Product Sample & Technical Tools & Support & Folder Buy Documents Software Community VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 VCA810 High Gain Adjust Range, Wideband and Variable Gain Amplifier 1 Features Operating from ±5-V supplies, the device gain control voltage adjusts the gain from –40 dB at a 0-V input to • HighGainAdjustRange: ±40dB 1 40 dB at a –2-V input. Increasing the control voltage • DifferentialIn,Single-EndedOut above ground attenuates the signal path to greater • LowInputNoiseVoltage:2.4nV/√Hz than 80 dB. Signal bandwidth and slew rate remain constant over the entire gain adjust range. This 40- • ConstantBandwidthvsGain:35MHz dB/V gain control is accurate within ±1.5 dB (±0.9 dB • HighdB/VGainLinearity: ±0.3dB forhighgrade),allowingthegaincontrolvoltageinan • GainControlBandwidth:25MHz AGC application to be used as a received signal strengthindicator(RSSI)with ±1.5-dBaccuracy. • LowOutputDCError: <±40mV • HighOutputCurrent: ±60mA Excellent common-mode rejection and common- mode input range at the two high-impedance inputs • LowSupplyCurrent:24.8mA allow the device to provide a differential receiver (Maximumfor–40°Cto85°CTemperatureRange) operation with gain adjust. The output signal is referenced to ground. Zero differential input voltage 2 Applications gives a 0-V output with a small DC offset error. Low • OpticalReceiverTimeGainControl input noise voltage ensures good output SNR at the highestgainsettings. • SonarSystems • Voltage-TunableActiveFilters In applications where pulse edge information is critical, and the device is being used to equalize • LogAmplifiers varying channel loss, minimal change in group delay • PulseAmplitudeCompensation over gain setting retains excellent pulse edge • AGCreceiversWithRSSI information. • ImprovedReplacementforVCA610 An improved output stage provides adequate output current to drive the most demanding loads. Although 3 Description principally intended to drive analog-to-digital The VCA810 is a DC-coupled, wideband, converters (ADCs) or second-stage amplifiers, the continuously variable, voltage-controlled gain ±60-mA output current easily drives doubly- amplifier. The device provides a differential input to terminated 50-Ω lines or a passive post-filter stage single-ended output conversion with a high- overthe±1.7-Voutputvoltagerange. impedance gain control input used to vary the gain overa–40-dBto40-dBrangelinearindB/V. DeviceInformation PARTNUMBER PACKAGE BODYSIZE(NOM) VCA810 SOIC(8) 4.90mm×3.91mm FunctionalBlockDiagram +5V 6 1 VCA810 V+ 8 V- Gain Adjust + X1 V 5 OUT 2 3 V C 0® -2V -40dB®+40dB Gain 7 -5V 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectualpropertymattersandotherimportantdisclaimers.PRODUCTIONDATA.

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com Table of Contents 1 Features.................................................................. 1 8.3 FeatureDescription.................................................16 2 Applications........................................................... 1 8.4 DeviceFunctionalModes........................................20 3 Description............................................................. 1 9 ApplicationsandImplementation...................... 21 4 RevisionHistory..................................................... 2 9.1 ApplicationInformation............................................21 9.2 TypicalApplication..................................................30 5 DeviceComparisonTable..................................... 3 10 PowerSupplyRecommendations..................... 31 6 PinConfigurationandFunctions......................... 3 11 Layout................................................................... 31 7 Specifications......................................................... 4 11.1 LayoutGuidelines.................................................31 7.1 AbsoluteMaximumRatings .....................................4 11.2 LayoutExample....................................................32 7.2 ESDRatings..............................................................4 12 DeviceandDocumentationSupport................. 33 7.3 RecommendedOperatingConditions.......................4 7.4 ThermalInformation..................................................4 12.1 DeviceSupport......................................................33 7.5 ElectricalCharacteristics...........................................5 12.2 DocumentationSupport........................................33 7.6 HighGradeDCCharacteristics:V =±5V 12.3 CommunityResources..........................................33 S (VCA810AID).............................................................9 12.4 Trademarks...........................................................33 7.7 TypicalCharacteristics............................................11 12.5 ElectrostaticDischargeCaution............................33 8 DetailedDescription............................................ 16 12.6 Glossary................................................................33 8.1 Overview.................................................................16 13 Mechanical,Packaging,andOrderable 8.2 FunctionalBlockDiagram.......................................16 Information........................................................... 33 4 Revision History ChangesfromRevisionF(December2010)toRevisionG Page • AddedESDRatingstable,FeatureDescriptionsection,DeviceFunctionalModes,ApplicationandImplementation section,PowerSupplyRecommendationssection,Layoutsection,DeviceandDocumentationSupportsection,and Mechanical,Packaging,andOrderableInformationsection.................................................................................................. 1 • ChangedDCPerformance,InputoffsetcurrentparameterunitfrommAtonAinHighGradeDCCharacteristicstable.....9 ChangesfromRevisionE(August2008)toRevisionF Page • DeletedleadtemperaturespecificationfromAbsoluteMaximumRatingstable ................................................................... 4 • CorrectedtypoinFigure34.................................................................................................................................................. 21 ChangesfromRevisionD(February,2006)toRevisionE Page • ChangedstoragetemperatureminimumvalueinAbsoluteMaximumRatingstablefrom–40°Cto–65°C..........................4 2 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 5 Device Comparison Table SINGLES DUALS GAINADJUSTRANGE(dB) INPUTNOISE(nV/√Hz) SIGNALBANDWIDTH(MHz) VCA811 — 80 2.4 80 — VCA2612 45 1.25 80 — VCA2613 45 1 80 — VCA2614 45 3.6 40 — VCA2616 45 3.3 40 — VCA2618 45 5.5 30 6 Pin Configuration and Functions DPackage 8-PinSOIC TopView -In -V +V V S S OUT 8 7 6 5 A(1) VCA810 1 2 3 4 (2) +In GND Gain NC Control, V C (1) Highgradeversionindicator. (2) NC=Notconnected. PinFunctions PIN I/O DESCRIPTION NO. NAME 1 +In I Noninvertinginput 2 GND P Ground,servesasreferenceforgaincontrolpin GainControl, 3 I Gaincontrol V C 4 NC — Noconnect 5 V O Output OUT 6 +V P Positivesupply S 7 –V P Negativesupply S 8 –In I Invertinginput Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 3 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com 7 Specifications 7.1 Absolute Maximum Ratings Overoperatingfree-airtemperaturerange,unlessotherwisenoted.(1) MIN MAX UNIT Powersupply ±6.5 V Internalpowerdissipation SeeThermalInformation Differentialinputvoltage ±V V S Inputcommon-modevoltage ±V V S Junctiontemperature,T 150 °C J Storagetemperature,T –65 125 °C stg (1) StressesbeyondthoselistedunderAbsoluteMaximumRatingsmaycausepermanentdamagetothedevice.Thesearestressratings only,whichdonotimplyfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunderRecommended OperatingConditions.Exposuretoabsolute-maximum-ratedconditionsforextendedperiodsmayaffectdevicereliability. 7.2 ESD Ratings VALUE UNIT Human-bodymodel(HBM),perANSI/ESDA/JEDECJS-001(1) ±2000 Charged-devicemodel(CDM),perJEDECspecificationJESD22- V(ESD) Electrostaticdischarge C101(2) ±1500 V MachineModel(MM) ±200 (1) JEDECdocumentJEP155statesthat500-VHBMallowssafemanufacturingwithastandardESDcontrolprocess. (2) JEDECdocumentJEP157statesthat250-VCDMallowssafemanufacturingwithastandardESDcontrolprocess. 