AnalogTestWord下载.docx

AnalogTestWord下载.docx

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AnalogTest:

Hardwareneeded:

a.Voltagesource

b.Previsionreferenceresistor

c.MOA

d.Internalvoltmeter

e.Relayforconnection

s-bus

i-bus

IRx

IRef

Gain=Vmoa/Vs

IRx=IRef;

wheresummingNode=0voltwithhighinputimpedanceofop-amp

Vs/Rx=Vmoa/Rref=0volt

Vs/Rx=-Vmoa/Rref

Rx=-（Vs/Vmoa）Rref

Gain=-Rref/Rx

Tomakeagoodmeasurement,Galwaysneedtobebetween–1to–10.Closerto–1,thebestandstabletestwillbe.

WhatNeedToDoIfRmeasure<

Rxactual

Question:

WhatcancausevoltagedroponRxis<

actual?

?

Answer:

Rxisfix,wheretheonlyvariableiscurrentflowthruRx,IRx

Example:

IfthereisanotherpathwhichisconnecttoRx,IRx<

IRef,whereIRef=IRx+Ip

Solution:

GroundingtheZsgandZig,willpreventcurrentflowonthatpath.

Therefore,thecurrentflowthruRxwillresumeas:

IRxΞIRef;

whereIp=0amp

WhatYouNeedToDoIfRmeasure>

WhatcancausevoltagedroponRxbiggerthenexpected?

Additionimpedancefroms-busortheinternalvoltagesourcefromASRUcard,wheretheRx=Rx+Z

IRef=Vmoa/Rref,

However…………

IRx<

>

Vs/Rx,but

IRx=Vs/（Rx+Rs+Ri）

SolutiononadditionimpedanceformS-bus,Zs:

∙PlaceaDVMtosensethevoltagedroponZsbyadding“a-bus”

∙TheinputimpedanceofDVMisprettyhighandnocurrentwillthanflowthru.ThiswillnotreducethecurrentflowthurRx.

SolutiononadditionimpedancefromI-bus,Zi:

Addb-bustomovethevirtualgroundclosetoDUT

Add“en”option,toenhance

a.VoltagemeasurementacrossRRef

b.ActualmeasurementonVsinsteadofassumeduringmeasurementcalculation

WhathappenifthereisG-BusImpedance:

WithG-Businternalimpedance,itmaycauseIRx<

IRef.

Rxmeasure>

Rxactual

AdditionlbustothecircuitrywillhelptoreduceG-busimpedance.

Note:

TheMOAimpedanceisinfinite,andnocurrentwillthenflowthruL-bus

path.

Thereis2waysofwritingthel-busconnection:

a.connectgto“node#”;

lto“node#”

b.connectglto“node#”

CompleteExamplewithallOption:

AnalogOption:

a.reX

∙referenceresistorforMOA

∙range:

re1tore6:

re1=10ohm;

101

re2=100ohm;

102

∙usetodefineamostaccurateGforanalogmeasurement

c.arX

∙specifyrangesettingforASRU’sinternalmultimeter,MOA

∙arXusetosetcorrectexpectedoutputvoltage

∙userseldonchangeonthissetting

∙default:

100mVforanalogmeasurement

d.amX

∙Vs,sourcevoltagerangesetting

∙Rangeof–10Vto+10V

∙Defaultvalue,Vs=100mV

∙Withrefertospec,measurepassivecomponentbyusingsourceof100mV

e.wb

∙bandwidthofMOA

∙useduringhihgMOAgainisneededathighfrequencytest

∙wbnormallynotuseduringre1&

re2setting,oritwillintenttosendMOAtosaturationstatus

f.waitX

∙delaystatement

∙itwillwaittoexecuteeachtimevoltagesourceischanges

∙rangefrom0to9.99999sec

∙normalcaseusingmsec

g.icoX

∙currentcomplianceofsource

∙ico0:

35mA

∙ico1:

150mA

∙bydefault35mA

h.frX

∙frequencyofsource,Vs

∙Usingduringcapacitor&

inductormeasurement,accomponentmeasurement

∙3ranges:

128,1024&

8192

∙iffrXisused,thesourcewillautomaticallychangefromDCtoAC

i.comp/nocomp

∙forcapacitorlearningpurpose

∙comp:

willrequestalearnstatementtothecapacitor,normallyuseon<

200pF

∙nocomp:

indicatethecapacitorwillnotperformlearningsection.

∙Learncapacitorwillalwaysdoduringthe1strunofthetest

j.Ed

∙Forlinenoiserejection

∙Usetogetherwithfr128

∙Thisstatementwillincreasetesttimeofabout17.5msecto20msec

k.En

Enhanceoption

Thisresultamultiplemeasurementondevice

With“en”,Vs,Vmoa,VrefandVitoMOAwillmeasure

Itwillincuradditiontesttime

l.sa

sensebustoreduceimpedanceofs-bustoRxmeasurement

m.sb

sensebustomovethevirtualgroundreferencetoavoidimpactfromimpedanceofI-bustoRx

n.sl

sensebustoreduceimpactfromg-busimpedancetoRxmeasurement

CapacitorTestingHint:

Someteststructureusingasresistor,capacitorisusingMOAconceptwithACsourceinsteadofDC.

Therewillbeneededforcapacitortohaveacompensationstatementduetosomecapacitorinducebetweentesterandfixturewillcausesomemis-readingonthemeasurement.

Thecompensationstatementwillbeuseonthecapacitorwhich<

100pF（Sometimetobesafe,470pFwillexecuteundercompoption）

RecommendedCapacitorMeasurementOption:

Diode&

ZenerDiodeTestConfiguration:

Zenerwillusethesameconfiguration,whereforwardbiasvoltagemeasurementfordiodeandreversebiasvoltageforzener.

Diode:

0.7volt（700mvolt）:

forwardbiasvoltage

Zener:

18volt:

reversebiasvoltage

LED:

2.5volt:

HinttoTestDiode&

a.Diode:

Setvoltagecompliance（co）valueatealst1voltgreaterthanhihgtestlimit

Useguardingtoeliminatetheeffectogimpedanceinparallelwithdiodeundertest

EnsureMOAoutputdoesnotexceed15Vdcor14Vpk

b.Zener:

Setvoltagecompliance,coto10volt,and8.99voltsforauxiliarysource.

aroptionforzenerwillbewithinrangeof0to18volt

Donotuseguardingonzenertest

FETTestConfiguration:

TheFETtest,nfetrandpfetr,measureontheresistor（Ron）ofN-channelandP-channelFETsresepctively.

Thes-bus（sourcebus）andI-bus（detectorbus）areconnectedtothesourceanddrainoftheFET.

Theguard,G-busisconnectedtothegateoftheFET.

N-channelFETsaretestedwithapositivesource

P-ChannelFETsaretestedwithanegativesource

HintForFETstest:

BelowshowntherecommendedReferenceElement（re）RangeofRontest

froption,ACsourcecanbeusetoreducetheeffectofparallelimpedance