Using GigaProbes Agilent TDR D5

7/29/2019 Using GigaProbes Agilent TDR D5

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1

CopyrightDVTSolutions,LLC2009

UsingtheGigaProbes30GhzTDRHandProbes

Withthe

Agilent

86100C

DCA

-Jmainframe

54754ATDRmodule

Perform

SingleEndedorDifferentialImpedanceMeasurements

andExtractInsertionandReturnLossS-parameters

onGiga/bitInterconnects

Thisapplication

note

demonstrates

how,

using

the

GigaProbes,

atrue

multi

mode

30GHz

TDR

hand

probe,

to

set

up

andperformSingleEndedorDifferential Impedancemeasurementsandextract Insertion/Return lossSparameters

fromTDR/TDTmeasurementsonavarietyofGigabitinterconnectswheredirectconnectiontotheDeviceUnderTest

(DUT)andtheAgilent86100CDCAJmainframeTDRmodulesisnotpractical.

ThisdocumentdescribeshowtosetuptheprobesontheDUTandcalibratetheGigaProbestotheAgilent86100CDCA

Jmainframesand54754ATDRmodules.Systemcomponentpartnumbersareprovidedforeachmeasurement

proceduretoincludetestresultsprintoutsforeachthefollowingGigabitinterconnects:

50ohmPackageTestingandFailureAnalysis:ImpedanceandComparativeFAAnalysisTechnique

10G/bitMolexIpassSAS/SATAConnectorPCB:DifferentialandSparameterAnalysis

1.5G/bitSATACable:DifferentialandSparameterAnalysis

DifferentialCouponTesting:DifferentialandSparameterAnalysis


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2


Index

Page# Description

1 Introduction

2 Index

3 SystemComponents

4 SettingTDRReferencePlane

a. 50ohmSingleEndedTDR:SettingTDRReferencePlaneatGigaProbes ProbeTips

5 50ohmSingleEnded:SettingTDRReferencePlaneatCableSMAEnd

6 100ohmDifferential:SetTDR/TReferencePlaneatCableSMAEnd

7 MeasurementApplications

a. 50ohm

Package

Testing

and

Failure

Analysis:

Impedance

and

Comparative

FA

Analysis

Technique

8 10G/bitMolexIpassSAS/SATAConnectorPCB:DifferentialandSparameterAnalysis

9 1.5G/bitSATACable:DifferentialandSparameterAnalysis

10 DifferentialCouponTesting:DifferentialandSparameterAnalysis

11 TechnicalReferences


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3


SystemComponents

TestEquipmentSystemComponents

Usedto

make

all

Application

Measurements

in

this

Document

Agilent86100CDCAJMainframe

(2)Agilent54754A DifferentialTDRmodules.(Somemeasurementsweremadewiththe(obsolete)54753Abutthismodulecanbe

replacedwiththe54754AfortwoportTDR/TSparametermeasurements)

DVTSolutions,LLC:DVT301MM GigaProbes(setoftwoprobesandaccessorieskit)

DVTSolutions,LLC:DVT24GHZ10Qtyfour(4)12 24GhzSMAtoSMAcables

DVTSolutions,LLC:DVT2650Qtyone(1)50ohmSMAMaleLoad

AgilentPart#N1020AK05 CalibrationSubstrate(50ohmcalibrateatprobetips)

TheDVT

Solutions,

LLC

SOLT

KIT

(#TDRSOLTKIT)

was

used

to

Calibrate

the

TDR

reference

plane

to

the

SMA

cable

end

in

this

paper.TheAgilentN1024ASOLTcalibrationkitseenbelowisalsorecommendedforthiscalibrationprocedure:

AgilentSOLTkitProductNumber:N1024A

TheDVTSolutions,LLC:TDRTSLOTKITQtytwo(2)each:FemaleSMAShort,Load,Open,Through)

ProbingSolutions,IncGP245L12ALVM Qtytwo(2)ProbeManipulatororCascadeEzProbe

ProbingSolutions,IncFS2VB FixedVacuumChuckForholdingUpTo2"X2"DevicePackagesandSmallPCBs

