Product Sample & Technical Tools & Support & Folder Buy Documents Software Community VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 VCA822 Wideband, > 40-dB Gain Adjust Range, Linear in V/V Variable Gain Amplifier 1 Features 3 Description • 150-MHzSmall-SignalBandwidth The VCA822 device is a DC-coupled, wideband, 1 linear in V/V, continuously variable, voltage-controlled (G=+10V/V) gain amplifier. It provides a differential input to single- • 137MHz,5V Bandwidth(G=+10V/V) PP ended conversion with a high-impedance gain control • 0.1-dBGainFlatnessto28MHz input used to vary the gain down 40dB from the • 1700V/μsSlewRate nominal maximum gain set by the gain resistor (RG) andfeedbackresistor(R ). • >40-dBGainAdjustRange F The internal architecture of the VCA822 device • HighGainAccuracy:20dB ±0.3dB consists of two input buffers and an output current • HighOutputCurrent: ±160mA feedback amplifier stage integrated with a multiplier core to provide a complete variable gain amplifier 2 Applications (VGA) system that does not require external • DifferentialLineReceivers buffering. The maximum gain is set externally with two resistors, providing flexibility in designs. The • DifferentialEqualizers maximum gain is intended to be set between +2 V/V • PulseAmplitudeCompensation and+100V/V.Operatingfrom ±5-Vsupplies,thegain • VariableAttenuators control voltage for the VCA822 device adjusts the gain linearly in V/V as the control voltage varies from • Voltage-TunableActiveFilters +1 V to 1 V. For example, set for a maximum gain of • Drop-InUpgradetoLMH6503 +10V/V,theVCA822deviceprovides10V/V,at 1-V input, to 0.1 V/V at –1 V input of gain control range. The VCA822 device offers excellent gain linearity. For a 20-dB maximum gain and a gain- control input voltage varying between 0 V and 1 V, the gain does not deviate by more than ±0.3 dB (maximumat+25°C). DeviceInformation(1) PARTNUMBER PACKAGE BODYSIZE(NOM) SOIC(14) 8.65mm×3.91mm VCA822 VSSOP(10) 3.00mm×3.00mm (1) Formoreinformation,seeMechanicalPackagingand OrderableInformation. DifferentialEqualizer DifferentialEqualizationofanRCLoad R V +V F 9 IN1 IN Equalized Frequency R RG+ 6 Response S R FB RL 3 1 RG VCA822 VOUT 0 VIN2 C1 R-VGI-N 20W CL Gain (dB) -1---3296 Inoift iaVlC FAre8q2u2e wncityh RReCs pLoonasde RS -15 -18 R = 75W -21 CL= 100pF -24 F 1M 10M 100M 1G Frequency (Hz) 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectualpropertymattersandotherimportantdisclaimers.PRODUCTIONDATA.

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com Table of Contents 1 Features.................................................................. 1 9 DetailedDescription............................................ 22 2 Applications........................................................... 1 9.1 Overview.................................................................22 3 Description............................................................. 1 9.2 FeatureDescription.................................................22 4 RevisionHistory..................................................... 2 9.3 DeviceFunctionalModes........................................22 5 DeviceComparisonTable..................................... 4 10 ApplicationandImplementation........................ 25 10.1 ApplicationInformation..........................................25 6 PinConfigurationandFunctions......................... 4 10.2 TypicalApplications..............................................27 7 Specifications......................................................... 5 10.3 SystemExamples.................................................34 7.1 AbsoluteMaximumRatings......................................5 11 PowerSupplyRecommendations..................... 36 7.2 ESDRatings..............................................................5 12 Layout................................................................... 36 7.3 RecommendedOperatingConditions.......................5 7.4 ThermalInformation..................................................5 12.1 LayoutGuidelines.................................................36 7.5 ElectricalCharacteristics:V =±5V.........................6 12.2 LayoutExample....................................................37 S 7.6 TypicalCharacteristics:V =±5V,DCParameters.9 12.3 ThermalConsiderations........................................37 S 7.7 TypicalCharacteristics:V =±5V,DCandPower- 13 DeviceandDocumentationSupport................. 38 S SupplyParameters..................................................10 13.1 DeviceSupport......................................................38 7.8 TypicalCharacteristics:VS=±5V,AVMAX=+2 13.2 CommunityResources..........................................38 V/V........................................................................... 11 13.3 Trademarks...........................................................38 7.9 TypicalCharacteristics:VS=±5V,AVMAX=+10 13.4 ElectrostaticDischargeCaution............................38 V/V........................................................................... 14 13.5 Glossary................................................................38 7.10 TypicalCharacteristics:V =±5V,A =+100 S VMAX 14 Mechanical,Packaging,andOrderable V/V........................................................................... 18 Information........................................................... 38 8 ParameterMeasurementInformation................21 4 Revision History NOTE:Pagenumbersforpreviousrevisionsmaydifferfrompagenumbersinthecurrentversion. ChangesfromRevisionC(December2008)toRevisionD Page • AddedPinConfigurationandFunctionssection,ESDRatingstable,RecommendedOperatingConditionstable, FeatureDescriptionsection,DeviceFunctionalModes,ApplicationandImplementationsection,PowerSupply Recommendationssection,Layoutsection,DeviceandDocumentationSupportsection,andMechanical, Packaging,andOrderableInformationsection ..................................................................................................................... 1 ChangesfromRevisionB(August2008)toRevisionC Page • RevisedsecondparagraphintheWidebandVariableGainAmplifierOperationsectiondescribingpin9.......................... 27 ChangesfromRevisionA(October2007)toRevisionB Page • ChangedstoragetemperaturerangeratinginAbsoluteMaximumRatingstablefrom–40°Cto+125°Cto–65°Cto +125°C.................................................................................................................................................................................... 5 ChangesfromOriginal(September2007)toRevisionA Page • ChangedG toA throughoutdocument....................................................................................................................... 1 MAX VMAX • ChangedGtoA inconditionsintheElectricalCharacteristics:V =±5Vtable............................................................. 6 VMAX S • Changed5throwofACPerformancesectionintheElectricalCharacteristics:V =±5Vtable .......................................... 6 S • Changed4throwofOutputsectionintheElectricalCharacteristics:V =±5Vtable........................................................... 6 S • ChangedFigure7,thetitleofFigure8,thetitleofFigure9,thetitleofFigure10,andFigure11inthe±5V,DCand Power-SupplyParametersTypicalCharacteristics ............................................................................................................. 10 • ChangedFigure78,Figure18,Figure20,Figure22,andFigure27inthe±5V,A =+2V/VTypical VMAX Characteristics ..................................................................................................................................................................... 11 2 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 • ChangedFigure32,Figure48,andFigure52inthe±5V,A =+10V/VTypicalCharacteristics................................... 14 VMAX • ChangedFigure53andFigure72inthe±5V,A =+100V/VTypicalCharacteristics ................................................ 18 VMAX • ChangedTable1intheDemonstrationBoardssection....................................................................................................... 25 • Changed2200V/μsto1700V/μsinfirstparagraphoftheWidebandVariableGainAmplifierOperationApplication section.................................................................................................................................................................................. 27 • ChangedrailquantityforVCA822IDintheOrderingInformationtable .............................................................................. 38 Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 5 Device Comparison Table VCA822RelatedProducts GAINADJUSTRANGE INPUTNOISE SINGLES DUALS SIGNALBANDWIDTH(MHz) (dB) (nV/√Hz) VCA810 — 80 2.4 35 — VCA2612 45 1.25 80 — VCA2613 45 1 80 — VCA2615 52 0.8 50 — VCA2617 48 4.1 50 VCA820 — 40 8.2 150 VCA821 — 40 7.0 420 VCA822 — 40 8.2 150 VCA824 — 40 7.0 420 6 Pin Configuration and Functions DPackage 14-PinSOIC DGSPackage TopView 10-PinVSSOP TopView +V 1 14 +V CC CC FB 1 10 GND V 2 13 NC G +V 2 9 V CC OUT +V 3 12 FB IN V 3 8 -V G CC +R 4 11 GND G +V 4 7 -V IN IN -R 5 10 V G OUT +R 5 6 -R G G -V 6 9 V IN REF -V 7 8 -V CC CC NC=NoConnection PinFunctions PIN I/O DESCRIPTION NAME SOIC VSSOP FB 12 1 I FeedbackResistorInput GND 11 10 — Ground NC 13 — — NoConnect +R 4 5 I GainSetResistor G –R 5 6 I GainSetResistor G –V 7,8 8 P NegativeSupply CC +V 1,14 2 P PositiveSupply CC V 2 3 I GainControl G –V 6 7 I InvertingInput IN +V 3 4 I NoninvertingInput IN V 10 9 O Output OUT V 9 — I OutputVoltageReference REF 4 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 7 Specifications 7.1 Absolute Maximum Ratings Overoperatingfree-airtemperaturerange,unlessotherwisenoted.