7.3 Recommended Operating Conditions overoperatingfree-airtemperaturerange(unlessotherwisenoted) MIN NOM MAX UNIT Temperature –40 25 85 °C Supplyvoltage ±4 ±5 ±5.5 V 7.4 Thermal Information VCA810 THERMALMETRIC(1) D(SOIC) UNIT 8PINS R Junction-to-ambientthermalresistance 80 °C/W θJA R Junction-to-case(top)thermalresistance 51 °C/W θJC(top) R Junction-to-boardthermalresistance 45 °C/W θJB ψ Junction-to-topcharacterizationparameter 14 °C/W JT ψ Junction-to-boardcharacterizationparameter 45 °C/W JB R Junction-to-case(bottom)thermalresistance n/a °C/W θJC(bot) (1) Formoreinformationabouttraditionalandnewthermalmetrics,seetheSemiconductorandICPackageThermalMetricsapplication report,SPRA953. 4 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 7.5 Electrical Characteristics AtR =500ΩandV =single-endedinputonV+withV−atground,V =±5V,unlessotherwisenoted. L IN S PARAMETER TESTCONDITIONS TESTLEVEL(1) MIN TYP MAX UNIT ACPERFORMANCE TJ=25°C 35 SFumnacltl-iosniganlaBllboacnkdDwiaidgtrha(mse)e −2V≤VC≤0V TTJJ==20°5C°Cto(2)70°C(3) B 3209 MHz TJ=–40°Cto85°C(3) 29 TJ=25°C 35 Large-signalbandwidth VO=2VPP,−2≤VC≤−1 TTJJ==20°5C°Cto(2)70°C(3) B 3209 MHz TJ=–40°Cto85°C(3) 29 TJ=25°C 0.1 Frequencyresponsepeaking VO<500mVPP,−2V≤VC≤0V TTJJ==20°5C°Cto(2)70°C(3) B 00..55 dB TJ=–40°Cto85°C(3) 0.5 TJ=25°C 350 Slewrate VO=3.5-Vstep,−2≤VC≤−1, TJ=25°C(2) B 300 V/μs 10%to90% TJ=0°Cto70°C(3) 300 TJ=–40°Cto85°C(3) 295 TJ=25°C 30 Settlingtimeto0.01% VO=1-Vstep,−2≤VC≤−1 TTJJ==20°5C°Cto(2)70°C(3) B 4401 ns TJ=–40°Cto85°C(3) 41 TJ=25°C 10 Rise-and-falltime VO=1-Vstep,−2≤VC≤−1 TTJJ==20°5C°Cto(2)70°C(3) B 121.12 ns TJ=–40°Cto85°C(3) 12.1 Groupdelay GVO==05d0B0,mVVC=PP−1V,f=5MHz, TJ=25°C C 6.2 ns Groupdelayvariation Vf=O5<M50H0zmVPP,−2V≤VC≤0V, TJ=25°C C 3.5 ns TJ=25°C –71 HD2 Secondharmonicdistortion VO=1VPP,f=1MHz, TJ=25°C(2) B –51 dBc VC=−1V,G=0dB TJ=0°Cto70°C(3) –50 TJ=–40°Cto85°C(3) –49 TJ=25°C −35 HD3 Thirdharmonicdistortion VO=1VPP,f=1MHz, TJ=25°C(2) B –34 dBc VC=−1V,G=0dB TJ=0°Cto70°C(3) –32 TJ=–40°Cto85°C(3) –29 TJ=25°C 2.4 Inputvoltagenoise VC=−2V TTJJ==20°5C°Cto(2)70°C(3) B 23..84 nV/√Hz TJ=–40°Cto85°C(3) 3.5 TJ=25°C 1.4 Inputcurrentnoise −2V≤VC≤0V TTJJ==20°5C°Cto(2)70°C(3) B 1.82 pA/√Hz TJ=–40°Cto85°C(3) 2.1 Fullyattenuatedfeedthrough f≤1MHz,VC>200mV TTJJ==2255°°CC(2) B −80 −70 dB Overdriverecovery VIN=2Vto0V,VC=−2V, TJ=25°C B 100 ns G=40dB TJ=25°C(2) 150 (1) Testlevels:(A)100%testedat25°C.Overtemperaturelimitssetbycharacterizationandsimulation.(B)Limitssetbycharacterization andsimulation.(C)Typicalvalue;onlyforinformation. (2) Junctiontemperature=ambientfor25°Ctestedspecifications. (3) Junctiontemperature=ambientatlowtemperaturelimit;junctiontemperature=ambient30°Cathightemperaturelimitforover temperaturespecifications. Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 5 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com Electrical Characteristics (continued) AtR =500ΩandV =single-endedinputonV+withV−atground,V =±5V,unlessotherwisenoted. L IN S PARAMETER TESTCONDITIONS TESTLEVEL(1) MIN TYP MAX UNIT DCPERFORMANCE(Single-EndedorDifferentialInput) TJ=25°C ±4 Oinuptuptustgorfofsuentdveodl)t(a4g)e(both −2V≤VC≤0V TTJJ==20°5C°Cto(2)70°C(3) A ±±2320 mV TJ=–40°Cto85°C(3) ±32 Outputoffsetvoltagedrift TJ=0°Cto70°C(3) B ±125 V/°C TJ=–40°Cto85°C(3) ±125 TJ=25°C ±0.1 Inputoffsetvoltage(4) Bothinputsgrounded TJ=25°C(2) A ±0.25 mV TJ=0°Cto70°C(3) ±0.3 TJ=–40°Cto85°C(3) ±0.35 inputoffsetvoltagedrift TJ=0°Cto70°C(3) B ±1 μV/°C TJ=–40°Cto85°C(3) ±1.2 TJ=25°C −6 Inputbiascurrent −2V≤VC≤0V TTJJ==20°5C°Cto(2)70°C(3) A −–1102 μA TJ=–40°Cto85°C(3) −14 Inputbiascurrentdrift TJ=0°Cto70°C(3) B ±25 nA/°C TJ=–40°Cto85°C(3) ±30 TJ=25°C ±100 Inputoffsetcurrent −2V≤VC≤0V TTJJ==20°5C°Cto(2)70°C(3) A ±±670000 nA TJ=–40°Cto85°C(3) ±800 Inputoffsetcurrentdrift TJ=0°Cto70°C(3) B ±1.4 nA/°C TJ=–40°Cto85°C(3) ±2.2 INPUT TJ=25°C ±2.4 Common-modeinputrange TJ=25°C(2) A ±2.3 V TJ=0°Cto70°C(3) ±2.3 TJ=–40°Cto85°C(3) ±2.2 TJ=25°C 95 Common-moderejectionratio VCM=0.5V,VC=−2V,input- TJ=25°C(2) A 85 dB referred TJ=0°Cto70°C(3) 83 TJ=–40°Cto85°C(3) 80 Inputimpedance VCM=0V,single-ended TJ=25°C C 1||1 MΩ||pF VCM=0V,differential TJ=25°C C >10||<2 MΩ||pF Differentialinputrange(5) VC=0V,VCM=0V TJ=25°C C 3 VPP OUTPUT TJ=25°C ±1.8 VC=−2V,RL=100Ω TTJJ==20°5C°Cto(2)70°C(3) A ±±11..74 V Voltageoutputswing TJ=–40°Cto85°C(3) ±1.3 TJ=25°C ±1.7 VC=−2V,RL=100Ω TTJJ==20°5C°Cto(2)70°C(3) A ±±11..63 V TJ=–40°Cto85°C(3) ±1.2 TJ=25°C ±60 Outputcurrent VO=0V TTJJ==20°5C°Cto(2)70°C(3) A ±±4305 mA TJ=–40°Cto85°C(3) ±32 Outputshort-circuitcurrent VO=0V TJ=25°C C ±120 mA Outputimpedance VO=0V,f<100kHz TJ=25°C C 0.2 Ω (4) Totaloutputoffsetis:(OutputOffsetVoltage±InputOffsetVoltagexGain). (5) Maximuminputatminimumgainfor<1-dBgaincompression. 6 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 Electrical Characteristics (continued) AtR =500ΩandV =single-endedinputonV+withV−atground,V =±5V,unlessotherwisenoted. L IN S PARAMETER TESTCONDITIONS TESTLEVEL(1) MIN TYP MAX UNIT GAINCONTROL(VC,Pin3,Single-EndedorDifferentialInput) Specifiedgainrange ΔVC/ΔdB=25mV/dB TJ=25°C C ±40 dB Maximumcontrolvoltage G=−40dB TJ=25°C C 0 V Minimumcontrolvoltage G=40dB TJ=25°C C –2 V TJ=25°C ±0.4 −1.8V≤VC≤−0.2V TTJJ==20°5C°Cto(2)70°C(3) A ±±12..55 dB Gainaccuracy TJ=–40°Cto85°C(3) ±3.5 TJ=25°C ±0.5 VC<−1.8V,VC>−0.2V TTJJ==20°5C°Cto(2)70°C(3) A ±±23..27 dB TJ=–40°Cto85°C(3) ±4.7 Gaindrift −1.8V≤VC≤−0.2V TTJJ==0–°4C0°tCot7o0°8C5°(3C)(3) B ±±00..0023 dB/°C VC<−1.8V,VC>−0.2V TTJJ==0–°4C0°tCot7o0°8C5°(3C)(3) B ±±00..0034 dB/°C Gaincontrolslope 25°C C –40 dB/V TJ=25°C ±0.3 −1.8V≤VC≤0V TTJJ==20°5C°Cto(2)70°C(3) A ±1±.11 dB Gaincontrollinearity(6) TJ=–40°Cto85°C(3) ±1.2 TJ=25°C ±0.7 VC<−1.8V TTJJ==20°5C°Cto(2)70°C(3) A ±±12..65 dB TJ=–40°Cto85°C(3) ±3.2 TJ=25°C 25 Gaincontrolbandwidth TJ=25°C(2) B 20 MHz TJ=0°Cto70°C(3) 19 TJ=–40°Cto85°C(3) 19 Gaincontrolslewrate 80-dBgainstep TJ=25°C C 900 dB/ns Gainsettlingtime 1%,80-dBstep TJ=25°C C 0.8 μs TJ=25°C –1.5 Inputbiascurrent VC=−1V TTJJ==20°5C°Cto(2)70°C(3) A ––34..55 μA TJ=–40°Cto85°C(3) –8 TJ=25°C 0.5 Gain+power-supplyrejection VC=−2V,G=40dB,+VS=5V TJ=25°C(2) A 1.5 dB/V ratio ±0.5V TJ=0°Cto70°C(3) 1.8 TJ=–40°Cto85°C(3) 2 TJ=25°C 0.7 Gain–power-supplyrejection VC=−2V,G=40dB, TJ=25°C(2) A 1.5 dB/V ratio –VS=–5V±0.5V TJ=0°Cto70°C(3) 1.8 TJ=–40°Cto85°C(3) 2 POWERSUPPLY Specifiedoperatingvoltage TJ=25°C(2) C ±5 V TJ=25°C(2) ±4 Minimumoperatingvoltage TJ=0°Cto70°C(3) A ±4 V TJ=–40°Cto85°C(3) ±4 TJ=25°C(2) ±6 Maximumoperatingvoltage TJ=0°Cto70°C(3) A ±6 V TJ=–40°Cto85°C(3) ±6 (6) Maximumdeviationfrombestlinefit. Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 7 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com Electrical Characteristics (continued) AtR =500ΩandV =single-endedinputonV+withV−atground,V =±5V,unlessotherwisenoted. L IN S PARAMETER TESTCONDITIONS TESTLEVEL(1) MIN TYP MAX UNIT TJ=25°C 10 +VS=5V,G=−40dB TTJJ==20°5C°Cto(2)70°C(3) A 1122..56 mA Positivemaximumsupply TJ=–40°Cto85°C(3) 12.7 quiescentcurrent TJ=25°C 18 +VS=5V,G=40dB TTJJ==20°5C°Cto(2)70°C(3) A 202.52 mA TJ=–40°Cto85°C(3) 22.3 TJ=25°C 10 +VS=5V,G=–40dB TTJJ==20°5C°Cto(2)70°C(3) A 77..52 mA Positiveminimumsupply TJ=–40°Cto85°C(3) 7.1 quiescentcurrent TJ=25°C 18 +VS=5V,G=40dB TTJJ==20°5C°Cto(2)70°C(3) A 1154..55 mA TJ=–40°Cto85°C(3) 13.5 TJ=25°C 12 −VS=−5V,G=−40dB TTJJ==20°5C°Cto(2)70°C(3) A 1144..56 mA Negativemaximumsupply TJ=–40°Cto85°C(3) 14.7 quiescentcurrent(7) TJ=25°C 20 −VS=−5V,G=40dB TTJJ==20°5C°Cto(2)70°C(3) A 2224..55 mA TJ=–40°Cto85°C(3) 24.8 TJ=25°C 12 −VS=−5V,G=−40dB TTJJ==20°5C°Cto(2)70°C(3) A 99..54 mA Negativeminimumsupply TJ=–40°Cto85°C(3) 9.3 quiescentcurrent(7) TJ=25°C 20 −VS=−5V,G=40dB TTJJ==20°5C°Cto(2)70°C(3) A 1176..55 mA TJ=–40°Cto85°C(3) 16 TJ=25°C 90 +PSRR Praotisoitivepower-supplyrejection Input-referred,VC=−2V TTJJ==20°5C°Cto(2)70°C(3) A 7755 dB TJ=–40°Cto85°C(3) 73 TJ=25°C 85 –PSRR Nreejegcattioivnerpaotiwoer-supply Input-referred,VC=−2V TTJJ==20°5C°Cto(2)70°C(3) A 7700 dB TJ=–40°Cto85°C(3) 68 THERMALCHARACTERISTICS Specifiedoperatingrange,ID C –40 85 °C package (7) Magnitude. 