Texas Instruments LM3678 Handleiding

Bekijk gratis de handleiding van Texas Instruments LM3678 (18 pagina’s), behorend tot de categorie Niet gecategoriseerd. Deze gids werd als nuttig beoordeeld door 2 mensen en kreeg gemiddeld 4.9 sterren uit 3 reviews. Heb je een vraag over Texas Instruments LM3678 of wil je andere gebruikers van dit product iets vragen? Stel een vraag

LOAD (A)

EFFICIENCY (%)

90

80

70

60

50

40

30

20

10

0

0.0100.1001.00010.000

V

IN

= 3.6V

V

IN

= 4.5V

V

IN

= 5.5V

V

IN

= 2.5V, 2.7V

1 PH

LM3678

V

IN

= 2.5V to 5.5V

PWM

GND

SW

VDD

FB

EN

CIN

10 PF

V

OUT

GND

VDD

VSELECT

PGOOD

C

OUT

22 PF

0.8V/1.2V

LM3678

www.ti.com

SNVS464C–APRIL2008–REVISEDMAY2013

High-PerformanceMiniature1.5-AStep-DownDC-DCConverterforHandheldApplications

CheckforSamples:LM3678

1

FEATURES

DESCRIPTION

TheLM3678step-downDC-DCconverteris

2

•V

OUT

=0.8Vor1.2V

optimizedforpoweringlow-voltagecircuitsfroma

•V

IN

=2.5Vto5.5V

singleLi-Ioncellbatteryandinputvoltagerailsfrom

•1.5-AMaximumLoadCapability

2.5Vto5.5V.Itprovidesupto1.5-Aloadcurrent,

overtheentireinputvoltagerange.LM3678offersa

•3.3-MHz(Typical)PWMFixedSwitching

0.8Vor1.2Voption.Oneofthepairofvoltagesisset

FrequencyAllowsUseof1-µHInductor

throughtheVSELECTpin.

•±3%DCOutputVoltagePrecision

LM3678operatesinPWMmodewithafixed

•0.01-µA(Typical)ShutdownCurrent

frequencyof3.3MHz.Internalsynchronous

•InternalSynchronousRectificationforHigh

rectificationprovideshighefficiencyduringPWM

Efficiency

modeoperation.Inshutdownmode,thedeviceturns

offandreducesbatteryconsumptionto0.01µA

•InternalSoftStart

(typical).

•CurrentOverloadandThermalShutdown

Protection

TheLM3678isavailableina3mmx3mmDSC-10

package.Ahighswitchingfrequencyof3.3MHz

(typical)allowsuseoftinysurface-mount

APPLICATIONS

components.Onlythreeexternalsurface-mount

•PDAsandSmartPhones

components,aninductorandtwoceramiccapacitors,

•PersonalMediaPlayers

arerequired(solutionsizelessthan33mm

2

).For

voltagesotherthanthevoltageshown,contactTIor

•W-LAN

yourdistributor.

•USBModemApplications

•DigitalStillCameras

•PortableHardDiskDrives

Efficiencyvs.OutputCurrent

TypicalApplicationCircuit(V

OUT

=1.2V)

NOTE:V

SEL

H=1.2V,V

SEL

L=0.8V

Figure1.Figure2.

1

Pleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsof

TexasInstrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet.

2Alltrademarksarethepropertyoftheirrespectiveowners.

PRODUCTIONDATAinformationiscurrentasofpublicationdate.

Copyright©2008–2013,TexasInstrumentsIncorporated

ProductsconformtospecificationsperthetermsoftheTexas

Instrumentsstandardwarranty.Productionprocessingdoesnot

necessarilyincludetestingofallparameters.

Product specificaties