(1) MIN MAX UNIT Powersupply ±6.5 V Internalpowerdissipation SeeThermalInformation Inputvoltage ±V V S Leadtemperature(soldering,10s) 260 °C Junctiontemperature(T) 150 °C J Junctiontemperature(T),maximumcontinuousoperation 140 °C J Storagetemperature –65 125 °C (1) StressesbeyondthoselistedunderAbsoluteMaximumRatingsmaycausepermanentdamagetothedevice.Thesearestressratings only,whichdonotimplyfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunderRecommended OperatingConditions.Exposuretoabsolute-maximum-ratedconditionsforextendedperiodsmayaffectdevicereliability. 7.2 ESD Ratings VALUE UNIT Human-bodymodel(HBM),perANSI/ESDA/JEDECJS-001(1) ±2000 V Electrostaticdischarge Charged-devicemodel(CDM),perJEDECspecificationJESD22-C101(2) ±500 V (ESD) Machinemodel(MM) ±200 (1) JEDECdocumentJEP155statesthat500-VHBMallowssafemanufacturingwithastandardESDcontrolprocess. (2) JEDECdocumentJEP157statesthat250-VCDMallowssafemanufacturingwithastandardESDcontrolprocess. 7.3 Recommended Operating Conditions overoperatingfree-airtemperaturerange(unlessotherwisenoted) MIN NOM MAX UNIT Operatingvoltage 7 10 12 V Operatingtemperature –40 25 85 °C 7.4 Thermal Information VCA822 THERMALMETRIC(1) D[SOIC] DGS[VSSOP] UNIT 14PINS 10PINS R Junction-to-ambientthermalresistance 90.3 173.1 °C/W θJA R Junction-to-case(top)thermalresistance 49.8 46.6 °C/W θJC(top) R Junction-to-boardthermalresistance 44.9 94.3 °C/W θJB ψ Junction-to-topcharacterizationparameter 13.8 2.2 °C/W JT ψ Junction-to-boardcharacterizationparameter 44.6 92.7 °C/W JB R Junction-to-case(bottom)thermalresistance n/a n/a °C/W θJC(bot) (1) Formoreinformationabouttraditionalandnewthermalmetrics,seetheSemiconductorandICPackageThermalMetricsapplication report,SPRA953. Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 7.5 Electrical Characteristics: V = ±5 V S AtA =+10V/V,R =1kΩ,R =200Ω,andR =100Ω,25°C,unlessotherwisenoted. VMAX F G L TEST PARAMETER TESTCONDITIONS MIN TYP MAX UNIT LEVEL(1) ACPERFORMANCE AVMAX=+2V/V,VO=1VPP,VG=1V 168 MHz C Small-signalbandwidth(SOIC-14 Package) AVMAX=+10V/V,VO=1VPP,VG=1V 150 MHz C AVMAX=+100V/V,VO=1VPP,VG=1V 118 MHz C Large-signalbandwidth AVMAX=+10V/V,VO=5VPP,VG=1V 137 MHz C 25°C(2) 170 200 Gaincontrolbandwidth VG=0VDC+10mVPP 0°Cto70°C(3) 170 MHz B –40°Cto+85°C(3) 165 Bandwidthfor0.1dBflatness AVMAX=+10V/V,VO=1VPP,VG=1V 28 MHz C 25°C(2) 1500 1700 Slewrate AVMAX=+10V/V,VO=5-VStep,VG=1 0°Cto70°C(3) 1500 V/μs B V –40°Cto+85°C(3) 1450 25°C(2) 2.5 3.1 Rise-and-falltime AVMAX=+10V/V,VO=5-VStep,VG=1 0°Cto70°C(3) 3.2 ns B V –40°Cto+85°C(3) 3.2 Settlingtimeto0.01% AVMAX=+10V/V,VO=5VStep,VG=1V 11 ns C 25°C(2) –60 –62 Harmonicdistortion,2nd-harmonic VO=2VPP,f=20MHz,VG=1V 0°Cto70°C(3) –60 dBc B –40°Cto+85°C(3) –60 25°C(2) –66 –68 Harmonicdistortion,3rd-harmonic VO=2VPP,f=20MHz,VG=1V 0°Cto70°C(3) –66 dBc B –40°Cto+85°C(3) –66 Inputvoltagenoise f>100kHz,VG=1V 8.2 nV/√Hz C Inputcurrentnoise f>100kHz,VG=1V 2.6 pA/√Hz C GAINCONTROL 25°C(2) ±0.1 ±0.4 Absolutegainerror AVMAX=+10V/V,VG=1V 0°Cto70°C(3) ±0.5 dB A –40°Cto+85°C(3) ±0.6 25°C(2) ±0.05 ±0.3 Gaindeviation AVMAX=+10V/V,0<VG<1V 0°Cto70°C(3) ±0.34 dB A –40°Cto+85°C(3) ±0.37 25°C(2) ±1.06 ±1.9 Gaindeviation AVMAX=+10V/V,–0.8<VG<1V 0°Cto70°C(3) ±2.1 dB A –40°Cto+85°C(3) ±2.2 25°C(2) –26 –24 GainatVG=–0.9V Relativetomaximumgain 0°Cto70°C(3) –24 dB A –40°Cto+85°C(3) –23 25°C(2) 22 30 Gaincontrolbiascurrent VG=0V 0°Cto70°C(3) 35 μA A –40°Cto+85°C(3) 37 0°Cto70°C(3) ±100 Averagegaincontrolbiascurrentdrift VG=0V –40°Cto+85°C(3) ±100 nA/°C B Gaincontrolinputimpedance 70||1 kΩ||pF C DCPERFORMANCE 25°C(2) ±4 ±17 Inputoffsetvoltage AVMAX=+10V/V,VCM=0V,VG=0V 0°Cto70°C(3) ±17.8 mV A –40°Cto+85°C(3) ±19 0°Cto70°C(3) ±30 Averageinputoffsetvoltagedrift AVMAX=+10V/V,VCM=0V,VG=0V –40°Cto+85°C(3) ±30 μV/°C B (1) Testlevels:(A)100%testedat25°C.Overtemperaturelimitssetbycharacterizationandsimulation.(B)Limitssetbycharacterization andsimulation.(C)Typicalvalueonlyforinformation. (2) Junctiontemperature=ambientfor+25°Ctestedspecifications. (3) Junctiontemperature=ambientatlowtemperaturelimit;junctiontemperature=ambient+23°Cathightemperaturelimitforover temperaturespecifications. 6 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 Electrical Characteristics: V = ±5 V (continued) S AtA =+10V/V,R =1kΩ,R =200Ω,andR =100Ω,25°C,unlessotherwisenoted. VMAX F G L TEST PARAMETER TESTCONDITIONS MIN TYP MAX UNIT LEVEL(1) 25°C(2) 19 25 Inputbiascurrent AVMAX=+10V/V,VCM=0V,VG=0V 0°Cto70°C(3) 29 μA A –40°Cto+85°C(3) 31 0°Cto70°C(3) ±90 Averageinputbiascurrentdrift AVMAX=+10V/V,VCM=0V,VG=0V –40°Cto+85°C(3) ±90 nA/°C B 25°C(2) ±0.5 ±2.5 Inputoffsetcurrent AVMAX=+10V/V,VCM=0V,VG=0V 0°Cto70°C(3) ±3.2 μA A –40°Cto+85°C(3) ±3.5 0°Cto70°C(3) ±16 Averageinputoffsetcurrentdrift AVMAX=+10V/V,VCM=0V,VG=0V –40°Cto+85°C(3) ±16 nA/°C B 25°C(2) ±2.6 ±2.55 IRGMAX Mreasxisimtaunmcecurrentthroughgain 0°Cto70°C(3) ±2.55 mA B –40°Cto+85°C(3) ±2.5 INPUT 25°C(2) +1.6 +1.6 Mostpositiveinputvoltage RL=100Ω 0°Cto70°C(3) +1.6 V A –40°Cto+85°C(3) +1.6 25°C(2) –2.1 –2.1 Mostnegativeinputvoltage RL=100Ω 0°Cto70°C(3) –2.1 V A –40°Cto+85°C(3) –2.1 25°C(2) 65 80 Common-moderejectionratio VCM=±0.5V 0°Cto70°C(3) 60 dB A –40°Cto+85°C(3) 60 Inputimpedance,differential 0.5||1 MΩ||pF C Inputimpedance,common-mode 0.5||2 MΩ||pF C OUTPUT 25°C(2) ±3.8 ±4.0 RL=1kΩ 0°Cto70°C(3) ±3.75 V A –40°Cto+85°C(3) ±3.7 Outputvoltageswing 25°C(2) ±3.7 ±3.9 RL=100Ω 0°Cto70°C(3) ±3.6 V A –40°Cto+85°C(3) ±3.5 25°C(2) ±140 ±160 Outputcurrent VO=0V,RL=5Ω 0°Cto70°C(3) ±130 mA A –40°Cto+85°C(3) ±130 Outputimpedance AVMAX=+10V/V,f>100kHz,VG=1V 0.01 Ω C POWERSUPPLY Specifiedoperatingvoltage ±5 V C Minimumoperatingvoltage ±3.5 V C 25°C(2) Maximumoperatingvoltage 0°Cto70°C(3) V A –40°Cto+85°C(3) 25°C(2) 36 37 Maximumquiescentcurrent VG=0V 0°Cto70°C(3) 37.5 mA A –40°Cto+85°C(3) 38 25°C(2) 36 34.5 Minimumquiescentcurrent VG=0V 0°Cto70°C(3) 34 mA A –40°Cto+85°C(3) 33.5 25°C(2) –61 –68 –PSRR Power-supplyrejectionratio VG=+1V 0°Cto70°C(3) –59 dB A –40°Cto+85°C(3) –58 Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com Electrical Characteristics: V = ±5 V (continued) S AtA =+10V/V,R =1kΩ,R =200Ω,andR =100Ω,25°C,unlessotherwisenoted. VMAX F G L TEST PARAMETER TESTCONDITIONS MIN TYP MAX UNIT LEVEL(1) THERMALCHARACTERISTICS Specifiedoperatingrange,Dpackage –40to+85 °C C Junction-to-ambientThermal MSOP-10(DGS) 130 °C/W C θJA resistance SOIC-14(D) 80 °C/W C 8 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 7.6 Typical Characteristics: V = ±5 V, DC Parameters S AtT =25°C,R =100Ω,V =1V,andV =single-endedinputon+V with–V atground,unlessotherwisenoted. A L G IN IN IN 10 40 I = 2.6mA I = 2.6mA V)PP VRIGN MMAAXX(VPP) = 2´RG´IRGMAX(AP) e (dB) 35 ARVGMAX(V/V) = 2´[RF/VIN(VPP)]´2´IRG(AP) age ( Rang 30 Volt ust 25 VO= 1VPP al Input 1 Gain Adj 2105 VO= 2VPP erenti mum 10 VO= 4VPP Diff Maxi 5 VO= 3VPP 0.1 0 10 100 1k 100 1k 10k Gain Resistor (W) Feedback Resistor (W) Figure1.MaximumDifferentialInputVoltagevsR Figure2.MaximumGainAdjustRangevsR G F 60 11 B) A (V/V) = 2´[R/V (V )]´IR2G´=I 2.6(mAA) 10 Absolute Error Range (d 5400 VMAX RF= 3kW F IN PP RG P 987 Adjust 30 RF= 4kW RF= 5kW n (V/V) 65 RMealaxtiimveu mEr Groar itno m Gain 20 RF= 500W Gai 43 mu RF= 1kW 2 xi 10 1 Ma RF= 1.5kW R = 2kW 0 F 0 -1 0.1 1 10 -1.2 -0.8 -0.4 0 0.4 0.8 1.2 Output Voltage (V ) Control Voltage (V) PP Figure3.MaximumGainAdjustRangevs Figure4.GainErrorBandvs Peak-to-PeakOutputVoltage GainControlVoltage 21 24 Data Equation: 22 20 y = 20log (4.9619x + 5.0169) 20 18 19 16 14 Gain (V/V) 111876 Data Gain (V/V) 112086 Relative Error to Linear Regression Relative Error to Linear Regression 4 15 2 Linear Regression 0 14 -2 Data Data Equation: Linear Regression -4 y = 20log (4.9619x + 5.0169) 13 -6 0 0.2 0.4 0.6 0.8 1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 Control Voltage (V) Control Voltage (V) Figure5.GainErrorBandvs Figure6.GainErrorBandvs GainControlVoltage GainControlVoltage Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 7.7 Typical Characteristics: V = ±5 V, DC and Power-Supply Parameters S AtT =+25°C,R =100Ω,V =+1V,andV =single-endedinputon+V with–V atground,unlessotherwisenoted. A L G IN IN IN 1500 40 For > 40dB Gain Adjust Range 1400 39 Wesistor () 11320000 urrent (mA) 3387 -IQ +IQ R 1100 C 36 Feedback 1090000 Quiescent 3354 800 NOTE:-3dB bandwidth varies with package type. 33 See theApplicationsection for more details. 