SNOSBW2F –NOVEMBER 1999–REVISED …

1 ProductFolderSample &BuyTechnicalDocumentsTools &SoftwareSupport &CommunityLM13700 SNOSBW2F NOVEMBER1999 REVISEDNOVEMBER2015LM13700 Dual OperationalTransconductanceAmplifiersWit h LinearizingDiodesand Buffers1 Features3 DescriptionTheLM13700seriesconsistsof twocurrent-1 gmAdjustableOver6 Decadescontrolledtransconductanceamplifi ers,eachwith ExcellentgmLinearitydifferentialinputsan da ExcellentMatchingBetweenAmplifiersamplif ierssharecommonsuppliesbut LinearizingDiodesfor reducedoutputdistortionprovidedat the inputsto reducedistortionand allow resultis a 10-dBsignal-to- HighOutputSignal-to-NoiseRationoiseimpro vementreferencedto Applicationsespeciallydesignedto complementthe dynamicrangeof the the Current-ControlledAmplifiersLM13700diffe rfromthoseof the LM13600in that StereoAudioAmplifierstheirinputbiascurre nts(andthustheiroutputDC Current-ControlledImpedanceslevels)are independentof IABC.

2 Thismayresultinperformancesuperiorto that of the LM13600in audio Current-ControlledFiltersapplications. Current-ControlledOscillators MultiplexersDeviceInformation(1) TimersPARTNUMBERPACKAGEBODYSIZE(NOM)SOIC (16) Sample-and-HoldCircuitsLM13700 PDIP(16) (1) For all availablepackages,see the orderableaddendumatthe end of the IMPORTANTNOTICEat the end of this datasheetaddressesavailability,warranty, changes,use in safety-criticalapplications,intellectual propertymattersand NOVEMBER1999 Applicationand Pin Configurationand Deviceand Mechanical,Packaging,and RevisionHistoryNOTE:Pagenumbersfor previousrevisionsmay differfrompagenumbersin the (March2013)to RevisionFPage AddedESDR atingstable,FeatureDescriptionsection,De viceFunctionalModes,Applicationand Implementationsection,PowerSupplyRecomme ndationssection,Layoutsection,Deviceand DocumentationSupportsection,andMechanica l,Packaging,and (March2013)

3 To RevisionEPage Changedlayoutof NationalDataSheetto TI 1999 2015, NOVEMBER1999 REVISEDNOVEMBER20155 Pin Configurationand FunctionsD or NFGP ackage16-PinSOICor PDIPTop ViewPin input1, 16 ACurrentbias inputBufferinput7, 10 ABufferamplifierinputBufferoutput8, 9 ABufferamplifieroutputDiodebias2, 15 ALinearizingdiodebias inputInput+3, 14 APositiveinputInput 4, 13 ANegativeinputOutput5, 12 AUnbufferedoutputV+11 PPositivepowersupplyV 6 PNegativepowersupplyCopyright 1999 2015,TexasInstrumentsIncorporatedSubmitD ocumentationFeedback3 ProductFolderLinks:LM13700LM13700 SNOSBW2F NOVEMBER1999 (unlessotherwisenoted)(1)MINMAXUNITS upplyvoltage36 VDCor 18 VDC inputvoltage+VS VSVD ifferentialinputvoltage 5 VDiodebias current(ID)2mAAmplifierbias current(IABC)2mABufferoutputcurrent(2)20 mAPowerdissipation(3)TA= 25 C LM13700N570mWOutputshortcircuitdurationC ontinuousStoragetemperature,Tstg 65150 C(1)StressesbeyondthoselistedunderAbsolu teMaximumRatingsmay causepermanentdamageto the stressratingsonly,whichdo not implyfunctionaloperationof the deviceat theseor any otherconditionsbeyondthoseindicatedunder RecommendedOperatingConditions.

4 Exposureto absolute-maximum-ratedconditionsfor extendedperiodsmay affectdevicereliability.(2)Bufferoutputc urrentshouldbe limitedso as to not exceedpackagedissipation.(3)For operationat ambienttemperaturesabove25 C, the devicemustbe deratedbasedon a 150 C maximumjunctiontemperatureand athermalresistance,junctionto ambient,as follows:LM13700N,90 C/W;LM13700M,110 (unlessotherwisenoted)MINMAXUNITV+ (single-supplyconfiguration) + (dual-supplyconfiguration) (dual-supplyconfiguration) 16 ,TALM13700N070 (1)D (SOIC)NFG(PDIP)UNIT16 PINS16 PINSR C/WR JC(top)Junction-to-case(top) C/WR C/W C/W C/W(1)For moreinformationabouttraditionaland new thermalmetrics,see theSemiconductorand IC PackageThermalMetricsapplicationreport, 1999 2015, NOVEMBER1999 VS= 15 V, TA= 25 C, amplifierbias current(IABC) = 500 A, pins 2 and 15 inputsto the buffersare groundedand outputsare (VOS)mVIABC= 5 current(ID) = 500 A IABC 500 current AOverspecifiedtemperaturerange1867009600 13000 Forwardtransconductance(gm)

5 0, IABC= 5 A5 PeakoutputcurrentRL= 0, IABC= 500 A350500650 ARL= 0, OverSpecifiedTempRange300 SupplycurrentIABC= 500 A, 12 input(1)Crosstalk100dB20 Hz < f < 20 kHzDifferentialinputcurrentIABC= 0, input= 4 0 (referto test circuit) Open-loopbandwidth2 MHzSlewrateUnitygain compensated50V/ sBufferinputcurrentSee(1) APeakbufferoutputvoltageSee(1)10 VPEAKOUTPUTVOLTAGEP ositiveRL= , 5 A IABC 500 , 5 A IABC 500 A 12 VOS/ V+20150 V/VNegative VOS/ V 20150 V/V(1)Thesespecificationsapplyfor VS= 15 V, IABC= 500 A, ROUT= 5-k connectedfromthe bufferoutputto VSand the inputof thebufferis connectedto the 1999 2015,TexasInstrumentsIncorporatedSubmitD ocumentationFeedback5 ProductFolderLinks:LM13700LM13700 SNOSBW2F NOVEMBER1999 InputOffsetCurrentFigure1.

