COS29752WU

■OutputVoltageAdjustablefrom
-3Vto-24V
■OutputCurrentinExcessof1A
■LowQuiescentCurrent
■Drop-outVoltageTypically0.6Vat1ALoad
■InternalShortCircuitCurrentLimit
■InternalThermalShutdownwithHysteresis
■CMOS,TTLCompatibleON/OFFSwitch
■ExtendedTemperatureRanges
From-40°Cto+125°C
■AvailableinGreenTO-263,TO-247and
TO-220Packages
Applications
■Industrial
■Battery-PoweredEquipment
■High-EfficiencyLinearPowerSupplies
■Instrumentation
■High-EfficiencyPost-Regulatorfor
SwitchingSupply
Rev1.0
Copyright@2018CosineNanoelectronicsInc.Allrightsreserved
Theinformationprovidedhereisbelievedtobeaccurateandreliable.CosineNanoelectronicsassumes
noreliabilityforinaccuraciesandomissions.Specificationsdescribedandcontainedherearesubjected
tochangewithoutnoticeonthepurposeofimprovingthedesignandperformance.Allofthisinformation
describedhereinshouldnotbeimpliedorgrantedforanythirdparty.GeneralDescription
TheCOS2991isafive-pin,low-dropout,1-A
negativeadjustablevoltageregulatorand
negativepowersupply,ideallysuitedfora
dual-supplysystemwhenusingtogetherwith
COS29152series.Thedevicemayalsobe
usedasanadjustablecurrent-sinkload.The
COS2991providesanoutputvoltagerange
between−3Vto−24V,andfeaturesaturnoff
pinforremoteshutdowncapability.
TheCOS2991providesalowdropoutvoltage,
lowquiescentcurrentandlowtemperature
coefficientprecisionreference.Thedropout
voltageat1-Aloadcurrentistypically0.6Vand
anensuredworst-casemaximumof1Vover
theentireoperatingtemperaturerange.The
quiescentcurrentistypically1mAwitha1-A
loadcurrentandaninput-outputvoltage
differentialgreaterthan3V.Auniquecircuit
designoftheinternalbiassupplylimitsthe
quiescentcurrenttoonly9mA(typical)when
theregulatorisinthedropoutmode(VOUT−VIN
≤3V).TheCOS2991arefullyprotectedagainst
overcurrentfaultsandovertemperature
operationwithahysteresistoenhancethe
reliabilityofthedevicewheninadvertently
overloadedforextendedperiods.NegativeAdjustableLow-DropoutRegulator
COS2991
www.cosine-ic.com 21PinConfigurationandFunctions
PinFunctions
PinNoPinNameI/O Description
1 ADJ IADJUST:Adjustableregulatorfeedbackinputthatconnectstothe
resistorvoltagedividerthatisplacedfromOUTtoGNDinorderto
settheoutputvoltage.
2 OFF ICMOScompatiblecontrolinput.
Logic-high=OFF(shutdown),logic-low=ON
OFFpincanbetiedtoGNDifitisnotrequiredforON/OFF
control.
3 IN IINPUT:Negativeinputvoltage.Internallyconnecteddirectlyto
thethermaltab
4 GND -GROUND
5 OUTOOUTPUT:Theregulatoroutputvoltage.
– TAB INegativeInputvoltage.Internallyconnecteddirectlytothedevice
pin3.Thethermaltabmustbeconnectedtoacopperareaonthe
PCBatthesamepotentialasdevicepin3(IN)toassurethermal
performance,orleavethethermaltabfloating.DoNOTconnect
thethermaltabtoanypotentialotherthanthesamepotentialat
devicepin3.DoNOTconnectthethermaltabtoground.
2PackageandOrderingInformation
Model OrderNumber Package PackageOptionMarkingInformation
COS2991 COS2991S TO-263-5TapeandReel,800 COS2991S
COS2991
www.cosine-ic.com 33ProductSpecification
3.1AbsoluteMaximumRatings(1)
Parameter Rating Units
MaximumInputVoltage:VIN -26to+0.3 V
PowerDissipation Internallylimited
StorageTemperatureRange -55to+150 °C
OperatingJunctionTemperature
Range-40to+125 °C
ESDSusceptibility,HBM 2000 V
(1)Stressesexceedingtheabsolutemaximumratingsmaydamagethedevice.Thedevicemaynotfunctionorbeoperable
abovetherecommendedoperatingconditionsandstressingthepartstotheselevelsisnotrecommended.Inaddition,
extendedexposuretostressesabovetherecommendedoperatingconditionsmayaffectdevicereliability.Theabsolute
maximumratingsarestressratingsonly.