700 32 1 10 100 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 A (V/V) Gain Control Voltage (V) VMAX Figure7.RecommendedR vsA Figure8.SupplyCurrentvsControlVoltage F VMAX (A =+2V/V) VMAX 40 40 39 39 A) 38 A) 38 nt (m 37 -IQ nt (m 37 -IQ e e Curr 36 Curr 36 cent 35 +IQ cent 35 +IQ s s e e Qui 34 Qui 34 33 33 32 32 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 Gain Control Voltage (V) Gain Control Voltage (V) Figure9.SupplyCurrentvsControlVoltage Figure10.SupplyCurrentvsControlVoltage (A =+10V/V) (A =+100V/V) VMAX VMAX 1.0 35 Input Offset Voltage (V ) V = 0V 0.5 Left ScOaSle G 30 Inp u mage (V) -0.05 IRnipguhtt BSicaasl eCurrent (IB) 2250 t Bias an et Volt -1.0 15 d Offs s e Off -1.5 10 t C nput -2.0 5 urren I -2.5 10x Input Offset Current (IOS) 0 t (Am Right Scale ) -3.0 -5 -50 -25 0 25 50 75 100 125 Temperature (°C) Figure11.TypicalDCDriftvsTemperature 10 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 7.8 Typical Characteristics: V = ±5 V, A = +2 V/V S VMAX AtT =+25°C,R =100Ω,R =1.33kΩ,R =1.33kΩ,V =+1V,V =single-endedinputon+V with–V atground,and A L F G G IN IN IN SOIC-14package,unlessotherwisenoted. 3 400 V = 250mV IN PP 0 300 f = 20MHz V = 1V dB) -3 O PP V) 200 Gain ( -6 ge (m 100 malized -9 VO= 2VPP ut Volta 0 Nor -12 VO= 5VPP Outp -100 -15 V = 7V -200 -18 O PP 1M 10M 100M 1G -300 Frequency (Hz) Time (10ns/div) Figure12.Large-SignalFrequencyResponse Figure13.Small-SignalPulseResponse 4 0.09 0.09 V = 2.5V -dG IN PP 3 f = 20MHz 0.08 VG= 1V 0.08 0.07 0.07 Output Voltage (V) -2101 Differential Gain (%) 00000.....0000065432 VG-d=P 0V VG-d=P 1V VG-d=G 0V 00000.....0000065432 Differential Phase ()° -2 0.01 0.01 0 0 -3 1 2 3 4 Time (10ns/div) Number of Video Loads Figure14.Large-SignalPulseResponse Figure15.CompositeVideodG/dP 0 0 -45 Magnitude (0.05dB/div) --------00000000........0112233450505050 AVMAXV=G +=2 +V1/VV --------00000000........0112233450505050 Deviation from Linear Phase monic Distortion (dBc) -------55667780505050 VAVRGVOLM===A X1+20V1=0V P+WP2V/V 2nd-Harmo3nridc-Harmonic -0.45 -0.45 ()° Har -85 -0.50 -0.50 -90 0 10 20 30 40 50 Frequency (MHz) -95 0.1 1 10 100 Frequency (MHz) Figure16.GainFlatness,DeviationFromLinearPhase Figure17.HarmonicDistortionvsFrequency Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com Typical Characteristics: V = ±5 V, A = +2 V/V (continued) S VMAX AtT =+25°C,R =100Ω,R =1.33kΩ,R =1.33kΩ,V =+1V,V =single-endedinputon+V with–V atground,and A L F G G IN IN IN SOIC-14package,unlessotherwisenoted. -60 -50 V = +1V G n (dBc) -65 2nd-Harmonic n (dBc) --5650 ARf =VL M=2A0 X1M0=H0 +Wz2V/V Distortio -70 Distortio -65 2nd-Harmonic onic -75 3rd-Harmonic onic -70 m A = +2V/V m Har -80 VVGM=A X+1V Har -75 3rd-Harmonic V = 2V O PP f = 20MHz -85 -80 100 1k 0.1 1 10 Resistance (W) Output Voltage Swing (V ) PP Figure18.HarmonicDistortionvsLoadResistance Figure19.HarmonicDistortionvs OutputVoltage -40 45 V = 2V O PP A = +2V/V Bc) -45 VMARfX =L =2 01M00HWz m) 40 on (d -50 +dB orti Maximum Current Through RGLimited nt ( 35 st -55 oi monic Di -60 2nd-Harmonic ercept P 30 Har -65 Int 25 3rd-Harmonic At 50WMatched Load -70 20 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 0 10 20 30 40 50 60 70 Gain Control Voltage (V) Frequency (MHz) Figure20.HarmonicDistortionvs Figure21.Two-Tone,Third-Order GainControlVoltage IntermodulationIntercept 40 3 V = 0V + 10mV 38 G DC PP Constant Input Voltage V = 0.5V IN DC 36 0 Intercept Point (+dBm) 333222420864 Constant Output Voltage Normalized Gain (dB) ---369 f = 20MHz 22 AINt 50WMatched Load 20 -12 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 1M 10M 100M 1G Gain Control Voltage (V) Frequency (Hz) Figure22.Two-Tone,Third-OrderIntermodulationIntercept Figure23.GainControlFrequencyResponse vsGainControlVoltage 12 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 Typical Characteristics: V = ±5 V, A = +2 V/V (continued) S VMAX AtT =+25°C,R =100Ω,R =1.33kΩ,R =1.33kΩ,V =+1V,V =single-endedinputon+V with–V atground,and A L F G G IN IN IN SOIC-14package,unlessotherwisenoted. 4 10 V = 1.25V IN DC 3 V )PP -100 VG= 1V 2 O V UT e ( -20 1.5 10-1 (V) nput Voltag ---345000 VG=-1V V) 10..05 erential I --6700 V(G 0 Diff --8900 V = 2V -0.5 -100 O PP -1.0 1M 10M 100M 1G Time (10ns/div) Frequency (Hz) Figure24.GainControlPulseResponse Figure25.Fully-AttenuatedResponse 1.8 1.6 1MHz 1.6 10MHz 1.4 1.4 1.2 ns) 1.2 ns) y ( 20MHz y ( 1.0 a 1.0 a Del Del 0.8 p 0.8 p ou ou 0.6 Gr 0.6 Gr 0.4 0.4 0.2 0.2 VG= +1V V = 1V O PP 0 0 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 0 20 40 60 80 100 Gain Control Voltage (V) Frequency (MHz) Figure26.GroupDelayvsGainControlVoltage Figure27.GroupDelayvsFrequency 100 d (dB) 96 VO= 0.5VPP CL= 22pF CL= 10pF a o L ve 3 citi CL= 47pF a W) ap 0 R(S 10 n to C -3 CL= 100pF malized Gai --96 VIN 1.33kW +-VVIVINNCA822 RF RS 20W 1kW(1) VOUT 0.1dB Flatness Targeted or NOTE: (1) 1kWis optional. 0 N -12 1 10 100 1k 1M 10M 100M 1G Capacitive Load (pF) Frequency (Hz) Figure28.RecommendedR vsCapacitiveLoad Figure29.FrequencyResponsevsCapacitiveLoad S Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com Typical Characteristics: V = ±5 V, A = +2 V/V (continued) S VMAX AtT =+25°C,R =100Ω,R =1.33kΩ,R =1.33kΩ,V =+1V,V =single-endedinputon+V with–V atground,and A L F G G IN IN IN SOIC-14package,unlessotherwisenoted. 1000 10 Öutput Voltage Noise Density (nV/)Hz 100 VG=V-G1V= +1V VG= 0V Önput Voltage Noise Density (pA/)Hz O I 10 1 100 1k 10k 100k 1M 10M 100 1k 10k 100k 1M 10M Frequency (Hz) Frequency (Hz) Figure30.OutputVoltageNoiseDensity Figure31.InputCurrentNoiseDensity 7.9 Typical Characteristics: V = ±5 V, A = +10 V/V S VMAX AtT =+25°C,R =100Ω,R =1kΩ,R =200Ω,V =+1V,andV =single-endedinputon+V with–V atground, A L F G G IN IN IN unlessotherwisenoted. 3 3 0 0 Gain (dB) --36 VG= 1V Gain (dB) --36 VO= 2VPP malized -9 malized -9 VO= 5VPP Nor -12 AVMAX= 10V/V Nor -12 VO= 7VPP -15 V = 200mV -15 IN PP -18 RL= 100W VG= 0V -18 1M 10M 100M 1G 0 50 100 150 200 250 300 350 400 Frequency (Hz) Frequency (MHz) Figure32.Small-SignalFrequencyResponse Figure33.Large-SignalFrequencyResponse 300 3 V = 50mV V = 0.5V IN PP IN PP f = 20MHz f = 20MHz 200 2 Output Voltage (mV) -1100000 Output Voltage (V) -101 -200 -2 -300 -3 Time (10ns/div) Time (10ns/div) Figure34.Small-SignalPulseResponse Figure35.Large-SignalPulseResponse 14 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 Typical Characteristics: V = ±5 V, A = +10 V/V (continued) S VMAX AtT =+25°C,R =100Ω,R =1kΩ,R =200Ω,V =+1V,andV =single-endedinputon+V with–V atground, A L F G G IN IN IN unlessotherwisenoted. 0.05 0.05 1000 )z H 0 0 D Ö dB/div) --00..0150 --00..0150 eviation F nsity (nV/ VG= +1V Magnitude (0.05 ---000...122505 ---000...122505 rom Linear Phase Voltage Noise De 100 VG=-1VVG= 0V -0.30 VG= +1V -0.30 ()° put -0.35 AVMAX= +10V/V -0.35 Out 10 0 10 20 30 40 50 100 1k 10k 100k 1M 10M Frequency (MHz) Frequency (Hz) Figure36.GainFlatness,DeviationFromLinearPhase Figure37.OutputVoltageNoiseDensity -45 -60 V = +1V -50 AG = +10V/V 2nd-Harmonic VMAX -65 -55 RVO== 120V0PWP Bc) L d Gain (dB) ---667050 2nd-Harmonic3rd-Harmonic onic Distortion ( ---778050 3rd-Harmonic -75 Harm -85 VAGVM=A X+1=V +10V/V -80 VO= 2VPP f = 20MHz -85 -90 0.1 1 10 100 100 1k Frequency (MHz) Resistance (W) Figure38.HarmonicDistortionvsFrequency Figure39.HarmonicDistortionvsLoadResistance -55 -45 V = 2V O PP A = +10V/V VMAX n (dBc) -60 2nd-Harmonic n (dBc) -50 Rf =L =2 01M00HWz stortio -65 stortio -55 MRGaxL iCmuitrerednt Through Di Di c -70 c -60 ni ni o o m V = +1V 3rd-Harmonic m 2nd-Harmonic Har -75 AGVMAX= +10V/V Har -65 R = 100W L f = 20MHz 3rd-Harmonic -80 -70 0.1 1 10 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 Output Voltage Swing (V ) Gain Control Voltage (V) PP Figure40.HarmonicDistortionvs Figure41.HarmonicDistortionvs OutputVoltage GainControlVoltage Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com Typical Characteristics: V = ±5 V, A = +10 V/V (continued) S VMAX AtT =+25°C,R =100Ω,R =1kΩ,R =200Ω,V =+1V,andV =single-endedinputon+V with–V atground, A L F G G IN IN IN unlessotherwisenoted. 45 40 38 Constant Output Voltage 40 36 m) m) B B 34 Point (+d 35 Point (+d 3320 Constant Input Voltage Intercept 3205 Intercept 222864 At 50WMatched Load 22 At 50WMatched Load 20 20 5 10 15 20 25 30 35 40 45 50 55 60 65 70 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 Frequency (MHz) Gain Control Voltage (V) Figure42.Two-Tone,Third-Order Figure43.Two-Tone,Third-OrderIntermodulationIntercept IntermodulationIntercept vsGainControlVoltage(fIN=20MHz) 11 6 V = 0V + 10mV 10 G DC PP 3 V = 0.1V 9 IN DC 8 B) 0 V) 76 ain (d -3 Gain (V/ 54 alized G --69 3 m 2 Nor -12 1 -15 0 -1 -18 -1.2 -0.8 -0.4 0 0.4 0.8 1.2 1M 10M 100M 1G Gain Control Voltage (V) Frequency (Hz) Figure44.GainvsGainControlVoltage Figure45.GainControlFrequencyResponse 4 5 V = 0.25V IN DC 3 4 2 OUV 3 1W Internal Load1 L0i0nWe 11..50 10-1 T(V) Output Voltage (V) --21012 Power Dissipation Load L2i5nWe 5L0oaWd Line 1PWow Ienrt eDrnisaslipation V) 0.5 ( -3 VG 0 -4 -0.5 -5 -1.0 -300 -200 -100 0 100 200 300 Time (10ns/div) Output Current (mA) Figure46.GainControlPulseResponse Figure47.OutputVoltageandCurrentLimitations 16 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 Typical Characteristics: V = ±5 V, A = +10 V/V (continued) S VMAX AtT =+25°C,R =100Ω,R =1kΩ,R =200Ω,V =+1V,andV =single-endedinputon+V with–V atground, A L F G G IN IN IN unlessotherwisenoted. 