L4956
5ALOWDROPLINEARREGULATOR
SPLITTEDSUPPLYVOLTAGEFORIM-PROVEDEFFICIENCY:
-VPW:3VMIN.POWERSUPPLYVOLTAGE-VSIG:4.5VMIN.SIGNALSUPPLYVOLTAGE5AOUTPUTCURRENT
FASTLOADTRANSIENTRESPONSE0.75VTYP.DROPOUTVOLTAGEAT5AINHIBITWITHZEROCURRENTCOMSUMPTIONPOWERGOOD
SHORTCIRCUITPROTECTIONTHERMALSHUTDOWNHEPTAWATTPACKAGEAPPLICATIONS
PENTIUM™ANDPOWERPC™SUPPLIESLOWCOSTSOLUTIONFOR3.3VTO1.5VCONVERSION
SUITABLEFORAPPLICATIONSWITHSTANDBYFEATUREDESCRIPTION
TheL4956isanadjustablemonolithiclinearregu-latordesignedtosatisfyveryheavyloadtransientandefficientpowerconversionfrom3.3Vto1.26Vandlower,upto5A.TYPICALAPPLICATION
MULTIPOWERBCDTECHNOLOGY
HEPTAWATT
ORDERINGNUMBER:L4956
DesignedinBCDIItechnology,itusesachargepumptechniquetohaveaproperinternalN-chan-nelgatedrive.ThesignalsupplyvoltageinputVSIGcanoperatefrom4.5Vuptoanabsoluteof7VandthepowersupplyvoltageinputVPWcanopeartefrom3Vmintoanabsoluteof7V.AnRDSONof150mVgivesavoltagedropof750mVat5Aofloadcurrent.
Veryfastloadtransientsand±1%ofreferencevoltageprecisionmakesthisdevicesuitableforsupplyinglastmicrprocessorsgenerationandlowvoltagelogics.
TheHeptawattpackageenrichesthedevicewithauxiliaryfunctionslikepowergoodandinhibit.
INH
VPW=3.3Vbus
VSIG= 5Vbus
C1
C3
VPWVSIG
12
3
PG6
7
OUT
R1
5
4GND
D96IN374BVO
L4956
ADJ
R2
C2
March1998
1/8
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L4956
ABSOLUTEMAXIMUMRATINGS
SymbolVPW,VSIG
SupplyInputVoltageADJpin
PGandINHpins
PTOTTst,Ti
PowerDissipation@Tamb=50°CPowerDissipation@Tcase=90°CStorageTemperature
Parameter
Value7-0.3to40toVSIG
215-40to+150
UnitVVVWW°C
PINCONNECTION(Topview)
7654321
tabconnectedtopin4
D96IN373OUTPGADJGNDINHVSIGVPW
PINFUNCTIONS
No.1234567
NameVPWVSIGINHGNDADJPGOUT
Function
Unregulatedpowerinputvoltage;thispinmustbebypassedwithacapacitorlargerthan10µF.Unregulatedsignalinputvoltagethispinhastobebypassedwithaminimumcapacitorof0.1µF.TTL-CMOSinput.Alogiclevelonthisinputdisablethedevice.Aninternalpull-downinsuresinsuresfullfunctionallyevenifthepinisopen.Ground.
Theoutputisconnecteddirectlytothisterminalfor1.26Voperationviadividerforhighervoltages.Opendrainoutput,thispinislowwhentheoutputvoltageislowerthan90%,otherwiseishigh.Regulatedoutputvoltage.Aminimumbypasscapacitorof22µFisrequiredtoinsurestability.
BLOCKDIAGRAM
VPW10µFVSIG
VSIG
2
VPW
1
VREF= 1.26V
CURRENT LIMITATION
FOLDBACK
CHARGE PUMP
PRE REGULATOR
+-
E/A
BUFFER
POWER DMOS 150mΩ
OUT7
R1ADJ5
R2
VOUT22µF
THERMAL SHUTDOWN
INH
31.26V
0.9VREF
4GND
+-6PG
INHIBIT ACTIVEHIGH
D96IN372A2/8
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L4956
THERMALDATA
SymbolRthj-pinsRthj-amb
Parameter
ThermalResistanceJunction-caseThermalResistanceJunction-ambientThermalShutdownThermalHysteresis
Typ.Typ.