8 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 7.6 High Grade DC Characteristics: V = ±5 V (VCA810AID) S AtR =500ΩandV =single-endedinputonV+withV−atground,unlessotherwisenoted. L IN PARAMETER TESTCONDITIONS TESTLEVEL(1) MIN TYP MAX UNIT DCPERFORMANCE(Single-EndedorDifferentialInput) TJ=25°C ±4 Outputoffsetvoltage −2V<VC<0V TTJJ==20°5C°Cto(2)70°C(3) A ±±1244 mV TJ=–40°Cto85°C(3) ±26 TJ=25°C ±0.1 Inputoffsetvoltage TJ=25°C(2) A ±0.2 mV TJ=0°Cto70°C(3) ±0.25 TJ=–40°Cto85°C(3) ±0.3 TJ=25°C ±100 Inputoffsetcurrent TJ=25°C(2) A ±500 nA TJ=0°Cto70°C(3) ±600 TJ=–40°Cto85°C(3) ±700 GAINCONTROL(VC,Pin3,Single-EndedorDifferentialInput) TJ=25°C ±0.4 −1.8V≤VC≤−0.2V TTJJ==20°5C°Cto(2)70°C(3) A ±±01..99 dB Gainaccuracy TJ=–40°Cto85°C(3) ±2.9 TJ=25°C ±0.5 VC<−1.8V,VC>−0.2V TTJJ==20°5C°Cto(2)70°C(3) A ±±13..50 dB TJ=–40°Cto85°C(3) ±4.0 TJ=25°C ±0.3 −1.8V≤VC≤0V TTJJ==20°5C°Cto(2)70°C(3) A ±±00..67 dB Gaincontrollinearity(4) TJ=–40°Cto85°C(3) ±0.8 TJ=25°C ±0.7 VC<−1.8V TTJJ==20°5C°Cto(2)70°C(3) A ±±11..19 dB/V TJ=–40°Cto85°C(3) ±2.7 POWERSUPPLY TJ=25°C 10 +VS=5V,G=−40dB TTJJ==20°5C°Cto(2)70°C(3) A 1111..56 mA Positivemaximumsupply TJ=–40°Cto85°C(3) 11.7 quiescentcurrent TJ=25°C 18 +VS=5V,G=40dB TTJJ==20°5C°Cto(2)70°C(3) A 192.51 mA TJ=–40°Cto85°C(3) 21.3 TJ=25°C 10 +VS=5V,G=−40dB TTJJ==20°5C°Cto(2)70°C(3) A 88..52 mA Positiveminimumsupply TJ=–40°Cto85°C(3) 8.1 quiescentcurrent TJ=25°C 18 +VS=5V,G=40dB TTJJ==20°5C°Cto(2)70°C(3) A 1165..55 mA TJ=–40°Cto85°C(3) 14.5 (1) Testlevels:(A)100%testedat25°C.Overtemperaturelimitssetbycharacterizationandsimulation.(B)Limitssetbycharacterization andsimulation.(C)Typicalvalue;onlyforinformation. (2) Junctiontemperature=ambientfor25°Ctestedspecifications. (3) Junctiontemperature=ambientatlowtemperaturelimit;junctiontemperature=ambient30°Cathightemperaturelimitforover temperaturespecifications. (4) Maximumdeviationfrombestlinefit. Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 9 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com High Grade DC Characteristics: V = ±5 V (VCA810AID) (continued) S AtR =500ΩandV =single-endedinputonV+withV−atground,unlessotherwisenoted. L IN PARAMETER TESTCONDITIONS TESTLEVEL(1) MIN TYP MAX UNIT TJ=25°C 12 −VS=−5V,G=−40dB TTJJ==20°5C°Cto(2)70°C(3) A 141.14 mA Negativemaximumsupply TJ=–40°Cto85°C(3) 14.2 quiescentcurrent(5) TJ=25°C 20 −VS=−5V,G=40dB TTJJ==20°5C°Cto(2)70°C(3) A 2224 mA TJ=–40°Cto85°C(3) 24.3 TJ=25°C 12 −VS=−5V,G=−40dB TTJJ==20°5C°Cto(2)70°C(3) A 91.09 mA Negativeminimumsupply TJ=–40°Cto85°C(3) 9.8 quiescentcurrent(5) TJ=25°C 20 −VS=−5V,G=40dB TTJJ==20°5C°Cto(2)70°C(3) A 1187 mA TJ=–40°Cto85°C(3) 16.5 (5) Magnitude. 10 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 7.7 Typical Characteristics AtR =500ΩandV =single-endedinputonV+withV−atground,V =±5V,unlessotherwisenoted. L IN S 60 3 R = 500W V = 10mV ,V = 1V L 40 IN PP OUT PP 0 VIN= 100mVPP,VOUT= 1VPP -3 20 dB) VIN= 1VPP,VOUT= 1VPP dB) -6 n ( 0 n ( Gai V = 2V , V = 200mV Gai -9 OUT PP IN PP -20 -12 V = 2V , V = 20mV -40 OUT PP IN PP -15 V =-1V + 10mV C DC PP -60 -18 1 10 100 1000 1 10 100 Frequency (MHz) Frequency (MHz) Figure1.Small-SignalFrequencyResponse Figure2.GainControlFrequencyResponse 150 0.6 G =-20dB VIN= 2VPP G = +40dB VIN= 10mVPP 100 0.4 Output Voltage (mV) -55000 G =-40dB Output Voltage (V) -00..202 G = +20dB -100 -0.4 -150 -0.6 Time (20ns/div) Time (20ns/div) Figure3.AttenuatedPulseResponse Figure4.HighGainPulseResponse 1.2 60 G = 0dB to-40dB, VIN= 1VDC Specified Operating Range 1.0 40 20 V) 0.8 Voltage ( 0.6 ain (dB) -200 ut 0.4 G -40 p Out 0.2 -60 Output Disabled for +0.15V£V £+2V -80 C 0 G = 0dB to +40dB, VIN= 10mVDC -100 -0.2 0.5 0 -0.5 -1.0 -1.5 -2.0 -2.5 Time (20ns/div) Control Voltage, V (V) C Figure5.GainControlPulseResponse Figure6.GainvsControlVoltage Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 11 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com Typical Characteristics (continued) AtR =500ΩandV =single-endedinputonV+withV−atground,V =±5V,unlessotherwisenoted. L IN S -30 -20 V = 1V G = 0dB, Third Harmonic -35 RO= 500PWP G = 0dB, Third Harmonic L -30 Bc) -40 Bc) d d n ( -45 n ( -40 o o G = +40dB, Third Harmonic orti -50 G = +40dB, Third Harmonic orti st st -50 Di -55 Di monic -60 G = +40dB, Second Harmonic monic -60 G = +40dB, Second Harmonic Har -65 Har -70 fV = 1=M 1HVz -70 G = 0dB, Second Harmonic ROL= 500PWP G = 0dB, Second Harmonic -75 -80 0.1 1 10 100 1000 Frequency (MHz) Load (W) Figure7.HarmonicDistortionvsFrequency Figure8.HarmonicDistortionvsR LOAD -20 -20 f = 1MHz f= 1MHz Distortion (dBc) ----34560000 RL= 500W GG = =+ 400ddBB, ,T Sheircdo Hnda rHmaornmiconic Distortion (dBc) ---345000 Third Harmonic VROL== 510V0PWP monic -70 monic -60 Har --8900 G = +40dB, Third Harmonic Har -70 Second Harmonic G = 0dB, Second Harmonic -100 -80 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 5 10 15 20 25 30 35 40 Output Voltage (V ) Gain (dB) PP Figure9.HarmonicDistortionvsOutputVoltage Figure10.HarmonicDistortionvsGain 10 -20 Input Output f= 1MHz Limited Limited -30 VIN= 1VPP oltage (V)PP 1 MInapxu tU Vsoeltfaugle Range MORauantxpg Uuets Veofultlage ortion (dBc) -40 RL= 500W Third Harmonic ut V Dist -50 Outp 0.1 onic -60 Input/ ROeustpuultti nVgoltage RInepsuut lVtinogltage Harm -70 Second Harmonic Input and Output Measured at 1dB Compression 0.01 -80 -40 -30 -20 -10 0 10 20 30 40 -40 -35 -30 -25 -20 -15 -10 -5 0 Gain (dB) Attenuation (dB) Figure11.Input,OutputRangevsGain Figure12.HarmonicDistortionvsAttenuation 12 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 Typical Characteristics (continued) AtR =500ΩandV =single-endedinputonV+withV−atground,V =±5V,unlessotherwisenoted. L IN S 10000 10 Input-Referred Voltage Noise Density RS= 20W on Each Input 1000 )HzH)z H)z)Hz ?V/?V/ 100 ?V/?A/ Differential Input (n(n (n(p Voltage Noise (2.4nV/ÖHz) eneO enin Output-Referred Voltage Noise Density 10 Current Noise (1.8pA/ÖHz) Each Input 1 1 0 -0.2 -0.4 -0.6 -0.8 -1.0 -1.2 -1.4 -1.6 -1.8 -2.0 100 1k 10k 100k 1M 10M Control Voltage (V) Frequency (Hz) Figure13.NoiseDensityvsControlVoltage Figure14.InputVoltageandCurrentNoise 0 50 40 -20 B) -40 VC= +0.1V or (mV) 3200 Maximum Error Band on (d -60 et Err 100 Typical Devices olati VC= +0.2V Offs -10 Is -80 put -20 ut -100 O -30 -40 -120 -50 1M 10M 100M -40 -30 -20 -10 0 10 20 30 40 Frequency (Hz) Gain (dB) Figure15.FullyAttenuatedIsolationvsFrequency Figure16.OutputOffsetVoltageTotalErrorBandvsGain 0.4 250 Deviation from-40dB/V Gain Slope Total Tested = 1462 G = +40dB 0.3 200 0.2 B) 0.1 d 150 or ( 0 unt n Err-0.1 Co 100 Gai-0.2 -0.3 50 -0.4 0 -0.5 0505050505050505050500 0 -0.5 -1 -1.5 -2 -5-4-4-3-3-2-2-1-1-<<<<1<1<2<2<3<3<4<4<5>5 <<<<<<<<< Control Voltage (V) Output Offset Voltage (mV) Figure17.TypicalGainErrorPlot Figure18.OutputOffsetVoltageDistribution Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 13 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com Typical Characteristics (continued) AtR =500ΩandV =single-endedinputonV+withV−atground,V =±5V,unlessotherwisenoted. L IN S 10 10 9 RVLO== 510V0PWP RVLO== 510V0PWP 8 G = 0dB ns) 8 ns) ay ( 1MHz ay ( 6 Del 7 Del up up 4 G = +40dB Gro 6 Gro 5MHz 2 5 10MHz 4 0 -40 -30 -20 -10 0 10 20 30 40 1 10 100 Gain (dB) Frequency (MHz) Figure19.GroupDelayvsGain Figure20.GroupDelayvsFrequency 2.5 15 2.0 VOUT 10 VOUT V) 1.5 mV) 5 Input/Output Voltage ( ---10011.....050505 10x VIN Input/Output Voltage ( --11-0505 2V0IN0 -2.0 -20 -2.5 -25 Time (100ns/div) Time (100ns/div) Figure21.OverdriveRecoveryatMaximumGain Figure22.OverdriveRecoveryatMaximumAttenuation 110 110 Input-Referred 100 100 CMRR, 90 90 CMRR G =±40dB 80 80 B)B) 70 B)B) 70 R (dR (d 60 R (dR (d 60 RR 50 RR 50 MS PSRR MS CMRR, CP 40 CP 40 G = 0dB 30 30 PSRR, G = 0dB 20 20 PSRR, 10 10 G = +40dB 00 0 -40 -30 -20 -10 0 10 20 30 40 0.1 1 10 100 Gain (dB) Frequency (MHz) Figure23.Common-ModeRejectionRatioand Figure24.Common-ModeRejectionRatioand Power-SupplyRejectionRatiovsGain Power-SupplyRejectionRatiovsFrequency 14 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 Typical Characteristics (continued) AtR =500ΩandV =single-endedinputonV+withV−atground,V =±5V,unlessotherwisenoted. L IN S 6 6 5 5 4 4 B) B) d d n ( 3 n ( 3 ai ai G G 2 2 1 1 0 0 1k 10k 100k 1M 10M 100M 1k 10k 100k 1M 10M 100M Frequency (Hz) Frequency (Hz) Figure25.GainControl+PSRRatMaxGain Figure26.GainControl−PSRRatMaxGain 16 25 20 Output Offset Voltage (V ) A) 14 OS 20 19 m nt ( 12 15 Ou 18 