30 2.0 8 20 Input Voltage AVMAX= +10V/V 10 VG= 1V 1.5 Left Scale VG=-0.3V 0 1.0 4 -10 Gain (dB) ----23450000 Input-Referred V(V)IN 0.50 0 OUTV(V -60 -0.5 ) --7800 VG=-1V -1.0 ORiugthptu St cVaolletage -4 -90 V = 2V -1.5 O PP -100 1M 10M 100M 1G -2.0 -8 Frequency (Hz) Time (40ns/div) Figure48.Fully-AttenuatedResponse Figure49.IRGLimitedOverdriveRecovery 2.0 8 1.85 A = +10V/V Output Voltage VMAX 1.5 Right Scale VG= 1.0V 6 1.80 1MHz nput Voltage (V) -100...0550 InpLuet fVt oSltcaaglee 420-2 OUTV(V) Group Delay (ns) 1111....77665050 10MHz I -1.0 -4 20MHz 1.55 -1.5 -6 1.50 -2.0 -8 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 Time (40ns/div) Gain Control Voltage (V) Figure50.OutputLimitedOverdriveRecovery Figure51.GroupDelayvsGainControlVoltage 1.9 1.8 1.7 ns) 1.6 y ( a 1.5 el D p 1.4 u o Gr 1.3 1.2 V = +1V 1.1 G V = 1V O PP 1.0 0 20 40 60 80 100 Frequency (MHz) Figure52.GroupDelayvsFrequency Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 17 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 7.10 Typical Characteristics: V = ±5 V, A = +100 V/V S VMAX AtT =+25°C,R =100Ω,R =845Ω,R =16.9Ω,V =+1V,V =single-endedinputon+V with–V atground,and A L F G G IN IN IN SOIC-14package,unlessotherwisenoted. 3 3 V = 1V 0 G 0 B) -3 -3 d Gain (d -6 VG= 0V n (dB) -6 VO= 2VPP malize -9 Gai -9 VO= 7VPP or -12 -12 N A = 100V/V -15 VVM=AX 20mV -15 IN PP V = 5V R = 100W O PP -18 L -18 1 10 100 500 0 50 100 150 200 250 300 Frequency (MHz) Frequency (MHz) Figure53.Small-SignalFrequencyResponse Figure54.Large-SignalFrequencyResponse 300 3 VIN= 5mVPP VIN= 50mVPP f = 20MHz f = 20MHz 200 2 e (mV) 100 ge (V) 1 g a olta 0 Volt 0 utput V -100 Output -1 O -200 -2 -300 -3 Time (10ns/div) Time (10ns/div) Figure55.Small-SignalPulseResponse Figure56.Large-SignalPulseResponse 0.10 0.1 1000 VG= +1V )Hz V = +1V Magnitude (0.05dV/div) ----00000.....00112550500 AVMAX= +100V/V 0-----00000.....12345 Deviation from Linear Phase ÖVoltage Noise Density (nV/ 100 VVGGG== -01VV -0.25 -0.6 ()° put ut O -0.30 -0.7 10 0 10 20 30 40 50 100 1k 10k 100k 1M 10M Frequency (MHz) Frequency (Hz) Figure57.GainFlatness Figure58.OutputVoltageNoiseDensity 18 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 Typical Characteristics: V = ±5 V, A = +100 V/V (continued) S VMAX AtT =+25°C,R =100Ω,R =845Ω,R =16.9Ω,V =+1V,V =single-endedinputon+V with–V atground,and A L F G G IN IN IN SOIC-14package,unlessotherwisenoted. -35 -40 V = +1V 2nd-Harmonic -40 AG = +100V/V -45 VMAX c) -45 VO= 2VPP c) -50 n (dB -50 RL= 100W n (dB -55 3rd-Harmonic stortio -55 2nd-Harmonic stortio --6605 Di -60 Di c c -70 moni -65 moni -75 Har -70 3rd-Harmonic Har -80 VAVGM=A X+1=V +100V/V -75 -85 VO= 2VPP f = 20MHz -80 -90 0.1 1 10 100 100 1k Frequency (MHz) Resistance (W) Figure59.HarmonicDistortionvsFrequency Figure60.HarmonicDistortionvsLoadResistance -40 -30 2nd-Harmonic 3rd-Harmonic Distortion (dBc) --4550 3rd-Harmonic Distortion (dBc) --4500 Maximum Current Through RGLimited Harmonic --5650 VARGVLM==A X110V=0 P+WP100V/V Harmonic --6700 2nd-Harmonic AVMAX=RV L+O1==0 1020VV0/PWVP f = 20MHz f = 20MHz -65 -80 0.1 1 10 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 Output Voltage Swing (V ) Gain Control Voltage (V) PP Figure61.HarmonicDistortionvs Figure62.HarmonicDistortionvs OutputVoltage GainControlVoltage 33 31 Constant Input Voltage 31 29 m) 29 m) 27 B B d 27 d + + 25 nt ( 25 nt ( Constant Output Voltage Poi Poi 23 pt 23 pt e e 21 erc 21 erc nt nt 19 I 19 I 17 17 At 50WMatched Load At 50WMatched Load 15 15 5 10 15 20 25 30 35 40 45 50 55 60 65 70 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 Frequency (MHz) Gain Control Voltage (V) Figure63.Two-Tone,Third-Order Figure64.Two-Tone,Third-OrderIntermodulationIntercept IntermodulationIntercept vsGainControlVoltage(f =20MHz) IN Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 19 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com Typical Characteristics: V = ±5 V, A = +100 V/V (continued) S VMAX AtT =+25°C,R =100Ω,R =845Ω,R =16.9Ω,V =+1V,V =single-endedinputon+V with–V atground,and A L F G G IN IN IN SOIC-14package,unlessotherwisenoted. 110 3 V = 0V + 10mV 100 G DC PP V = 10mV 90 IN DC 0 80 B) V) 7600 ain (d -3 Feedthrough V/ G n ( 50 ed Gai 40 aliz -6 30 m or 20 N -9 10 0 -10 -12 -1.2 -0.8 -0.4 0 0.4 0.8 1.2 1M 10M 100M 1G 2G Gain Control Voltage (V) Frequency (Hz) Figure65.GainvsGainControlVoltage Figure66.GainControlFrequencyResponse 4 50 V = 25mV IN DC 3 40 V = 1V V 30 G 2 O UT B) 20 1 (V) n (d 10 0 ai G 0 1.5 -1 ed -10 z 1.0 mali -20 V(V)G 0.50 Nor ---345000 V = 2V VG=-1V -0.5 -60 O PP -1.0 1M 10M 100M 1G Time (10ns/div) Frequency (Hz) Figure67.GainControlPulseResponse Figure68.Fully-AttenuatedResponse 0.8 8 0.20 8 0.6 InpLuet fVt oSltcaaglee AVMAXV=G +=10-00V.3/VV 6 0.15 ORiugthptu St cVaolletage AVMAX=V +G1=0 01V.0/VV 6 0.4 4 0.10 4 Input Voltage (V) --000...2024 ORiugthptu St cVaolletage 20--24 Output Voltage (V) Input Voltage (V) --000...0015500 InpLuet fVt oSltcaaglee 20--24 Output Voltage (V) -0.6 -6 -0.15 -6 -0.8 -8 -0.20 -8 Time (40ns/div) Time (40ns/div) Figure69.IRGLimitedOverdriveRecovery Figure70.OutputLimitedOverdriveRecovery 20 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 Typical Characteristics: V = ±5 V, A = +100 V/V (continued) S VMAX AtT =+25°C,R =100Ω,R =845Ω,R =16.9Ω,V =+1V,V =single-endedinputon+V with–V atground,and A L F G G IN IN IN SOIC-14package,unlessotherwisenoted. 3.0 3.5 20MHz 2.5 3.0 ns) 2.0 ns) 2.5 ay ( 10MHz 1MHz ay ( 2.0 Del 1.5 Del p p 1.5 u u o o Gr 1.0 Gr 1.0 0.5 0.5 VG= +1V V = 1V O PP 0 0 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 0 20 40 60 80 100 Gain Control Voltage (V) Frequency (MHz) Figure71.GroupDelayvsGainControlVoltage Figure72.GroupDelayvsFrequency 8 Parameter Measurement Information +V V IN R IN F R 50W 1 RG+ Source 50W R V G OUT R G- 50W R Load 3 -V R IN 2 50W V G Figure73. TestCircuit Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 21 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 9 Detailed Description 9.1 Overview The VCA822 is a voltage controlled variable gain amplifier with differential inputs and a single ended output. The maximum gain is set by external resistors while the gain range is controlled by an external analog voltage. The maximum gain is designed for gains of 2 V/V up to 100 V/V and the analog control allows a gain range of over 40 dB. The VCA822 input consists of two buffers which together create a fully symmetrical, high impedance differential input with a typical common mode rejection of 80 dB. The gain set resistor is connected between the two input buffer output pins, so that the input impedance is independent of the gain settings. The bipolar inputs have a input voltage range of +1.6 and –2.1 V on ±5 V supplies. The amplifier maximum gain is set by external resistors, but the internal gain control circuit is controlled by a continuously variable, analog voltage. The gain control is a multiplier stage which is linear in V/V. The gain control input pin operates over a 2-V voltage range (–1 V to +1 V). The VCA822 contains a high speed, high current output buffer. The output stage can typically swing±3.9Vandsource/sink ±160mA.TheVCA822canbeoperatedoveravoltagerangeof ±3.5Vto ±6V. 9.2 Feature Description The VCA822 can be operated with both single ended or differential input signals. The inputs present consistently high impedance across all gain configurations. By using an analog control signal the amplifier gain is continuously variable for smooth, glitch free gain changes. With a large signal bandwidth of 137 Mhz and a slew rate of 1700 V/us the VCA822 offers linear performance over a wide range of signal amplitudes and gain settings. The low impedance/high current output buffer can drive loads ranging from low impedance transmission lines to high-impedance, switched-capacitor analog to digital converters. By using closely matched internal componentstheVCA822offersatypicalgainaccuracyof ±0.1dB. 9.3 Device Functional Modes The VCA822 functions as a differential input, single-ended output variable gain amplifier. This functional mode is enabledbyapplyingpowertotheamplifiersupplypinsandisdisabledbyturningthepoweroff. The gain is continuously variable through the analog gain control input. While the gain range is fixed the maximum gain is set by two external components, Rf and Rg as shown in the Parameter Measurement Information. The maximum gain is equal to 2x (Rf / Rg). This gain is achieved with a 2-V voltage on the gain adjust pin VG. As the voltage decreases on the VG pin, the gain decreases in a linear in dB fashion with over 40 dBofgainrangefrom2-Vto0-Vcontrolvoltage. As with most other differential input amplifiers, inputs can be applied to either one or both of the amplifier inputs. Theamplifiergainiscontrolledthroughthegaincontrolpin. 9.3.1 MaximumGainofOperation This section describes the use of the VCA822 device in a fixed-gain application in which the V control pin is set G atV =+1V.Thetradeoffsdescribedherearewithbandwidth,gain,andoutputvoltagerange. G In the case of an application that does not make use of the V , but requires some other characteristic of the GAIN VCA822, the R resistor must be set such that the maximum current flowing through the resistance I is less G RG than±2.6mAtypical,or5.2mA asdefinedinElectricalCharacteristics:V =±5V,andmustfollowEquation1. PP S V OUT I = RG A ´R VMAX G (1) As demonstrated by Equation 1, when the output dynamic range and maximum gain are defined, the gain resistor is set. This gain setting in turn affects the bandwidth because in order to achieve the gain (and with a set gain element), the feedback element of the output stage amplifier is set as well. Keeping in mind that the output amplifier of the VCA822 device is a current-feedback amplifier, the larger the feedback element, the lower the bandwidthasthefeedbackresistoristhecompensationelement. Limiting the discussion to the input voltage only and ignoring the output voltage and gain, Figure 1 illustrates the tradeoffbetweentheinputvoltageandthecurrentflowingthroughthegainresistor. 22 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 Device Functional Modes (continued) 9.3.2 OutputCurrentandVoltage The VCA822 device provides output voltage and current capabilities that are unsurpassed in a low-cost monolithic VCA. Under no-load conditions at +25°C, the output voltage typically swings closer than 1 V to either supply rails; the +25°C swing limit is within 1.2 V of either rails. Into a 15-Ω load (the minimum tested load), it is testedtodelivermorethan±160mA. The specifications described previously, though familiar in the industry, consider voltage and current limits separately. In many applications, it is the voltage × current, or V-I product, that is more relevant to circuit operation. Refer to the Output Voltage and Current Limitations plot (Figure 47) in the Typical Characteristics section. The X-axis and Y-axis of this graph show the zero-voltage output current limit and the zero-current output voltage limit, respectively. The four quadrants give a more detailed view of the VCA822 device output drive capabilities, noting that the graph is bounded by a Safe Operating Area of 1-W maximum internal power dissipation. Superimposing resistor load lines onto the plot shows that the VCA822 device can drive ±2.5 V into 25 Ω or ±3.5 V into 50 Ω without exceeding the output capabilities or the 1 W dissipation limit. A 100-Ω load line (the standard test circuit load) shows the full ±3.9 V output swing capability, as shown in the Typical Characteristics. The minimum specified output voltage and current over-temperature are set by worst-case simulations at the cold temperature extreme. Only at cold start-up do the output current and voltage decrease to the numbers shown in Electrical Characteristics: V = ±5 V. As the output transistors deliver power, the respective junction S temperaturesincrease,increasingtheavailableoutputvoltageswing,andincreasingtheavailableoutputcurrent. In steady-state operation, the available output voltage and current is always greater than that temperature shown in the over-temperature specifications because the output stage junction temperatures are higher than the specifiedoperatingambient. 9.3.3 InputVoltageDynamicRange The VCA822 device has a input dynamic range limited to +1.6 V and –2.1 V. Increasing the input voltage dynamic range can be done by using an attenuator network on the input. If the VCA822 device is trying to regulate the amplitude at the output, such as in an AGC application, the input voltage dynamic range is directly proportionaltoEquation2. V = R ´I IN(PP) G RG(PP) (2) As such, for unity-gain or under-attenuated conditions, the input voltage must be limited to the CMIR of ±1.6 V (3.2 V ) and the current (I ) must flow through the gain resistor, ±2.6 mA (5.2 mA ). This configuration sets a PP RQ PP minimumvalueforR suchthatthegainresistorhastobegreaterthanEquation3. E 3.2V R = PP = 615.4W GMIN 5.2mA PP (3) Values lower than 615.4Ω are gain elements that result in reduced input range, as the dynamic input range is limited by the current flowing through the gain resistor R (I ). If the I current is limiting the performance of G RG RG the circuit, the input stage of the VCA822 device goes into overdrive, resulting in limited output voltage range. Such I -limited overdrive conditions are shown in Figure 49 for the gain of +10 V/V and Figure 69 for the +100 RG V/Vgain. 9.3.4 OutputVoltageDynamicRange With its large output current capability and its wide output voltage swing of ±3.9-V typical on a 100-Ω load, it is easy to forget other types of limitations that the VCA822 device can encounter. For these limitations, careful analysis must be done to avoid input stage limitation, either voltage or I current; also, consider the gain RG limitation,asthecontrolpinV varies,affectingotheraspectsofthecircuit. G 9.3.5 Bandwidth The output stage of the VCA822 device is a wideband current-feedback amplifier. As such, the feedback resistance is the compensation of the last stage. Reducing the feedback element and maintaining the gain constant limits the useful range of I , and therefore reducing the gain adjust range. For a given gain, reducing RG thegainelementlimitsthemaximumachievableoutputvoltageswing. Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 23 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com Device Functional Modes (continued) 9.3.6 OffsetAdjustment As a result of the internal architecture used on the VCA822 device, the output offset voltage originates from the output stage and from the input stage and multiplier core. Figure 91 shows how to compensate both sources of the output offset voltage. Use this procedure to compensate the output offset voltage: starting with the output stage compensation, set V = –1 V to eliminate all offset contribution of the input stage and multiplier core. G Adjust the output stage offset compensation potentiometer. Finally, set V = +1 V to the maximum gain and G adjust the input stage and multiplier core potentiometer. This procedure effectively eliminates all offset contributionatthemaximumgain.Becauseadjustingthegainmodifiesthecontributionoftheinputstageandthe multipliercore,someresidualoutputoffsetvoltageremains. 9.3.7 Noise The VCA822 device offers 8.2 nV/√Hz input-referred voltage noise density at a gain of +10 V/V and 1.8 pA/√Hz input-referred current noise density. The input-referred voltage noise density considers that all noise terms, except the input current noise but including the thermal noise of both the feedback resistor and the gain resistor, areexpressedasoneterm. ThismodelisformulatedinEquation4andFigure90. e = A ´ 2´(R ´i )2+ e 2+ 2´4kTR O VMAX S n n S (4) A more complete model is shown in Figure 92. For additional information on this model and the actual modeled noiseterms,pleasecontacttheHigh-SpeedProductApplicationSupportteamatwww.ti.com. 9.3.8 InputandESDProtection The VCA822 device is built using a very high-speed complementary bipolar process. The internal junction breakdown voltages are relatively low for these very small geometry devices. These breakdowns are reflected in AbsoluteMaximumRatings. All pins on the VCA822 device are internally protected from ESD by means of a pair of back-to-back reverse- biased diodes to either power supply, as shown in Figure 74. These diodes begin to conduct when the pin voltage exceeds either power supply by about 0.7 V. This situation can occur with loss of the amplifier power supplies while a signal source is still present. The diodes can typically withstand a continuous current of 30 mA without destruction. To ensure long-term reliability, however, diode current should be externally limited to 10 mA wheneverpossible. ESD protection diodes internally +VS connected to all pins. External Internal Pin Circuitry -V S Figure74. InternalESDProtection 24 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 10 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validateandtesttheirdesignimplementationtoconfirmsystemfunctionality. 10.1 Application Information The VCA822 has flexible maximum gain which is set by the Rf and Rg resistors shown in Parameter Measurement Information. The maximum gain is equal to 2x (Rf / Rg). This gain is achieved with a 2-V voltage on the gain adjust pin VG. As the voltage decreases on the VG pin, the gain decreases in a linear in dB fashion withover40dBofgainrangefrom2-Vto0-Vcontrolvoltage. 10.1.1 Design-InTools 10.1.1.1 DemonstrationBoards Two printed circuit boards (PCBs) are available to assist in the initial evaluation of circuit performance using the VCA822 device in the two package options. Both of these are offered from ti.com as unpopulated PCBs, deliveredwithauser'sguide.ThesummaryinformationforthesefixturesisshowninTable1. Table1.EVMOrderingInformation PRODUCT PACKAGE BOARDPARTNUMBER LITERATURENUMBER VCA822ID SOIC-14 DEM-VCA-SO-1B SBOU050 VCA822IDGS MSOP-10 DEM-VCA-MSOP-1A SBOU051 ThedemonstrationfixturescanberequestedattheTI'swebsitethroughtheVCA822 deviceproductfolder. 