Value2.55015020
Unit°C/W°C/W°C°C
ELECTRICALCHARACTERISTICS(Tj=25°C,unlessotherwisespecified)
SymbolVPWVSIGVOUT
Parameter
PowerOperatingSupplyVoltageSignalOperatingSupplyVoltageOutputVoltage
(1)
0 Lineregulation (1) 3V TestCondition Min.34.51.2401.224 1.2601.2600.510.751.16.31.81.51001.260.250.9xVOUT I6=4mA 0.10.2 0.41031501.42 Typ. Max.6.56.51.2801.296351.11.57.5 UnitVVVVmVmVVVAAmAµAVVµAVVV Loadregulation(1)Drop-outVoltage IOIQ CurrentLimitingShortCircuitCurrentQuiescentCurrentatpinVSIGStandByCurrentatpinVSIGInhibitThresholdInhibitHisteresysInhibitBiasSinkCurrentPowerGoodThresholdPowerGoodSaturationPowerGoodHisteresys (1)OutputvoltageconnectedtoADJ. 3/8 元器件交易网www.cecb2b.com L4956 Figure1.DCOperatingArea. OutputCurrent[A]8765432100 1 2 3456(Vpw-Vout)[V] 7 8 Vpw>3VVsig>4.5VTj=125°C CurrentLimitation Tc=25°C Pdmax=40W Figure2.OutputVoltageStabilityvs. JunctionTemperature Vout[V]1.28 1.2751.271.2651.261.2551.251.2451.24 -40 0 4080Tj[°C] 120 160 Vpw=3.3VVsig=5VIout=10mA Rdsonlimit Power DissipationLimit Tc=70°CPdmax=22W DCOperatingArea Figure3.LoadRegulation. [m543210-1-2-3-4-50 1 Pulsedtecniquehasbeenused Figure4.DropoutVoltage. 1.25[V]Vpw-VoutVoltage1 Tj=125°C 0.75 Tj=25°C 0.5 Tj=-40°C Minimum0.25 Pulsedtechniquehasbeenused DeviationVpw=3.3VVsig=5VVout=VadjTj=25°C OutputVoltage23Iout[A] 45 0 012 3Iout[A] 456 Figure5.MaximumOutputCurrentvs. JunctionTemperature OutputCurrent[A] 109876543210 -40-20 0 Pulsedtecniquehasbeenused (Vpw-Vout)>2V Figure6.QuiescentCurrentatpinVSIGvs. JunctionTemperature. Iq[mA]21.81.61.41.210.80.6 0.4 -40-20 0 20 40 6080100120140160Tj[°C] VSIG=6.5V Iout=10mAto5A3V 406080100120140160Tj[ºC] 4/8 元器件交易网www.cecb2b.com L4956 Figure7.QuiescentCurrentatpinVSIGvs. SignalInputVoltage. Iq[mA]32.521.510.500 1 2 34VSIG[V] 5 6 7 Io=10mAto Tj=25°C Figure8.Stand-ByCurrentatpinVSIGvs.Signal InputVoltagewithINH=LOGICHIGH Iq[µA]150 5A 1251007550250 Tj=25°C 3V 5.56VSIG[V] 6.57 Figure9.PowerGoodFunction VADJ VOUT=VADJ(R1+R2)/R2 0.9VADJ hyst=200mV t PG Low High Low D96IN364Bt Figure10.InhibitFunction VINH Vref=1.26V hyst=200mV t regulator ONregulator OFFregulator ON D96IN365At 5/8 元器件交易网www.cecb2b.com L4956 LOADTRANSIENTRESPONSEFigure11. Figure12. Vout 50mV/divCH1gnd Vout 50mV/divCH1gnd 5A5A 0.5ACH2gndIout2A/div t=5µs/div 0.5ACH2gndIout2A/div t=5µs/div Figure13. Testconditions: VPW=3.3V;VSIG=5;Vout=1.5V;LoadTransientfrom0.5Ato5A;dlout =20A/µs;Tj=25°Cdt Vout 50mV/divCH1gnd 5A 0.5ACH2gndIout2A/div t=100µs/div Figure14.Loadtransienttestcircuit. VIN=3.3V VPW VSIG=5VVSIG PG 12 6 7 OUT R4 24ΩR5 126Ω C4toC9 100µF/10V AVXTPS 6each VOUT=1.5V L4956 4 3INH 5 C1,C2 470µF Panasonic HFQ ADJ C16 220nF GND C10toC15 1µF AVXX7R 6each D97IN5936/8 元器件交易网www.cecb2b.com L4956 HEPTAWATTPACKAGEMECHANICALDATA DIM.ACDD1EFF1GG1G2H2H3LL1L2L3L5L6L7MM1Dia 3.652.615.16 2.85.08 3.85 0.144 10.05 16.9714.9221.5422.62 315.86.6 0.1020.5940.236 0.1100.200 0.152 2.414.917.49 2.545.087.62 2.41.20.350.6MIN. mmTYP. MAX.4.81.372.81.350.550.80.92.675.217.810.410.4 0.396 0.6680.5870.8480.891 0.1180.6220.260 0.0950.1930.295 0.1000.2000.300 0.0940.0470.0140.024MIN. inchTYP. MAX.0.1890.0540.1100.0530.0220.0310.0350.1050.2050.3070.4090.409 7/8 元器件交易网www.cecb2b.com L4956 Informationfurnishedisbelievedtobeaccurateandreliable.However,SGS-THOMSONMicroelectronicsassumesnoresponsibilityfortheconsequencesofuseofsuchinformationnorforanyinfringementofpatentsorotherrightsofthirdpartieswhichmayresultfromitsuse.NolicenseisgrantedbyimplicationorotherwiseunderanypatentorpatentrightsofSGS-THOMSONMicroelectronics.Specificationmentionedinthispublicationaresubjecttochangewithoutnotice.Thispublicationsupersedesandreplacesallinformationpreviouslysupplied.SGS-THOMSONMicroelectronicsproductsarenotauthorizedforuseascriticalcomponentsinlifesupportdevicesorsystemswithoutexpresswrittenapprovalofSGS-THOMSONMicroelectronics. ©1998SGS-THOMSONMicroelectronics–PrintedinItaly–AllRightsReserved SGS-THOMSONMicroelectronicsGROUPOFCOMPANIES Australia-Brazil-Canada-China-France-Germany-Italy-Japan-Korea-Malaysia-Malta-Morocco-TheNetherlands-Singapore-Spain-Sweden-Switzerland-Taiwan-Thailand-UnitedKingdom-U.S.A. 8/8 因篇幅问题不能全部显示，请点此查看更多更全内容