nput Bias and Offset Curre 1086420 10x InpIuntp Outf fBseiat sC Cuurrrerennt t( I(OIBS)) 150---511005 tput Offset Voltage (mA) Supply Current (mA) 11111117654321 Quiesfcoern-tV CSurrent Quiescent Current I for +V S -2 -20 10 -50 -25 0 25 50 75 100 125 0 -0.5 -1.0 -1.5 -2.0 Temperature (°C) Control Voltage (V) Figure27.TypicalDCDriftvsTemperature Figure28.TypicalSupplyCurrentvsControlVoltage Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 15 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com 8 Detailed Description 8.1 Overview The VCA810 is a high gain adjust range, wideband, voltage amplifier with a voltage-controlled gain, as shown in Functional Block Diagram. The circuit’s basic voltage amplifier responds to the control of an internal gain-control amplifier. At its input, the voltage amplifier presents the high impedance of a differential stage, permitting flexible input impedance matching. To preserve termination options, no internal circuitry connects to the input bases of this differential stage. For this reason, the user must provide DC paths for the input base currents from a signal source, either through a grounded termination resistor or by a direct connection to ground. The differential input stage also permits rejection of common-mode signals. At its output, the voltage amplifier presents a low impedance, simplifying impedance matching. An open-loop design produces wide bandwidth at all gain settings. Aground-referenceddifferentialtosingle-endedconversionattheoutputretainsthelowoutputoffsetvoltage. A gain control voltage, V , controls the amplifier gain magnitude through a high-speed control circuit. Gain C polarity can be either inverting or noninverting, depending upon the amplifier input driven by the input signal. The gain control circuit presents the high-input impedance of a noninverting operational amplifier connection. The control voltage pin is referred to ground as shown in Functional Block Diagram. The control voltage V varies the C amplifiergainaccordingtotheexponentialrelationship: G(V/V)=10-2(VC+ 1) (1) Thistranslatestotheloggainrelationship: G =–40×(V +1)dB (2) (dB) C Thus, G varies linearly over the specified −40 dB to 40 dB range as V varies from 0 V to −2 V. Optionally, (dB) C making V slightly positive (≥ 0.15 V) effectively disables the amplifier, giving greater than 80 dB of signal path C attenuationatlowfrequencies. Internally, the gain-control circuit varies the amplifier gain by varying the transconductance, g , of a bipolar m transistor using the transistor bias current. Varying the bias currents of differential stages varies g to control the m voltage gain of the VCA810. A g -based gain adjust normally suffers poor thermal stability. The VCA810 m includescircuitrytominimizethiseffect. 8.2 Functional Block Diagram +5V 6 1 VCA810 V+ 8 V- Gain Adjust + X1 V 5 OUT 2 3 V C 0® -2V -40dB®+40dB Gain 7 -5V 8.3 Feature Description 8.3.1 InputandOutputRange The VCA810’s 80 dB gain range allows the user to handle an exceptionally wide range of input signal levels. If theinputandoutputvoltagerangespecificationsareexceeded,however,signaldistortionandamplifieroverdrive will occur. Figure 11 shows the maximum input and output voltage range. This chart plots input and output voltagesversusgainindB. 16 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 Feature Description (continued) Themaximuminputvoltagerangeisthelargestatfullattenuation(−40dB)anddecreasesasthegainincreases. Similarly, the maximum useful output voltage range increases as the input decreases. We can distinguish three overloading issues as a result of the operating mode: high attenuation, mid-range gain-attenuation, and high gain. From –40 dB to –10 dB, gain overdriving the input stage is the only method to overdrive the VCA810. Preventing thistypeofoverdriveisachievedbylimitingtheinputvoltagerange. From –10 dB to 40 dB, overdriving can be prevented by limiting the output voltage range. There are two limiting mechanisms operating in this situation. From –10 dB to 10 dB, an internal stage is the limiting factor; from 10 dB to40dB,theoutputstageisthelimitingfactor. Output overdriving occurs when either the maximum output voltage swing or output current is exceeded. The VCA810 high output current of ±60 mA ensures that virtually all output overdrives will be limited by voltage swing ratherthanbycurrentlimiting.Table1summarizestheseoverdriveconditions. Table1.OutputSignalCompression GAINRANGE LIMITINGMECHANISM TOPREVENT,OPERATEDEVICEWITHIN: −40dB<G<−10dB InputStageOverdrive InputVoltageRange −10dB<G<10dB InternalStageOverdrive OutputVoltageRange 5dB<G<40dB OutputStageOverdrive OutputVoltageRange 8.3.2 OverdriveRecovery As shown in Figure 11, the onset of overdrive occurs whenever the actual output begins to deviate from the ideal expected output. If possible, the user should operate the VCA810 within the linear regions shown in order to minimize signal distortion and overdrive delay time. However, instances of amplifier overdrive are quite common in automatic gain control (AGC) circuits, which involve the application of variable gain to input signals of varying levels. The VCA810 design incorporates circuitry that allows it to recover from most overdrive conditions in 200 nsorless.Overdriverecoverytimeisdefinedasthetimerequiredfortheoutputtoreturnfromoverdrivetolinear operation, following the removal of either an input or gain-control overdrive signal. See Typical Characteristics for theoverdriveplotsformaximumgainandmaximumattenuation. 8.3.3 OutputOffsetError Several elements contribute to the output offset voltage error; among them are the input offset voltage, the output offset voltage, the input bias current and the input offset current. To simplify the following analysis, the output offset voltage error is dependent only on the output-offset voltage of the VCA810 and the input offset voltage.TheoutputoffseterrorcanthenbeexpressedasEquation3: (G ( dB V = V + 10 20 ·V OS OSO IOS where • V =Outputoffseterror OS • V =Outputoffsetvoltage OSO • G =VCA810gainindB dB • V =Inputoffsetvoltage (3) IOS ThisisshowninFigure29. Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 17 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com 50 40 V) 30 Maximum Error Band m or ( 20 Err 10 Typical Devices et 0 s Off -10 put -20 ut O -30 -40 -50 -40 -30 -20 -10 0 10 20 30 40 Gain (dB) Figure29. OutputOffsetErrorversusGain Figure18showsthedistributionfortheoutputoffsetvoltageatmaximumgain. 8.3.4 OffsetAdjustment Where desired, the offset of the VCA810 can be removed as shown in Figure 30. This circuit simply presents a DC voltage to one of the amplifier inputs to counteract the offset error voltage. For best offset performance, the trim adjustment should be made with the amplifier set at the maximum gain of the intended application. The offset voltage of the VCA810 varies with gain as shown in Figure 29, limiting the complete offset cancellation to one selected gain. Selecting the maximum gain optimizes offset performance for higher gains where high amplification of the offset effects produces the greatest output offset. Two features minimize the offset control circuitnoisecontributiontotheamplifierinputcircuit.First,makingtheresistanceofR alowvalueminimizesthe 2 noise directly introduced by the control circuit. This approach reduces both the thermal noise of the resistor and the noise produced by the resistor with the amplifier input noise current. A second noise reduction results from capacitive bypass of the potentiometer output. This reduction filters out power-supply noise that would otherwise coupletotheamplifierinput. V+ V R IN R 10k1W VCA810 VO V 100kW R V- 1mF 102W VC Figure30. OptionalOffsetAdjustment This filtering action diminishes as the wiper position approaches either end of the potentiometer, but practical conditions prevent such settings. Over its full adjustment range, the offset control circuit produces a ±5-mV input offset correction for the values shown. However, the VCA810 only requires one-tenth of this range for offset correction, assuring that the potentiometer wiper will always be near the potentiometer center. With this setting, theresistanceseenatthewiperremainshigh,whichstabilizesthefilteringfunction. 