ProbingSolutions,IncAVPLNV1 VacuumPump,LowNoise45dbDimension17"Cube(vacuumholddownforGP245L12ALVM

&FS2VB)


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4


SettingTDRReferencePlane50ohmSingle-EndedTDR:

SetTDRReferencePlaneatGigaProbesProbeTips

1) Connect

the

GigaProbes

configured

to

50

ohm

mode

(fig

1)

to

a

SMA

Cable

2) SelecttheTDR/TsetupmenuontheAgilent86100CDCAJmainframeandfollowCalibrationinstructions(fig2)3) UsetheAgilentPart#N1020AK05(Fig4)CalibrationSubstrateforthe50ohm&ShortmeasurementtoestablishTDRreferenceplaneat

probetips(Fig3).Important:Usethe5xmicrolensenclosedintheGigaProbesaccessorykit(orequivalent)tovisuallyverifythatbothprobetipsaremakingcontactsoexcessiveforceisnotappliedtoeitherprobetips

4)

CalibrationResults:50ohmTDRReferenceatProbeTipThefollowingscreendisplaysvalidatethecalibrationasaccurate.Figure5demonstratesnoloadacrosstheprobetipsandtheorangearrowisthe

TDRreference

plane

marker

established

at

the

probe

tip.

Without

aload

across

the

probes

the

waveform

appears

to

oscillate

but

this

oscillation

is

eliminatedwhenaloadisappliedacrosstheprobe.SeveralmeasurementsweretakenacrosstheCalibrationSubstratetovalidatemeasuremen

accuracy.

Fig1)Use50ohmconversionkitto

shortoneprobetiptoTwinAxprobe

shield.Instructions:

http://www.gigaprobes.com/usingac

cessories/50ohmprobesetup.html

Fig 2) On the Agilent 86100C DCAJ

mainframe menu select TDR/T

setup. The above display will

appear. Select Single Ended and

follow calibration instructions

Fig3)UsetheAgilentPart#N1020AK05

Calibration Substrate for the 50 ohm &

Short measurement to establish TDR

reference plane at probe tips

Fig

4)

Agilent

Part#

N1020K05CalibrationSubstrate

Fig5)NoloadonGigaProbestip. TDRreferencemarkeristurnedon.

Turningona2nd

markerthemeasurementsarereferencebetweenthe

two markers. The Gray out sections are data outside the time base

calibration zone. The time base for this setup is 200ps and shows

ringing from the probe tips multi path reflections but the ringing is

significantlyreducedwhenalodeisapplied,asinFig.6(SHORT),Fig.7

(75ohm),Fig.8(50ohm)&Fig.9(28ohm).

Fig6)GigaProbes tipacrossSHORTpad. Fig7)GigaProbestipacross75ohmpad.

Fig8)GigaProbes tipacross50ohmpad. Fig9)GigaProbestipacross28ohmpad.


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SettingTDRReferencePlane

50ohmSingle-EndedTDR:

SettingTDRReferencePlaneatCableSMAEnd

1) ConnectSMASMAcablestoAgilent54754ADifferentialTDRmodulechannel1(donotattachprobeatthistime)

2) SelecttheTDR/Tsetupmenu(Fig10)ontheAgilent86100CDCAJMainframe,followcalibrationinstructions3) AttachtotheendoftheSMACableaFemaleSMALoadandShortcontainedintheSLOTkit(Fig11)whenrequiredbytheAgilent86100CDCA

JmainframeTDRreferenceplanecalibrationroutine.

4) WiththeTDRreferenceplanecompleted,thereferenceplaneisnowestablishedattheSMAendofthecable.