3.2ThermalData
Parameter Rating Unit
PackageThermalResistance,RθJC
(Juntion-to-case)2(TO-220)
2(TO-263)
1.5(TO-247)
3(TO-252)°C/W
3.3RecommendedOperatingConditions
Parameter Rating Unit
InputSupplyVoltage -25to-5 V
Operatingambienttemperature -40to+85 °C
COS2991
www.cosine-ic.com 43.4ElectricalCharacteristics
(VIN=-10V,VOUT=-3V,IOUT=1A,COUT=47µF,R1=2.7K,TJ=+25°C,unlessotherwisenoted)
Parameter Symbol Conditions Min.Typ.Max.Unit
OutputVoltage VOUT -24 -3 V
LineRegulation IOUT=10mA 0.0040.04%/V
LoadRegulation 10mA≦IOUT≦1.5A 0..040.4%
DropoutVoltageIOUT=0.1A,ΔVOUT≤100mV 0.3V
IOUT=1A,ΔVOUT≤100mV 1 V
CurrentLimit ILIMVOUT=0V 1.52 A
QuiescentCurrent IQ -0.75mA
RegulatorOutputCurrentin
ShutdownVIN=−25V,VOFF=2.4V,
VOUT=0V–1 µA
OutputNoise enIL=100mA,10Hzto100kHz -390-µVrms
Reference
ReferenceVoltage VREF5mA≤IOUT≤1A -1.24-1.21-1.18V
ReferenceVoltage
TemperatureCoefficientΔVo/ΔT -20-ppm/°C
AdjustPinBiasCurrent – -100pA
OFFInput
InputLogicVoltageLow(ON) – 00.1V
InputLogicVoltageHigh(OFF) 1.2– V
OFFPinInputCurrentVOFF=0V,VOUT:ON -100150µA
VOFF=2.4V,VOUT:OFF –10nA
COS2991
www.cosine-ic.com 54ApplicationNotes
TheCOS2991isa1-AnegativeadjustablevoltageregulatorwithanoperatingVINrangeof–5Vto
–25V,andaregulatedVOUThaving5%accuracywithamaximumratedIOUTcurrentof1A.The
COS2991isideallysuitedforadual-supplysystemwhenusingtogetherwithCOS29152series.The
devicemayalsobeusedasanadjustablecurrent-sinkload.
4.1TypicalApplicationCircuit
Figure1TypicalApplicationCircuit
4.2SettingTheOutputVoltage
TheoutputvoltageoftheCOS2991issetexternallybyaresistordividerusingfollowingEquation:
VOUT=VREF×(1+R2/R1)
WhereVREF=−1.21V.Theoutputvoltagecanbeprogrammedwithintherangeof−3Vto−24V.
COS2991
www.cosine-ic.com 64.3OutputCapacitorRequirements
Forstabilityandminimumoutputnoise,acapacitorontheregulatoroutputisnecessary.Theoutput
capacitormustbeatleast10µFaluminumelectrolyticor1µFsolidtantalum.Theequivalentseries
resistance(ESR)oftheoutputcapacitormustbebetweenabout25mΩand10Ω,orthezeroadded
totheregulatorfrequencyresponsebytheESRcouldreducethephasemargin,creating
oscillations.
4.4InputCapacitorRequirements
Aninputcapacitor,ofatleast1µFsolidtantalumor10µFaluminumelectrolytic,isalsoneededifthe
regulatorissituatedmorethan6inchesfromtheinputpowersupplyfilter.However,aluminum
electrolytictypesshouldnotbeusedinapplicationswheretheambienttemperaturecandropbelow
0°Cbecausetheirinternalimpedanceincreasessignificantlyatcoldtemperatures.
4.5MinimumLoadCurrent
Aminimumloadcurrentof500µAisrequiredforproperoperation.Theexternalresistordividercan
providetheminimumload,withtheresistorfromtheadjustpintogroundsetto2.4kΩ.
4.6ThermalShutdown
TheCOS2991hasaninternallysetthermalshutdownpointoftypically160°C,withapproximately
10°Cofhysteresis.ThisthermalshutdowntemperaturepointisoutsidethespecifiedRecommended
OperatingConditionsrange,abovetheAbsoluteMaximumRatings,andisintendedasasafety
featureformomentaryfaultconditionsonly.Avoidcontinuousoperationnearthethermalshutdown
temperatureasitmayhaveanegativeeffectonthelifeofthedevice.
4.7OFFPin
COS2991versionsfeatureadisable(OFF)inputthatallowsON/OFFcontrolofthedevice.Special
designallows“zero”currentdrainwhenthedeviceisdisabled;onlymicro-amperesofleakage
currentflows.TheOFFinputhasTTL/CMOScompatiblethresholdsforsimpleinterfacingwithlogic.
IftheON/OFFfunctionisnotneeded,connectthepintoGND.TheON/OFFpinshouldnotbeleft
floating,asthisisnotanensuredoperatingcondition.
COS2991
www.cosine-ic.com 75PackageInformation
5.1TO-263-5(PackageOutlineDimensions)