18 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 8.3.5 GainControl The VCA810 gain is controlled by means of a unipolar negative voltage applied between ground and the gain control input, pin 3. If use of the output disable feature is required, a ground-referenced bipolar voltage is needed. Output disable occurs for 0.15 V ≤ V ≤ 2 V, and produces greater than 80 dB of attenuation. The C controlvoltageshouldbelimitedto2Vindisablemode,and –2.5Vingainmodetopreventsaturationofinternal circuitry. The VCA810 gain-control input has a –3-dB bandwidth of 25 MHz and varies with frequency, as shown in Typical Characteristics. This wide bandwidth, although useful for many applications, can allow high-frequency noise to modulate the gain control input. In practice, this can be easily avoided by filtering the control input, as shown in Figure 31. R should be no greater than 100 Ω so as not to introduce gain errors by interacting with the P gaincontrolinputbiascurrentof6μA. VCA610 VO C P 1 f = -3dB 2pR C P P R P V C Figure31. ControlLineFiltering 8.3.6 GainControlandTeeplePoint When the VCA810 control voltage reaches −1.5 V, also referred to as the Teeple point, the signal path undergoes major changes. From 0 V to the Teeple point, the gain is controlled by one bank of amplifiers: a low- gain VCA. As the Teeple point is passed, the signal path is switched to a higher gain VCA. This gain-stage switching can be seen most clearly in Figure 13. The output-referred voltage noise density increases proportionally to the control voltage and reaches a maximum value at the Teeple point. As the gain increases and the internal stages switch, the output-referred voltage noise density drops suddenly and restarts its proportionalincreasewiththegain. 8.3.7 NoisePerformance The VCA810 offers 2.4-nV/√Hz input-referred voltage noise and 1.8-pA/√Hz input-referred current noise at a gain of40dB.Theinput-referredvoltagenoise,andtheinput-referredcurrent noise terms, combine to give low output noise under a wide variety of operating conditions. Figure 32 shows the operational amplifier noise analysis model with all the noise terms included. In this model, all noise terms are taken to be noise voltage or current densitytermsineithernV/√HzorpA/√Hz. +5V I BN * E VCA810 EO R NI S ERS * -IBI VC 4kTRS RT -5V * 4kTR T Figure32. VCA810NoiseAnalysisModel Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 19 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com The total output spot noise voltage can be computed as the square root of the sum of all squared output noise voltage contributors. Equation 4 shows the general form for the output noise voltage using the terms shown in Figure32. E = G · E 2+ (I R )2+ (I R )2+ 4kT(R + R ) O (V/V) NI BI T BN S S T (4) Dividing this expression by the gain will give the equivalent input-referred spot-noise voltage at the noninverting inputasshownbyEquation5. E = E 2+ (I R )2+ (I R )2+ 4kT(R + R ) N NI BI T BN S S T (5) Evaluating these two equations for the VCA810 circuit and component values shown in Figure 34 (maximizing gain) will give a total output spot-noise voltage of 272.3 nV√Hz and a total equivalent input-referred spot-noise voltage of 2.72 nV√Hz. This total input-referred spot-noise voltage is higher than the 2.4-nV√Hz specification for the VCA810 alone. This reflects the noise added to the output by the input current noise times the input resistance R and R . Keeping input impedance low is required to maintain low total equivalent input-referred S T spot-noisevoltage. 8.3.8 InputandESDProtection The VCA810 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 Absolute MaximumRatings All pins on the VCA810 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 33. 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 Figure33. InternalESDProtection 8.4 Device Functional Modes The VCA824 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. The gain is set by an external, analog, control voltage as shown in the functional block diagram. The signal gain is equal to G = (V/V) 10–2(V + 1) as detailed in Overview. The gain changes in a linear in dB fashion with over 80 dB of gain range from –2-V to –0-V control voltage. As with most other differential input amplifiers, inputs can be applied to either one or both of the amplifierinputs.Theamplifiergainiscontrolledthroughthegaincontrolpin. In addition to gain control, the gain control pin can also be used to disable the amplifier. This is accomplished by applyingaslightlypositivevoltagetothispin.ThisisdetailedFeatureDescription. 20 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 9 Applications 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. 9.1 Application Information 9.1.1 VCA810Operation Figure 34 shows the circuit configuration used as the basis of the Electrical Characteristics and Typical Characteristics. Voltage swings reported in the specifications are taken directly at the input and output pins. For test purposes, the input impedance is set to 50 Ω with a resistance to ground. A 25-Ω resistance (R ) is included T on the V− input to get bias current cancellation. Proper supply bypassing is shown in Figure 34, and consists of two capacitors on each supply pin: one large electrolytic capacitor (2.2 μF to 6.8 μF), effective at lower frequencies,andonesmallceramiccapacitor(0.1μF)forhigh-frequencydecoupling. +5V -5V 0.1mF 0.1mF 6.8mF 6.8mF + + 6 1 V 7 I 2 50W RS VCA810 5 VO Source 50W 8 3 RL R 500W T 25W R C V C Figure34. VariableGain,SpecificationandTestCircuit Notice that both inverting and noninverting inputs are connected to ground with a resistor (R and R ). Matching S T theDCsourceimpedancelookingoutofeachinputwillminimizeinputoffsetvoltageerror. 9.1.2 Range-FindingTGCAmplifier The block diagram in Figure 35 illustrates the fundamental configuration common to pulse-echo range finding systems.Aphotodiodepreampprovidesaninitialgainstagetothephotodiode. Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 21 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com Application Information (continued) 20W OPA657 ADC VCA810 and DSP 20kW 20W VC C F V C -VB 0 t -2V Time-Gain Compensated Control Voltage Figure35. TypicalRange-FindingApplication The control voltage V varies the amplifier gain for a basic signal-processing requirement: compensation for C distance attenuation effects, sometimes called time-gain compensation (TGC). Time-gain compensation increases the amplifier gain as the signal moves through the air to compensate for signal attenuation. For this purpose, a ramp signal applied to the VCA810 gain control input linearly increases the dB gain of the VCA810 withtime. 9.1.3 Wide-RangeAGCAmplifier The voltage-controlled gain feature of the VCA810 makes this amplifier ideal for precision AGC applications with control ranges as large as 60 dB. The AGC circuit of Figure 36 adds an operational amplifier and diode for amplitude detection, a hold capacitor to store the control voltage and resistors R through R that determine 1 3 attack and release times. Resistor R and capacitor C phase-compensate the AGC feedback loop. The 4 C operational amplifier compares the positive peaks of output V with a DC reference voltage, V . Whenever a V O R O peak exceeds V , the OPA820 output swings positive, forward-biasing the diode and charging the holding R capacitor. This charge drives the capacitor voltage in a positive direction, reducing the amplifier gain. R and the 3 C largely determine the attack time of this AGC correction. Between gain corrections, resistor R charges the H 1 capacitor in a negative direction, increasing the amplifier gain. R , R , and C determine the release time of this 1 2 H action. Resistor R forms a voltage divider with R , limiting the maximum negative voltage developed on C . This 2 1 H limitpreventsinputoverloadoftheVCA810gaincontrolcircuit. Figure37showstheAGCresponseforthevaluesshowninFigure36. V IN 2mV to 2V VCA810 V O RSSI 100kHz V = V Port VC R3 OUTPEAK R 1kW HP5082 R 4 OPA820 100W V R R R C 501kW 502kW 0.H1mF CC 0.1 VDC 47pF V- Figure36. 60-dBInputRangeAGC 22 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 Application Information (continued) 0.15 0.10 v) di 0mV/ 0.05 VIN= 1VPP VIN= 100mVPP e (5 0 g a olt -0.05 V put -0.10 VIN= 10mVPP ut O -0.15 -0.20 Time (5ms/div) Figure37. AGCOutputVoltagefor100-kHzSinewaveat10mV ,100mV ,and1V PP PP PP 9.1.4 StabilizedWein-BridgeOscillator Adding Wein-bridge feedback to the above AGC amplifier produces an amplitude-stabilized oscillator. As Figure 38 shows, this alternative requires the addition of just two resistors (R , R ) and two capacitors W1 W2 (C ,C ). W1 W2 Connecting the feedback network to the amplifier noninverting input introduces positive feedback to induce oscillation. The feedback factor displays a frequency dependence due to the changing impedances of the C W capacitors. As frequency increases, the decreasing impedance of the C capacitor increases the feedback W2 factor. Simultaneously, the decreasing impedance of the C capacitor decreases this factor. Analysis shows W1 1 f = W 2pR C that the maximum factor occurs at W W Hz, making this the frequency most conducive to oscillation. At this frequency, the impedance magnitude of C equals R , and inspection of the circuit shows that this condition W W produces a feedback factor of 1/3. Thus, self-sustaining oscillation requires a gain of three through the amplifier. The AGC circuitry establishes this gain level. Following initial circuit turn-on, R begins charging C negative, 1 H increasing the amplifier gain from its minimum. When this gain reaches three, oscillation begins at f ; the W continued charging effect of R makes the oscillation amplitude grow. This growth continues until that amplitude 1 reachesapeakvalueequaltoV .Then,theAGCcircuitcounteractstheR effect,controllingthepeakamplitude R 1 at V by holding the amplifier gain at a level of three. Making V an AC signal, rather than a DC reference, R R producesamplitudemodulationoftheoscillatoroutput. R C W2 W2 300W 4700pF CW1 RW1 f = 1/2pRW1CW1 4700pF 300W RW1=RW2 C =C W1 W2 VCA810 V O VC VOPEAK= VR R 3 1kW HP5082 R 4 OPA820 100W V R R R C 0.1 VDC 1 2 H C 50kW 50kW 1mF C 10pF V- Figure38. Amplitude-StabilizedOscillator Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 23 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com Application Information (continued) 9.1.5 Low-DriftWidebandLogAmplifier The VCA810 can be used to provide a 2.5-MHz (–3 dB) log amp with low offset voltage and low gain drift. The exponential gain-control characteristic of the VCA810 permits simple generation of a temperature-compensated logarithmic response. Enclosing the exponential function in an op-amp feedback path inverts this function, producing the log response. Figure 39 shows the practical implementation of this technique. A DC reference voltage, V , sets the VCA810 inverting input voltage. This configuration makes the amplifier output voltage R -2(V + 1) V =−GV ,where G =10 C . OA R V -10RmV VOA=-GVR VCA810 VC V =-(1 + R 1)1 + 0.5 Log(-V /V ) R OL R IN R 1 2 470W R 2 330W R 3 VOL OPA820 100W V IN C C 50pF Figure39. Temperature-CompensatedLogResponse A second input voltage also influences V through control of gain G. The feedback operational amplifier forces OA V to equal the input voltage V connected at the operational amplifier inverting input. Any difference between OA IN these two signals drops across R , producing a feedback current that charges C . The resulting change in V 3 C OL adjuststhegainoftheVCA810tochangeV . OA Atequilibrium: VOA= VIN=-VR·10-2(VC+ 1) (6) R ·V V = 1 OL C R + R Theoperationalamplifierforcesthisequalitybysupplyingthegaincontrolvoltage, 1 2. CombiningthelasttwoexpressionsandsolvingforV yieldsthecircuit’slogarithmicresponse: OL V = -(1 + R2 (· 1 + 0.5·log(- VIN ( OL R V 1 R (7) Anexaminationofthisresultillustratesseveralcircuitcharacteristics.First,theargumentofthelogterm, −V /V , IN R reveals an option and a constraint. In Figure 39, V represents a DC reference voltage. Optionally, making this R voltage a second signal produces log-ratio operation. Either way, the log term’s argument constrains the polarities of V and V . These two voltages must be of opposite polarities to ensure a positive argument. This R IN polarity combination results when V connects to the inverting input of the VCA810. Alternately, switching V to R R theamplifiernoninvertinginputremovestheminussignofthelogtermargument.Then,bothvoltagesmustbeof the same polarity in order to produce a positive argument. In either case, the positive polarity requirement of the argumentrestrictsV toaunipolarrange.Figure40illustratestheseconstraints. IN 24 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 Application Information (continued) 5 4 3 V) 2 age ( 1 II olt 0 V I ut -1 p Out -2 III -3 -4 -5 0.001 0.01 0.1 1 10 100 V /V Voltage Ratio IN R Figure40. TestResultforLOGAmpforV =−100mV R The above V expression reflects a circuit gain introduced by the presence of R and R . This feature adds a OL 1 2 convenient scaling control to the circuit. However, a practical matter sets a minimum level for this gain. The voltage divider formed by R and R attenuates the voltage supplied to the V terminal by the operational 1 2 C amplifier. This attenuation must be great enough to prevent any possibility of an overload voltage at the V C terminal. Such an overload saturates the VCA810 gain-control circuitry, reducing the amplifier’s gain. For the feedback connection of Figure 39, this overload condition permits a circuit latch. To prevent this, choose R and 1 R to ensure that the operational amplifier cannot possibly deliver a more negative input than −2.5 V to the V 2 C terminal. Figure40exhibitsthreezonesofoperationdescribedbelow: Zone I: V > 0 V. The VCA810 is operating in full attenuation (−80 dB). The noninverting input of the OPA820 C willsee∼0V.V isgoingtobetheintegrationoftheinputsignal. OL Zone II: −2 V < V < 0 V. The VCA810 is in its normal operating mode, creating the log relationship in C Equation7. Zone III: V < −2 V. The VCA810 control pin is out of range, and some measure should be taken so that it does C notexceed–2.5V.Alimitingactioncouldbeachievedbyusingavoltagelimitingamplifier. 9.1.6 Voltage-ControlledLow-PassFilter In the circuit of Figure 41, the VCA810 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 response pole responds to control voltage V , C accordingtotherelationshipinEquation8: G f = P 2pR C 2 where -2(V + 1) • G =10 C (8) Withthecomponentsshown,thecircuitprovidesalinearvariationofthelow-passcutofffrom300Hzto1MHz. Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 25 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com Application Information (continued) R 2 330W R C 1 330W 0.047mF V I V OPA820 OA VCA810 V O V C VO = - R2 · 1 VI R1 1 + s R2C2 G G f = P 2pRC 2 G = 10-2(VC+ 1) Figure41. TunableLow-PassFilter The response control results from amplification of the feedback voltage applied to R . First, consider the case 2 wheretheVCA810producesG=1.Then,thecircuitperformsasifthisamplifierwerereplacedbyashortcircuit. Visually doing so leaves a simple voltage amplifier with a feedback resistor bypassed by a capacitor. This basic G f = P 2pR C circuitproducesaresponsepoleat 2 . For G > 1, the circuit applies a greater voltage to R , increasing the feedback current this resistor supplies to the 2 summing junction of the OPA820. The increased feedback current produces the same result as if R had been 2 decreased in value in the basic circuit described above. Decreasing the effective R resistance moves the circuit 2 G f = P 2pR C poletoahigherfrequency,producingthe 2 responsecontrol. Finite loop gain and a signal-swing limitation set performance boundaries for the circuit. Both limitations occur when the VCA810 attenuates, rather than amplifies, the feedback signal. These two limitations reduce the circuit’s utility at the lower extreme of the VCA810 gain range. For −1 ≤ V ≤ 0, this amplifier produces C attenuating gains in the range from 0 dB to −40 dB. This range directly reduces the net gain in the circuit’s feedbackloop,increasinggainerroreffects.Additionally,thisattenuationtransfersanoutputswinglimitationfrom the OPA820 output to the overall circuit’s output. Note that OPA820 output voltage, V , relates to V through OA O the expression, V = G × V . Thus, a G < 1 limits the maximum V swing to a value less than the maximum O OA O V swing. OA Figure42showsthelow-passfrequencyfordifferentcontrolvoltages. 