5) TakeofftheSMAadaptersandconnectaGigaProbesConfiguredto50ohmmode(fig12)

CalibrationResults:50ohmTDRReferenceatCableSMAEnd

Even

though

the

TDR

calibration

reference

plane

was

established

at

the

SMA

Cable

end

and

not

the

probe

tips,

several

measurements

taken

acrostheCalibrationSubstratetovalidatemeasurementaccuracywerebetterthan3%.TotheestablishedTDRreferenceplane,turnonmarkeroneand

setitattheprobetipwhenprobeisnotconnected(Fig13).ThisestablishestimeZero. Turnonthe2nd

markertomakeimpedancemeasurements

referencetothe1stmarker.SeveralmeasurementstakenacrosstheCalibrationSubstratetovalidatemeasurementaccuracywerebetterthan3%.


shortoneprobetiptoTwinAx probe

shield.Lookup

http://www.gigaprobes.com/usingac

cessories/50ohmprobesetup.html

Fig13)withno loadonGigaProbesprobetipssetaTDR

reference marker (solid line) to established a TDR

reference plane. Turning on a 2nd

marker and the

measurements are reference between the two markers

Measurements were taken to validate the accuracy as

showinFigures14(SHORT),Fig.)15(75ohm),Fig.)16 (50

ohm).

Fig14) GigaProbestipacrossSHORTpad.Fig15)GigaProbestipacross 75ohmpad.

Fig16) GigaProbestipacross50ohmpad.

Fig 11) DVT Solutions LLC

TDRSOLTKIT TDR CalibrationKit.

Recommendations: Ifaveraging isbeingused,

the user can simply depress the Clear Display

button to clear the measurement (clear older

data) tovalidatethemeasurementhasstabilized.

Put probes in manipulators when possible. Use

the 5x micro lens enclosed in the GigaProbes

accessorykit(orequivalent)tovisuallyverifythat

both probe tips are making contact so excessive

forceisnotappliedtoeitherprobetip.

Fig 10) On the Agilent 86100C DCAJ

mainframe menu select TDR/T setup. The

above display will appear. Select Single

Ended and follow Calibration instructions


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SettingTDRReferencePlane

100ohmDifferentialTDR:

SetTDR/TreferenceplaneatCableSMAEnd

1. ConnectFour

SMA

SMA

cables

to

the

two

Agilent

54754A

Differential

TDR

modules

(do

not

attach

probes)

2. SelecttheTDR/Tsetupmenu(Fig15)ontheAgilent86100CDCAJmainframe,followcalibrationinstructions3. Whenrequired,attachtoendoftheeachSMACableaFemaleSMASHORT,50ohmLOADfromtheSLOTkit(Fig17).

4. WhenrequiredconnectCh1&Ch3andCh2&Ch4(Fig16)usingtheTHROUGHadaptersfromtheSLOTkit(Fig17)

5. WhentheTDR/TreferenceplaneiscompletedthereferenceplaneisnowestablishedattheSMAendofeachofthecables.

6. TakeofftheSMAadaptersandattachbothGigaProbesconfiguredto100ohmmode.

CalibrationResults:100ohmTDRReferenceatCableSMAEnd

EventhoughtheTDRcalibrationreferenceplanewasestablishedattheSMACableendandnottheprobetips,measurementstakenacrossthe

calibrationsubstrate (Fig18)validates the impedancemeasurementaccuracyarebetter than3%.To theestablishedTDRreferenceplaneusing

markers, turnonmarkeroneandset itattheprobetipwhenprobe isnotconnected.Thisestablishes timeZero. Turnon2nd

markertomake

measurementsreferencedtothe1stmarkerasinFig.19.

Fig 15) On the Agilent 86100C DCAJ mainframe menu

selectTDR/Tsetup.SetStimulusModetoDifferentialand

follow calibration instructions

Fig 17) DVT Solutions, LLC TDRSLOTKIT

Qty two (2) each: Female SMA Short

Load, Open, Through). Contains optiona

Qty two (2) Male 50 ohm loads for TDR

modulecalibration

Fig16) ConnectCh1&Ch3andCh2&Ch4when

requiredfortheTHROUGHcalibration

Fig 18) Measurements taken across the calibration

substrate validates the impedance measurement

accuracyisbetterthan3%Fig19)Turnon2

ndmarkertomakemeasurementsreferencedto1

stmarker.


