mated connector pair.3.1.2 Cable assemblyAssembled connectors and cables, and mating connect
14、ors.3.1.3 SocketsA socket and test device or a socket and pluggable header adapter.EIA-364-102Page 444 Test procedureUnless otherwise specified the measurement system rise time shall be less than or equal to 70%of the measured rise time with the specimen; see figure 1. It is recommended to use the f
15、astestoutput signal of which the equipment is capable. Each of the two techniques below apply to bothsingle-ended and differential measurements. For differential measurements, it is necessary todetermine whether any phase and/or amplitude errors exist between the channels, and to providenecessary co
16、mpensation for these errors. Place the specimen a minimum of 5 cm from any objectthat would affect measured results.NOTE The test professional should be aware of limitations of any math operation(s)performed by an instrument, (e.g. normalization or software filtering).4.1 Insertion technique4.1.1 Me
17、asure the rise time and plot the waveform of the output signal that is transmittedthrough the fixture without the specimen and with filtering or normalization. This is themeasurement system rise time.4.1.2 Measure the rise time and plot the waveform of the output signal that is transmittedthrough th
18、e fixture with the specimen and with filtering or normalization. This is the measuredrise time.4.2 Reference fixture technique4.2.1 Measure the rise time and plot the waveform of the output signal that is transmittedthrough the reference fixture without the specimen and with filtering or normalizati
19、on. This isthe measurement system rise time.4.2.2 Measure the rise time and plot the waveform of the output signal that is transmittedthrough the reference fixture with the specimen and with filtering or normalization. This is themeasured rise time.4.3 Rise time degradation calculation4.3.1 If the s
20、ignal is gaussian in nature and the rise time was measured from 10% to 90% levels,see note; then calculate the rise time degradation as follows:Rise time degradation = square root(measured rise time)2- (measurement system rise time)2.NOTE The input and output step amplitudes may not be equal due to
21、attenuation inthe device under test. When this occurs, the output step 10% and 90% levelsare to be referenced from the maximum output voltage, regardless of whatvoltage was put in.EIA-364-102Page 54.3.2 The equation, see 4.3.1, may not be used if the signal was not gaussian in nature or thesignal ri
22、se time was not measured from 10% to 90% levels. In this case report the measured risetimes and waveform plots.5 Details to be specifiedThe following details shall be specified in the referencing document:5.1 Measurement system rise time (if available)5.2 Specimen environment impedance if other than
23、 50 ohms for single-ended or 100 ohms fordifferential.5.3 Signal/ground pattern, including the number and location of signal and grounds to be wiredfor this test.5.4 Fixture requirements, if any5.5 Rise time levels if other than 10% to 90%5.6 Method A (single-ended), method B (differentially driven)
24、, or both6 Test documentationDocumentation shall contain the details specified in clause 5, with any exceptions, and thefollowing:6.1 Title of test6.2 Test equipment used, and date of last and next calibration6.3 Test procedure and method6.4 Fixture description6.5 Measurement system rise time as app
25、licable (see clause 4)6.6 Measured rise times with specimen.6.7 Wave form plots, (required if the signals are not gaussian in nature or the rise time was notmeasured from 10% to 90% levels).6.8 Values and observations6.9 Name of operator and date of testEIA-364-102Page 66NOTE Ignore overshoot and un
26、dershoot when calculating 0% and 100% levels.Figure 1 - WaveformEIA-364-102Page A-1AnnexA NormativeFigure A.1.a - Insertion techniqueFigure A.1.b - Reference fixture techniqueFigure A.1 - Technique diagramsEIA-364-102Page A-2Minimum loss pad equations:R1= 50 1 - (Zo/ 50) 0.5R1= Zo 1 - (50 / Zo) 0.5R
27、2= Zo/ 1 - (Zo/ 50) 0.5R2= 50 / 1 - (50 / Zo) 0.5Figure A.2 - Single-ended terminationsEIA-364-102Page A-3Minimum loss pad equations:R1= Zo 1 - (100 / Zo) 0.5/ 2 R1= 100 1 - (Zo/ 100) 0.5/ 2R2= 100 / 1 - (100 / Zo) 0.5R2= Zo/ 1 - (Zo/ 100) 0.5Figure A.3 - Differential (balanced) terminationsEIA-364-
28、102Page B-1B InformativeB.1 Practical guidanceNear perfect resistive terminations of the signal lines may not be possible at high frequencies dueto parasitic reactances in both signal and ground conductors. These reactances will have animpact on measured results. In this case it is desirable that th
29、e test fixture duplicate the exactgeometry (parasitics) of the actual application. This may involve the use of transmission lines inaddition to the components of figures A.1 and A.2. Most instruments used for thesemeasurements are internally terminated in 50 ohms at both source and detector ports.EI
30、A Document Improvement ProposalIf in the review or use of this document, a potential change is made evident for safety, health or technicalreasons, please fill in the appropriate information below and mail or FAX to:Electronic Components Industry AssociationEngineering Department Publications Office
31、4212 Rock Hill Road, Suite 170Herndon, VA 20170-4212Phone: (571) 323-0294Document No. Document Title:Submitters Name: Telephone No.:FAX No.:e-mail:Address:Urgency of Change:Immediate: At next revision:Problem Area:a. Clause Number and/or Drawing:b. Recommended Changes:c. Reason/Rationale for Recommendation:Additional Remarks:Signature: Date:FOR EIA USE ONLYResponsible Committee:Chairman:Date comments forwarded to Committee Chairman:
