COS2277MRU

COS277,COS2277,COS4277
www.cosine-ic.com 1Features
■LowOffsetVoltage:50µV(Max.)
■LowDrift:0.2µV/ºC
■LowInputBiasCurrent:2nA(Max.)
■GainBandwidthProduct:2MHz
■WideSupplyRange：±2.25V~±18V
■LowQuiescentCurrent:330µA
■SlewRate:0.7V/µs
■UnityGainStable
■InputOver-VoltageProtection
■ExtendedTemperatureRanges
From-40°Cto+125°C
■SmallPackaging
COS277availableinSOP8/MSOP8
COS2277availableinSOP8/MSOP8
COS4277availableinSOP14/TSSOP14
Applications
■SensorsandControls
■PrecisionFilters
■DataAcquisition
■MedicalInstrumentation
■OpticalNetworkControlCircuits
■WirelessBaseStationControlCircuits
Rev1.5
Copyright@2018CosineNanoelectronicsInc.Allrightsreserved
Theinformationprovidedhereisbelievedtobeaccurateandreliable.CosineNanoelectronicsassumes
noreliabilityforinaccuraciesandomissions.Specificationsdescribedandcontainedherearesubjected
tochangewithoutnoticeonthepurposeofimprovingthedesignandperformance.Allofthisinformation
describedhereinshouldnotbeimpliedorgrantedforanythirdparty.GeneralDescription
TheCOS277(single),COS2277(dual)and
COS4277(quad)arelowpower,precision
operationalamplifiersoperatedon±2.25Vto
±18Vsupplies.TheCOSx277familyhasvery
lowinputoffsetvoltage(50μV)maximumthatis
obtainedbytrimmingatthewaferstage.These
lowoffsetvoltagesgenerallyeliminateany
needforexternalnulling.TheCOSx277also
featureslowinputbiascurrentandhigh
open-loopgain.Thelowoffsetandhigh
open-loopgainmaketheCOSx277particularly
usefulforhighgaininstrumentation
applications.
Thewideinputvoltagerangeof±13V
minimumcombinedwithahighCMRRof125
dBandhighinputimpedanceprovidehigh
accuracyinthenoninvertingcircuitconfig-
uration.Excellentlinearityandgainaccuracy
canbemaintainedevenathighclosed-loop
gains.Stabilityofoffsetsandgainwithtimeor
variationsintemperatureisexcellent.The
accuracyandstabilityoftheCOSx277,evenat
highgain,combinedwiththefreedomfrom
externalnullinghavemadetheCOSx277an
idealchoiceforinstrumentationapplications.36V,Precision
Low-NoiseOperationalAmplifiers
COS277,COS2277,COS4277
www.cosine-ic.com 21.PinConfigurationandFunctions
COS277 COS2277 COS4277
PinFunctions
Name Description Note
+VsPositivepowersupplyAbypasscapacitorof0.1μFasclosetothepartas
possibleshouldbeplacedbetweenpowersupplypins
orbetweensupplypinsandground.
-VsNegativepowersupply
orgroundIfitisnotconnectedtoground,bypassitwitha
capacitorof0.1μFasclosetothepartaspossible.
-IN NegativeinputInvertinginputoftheamplifier.Voltagerangeofthis
pincangofrom-Vsto+Vs
+IN PositiveinputNon-invertinginputoftheamplifier.Thispinhasthe
samevoltagerangeas-IN.
OUTOutputTheoutputvoltagerangeextendstowithinmillivolts
ofeachsupplyrail.
EPADThermalPadonBottomCOS4277hasanexposedthermalpadconnectto
+Vs
NC Noconnection
2.PackageandOrderingInformation
ModelChannelOrderNumber Package PackageOptionMarking
Information
COS2771COS277SR SOP-8TapeandReel,4000COS277SR
COS277MR MSOP-8TapeandReel,4000COS277MR
COS22772COS2277SR SOP-8TapeandReel,4000
COS2277MR/COS2177SR
U MSOP-8TapeandReel,3000COS2277MR
COS2277MR/UAMSOP-8TapeandReel,3000COS2277MR
COS42774COS4277SR SOP-14TapeandReel,3000COS4277SR
COS4277TR TSSOP-14TapeandReel,4000COS4277
COS277,COS2277,COS4277
www.cosine-ic.com 33.ProductSpecification
3.1AbsoluteMaximumRatings(1)
Parameter Rating Units
PowerSupply:+Vsto-Vs 36 V
DifferentialInputVoltageRange ±Vs V
CommonModeInputvoltageRange(2)-Vsto+Vs V
OutputCurrent 50 mA
StorageTemperatureRange -65to150 °C
JunctionTemperature 150 °C
OperatingTemperatureRange -40to125 °C
ESDSusceptibility,HBM 2000 V
(1)Stressesexceedingtheabsolutemaximumratingsmaydamagethedevice.Thedevicemaynotfunctionorbeoperable
abovetherecommendedoperatingconditionsandstressingthepartstotheselevelsisnotrecommended.Inaddition,
extendedexposuretostressesabovetherecommendedoperatingconditionsmayaffectdevicereliability.Theabsolute
maximumratingsarestressratingsonly.
(2)Inputterminalsarediode-clampedtothepower-supplyrails.Inputsignalsthatcanswingmorethan0.5Vbeyondthe
supplyrailsshouldbecurrent-limitedto10mAorless.
3.2ThermalData
Parameter Rating Unit
PackageThermalResistance,RθJA
(Juntion-to-ambient)190(SOT23-5)
206(MSOP8)
155(SOP8)
105(TSSOP14)
82(SOP14)°C/W
3.3RecommendedOperatingConditions
Parameter Rating Unit
DCSupplyVoltage ±2.5V~±18V V
Inputcommon-modevoltagerange -Vs+1~+Vs-1 V
Operatingambienttemperature -40to+85 °C
COS277,COS2277,COS4277
www.cosine-ic.com 43.4ElectricalCharacteristics
(+VS=+15V,-VS=-15V,TA=+25°C,RL=10kΩtoVS/2,unlessotherwisenoted)
Parameter Symbol Conditions MinTypMaxUnit
InputCharacteristics
InputOffsetVoltage VOSCOS277SR,
COS2277SR,
277MR,2277MR/U±15±50μV
COS2277MR/UA,
COS4277±25±125μV
InputOffsetVoltageDrift ΔVOS/ΔT-40to125°C 0.20.7μV/°C
InputBiasCurrent IB ±0.5±2nA
InputOffsetCurrent IOS ±0.2±1nA
Common-ModeVoltageRangeVCM ±13±14 V
Common-ModeRejectionRatioCMRR 120125 dB
Open-LoopVoltageGain AOLRL≥2kΩ,VO=±10V 100120 dB
OutputCharacteristics
OutputVoltageHigh VOH +14+14.1 V
OutputVoltageLow VOL -14.1-13.9V
OutputCurrent IOUT VDROPOUT<1.2V ±10 mA Short-CircuitCurrent ISC ±28 mA PowerSupply OperatingVoltageRange ±2.5 ±18V PowerSupplyRejectionRatioPSRR 120130 dB QuiescentCurrent/AmplifierIQ 330430μA DynamicPerformance GainBandwidthProduct GBWPCL=100pF,RL=10kΩ 2.0 MHz SlewRate SRCL=100pF,RL=10kΩ, Av=10.7 V/μs NoisePerformance VoltageNoiseDensity en f=1kHz 8.0 nV/√Hz COS277,COS2277,COS4277 www.cosine-ic.com 54.0ApplicationNotes DrivingCapacitiveLoads Drivinglargecapacitiveloadscancausestabilityproblemsforvoltagefeedbackopamps.Asthe loadcapacitanceincreases,thefeedbackloop’sphasemargindecreases,andtheclosedloop bandwidthisreduced.Thisproducesgainpeakinginthefrequencyresponse,withovershootand ringinginthestepresponse.Aunitygainbuffer(G=+1)isthemostsensitivetocapacitiveloads,but allgainsshowthesamegeneralbehavior. Whendrivinglargecapacitiveloadswiththeseopamps(e.g.,>100pFwhenG=+1),asmallseries
resistorattheoutput(RISOinFigure1)improvesthefeedbackloop’sphasemargin(stability)by
makingtheoutputloadresistiveathigherfrequencies.Itdoesnot,however,improvethebandwidth.
ToselectRISO,checkthefrequencyresponsepeaking(orstepresponseovershoot)onthebench.If
theresponseisreasonable,youdonotneedRISO.Otherwise,startRISOat1kΩandmodifyitsvalue
untiltheresponseisreasonable.
Figure1.IndirectlyDrivingHeavyCapacitiveLoad
AnimprovementcircuitisshowninFigure2.ItprovidesDCaccuracyaswellasACstability.RF
providestheDCaccuracybyconnectingtheinvertingsignalwiththeoutput,CFandRISOserveto
counteractthelossofphasemarginbyfeedingthehighfrequencycomponentoftheoutputsignal
backtotheamplifier’sinvertinginput,therebypreservingphasemarginintheoverallfeedbackloop.
Figure2.IndirectlyDrivingHeavyCapacitiveLoadwithDCAccuracy
COS277,COS2277,COS4277
www.cosine-ic.com 6Fornoninvertingconfiguration,therearetwootherswaystoincreasethephasemargin:(a)by
increasingtheamplifier’sgainor(b)byplacingacapacitorinparallelwiththefeedbackresistorto
counteracttheparasiticcapacitanceassociatedwithinvertingnode,asshowninFigure3.
Figure3.AddingaFeedbackCapacitorintheNoninvertingConfiguration
Power-SupplyBypassingandLayout
TheCOSx277operatesfromasingle+5Vto+36Vsupplyordual±2.5Vto±18Vsupplies.For
single-supplyoperation,bypassthepowersupply+Vswitha0.1μFceramiccapacitorwhichshould
beplacedclosetothe+Vspin.Fordual-supplyoperation,boththe+Vsandthe-Vssuppliesshould
bebypassedtogroundwithseparate0.1μFceramiccapacitors.2.2μFtantalumcapacitorcanbe
addedforbetterperformance.
Thelengthofthecurrentpathisdirectlyproportionaltothemagnitudeofparasiticinductancesand
thusthehighfrequencyimpedanceofthepath.Highspeedcurrentsinaninductivegroundreturn
createanunwantedvoltagenoise.Broadgroundplaneareaswillreducetheparasiticinductance.
Thusagroundplanelayerisimportantforhighspeedcircuitdesign.
TypicalApplicationCircuits
DifferentialAmplifier
ThecircuitshowninFigure4performsthedifferentialfunction.Iftheresistorsratiosareequal(R4/
R3=R2/R1),thenVOUT=(VIP–VIN)×R2/R1+VREF.
COS277,COS2277,COS4277
www.cosine-ic.com 7
Figure4.DifferentialAmplifier
LowPassActiveFilter
Whenreceivinglow-levelsignals,limitingthebandwidthoftheincomingsignalsintothesystemis
oftenrequired.ThesimplestwaytoestablishthislimitedbandwidthistoplaceanRCfilteratthe
noninvertingterminaloftheamplifier.Ifevenmoreattenuationisneeded,amultiplepolefilteris
required.TheSallen-Keyfiltercanbeusedforthistask,asFigure5.Forbestresults,theamplifier
shouldhaveabandwidththatis8to10timesthefilterfrequencybandwidth.Failuretofollowthis
guidelinecanresultinreductionofphasemargin.Thelargevaluesoffeedbackresistorscancouple
withparasiticcapacitanceandcauseundesiredeffectssuchasringingoroscillationinhigh-speed
amplifiers.Keepresistorsvalueaslowaspossibleandconsistentwithoutputloadingconsideration.
Figure5.Two-PoleLow-PassSallen-KeyActiveFilter
COS277,COS2277,COS4277
www.cosine-ic.com 85.PackageInformation
5.1SOP8(PackageOutlineDimensions)
5.2MSOP8(PackageOutlineDimensions)

COS277,COS2277,COS4277
www.cosine-ic.com 95.3SOP14(PackageOutlineDimensions)
5.4TSSOP14(PackageOutlineDimensions)