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MeasurementApplications

50ohmPackageTestingandFailureAnalysis1) ConverttheGigaProbes to50ohmasinFigure20

2) SettheTDRreferenceplaneoftheGigaProbes(atprobetiporatSMAconnectend)asdescribedinsection3.

3) HandProbingPackages:SliptheEzGrip(Fig.22)handholdadapterovertheGigaProbesandconnectthe GigaProbestothe

DVT24GHZ12

SMA

SMA

12

24

GHz

cable

to

the

Agilent

54754A

TDR

module.

4) UsingaProbeManipulator:Inthisexample(figure21),theGigaProbeswasinstalledintheGP245L12ALVMfromProbingSolutions

inc.orequivalentprobemanipulatorbyremovingtheEzGripadapterandattachingtheGPMMAadapterontheprobemanipulator.

LoosenthetwocrossbarsontheGPMMAandpushtheprobeforwarduntilthe1stcrossbarisoverthetwinSMAcouplerwhereit

attachestothe100ohmTwinAxcoax. Tightendownthe1stcrossbarovertheTwincouplerandthentightenthe2

ndcrossbar.Donot

tighten1stcrossbaroverTwinAxcoaxasthismaydamagetheprobe.

5) HoldingtheDevicePackage:PutDevicePackageontheFS2VB FixedVacuumChuck(Fig21)thataccommodatesupto2"X2"Device

Packages.ThisChuckcanalsobeusedtosecuresmallPCBs.

6) ConnecttheGP245L12ALVMandFS2VB FixedVacuumChucktotheAVPLNV1 VacuumPumptosecurethemanipulatorand

devicepackagetokeepfrommovingduringsetupandprobing.Usethe5xmicrolenstolocateandprobethepadsonthedevice

package.

7) ForafasterTDRpulse,connecttheoutputoftheAgilent54754A35psTDRmoduletothePSPL4020or4022TDRT9pspulsemoduleFig.23).ConnecttheGigaProbestothepulseheaddriverfor~15 22psTDRrisetimefromtheprobe(Rtvarydependingoncouplersand

cables

use

with

setup).

8) ComparativeFailureAnalysisTechnique:Figure25impedanceplotshowsoverlappingknowngoodwaveformsfromasimilarpartwithasuspectwaveformfromthedefectiveDevicePackagetolocatefailure.

Fig21) GigaProbes installed in a

probemanipulatortoprobeadevice

package held by a vacuum chuck.

ResultsdisplayinFig24.


shortoneprobetiptoTwinAxprobe

shield.

Fig22) Hand

probing

package

with

GigaProbes with Ezgrip adapter

sleeveFig23) ~1522ps TDR pulse can

achievedbyconnectingtheAgi

54754A to the PSPL 4000 pu

modules.

Fig24)GigaProbestestresultsofprobingadevicepackage.TheTDR

referenceplanewasestablishedattheprobetipusingtheAgilentSLOT

SubstratePart#N1020AK05

Fig25)ComparativeFailureAnalysisTechnique:Byoverlappingknowngoodwaveformsfr

asimilarpartwithasuspectwaveformthedefectiveDevicePackagefailurelocationcanbe

determined.Inthiscase,itisidentifiedasanopentrace.

Trace1(red)Probe

notconnectedto

devicepackage

Trace2(violet)

Probeconnected

tosuspectOpen

trace.

Trace3&4

(Green/Orange)Probe

connectedtoknown

goodtraces.

Opendefectivetrace


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10G/bitMolexIpassSAS/SATAConnectorPCB

DifferentialImpedanceandS-parameterAnalysis1. ConverttwoGigaProbes to100ohm

2. SettheTDR/TreferenceplaneofthefourcablestotheSMAconnectorendasdescribedonpage5

3. Installthe

Probes

in

two

probe

Manipulators:

In

this

example

(figure

26),

the

GigaProbes

was

installed

in

two

GP2

45

L12AL

VMsfromProbingSolutionsinc.orequivalentprobemanipulatorbyremovingtheEzGripadapterandattachingtheGPMMA

adapterontheprobemanipulator.LoosenthetwocrossbarsontheGPMMAandpushtheprobeforwarduntilthe1stcrossbaris

overthetwinSMAcouplerwhereitattachestothe100ohmTwinAxsemiridgedcoax. Tightendownthe1stcrossbaroverthe

Twincouplerandthentightenthe2nd

crossbar.Donottighten1stcrossbaroverTwinAxcoaxortheprobecouldbedamaged.