26 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 Application Information (continued) 3 0 V =-2V -3 C B) VC=-1.4V d n ( -6 Gai VC=-1.6V VC=-1.8V -9 -12 -15 10k 100k 1M 10M Frequency (Hz) Figure42. Voltage-ControlledLow-PassFilterFrequencyResponse 9.1.7 TunableEqualizer A circuit analogous to the above low-pass filter produces a voltage-controlled equalizer response. The gain control provided by the VCA810 of Figure 43 varies this circuit response zero from 1 Hz to 10 kHz, according to therelationshipofEquation9: G f ≈ Z 2pGR C 1 (9) To visualize the circuit’s operation, consider a circuit condition and an approximation that permit replacing the VCA810 and R with short circuits. First, consider the case where the VCA810 produces G = 1. Replacing this 3 amplifier with a short circuit leaves the operation unchanged. In this shorted state, the circuit is simply a voltage amplifier with an R-C bypass around R . The resistance of this bypass, R , serves only to phase-compensate the 1 3 circuit, and practical factors make R << R . Neglecting R for the moment, the circuit becomes just a voltage 3 1 3 1 f ≈ Z 2pR C amplifierwithacapacitivebypassofR .Thiscircuitproducesaresponsezeroat 1 . 1 Adding the VCA810 as shown in Figure 43 permits amplification of the signal applied to capacitor C, and produces voltage control of the frequency f . Amplified signal voltage on C increases the signal current Z conducted by the capacitor to the operational amplifier feedback network. The result is the same as if C had been increased in value to G . Replacing C with this effective capacitance value produces the circuit control C 1 f ≈ Z 2pR GC expression 1 . R R 1 2 750W 750W OPA820 V I 50W C R 3 2mF 3W V VCA810 OA OPA846 V O 50W V C fZ≈2p(GR1+ RC) with G = 10-2(VC+ 1) 1 3 Figure43. TunableEqualizer Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 27 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com Application Information (continued) Another factor limits the high-frequency performance of the resulting high-pass filter: the finite bandwidth of the operational amplifier. This limits the frequency duration of the equalizer response. Limitations such as bandwidth andstabilityareclearlyshowninFigure44. 100 A 90 OL G = +40dB 80 70 G = +15dB B) 60 d n ( 50 ai G 40 G =-15dB 30 20 G =-40dB 10 0 1 10 100 1k 10k 100k 1M 10M 100M Frequency (Hz) Figure44. AmplifierNoiseGainandA forDifferentGain OL Other limitations of this circuit are stability versus VCA810 gain and input signal level for the circuit. Figure 44 also illustrates these two factors. As the VCA810 gain increases, the crossover slope between the A curve of OL the OPA846 and noise gain will be greater than 20 dB/decade, rendering the circuit unstable. The signal level for high gain of the VCA810 will meet two limitations: the output voltage swings of both the VCA810 and the OPA846. The expression V = GV relates these two voltages. Thus, an output voltage limit V constrains the OA I OAL inputvoltagetoV ≤V /G. I OAL With the components shown, BW = 50 kHz. This bandwidth provides an integrator response duration of four decadesoffrequencyforf =1Hz,droppingtoonedecadeforf =10kHz. Z Z 9.1.8 Voltage-ControlledBand-Passfilter The variable gain of the VCA810 also provides voltage control over the center frequency of a band-pass filter. As shown in Figure 45, this filter follows from the state-variable configuration with the VCA810 replacing the inverter common to that configuration. Variation of the VCA810 gain moves the filter’s center frequency through a 100:1 rangefollowingtherelationshipofEquation10: 10-(VC+ 1) f = O 2pRC (10) As before, variable gain controls a circuit time constant to vary the filter response. The gain of the VCA810 amplifies or attenuates the signal driving the lower integrator of the circuit. This amplification alters the effective resistanceoftheintegratortimeconstant,producingtheresponseofEquation11: s - V nRC O = V s G I s2+ + nRC R2C2 (11) Evaluation of this response equation reveals a passband gain of A = –1, a bandwidth of BW = 1/(2πRC), and a O selectivityof Q = n·10-(VC+ 1).NotethatvariationofcontrolvoltageV altersQbutnotbandwidth. C The gain provided by the VCA810 restricts the output swing of the filter. Output signal V must be constrained to O a level that does not drive the VCA810 output, V , into its saturation limit. Note that these two outputs have OA voltageswingsrelatedbyV =G .Thus,aswinglimitV imposesacircuitoutputlimitofV ≤V /G. OA VO OAL OL OAL See Figure 46 for the frequency response for two different gain conditions of the schematic shown in Figure 45. Inparticular,noticethecenterfrequencyshiftandtheselectivityofQchangingasthegainisincreased. 28 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 Application Information (continued) C 0.047mF nR nR s - 5kW 5kW V nRC O = VI VI s2+ s + G nRC R2C2 R 330W 1/2 f = 10-(VC+ 1) OPA2822 VO O 2pRC C BW = 1 0.047mF 50W 2pRC R Q= n·10-(VC+ 1) 330W V OA VCA810 1/2 A =-1 OPA2822 O 50W V C Figure45. TunableBand-PassFilter 0 -5 -10 -15 B) -20 d n ( -25 Gai -30 -35 -40 -45 -50 100 1k 10k 100k Frequency (Hz) Figure46. TunableBand-PassFilterResponse Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 29 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com 9.2 Typical Application A common use of the log amplifier above involves signal compounding. The inverse function, signal expanding, requires an exponential transfer function. The VCA810 produces this latter response directly, as shown in Figure 47. DC reference V again sets the amplifier input voltage, and the input signal V now drives the gain R IN control point. Resistors R and R attenuate this drive to prevent overloading the gain control input. Setting these 1 2 resistors at the same values as in the preceding log amp produces an exponential amplifier with the inverse functionofthelogamplifier. TestingthecircuitgiveninFigure47givestheexponentialresponseshowninFigure48. V R -10mV +0.5V VCA810 VOL=-VRx 10-2(RR11+V IRN2+1( V C VI R2 330W OPA698 R V 1 L 470W -3.4V 500W 500W V IN Figure47. ExponentialAmplifier 9.2.1 DesignRequirements To build a wide dynamic range wide exponential amplifier we need an amplifier with continuous voltage gain control, gain range over 40 dB, low noise, and high maximum gain. The VCA810 has ±40 dB of gain range, so it meetsthiscriteria.Italsohascontinuousvoltagegaincontrolandcansupportupto100V/Vofvoltagegain. 9.2.2 DetailedDesignProcedure An exponential amplifier will have a linear response on a logarithmic scale. The linear in dB gain control of the VCA810 is ideal for this application. Note that the input to this circuit is the gain control pin. Using the gain control pin as the input is what gives an exponential gain response. The design involves the use of an OPA698 to provide the proper DC bias voltage to the gain control pin on the VCA810. The OPA698 supply voltage was chosenbasedontheinputvoltagerequirementoftheVCA810.Thereferencevoltage(VR)isusedtosettheDC output voltage. The reference voltage cannot be 0 V, but it must be small so that at maximum gain the amplifier outputsarenotsaturated.InFigure47designthereferencevoltageissetto –10mV. 9.2.3 ApplicationCurve 1 e (V) 0.1 g a olt V ut p ut 0.01 O 0.001 +3.0 +2.5 +2.0 +1.5 +1.0 +0.5 0 Input Voltage (V) Figure48. ExponentialAmplifierResponse 30 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 10 Power Supply Recommendations The VCA810 is designed for split supply operation with a nominal supply condition of 6 V. A power supply in the range of 8 V to 12 V is acceptable, and balanced supplies (negative and positive voltages equal) are recommended. The power supply should be regulated to 10% or better accuracy and capable of sourcing 100 mA of current. Thedevicequiescentcurrentisapproximately20mAandtheloadcurrentcanbeupto60mA. Single supply applications are possible, however, the control voltage is referenced to the ground pin, so a single supply application will require a mid supply reference voltage that can be applied to the ground pin. This referencevoltageshouldbesetto5%accuracyorbetterforaccurategaincontrol. 