10.1.1.2 MacromodelsandApplicationsSupport Computer simulation of circuit performance using SPICE is often useful when analyzing the performance of analog circuits and systems. This principle is particularly true for video and RF amplifier circuits where parasitic capacitance and inductance can play a major role in circuit performance. A SPICE model for the VCA822 device is available through the TI web page. The applications group is also available for design assistance. The models available from TI predict typical small-signal ac performance, transient steps, dc performance, and noise under a wide variety of operating conditions. The models include the noise terms found in the electrical specifications of therelevantproductdatasheet. 10.1.1.3 OperatingSuggestions Operating the VCA822 device optimally for a specific application requires trade-offs between bandwidth, input dynamic range and the maximum input voltage, the maximum gain of operation and gain, output dynamic range and the maximum input voltage, the package used, loading, and layout and bypass recommendations. The Typical Characteristics have been defined to cover as much ground as possible to describe the VCA822 device operation.TherearefoursectionsintheTypicalCharacteristics: • V = ±5 V DC Parameters and V = ±5 V DC and Power-Supply Parameters, which include dc operation and S S theintrinsiclimitationofaVCA822devicedesign • V =± 5V,A =+2V/VGainof+2V/VOperation S VMAX • V =±5V,A =+10V/VGainof+10V/VOperation S VMAX • V =±5V,A =+100V/VGainof+100V/VOperation S VMAX Where the Typical Characteristics describe the actual performance that can be achieved by using the amplifier properly,thefollowingsectionsdescribeindetailthetrade-offsneededtoachievethislevelofperformance. Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 25 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 10.1.1.4 PackageConsiderations The VCA822 device is available in both SOIC-14 and MSOP-10 packages. Each package has, for the different gains used in the typical characteristics, different values of R and R to achieve the same performance detailed F G inElectricalCharacteristics:V =±5V. S Figure 73 shows a test gain circuit for the VCA822 device. Table 2 lists the recommended configuration for the SOIC-14andMSOP-10package. Table2.SOIC-14andMSOP-10R andR Configurations F G G=2 G=10 G=100 R 1.33kΩ 1kΩ 845Ω F R 1.33kΩ 200Ω 16.9Ω G There are no differences between the packages in the recommended values for the gain and feedback resistors. However, the bandwidth for the VCA822IDGS (MSOP-10 package) is lower than the bandwidth for the VCA822ID (SOIC-14 package). This difference is true for all gains, but especially true for gains greater than 5 V/V,ascanbeseeninFigure75andFigure76. NOTE Thescalemustbechangedtoalinearscaletoviewthedetails. 3 3 0 0 B) AVMAX= 2V/V B) AVMAX= 10V/V ain (d -3 ain (d -3 AVMAX= 2V/V G G malized -6 AVAMVAMXA=X 5=V 1/0VV/V malized -6 AVMAX= 20V/V Nor -9 AVMAX= 20V/V Nor -9 AVMAX= 50V/V AVMAX= 50V/V AVMAX= 100V/V -12 AVMAX= 100V/V -12 AVMAX= 5V/V 0 50 100 150 200 0 50 100 150 200 Frequency (MHz) Frequency (MHz) Figure75.SOIC-14RecommendedR andR vsA Figure76.MSOP-10RecommendedR andR vsA F G VMAX F G VMAX 26 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 10.2 Typical Applications 10.2.1 WidebandVariableGainAmplifierOperationApplication 0.1mF X2Yâ Capacitor +5V -5V + 2.2mF 2.2mF + V G +V V IN IN 20W x1 FB I R RG G+ R F R 1kW G 200W RG- x2 VOUT V OUT x1 -V V VCA822 IN REF 20W 20W Figure77. DC-Coupled,A =+10V/V,BipolarSupplySpecificationandTestCircuit VMAX 10.2.1.1 DesignRequirements The design shown in Figure 77 requires a single-ended input, continuously variable gain control and a single- ended output. This configuration is used to achieve the best performance with a bipolar supply. This circuit also requiresamaximumgainof10V/Vandlownoise. 10.2.1.2 DetailedDesignProcedure The VCA822 device provides an exceptional combination of high output power capability with a wideband, greater than 40-dB gain adjust range, linear in V/V variable gain amplifier. The input stage of the VCA822 device places the transconductance element between two input buffers, using the output currents as the forward signal. As the differential input voltage rises, a signal current is generated through the gain element. This current is then mirrored and gained by a factor of two before reaching the multiplier. The other input of the multiplier is the voltage gain control pin, V . Depending on the voltage present on V , up to two times the gain current is G G provided to the transimpedance output stage. The transimpedance output stage is a current-feedback amplifier providing high output current capability and high slew rate, 1700 V/μs. This exceptional full-power performance comes at the price of a relatively high quiescent current (36 mA), but a low input voltage noise for this type of architecture(8.2nV/√Hz). Figure 77 shows the dc-coupled, gain of +10 V/V, dual power-supply circuit used as the basis of the ±5 V Electrical Characteristics: V = ±5 V and Typical Characteristics: V = ±5 V, DC Parameters. For test purposes, S S the input impedance is set to 50 Ω with a resistor to ground and the output impedance is set to 50 Ω with a series output resistor. Voltage swings reported in Electrical Characteristics: V = ±5 V are taken directly at the S input and output pins, while output power (dBm) is at the matched 50-Ω load. For the circuit in Figure 77, the totaleffectiveloadis100 Ω ∥ 1kΩ. Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 27 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com NOTE For the SOIC-14 package, there is a voltage reference pin, V (pin 9). For the SOIC-14 REF package, this pin must be connected to ground through a 20-Ω resistor in order to avoid possible oscillations of the output stage. In the MSOP-10 package, this pin is internally connected and does not require such precaution. An X2Y® capacitor has been used for power-supply bypassing. The combination of low inductance, high resonance frequency, and integration of three capacitors in one package (two capacitors to ground and one across the supplies) of this capacitor enables to achieve the low second-harmonic distortionreportedinElectricalCharacteristics:V =±5V. S MoreinformationonhowtheVCA822deviceoperatescanbefoundintheOperatingSuggestionssection. 10.2.1.3 ApplicationCurve 3 2.2 2.0 0 1.8 B) -3 1.6 Gain (d -6 VG= 0V V/V) 11..42 zed -9 ain ( 10..08 mali VG= 1V G 0.6 Nor -12 0.4 A = 2V/V -15 VVM=AX 1V 0.2 RIN= 100PWP 0 L -18 -0.2 1M 10M 100M 1G -1.2 -0.8 -0.4 0 0.4 0.8 1.2 Frequency (Hz) Gain Control Voltage (V) Figure78.Small-SignalFrequencyResponse Figure79.GainvsGainControlVoltage 10.2.2 Four-QuadrantMultiplierApplication R 1 V G R F V +V IN IN R R G+ FB SoRuSrce 2 RG VCA822 Impedance RG- -V IN 20W R 3 Figure80. Four-QuadrantMultiplierCircuit 10.2.2.1 DesignRequirements A multiplier requires two inputs, one for the X input and one for the Y input. The output of the multiplier circuit is in the form of V = aVin1 × bVin2 : where a and b are real numbers and should not be negative. For four OUT quadrantoperationbothpositiveandnegativeinputsmustbesupportedontheXandYinputs. 10.2.2.2 DetailedDesignProcedure A four-quadrant multiplier can easily be implemented using the VCA822. By placing a resistor between FB and V ,thetransferfunctiondependsuponbothV andV ,asshowninEquation5. IN IN G 28 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 R R R V = F ´V ´V + F - F ´V OUT R G IN R R IN G G 1 (5) Setting R to equal R , the term that depends only on V drops out of the equation, leaving only the term that 1 G IN dependsonbothV andV .V thenfollowsEquation6. G IN OUT R V = F ´V ´V OUT R IN G G (6) The behavior of this circuit is illustrated in Figure 81. Keeping the input amplitude of a 1MHz signal constant and varyingtheV voltage(100kHz,2V )givesthemodulatedoutputvoltageshowninFigure81. G PP 10.2.2.3 ApplicationCurves 1.5 f = 1MHz IN 1.0 f = 0.1MHz VG V) 0.5 e ( d u 0 plit m A -0.5 V V IN OUT -1.0 V G -1.5 0 1 2 3 4 5 6 7 8 9 10 Time (ms) Figure81.ModulatedOutputSignaloftheFour-QuadrantMultiplexerCircuit 10.2.3 DifferenceAmplifierApplication R F V +V IN+ IN R R G+ FB S RG VCA822 R G- V -V IN- IN 20W R S Figure82. DifferenceAmplifier 10.2.3.1 DesignRequirements For a difference amplifier, the design requirements are differential voltage gain, common mode rejection, and loaddrivecapability.Thiscircuitdeliversdifferentialgainof2*(Rf/Rg),andCMRRasshowninFigure83. 10.2.3.2 DetailedDesignProcedure Because both inputs of the VCA822 device are high-impedance, a difference amplifier can be implemented without any major problem. This implementation is shown in Figure 82. This circuit provides excellent common- mode rejection ratio (CMRR) as long as the input is within the CMRR range of –2.1 V to +1.6 V. Note that this circuit does not make use of the gain control pin, V . Also, it is recommended to choose R such that the pole G S formed by R and the parasitic input capacitance does not limit the bandwidth of the circuit. The common-mode S rejection ratio for this circuit implemented in a gain of +10 V/V for V = +1 V is shown in Figure 83. Note that G because the gain control voltage is fixed and is normally set to +1 V, the feedback element can be reduced in order to increase the bandwidth. When reducing the feedback element make sure that the VCA822 device is not limited by common-mode input voltage, the current flowing through R , or any other limitation described in this G datasheet. Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 29 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 10.2.3.3 ApplicationCurve 95 B) 90 d o ( 85 Rati 80 on 75 ecti 70 ej R 65 e od 60 M n- 55 o m 50 m Co 45 Input-Referred 40 100k 1M 10M 100M Frequency (Hz) Figure83.Common-ModeRejectionRatio 10.2.4 DifferentialEqualizerApplication R V +V F IN1 IN R R G+ S R FB 1 RG VCA822 C 1 R G- VIN2 -VIN 20W R S Figure84. DifferentialEqualizer 10.2.4.1 DesignRequirements Signals that travel over a length of cable experience an attenuation that is proportional to the square root of the frequency. For this reason, a fixed bandwidth amplifier will not restore the original signal. To replicate the original signal, the higher frequency signal components require more gain. The circuit in Figure 84 has one stage of frequency shaping to help restore a signal transmitted along a cable. If needed, additional frequency shaping stagescanbeaddedasshowninFigure85. 10.2.4.2 DetailedDesignProcedure Iftheapplicationrequiresfrequencyshaping(thetransitionfromonegaintoanother),theVCA822devicecanbe used advantageously because its architecture allows the application to isolate the input from the gain setting elements. Figure 84 shows an implementation of such a configuration. The transfer function is shown in Equation7. R 1 + sR C G = 2´ F ´ G 1 R 1 + sR C G 1 1 (7) Thistransferfunctionhasonepole,P (locatedatR C ),andonezero,Z (locatedatR C ).Whenequalizingan 1 G 1 1 1 1 RC load, R and C , compensate the pole added by the load located at R C with the zero Z . Knowing R , C , L L L L 1 L L and R allows the user to select C as a first step and then calculate R . Using R = 75 Ω, C = 100 pF and G 1 1 L L wanting the VCA822 device to operate at a gain of +2V/V, which gives R = R = 1.33 kΩ, allows the user to F G select C = 5 pF to ensure a positive value for the resistor R . With all these values known, R can be calculated 1 1 1 to be 170 Ω. The frequency response for both the initial, unequalized frequency response and the resulting equalizedfrequencyresponseareshowninFigure85. 30 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 10.2.4.3 ApplicationCurve 9 Equalized Frequency 6 Response 3 0 -3 dB) -6 Gain ( -9 Inoift iaVlC FAre8q2u2e wncityh RReCs pLoonasde -12 -15 -18 -21 -24 1M 10M 100M 1G Frequency (Hz) Figure85.DifferentialEqualizationofanRCLoad 10.2.5 DifferentialCableEqualizerApplication R 2 1.33kW V +V IN IN R8 RG+ R 50W R401k8W R171.75kW R8.271kW R1.927kW R1.927kW VCA822 VFB VOUT 751W0 VOUT C7 REF 100nF GND 75WLoad C6 R-VGIN- VG R201W 120nF R 5 50W C 5 V = +1V 1.42pF G DC C 9 10mF Figure86. DifferentialCableEqualizer 10.2.5.1 DesignRequirements Signals that travel over a length of cable experience an attenuation that is proportional to the square root of the frequency. For this reason, a fixed bandwidth amplifier will not restore the original signal. To replicate the original signal, the higher frequency signal components require more gain. The circuit in Figure 86 has multiple stages of frequency shaping to help restore a signal transmitted along a cable. This circuit is similar to the one shown in Figure84,butismuchmoreaccurateinreplicatingthe1/(sqrt(f))frequencyresponseshape. 10.2.5.2 DetailedDesignProcedure A differential cable equalizer can easily be implemented using the VCA822. An example of a cable equalization for 100 feet of Belden Cable 1694F is illustrated in Figure 86, with the result for this implementation shown in Figure87.Thisimplementationhasamaximumerrorof0.2dBfromdcto40MHz. Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 31 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 10.2.5.3 ApplicationCurve 2.0 Cable Attenuations B) 1.5 d on (B) uatin (d 1.0 F Cable AttenEqualizer Gai 0.05 VECqAua8l2iz2a twioitnh 4 9 6 -0.5 1 -1.0 1 10 100 Frequency (MHz) Figure87.CableAttenuationversusEqualizerGain NOTE This implementation shows the cable attenuation side-by-side with the equalization in the same plot. For a given frequency, the equalization function realized with the VCA822 device matches the cable attenuation. The circuit in Figure 86 is a driver circuit. To implement a receiver circuit, the signal is received differentially between the +V and –V IN IN inputs. 10.2.6 Voltage-ControlledLow-PassFilterApplication R 2 332W 24pF C R 1 332W R F V 1kW IN 24pF OPA690 +V IN R G+ FB R 200WG VCA822 Out VOUT RG- -V IN 20W 50W V G Figure88. Voltage-ControlLow-PassFilter 10.2.6.1 DesignRequirements A low pass filter should be DC coupled and should only pass frequencies up to the cut off frequency. A good filter provides increasing attenuation as the frequency increases above the cutoff frequency as well as a flat frequency response over the range of frequencies below the cutoff frequency. Passive filters have the limitation of a fixed cutoff frequency unless variable capacitors or inductors are used. This circuit uses the variable gain of theVCA822toprovideanelectronicallycontrolledcutofffrequency. 10.2.6.2 DetailedDesignProcedure In the circuit of Figure 88, the VCA822 device serves as the variable-gain element of a voltage-controlled low- pass filter. This section discusses how this implementation expands the circuit voltage swing capability over that normally achieved with the equivalent multiplier implementation. The circuit control voltage, V , is calculated as G accordingtothesimplifiedrelationshipinEquation8: 32 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 V R 1 OUT =- 2 ´ V R RC IN 1 1 + s 2 G (8) The response control results from amplification of the feedback voltage applied to R . First, consider the case 2 where the VCA822 device produces G = 1V/V. Then this circuit performs as if the amplifier were replaced by a short circuit. Visually replacing the amplifier by a short leaves a simple voltage-feedback amplifier with a feedbackresistorbypassedbyacapacitor.Replacingthisgainwithavariablegain,G,thepolecanbewrittenas showninEquation9: G f = 8 2pR C 2 (9) Because the VCA822 device is most linear in the midrange, the median of the adjustable pole should be set at V = 0V (see Figure 79, Figure 42, Figure 63, and Equation 10). Selecting R = R = 332 Ω, and targeting a G 1 2 median frequency of 10 MHz, the capacitance (C) is 24 pF. Because the OPA690 was selected for the circuit of Figure 88, and in order to limit peaking in the OPA690 frequency response, a capacitor equal to C was added on the inverting mode to ground. This architecture has the effect of setting the high-frequency noise gain of the OPA690to+2V/V,ensuringstabilityandprovidingflatfrequencyresponse. -0.8V£V £0.8V G (10) Once the median frequency is set, the maximum and minimum frequencies can be determined by using V = G –0.8V and V = +0.8 V in the gain equation of Equation 11. Note that this is a first-order analysis and does not G takeintoconsiderationtheopen-loopgainlimitationoftheOPA690. R V + 1 G = 2´ F ´ G R 2 G (11) With the components shown, the circuit provides a linear variation of the low-pass cutoff from 2MHz to 20MHz, using –1V ≤ V ≤ +1V. Practical evaluation shows that this circuit works from 8 MHz to 16 MHz with –0.8V < V G G <+0.8V,asshowninFigure89. 10.2.6.3 ApplicationCurve 3 V = +0.8V G 0 -3 V = +0.5V G -6 dB) -9 ain ( -12 VG= 0V G V =-0.5V -15 G -18 V =-0.8V -21 G V = 1V OUT PP -24 0 25 50 75 100 125 150 175 200 Frequency (MHz) Figure89.VCA822asaVoltage-Control,Low-PassFilter Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 33 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 10.3 System Examples R F +V IN R i R e G+ FB n S O RG VCA822 eO * R G- 4kTRS -VIN i R n S * 4kTRS NOTE: R and R are noiseless. F G Figure90. SimpleNoiseModel +5V Output Stage Offset 10kW Compensation Circuit 0.1mF 4kW -5V R F V +V IN IN R 50W G+ FB RG VCA822 VOUT R G- +5V -VIN 50W 1kW 10kW 0.1mF Input Stage and Multiplexer Core -5V Offset Compensation Circuit Figure91. AdjustingtheInputandOutputVoltageSources 34 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 System Examples (continued) V G i V nINPUT G +V IN V+ R S1 * enINPUT * 4kTRS1 FB x1 R F +RG * inINPUT * 4kTRF V OUT R e G O (Noiseless) ICORE iinOUTPUT -RG VREF x1 R F e i nOUTPUT niOUTPUT * enINPUT * 4kTRF -V IN V- RS2 inINPUT GND * 4kTRS2 Figure92. FullNoiseModel Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 35 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 11 Power Supply Recommendations High-speed amplifiers require low inductance power supply traces and low ESR bypass capacitors. The power supply voltage should be centered on the desired amplifier output voltage, so for ground referenced output signals,splitsuppliesarerequired.Thepowersupplyvoltageshouldbefrom7Vto12V. 12 Layout 12.1 Layout Guidelines Achieving optimum performance with a high-frequency amplifier such as the VCA822 device requires careful attention to printed circuit board (PCB) layout parasitics and external component types. Recommendations to optimizeperformanceinclude: a. Minimize parasitic capacitance to any AC ground for all of the signal I/O pins. This recommendation includes the ground pin (pin 2). Parasitic capacitance on the output can cause instability: on both the invertinginputandthenoninvertinginput,itcanreactwiththesourceimpedancetocauseunintentionalband limiting.Toreduceunwantedcapacitance,awindowaroundthesignalI/Opinsshouldbeopenedinallofthe ground and power planes around those pins. Otherwise, ground and power planes should be unbroken elsewhere on the board. Place a small series resistance (greater than 25 Ω) with the input pin connected to groundtohelpdecouplepackageparasitics. b. Minimize the distance (less than 0.25”) from the power-supply pins to high-frequency 0.1-μF decoupling capacitors. At the device pins, the ground and power plane layout should not be in close proximity to the signal I/O pins. Avoid narrow power and ground traces to minimize inductance between the pins and the decoupling capacitors. The power-supply connections should always be decoupled with these capacitors. Larger (2.2-μF to 6.8-μF) decoupling capacitors, effective at lower frequencies, should also be used on the main supply pins. These capacitors may be placed somewhat farther from the device and may be shared amongseveraldevicesinthesameareaofthePCB. c. Careful selection and placement of external components preserve the high-frequency performance of the VCA822. Resistors should be a very low reactance type. Surface-mount resistors work best and allow a tighter overall layout. Metal-film and carbon composition, axially-leaded resistors can also provide good high- frequency performance. Again, keep the leads and PCB trace length as short as possible. Never use wire- woundtyperesistorsinahigh-frequencyapplication.Becausetheoutputpinisthemostsensitivetoparasitic capacitance, always position the series output resistor, if any, as close as possible to the output pin. Other network components, such as inverting or non-inverting input termination resistors, should also be placed closetothepackage. d. Connections to other wideband devices on the board may be made with short direct traces or through onboard transmission lines. For short connections, consider the trace and the input to the next device as a lumped capacitive load. Relatively wide traces (50 mils to 100 mils, or 1.27 mm to 2.54 mm) should be used, preferablywithgroundandpowerplanesopeneduparoundthem. e. Socketing a high-speed part like the VCA822 device is not recommended. The additional lead length and pin-to-pin capacitance introduced by the socket can create an extremely troublesome parasitic network, which can make it almost impossible to achieve a smooth, stable frequency response. Best results are obtainedbysolderingtheVCA822deviceontotheboard. 36 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

VCA822 www.ti.com SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 12.2 Layout Example Figure93. LayoutRecommendation 12.3 Thermal Considerations The VCA822 device does not require heat-sinking or airflow in most applications. The maximum desired junction temperature sets the maximum allowed internal power dissipation as described in this section. In no case should themaximumjunctiontemperaturebeallowedtoexceed+150°C. Operatingjunctiontemperature(T )isgivenbyEquation12. J T = T + P ´q J A D JA (12) The total internal power dissipation (P ) is the sum of quiescent power (P ) and additional power dissipated in D DQ the output stage (P ) to deliver load power. Quiescent power is simply the specified no-load supply current DL times the total supply voltage across the part. P depends on the required output signal and load; for a DL grounded resistive load, however, it is at a maximum when the output is fixed at a voltage equal to one-half of eithersupplyvoltage(forequalbipolarsupplies).Underthisworst-casecondition,P =V 2/(4× R ),whereR DL S L L istheresistiveload. Note that it is the power in the output stage and not in the load that determines internal power dissipation. As a worst-case example, compute the maximum T using a VCA822ID (SOIC-14 package) in the circuit of Figure 77 J operatingatmaximumgainandatthemaximumspecifiedambienttemperatureof+85°C. P = 10V(38mA) + 52/(4´100W) = 442.5mW D (13) Maximum T = +85°C + (0.449W´80°C/W) = 120.5°C J (14) This maximum operating junction temperature is well below most system level targets. Most applications should be lower because an absolute worst-case output stage power was assumed in this calculation of V / 2, which CC isbeyondtheoutputvoltagerangefortheVCA822device. Copyright©2007–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 37 ProductFolderLinks:VCA822

VCA822 SBOS343D–SEPTEMBER2007–REVISEDOCTOBER2015 www.ti.com 13 Device and Documentation Support 13.1 Device Support 13.1.1 Third-PartyProductsDisclaimer TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER ALONEORINCOMBINATIONWITHANYTIPRODUCTORSERVICE. 13.2 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TIE2E™OnlineCommunity TI'sEngineer-to-Engineer(E2E)Community.Createdtofostercollaboration amongengineers.Ate2e.ti.com,youcanaskquestions,shareknowledge,exploreideasandhelp solveproblemswithfellowengineers. DesignSupport TI'sDesignSupport QuicklyfindhelpfulE2Eforumsalongwithdesignsupporttoolsand contactinformationfortechnicalsupport. 13.3 Trademarks E2EisatrademarkofTexasInstruments. X2YisaregisteredtrademarkofX2YATTENUATORS,LLC. Allothertrademarksarethepropertyoftheirrespectiveowners. 13.4 Electrostatic Discharge Caution Thesedeviceshavelimitedbuilt-inESDprotection.Theleadsshouldbeshortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamagetotheMOSgates. 13.5 Glossary SLYZ022—TIGlossary. Thisglossarylistsandexplainsterms,acronyms,anddefinitions. 14 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of thisdocument.Forbrowser-basedversionsofthisdatasheet,refertotheleft-handnavigation. 38 SubmitDocumentationFeedback Copyright©2007–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA822

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 PACKAGING INFORMATION Orderable Device Status Package Type Package Pins Package Eco Plan Lead/Ball Finish MSL Peak Temp Op Temp (°C) Device Marking Samples (1) Drawing Qty (2) (6) (3) (4/5) VCA822ID ACTIVE SOIC D 14 50 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 VCA822ID & no Sb/Br) VCA822IDG4 ACTIVE SOIC D 14 50 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 VCA822ID & no Sb/Br) VCA822IDGST ACTIVE VSSOP DGS 10 250 Green (RoHS NIPDAUAG Level-2-260C-1 YEAR -40 to 85 BOS & no Sb/Br) VCA822IDR ACTIVE SOIC D 14 2500 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 VCA822ID & no Sb/Br) VCA822IDRG4 ACTIVE SOIC D 14 2500 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 VCA822ID & no Sb/Br) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Addendum-Page 1

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 2

PACKAGE MATERIALS INFORMATION www.ti.com 8-Jun-2015 TAPE AND REEL INFORMATION *Alldimensionsarenominal Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1 Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant (mm) W1(mm) VCA822IDGST VSSOP DGS 10 250 180.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 VCA822IDR SOIC D 14 2500 330.0 16.4 6.5 9.0 2.1 8.0 16.0 Q1 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 8-Jun-2015 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) VCA822IDGST VSSOP DGS 10 250 210.0 185.0 35.0 VCA822IDR SOIC D 14 2500 367.0 367.0 38.0 PackMaterials-Page2

PACKAGE OUTLINE DGS0010A VSSOP - 1.1 mm max height SCALE 3.200 SMALL OUTLINE PACKAGE C 5.05 4.75 TYP SEATING PLANE A PIN 1 ID 0.1 C AREA 8X 0.5 10 1 3.1 2X 2.9 NOTE 3 2 5 6 0.27 10X 0.17 B 3.1 0.1 C A B 1.1 MAX 2.9 NOTE 4 0.23 TYP SEE DETAIL A 0.13 0.25 GAGE PLANE 0.15 0.7 0 - 8 0.05 0.4 DETAIL A TYPICAL 4221984/A 05/2015 NOTES: 1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. This dimension does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed 0.15 mm per side. 4. This dimension does not include interlead flash. Interlead flash shall not exceed 0.25 mm per side. 5. Reference JEDEC registration MO-187, variation BA. www.ti.com

EXAMPLE BOARD LAYOUT DGS0010A VSSOP - 1.1 mm max height SMALL OUTLINE PACKAGE 10X (1.45) 10X (0.3) SYMM (R0.05) TYP 1 10 SYMM 8X (0.5) 5 6 (4.4) LAND PATTERN EXAMPLE SCALE:10X SOOPLEDNEINRG MASK METAL MSOELTDAEL RU NMDAESRK SOOPLEDNEINRG MASK 0.05 MAX 0.05 MIN ALL AROUND ALL AROUND NON SOLDER MASK SOLDER MASK DEFINED DEFINED SOLDER MASK DETAILS NOT TO SCALE 4221984/A 05/2015 NOTES: (continued) 6. Publication IPC-7351 may have alternate designs. 7. Solder mask tolerances between and around signal pads can vary based on board fabrication site. www.ti.com

EXAMPLE STENCIL DESIGN DGS0010A VSSOP - 1.1 mm max height SMALL OUTLINE PACKAGE 10X (1.45) SYMM (R0.05) TYP 10X (0.3) 1 10 SYMM 8X (0.5) 5 6 (4.4) SOLDER PASTE EXAMPLE BASED ON 0.125 mm THICK STENCIL SCALE:10X 4221984/A 05/2015 NOTES: (continued) 8. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. 9. Board assembly site may have different recommendations for stencil design. www.ti.com

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