4. HoldingtheDevicePackage:PutSAS/SATAconnectorontheFS2VB FixedVacuumChuck(Fig27)thataccommodatesthissmall

PCBconnector.

5. ConnectthetwoGP245L12ALVMsandtheFS2VB FixedVacuumChucktotheAVPLNV1VacuumPumptosecurethe

manipulatorandPCBfrommovingduringsetupandprobing.Usethe5xmicrolenstolocateandprobethepadsonthedevice

package.

6. Figure28/29showdifferentialTDRimpedance,TDTmeasurement,andSAS/SATAconnectorinsertion/returnloss

9)

Fig.26)Fullsetup forhookingupGigaProbesto makeDifferential Impedanceand

twoport (SDD11/21)andreturnand insertion lossmeasurements. Thedisplayon

theAgilent86100CDCAJmainframeshowsthetwoSparameterplots.

Fig.27)CloseupoftheSAS/SATAconnectorontheFS2VB FixedVacuumC

bebeingprobedbytheGigaProbes.

Fig.28)PlottakenfromAgilent 86100CDCAJmainframeshowsthedifferentialTDR

impedance and TDT SAS/SATA connector measurements. Establish TDR reference

planeattheSMAconnectorend.Establishmeasurementplan,placecurser#1(solid

line)wheretheprobeconnectstothePCBandusecurser#2(dotted line)tomake

Impedancemeasurements.

Fig.29) This plot taken from the Agilent 86100C DCAJ mainframe T

measurements (Fig. 28) are then converted to Insertion and Return los

parameterstodeterminethebandwidthparameters.


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1.5G/bitSATACable

DifferentialImpedanceandS-parameterAnalysis1 ConverttwoGigaProbes to100ohm

2 Setthe

TDR/T

reference

plane

of

the

four

cables

to

the

SMA

connector

end

as

described

on

page

53 InstalltheProbesintwoprobeManipulators:Inthisexample(figure30),theGigaProbeswereinstalledaGP245L12ALVMs

fromProbingSolutionsinc.andtheotherprobeinaCascadeEzProbemanipulator.RemovetheEzGripadapterandattachthe

GPMMAadapterontheprobemanipulators.LoosenthetwocrossbarsontheGPMMAandpushtheprobeforwarduntilthe1st

crossbarisoverthetwinSMAcouplerwhereitattachestothe100ohmTwinAxcoax. Tightendownthe1stcrossbarovertheTwin

couplerandthentightenthe2nd


4 HoldingtheSATAConnectorsforprobing:Putbothconnectorendsinavice(Fig31)andcarefullyputenoughpressureonthemso

theyaresecure.Makesuretheconnectorspinlayoutsarecomplementtoeachothersopin1connector1linesuptopin1to

connector2.

5 Figure32/33showsdifferentialTDRimpedance,TDTmeasurementandinsertion/returnlossoftheSATAcable.

Fig.31)SATAcablesconnectorsbeingheldintheverticalvice.BothGigaProbe

areheldinplaceusingprobemanipulators.

Fig.30)PictureoftheSATAcabletestsetupusestwodifferentmanipulatorsanda

vicetoholdtheconnectors.

Fig.32)PlottakenfromtheAgilent86100CDCAJmainframeshows differentialTDR

impedanceandTDTSATAcablemeasurements.TDRreferenceplaneestablishedat

the SMA connector end. To establish a reference plane, curser #1(solid line) is

placed where the probe connects to the PCB and use curser #2 (dotted line) to

makeimpedancemeasurements.

Fig. 33) Plot taken from TDR/T measurements (Fig. 32) are then converted

Insertion and Return loss Sparameters to determine the SATA cable bandwid

parameters.