6 InputOffsetVoltageFigure3. InputBiasCurrentFigure4. PeakOutputCurrentFigure6. LeakageCurrentFigure5. PeakOutputVoltageand CommonModeRange6 SubmitDocumentationFeedbackCopyright 1999 2015, NOVEMBER1999 REVISEDNOVEMBER2015 TypicalCharacteristics(continued)Figure7 . InputLeakageFigure8. TransconductanceFigure9. InputResistanceFigure10. AmplifierBiasVoltagevs. AmplifierBiasCurrentFigure11. Inputand OutputCapacitanceFigure12. OutputResistanceCopyright 1999 2015,TexasInstrumentsIncorporatedSubmitD ocumentationFeedback7 ProductFolderLinks:LM13700LM13700 SNOSBW2F NOVEMBER1999 (continued)Figure13. Distortionvs. DifferentialInputVoltageFigure14. Voltagevs. AmplifierBiasCurrentFigure15.

7 OutputNoisevs Frequency8 SubmitDocumentationFeedbackCopyright 1999 2015, NOVEMBER1999 REVISEDNOVEMBER20157 LM13700is a two inputsincludelinearizingdiodesto reducedistortion,and the outputcurrentis controlledby adedicatedpin. The outputscan sustaina continuousshortto differentialtransistorpair Q4and Q5forma transconductancestagein that the ratioof theircollectorcurrentsis definedby the differentialinputvoltageaccordingto the transferfunction:(1)whereVINis the differentialinputvoltage,kT/qis approximately26 mV at 25 C and I5and I4are the collectorcurrentsof transistorsQ5and exceptionof Q12and Q13, all transistorsand diodesareidenticalin Q2with DiodeD1forma currentmirrorwhichforcesthe sumof currentsI4and I5to equalIABC.

8 I4+ I5= IABC(2)whereIABCis the amplifierbias currentappliedto the gain smalldifferentialinputvoltagesthe ratioof I4and I5approachesunityand the Taylorseriesof the In functionis approximatedas:(3)(4)Copyright 1999 2015,TexasInstrumentsIncorporatedSubmitD ocumentationFeedback9 ProductFolderLinks:LM13700LM13700 SNOSBW2F NOVEMBER1999 (continued)CollectorcurrentsI4and I5are not very usefulby themselvesand it is necessaryto subtractone remainingtransistorsand diodesformthreecurrentmirrorsthat producean outputcurrentequalto I5minusI4thus:(5)The termin bracketsis thenthe transconductanceof the amplifierand is proportionalto differentialvoltagesgreaterthana few millivolts,Equation3 becomesless validand the demonstrateshowthe internaldiodescan linearizethe transferfunctionof the convenienceassumethe diodesare biasedwithcurrentsourcesand the inputsignalis in the formof currentIS.

9 Sincethe sum of I4and I5is IABCand the differenceis IOUT, currentsI4and I5iswrittenas follows:(6)Sincethe diodesand the inputtransistorshaveidenticalgeometriesa nd are subjectto similarvoltagesandtemperatures,the followingis true:(7)Noticethat in derivingEquation7 no approximationshavebeenmadeand thereare no limitationsare that the signalcurrentnot exceedID/ 2 and that the diodesbe biasedwith ,replacingthe currentsourceswith resistorswill singleendedor outputscan supporta sustainedshortto use of the LM13700in 5 V supplysystemsrequireswill reducesignaldynamicrange;this is due to the PNPtransistorshavinga higherVBEthanthe separateoutputbufferwhichconsistsof a Darlingtonpair transistorthat can driveup 1999 2015, NOVEMBER1999 REVISEDNOVEMBER20158 Applicationand ImplementationNOTEI nformationin the followingapplicationssectionsis not partof the TI componentspecification,and TI doesnot warrantits accuracyor s customersareresponsiblefor determiningsuitabilityof componentsfor test theirdesignimplementationto OTAis a versatilebuildingblockanalogcomponenttha t can be consideredan LM13700can be usedin a widevarietyof applications,fromvoltage-controlledampli fiersand filtersto 2 well-matched.

10 Independentchannelsmakethe LDC13700well suitedfor this exampleapplication,the systemrequirementsprovidea volumecontrolfor a 1 VPinputsignalwith aTHD< 15 V volumecontrolvariesbetween-13 V and 15 V and needsto provideanadjustablegain rangeof > linearizingdiodesis recommendedfor mostapplications,as they greatlyreducethe requiredthat the diodebias current,IDbe greaterthantwicethe inputcurrent,IS. As the inputvoltagehas aDC levelof 0 V, the DiodeBiasinputpins are 1 diodedropabove0 V, whichis + Tyingthe bias to thecleanV+ supply,resultsin a voltagedropof acrossRD. Usingthe recommended1mAfor IDis appropriatehere,and with VS=+15V, the voltagedropis , and so usingthe standardvalueof 13-k is acceptableandwill providethe desiredgain obtainthe < ,the differentialinputvoltagemustbe <60mVppwhenthe linearizingdiodesare inputdivideron the inputwill reducethe 1 VPinputto 33mVPP, whichis withinthe ,set IBIAS.