11 Layout 11.1 Layout Guidelines Achievingoptimumperformancewithahigh-frequencyamplifiersuchastheVCA810requirescarefulattentionto boardlayoutparasiticandexternalcomponenttypes.Recommendationsthatwilloptimizeperformanceinclude: • Minimize parasitic capacitance to any AC ground for all of the signal I/O pins. This includes the ground pin (pin 2). Parasitic capacitance on the output can cause instability: on both the inverting input and the noninverting input, it can react with the source impedance to cause unintentional band limiting. To reduce unwanted capacitance, a window around the signal I/O pins should be opened in all of the ground and power planes around those pins. Otherwise, ground and power planes should be unbroken elsewhere on the board. Place a small series resistance (> 25 Ω) with the input pin connected to ground to help decouple package parasitic. • Minimize the distance (less than 0.25” or 6.35 mm) 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. • Careful selection and placement of external components will preserve the high-frequency performance of the VCA810. 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- wound type resistors in a high-frequency application. Since the output pin is the most sensitive to parasitic capacitance, always position the series output resistor, if any, as close as possible to the output pin. Other network components, such as inverting or noninverting input termination resistors, should also be placed closetothepackage. • Careful selection and placement of external components will preserve the high-frequency performance of the VCA810. 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- wound type resistors in a high-frequency application. Since the output pin is the most sensitive to parasitic capacitance, always position the series output resistor, if any, as close as possible to the output pin. Other network components, such as inverting or noninverting input termination resistors, should also be placed closetothepackage. • Socketing a high-speed part like the VCA810 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 obtained by solderingtheVCA810ontotheboard. Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 31 ProductFolderLinks:VCA810

VCA810 SBOS275G–JUNE2003–REVISEDDECEMBER2015 www.ti.com 11.2 Layout Example Figure49. LayoutExample 11.2.1 ThermalAnalysis The VCA810 will not require heatsinking or airflow in most applications. Maximum desired junction temperature would set the maximum allowed internal power dissipation as described in this section. In no case should the maximumjunctiontemperaturebeallowedtoexceed150°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 either supply voltage (for equal bipolar supplies). Under this worst-case condition, P = V .2/(4 ● R ), where R 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 an VCA810ID (SO-8 package) in the circuit of Figure 34 J operatingatmaximumgainandatthemaximumspecifiedambienttemperatureof85°C. P =10V(24.8mA)+52/(4×500Ω)=260.5mW (13) D MaximumT =85°C+(0.260W×125°C/W)=117.6°C (14) J This maximum operating junction temperature is well below most system level targets. Most applications will be lower since an absolute worst-case output stage power was assumed in this calculation of V /2 which is beyond S theoutputvoltagerangefortheVCA810. 32 SubmitDocumentationFeedback Copyright©2003–2015,TexasInstrumentsIncorporated ProductFolderLinks:VCA810

VCA810 www.ti.com SBOS275G–JUNE2003–REVISEDDECEMBER2015 12 Device and Documentation Support 12.1 Device Support 12.1.1 DevelopmentSupport 12.1.1.1 DemonstrationBoards A printed circuit board (PCB) is available to assist in the initial evaluation of circuit performance using the VCA810. This evaluation board (EVM) is available free, as an unpopulated PCB delivered with descriptive documentation.ThesummaryinformationforthisboardisshownintheDEM-VCA-SO-1Auser'sguide. 12.1.1.2 MacromodelsandApplicationsSupport Computer simulation of circuit performance using SPICE is often useful when analyzing the performance of analog circuits and systems. This 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 VCA810 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 awidevarietyofoperatingconditions.Themodelsincludethenoisetermsfoundintheelectricalspecificationsof therelevantproductdatasheet. 12.2 Documentation Support 12.2.1 RelatedDocumentation Unity-GainStable,Low-Noise,Voltage-FeedbackOperationalAmplifier,SBOS303 12.3 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. 12.4 Trademarks E2EisatrademarkofTexasInstruments. Allothertrademarksarethepropertyoftheirrespectiveowners. 12.5 Electrostatic Discharge Caution Thesedeviceshavelimitedbuilt-inESDprotection.Theleadsshouldbeshortedtogetherorthedeviceplacedinconductivefoam duringstorageorhandlingtopreventelectrostaticdamagetotheMOSgates. 12.6 Glossary SLYZ022—TIGlossary. Thisglossarylistsandexplainsterms,acronyms,anddefinitions. 13 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. Copyright©2003–2015,TexasInstrumentsIncorporated SubmitDocumentationFeedback 33 ProductFolderLinks:VCA810

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) VCA810AID ACTIVE SOIC D 8 75 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 VCA & no Sb/Br) 810 A VCA810AIDR ACTIVE SOIC D 8 2500 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 VCA & no Sb/Br) 810 A VCA810ID ACTIVE SOIC D 8 75 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 VCA & no Sb/Br) 810 VCA810IDG4 ACTIVE SOIC D 8 75 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 VCA & no Sb/Br) 810 VCA810IDR ACTIVE SOIC D 8 2500 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 VCA & no Sb/Br) 810 VCA810IDRG4 ACTIVE SOIC D 8 2500 Green (RoHS NIPDAU Level-2-260C-1 YEAR -40 to 85 VCA & no Sb/Br) 810 (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. Addendum-Page 1

PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 (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. 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 4-Mar-2014 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) VCA810AIDR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1 VCA810IDR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1 PackMaterials-Page1

PACKAGE MATERIALS INFORMATION www.ti.com 4-Mar-2014 *Alldimensionsarenominal Device PackageType PackageDrawing Pins SPQ Length(mm) Width(mm) Height(mm) VCA810AIDR SOIC D 8 2500 367.0 367.0 35.0 VCA810IDR SOIC D 8 2500 367.0 367.0 35.0 PackMaterials-Page2

PACKAGE OUTLINE D0008A SOIC - 1.75 mm max height SCALE 2.800 SMALL OUTLINE INTEGRATED CIRCUIT C SEATING PLANE .228-.244 TYP [5.80-6.19] .004 [0.1] C A PIN 1 ID AREA 6X .050 [1.27] 8 1 2X .189-.197 [4.81-5.00] .150 NOTE 3 [3.81] 4X (0 -15 ) 4 5 8X .012-.020 B .150-.157 [0.31-0.51] .069 MAX [3.81-3.98] .010 [0.25] C A B [1.75] NOTE 4 .005-.010 TYP [0.13-0.25] 4X (0 -15 ) SEE DETAIL A .010 [0.25] .004-.010 0 - 8 [0.11-0.25] .016-.050 [0.41-1.27] DETAIL A (.041) TYPICAL [1.04] 4214825/C 02/2019 NOTES: 1. Linear dimensions are in inches [millimeters]. Dimensions in parenthesis are for reference only. Controlling dimensions are in inches. 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 .006 [0.15] per side. 4. This dimension does not include interlead flash. 5. Reference JEDEC registration MS-012, variation AA. www.ti.com

EXAMPLE BOARD LAYOUT D0008A SOIC - 1.75 mm max height SMALL OUTLINE INTEGRATED CIRCUIT 8X (.061 ) [1.55] SYMM SEE DETAILS 1 8 8X (.024) [0.6] SYMM (R.002 ) TYP [0.05] 5 4 6X (.050 ) [1.27] (.213) [5.4] LAND PATTERN EXAMPLE EXPOSED METAL SHOWN SCALE:8X SOLDER MASK SOLDER MASK METAL OPENING OPENING METAL UNDER SOLDER MASK EXPOSED METAL EXPOSED METAL .0028 MAX .0028 MIN [0.07] [0.07] ALL AROUND ALL AROUND NON SOLDER MASK SOLDER MASK DEFINED DEFINED SOLDER MASK DETAILS 4214825/C 02/2019 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 D0008A SOIC - 1.75 mm max height SMALL OUTLINE INTEGRATED CIRCUIT 8X (.061 ) [1.55] SYMM 1 8 8X (.024) [0.6] SYMM (R.002 ) TYP [0.05] 5 4 6X (.050 ) [1.27] (.213) [5.4] SOLDER PASTE EXAMPLE BASED ON .005 INCH [0.125 MM] THICK STENCIL SCALE:8X 4214825/C 02/2019 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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