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DifferentialPCBCouponTesting

DifferentialImpedanceandS-parameterAnalysis1. ConverttwoGigaProbes to100ohm

2. SettheTDR/TreferenceplaneofthefourcablestotheSMAconnectorendasdescribedonpage5

3. Installthe

Probes

in

two

probe

Manipulators:

In

this

example

(figures

34/35),

the

GigaProbes

was

installed

in

two

GP2

45

L12AL

VMsfromProbingSolutionsinc.andtheCascadeEZProbemanipulatorbyremovingtheEzGripadapterandattachingthe

GPMMAadapteroneachprobemanipulator.LoosenthetwocrossbarsontheGPMMAandpushtheprobeforwarduntilthe1st

crossbarisoverthetwinSMAcouplerwhereitattachestothe100ohmTwinAxcoax. Tightendownthe1stcrossbarovertheTwin

couplerandthentightenthe2nd


4. HoldingtheTestPCBCoupon:Ifthereisnofixturetoholdtestcouponuseearthquakeputtyorapieceoftape.

5. Figure36/37showdifferentialTDRimpedance,TDTmeasurement,insertion/returnlossofthe6.2intestcoupon.

Fig. 35) Closeupofthe GigaProbesconnectedtoeachendoftheTestPCB

coupon.Usethe5xmicrolenstocarefullyplacetheprobeonthetestpads.

Fig.34)FullsetupforhookinguptheGigaProbestomakeDifferential Impedance

and two port (SDD11/21) and return and insertion loss measurements on a test

coupon. The display on the Agilent 86100C DCAJ mainframe shows the TDR/T

plots.

Fig.37) Insertion

and

Return

loss

Sparameters

plot

was

derived

from

TD

measurements (Fig. 36) and used to determine the test coupon bandw

parameters.

Fig.36) Plot taken from Agilent 86100C DCAJ mainframe shows differential TDR

impedance and TDT measurement of the 6.2 inch test coupon. The TDR reference

plane was established at the SMA connector end. To establish a measurement

referenceplane,curser#1(solid line) isplacedwheretheprobeconnectstothePCB

andusecurser#2(dottedline)tomakeImpedancemeasurements.


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TechnicalReferencesWebSites

Agilent:http://www.home.agilent.com

GigaProbes:http://www.gigaprobes.com/instrumentcompatibility/agilent.html

Characterizationof

Standards

Data

Rate

(Gb/s)

Required

bandwidth,

GHz

Infiniband,PCIExpress 2.50 6.25

SATAII 3.00 7.50

XAUI 3.125 7.813

4Gb/sFC 4.25 10.63

SATAII 6.00 15.00

DoubleXAUI 6.25 15.63

8Gb/sFC 8.50 21.25

10GBaseR 10.31 25.78

10GBaseRFEC 11.10 27.75

Aninnerboardlayer(astripline)ismuchmorerepresentativeofthetypicalboardrun.Additionally,itisusefultoprovidetheresolutiondatafor

propagationinfreeair.Forstripline,weassumeVp=0.446xclight=1.34x108,andtheresultingresolutiondata,basedontheruleoftTDR/2,is

summarizedin

table

below.

Risetime,ps Resolutioninair,mm ResolutioninFR4,buriedrun

(vp=0.446*Clight),mm

10 1.50 0.67

15 2.25 1.00

20 3.00 1.34

28 4.20 1.87

40 6.00 2.68

150 22.50 10.04

Accepted Rules for Resolving Discontinuit ies using TDR

tseparate

To resolve a1

and a2

as

separate discontinuities:

tseparate

> tTDR_risetime

/2a1

a2

tsingle a

1is not resolved if

tsingle


12/12

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HandHeldProbesf

Agilent86100CDCAJTDROscillosco

30 GHz 100Differential & 50 Impedan

With Gold Plated Conductive Diamond Probe T

Features & Benefits

30 GHz Bandwidth

True Odd Mode 100 ohm Differential Input Impedance

Probe can be converted to 50 ohm input i mpedance

TDR Launch Discon tinui ty

Documents

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