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POWER MANAGEMENT

SC635

Charge Pump

Flash LED Driver

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Twoselectablemodes-FlashandSpotlight

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200mAmaxoutput-FlashMode

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Spotlightmodesetto40%ofFlashCurrent

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3.0Vto5.25VInputRange

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Externalpinsforcontrolofflashandspotlightmodes

forsynchronizationtoacameramoduleorgraphics

controller

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Shortcircuit,over-voltage,andover-temperature

protection

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Soft-startfunctionality

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MicroLeadPackageMLPD-0,3mmx3mm

December2,2005

Description

Features

TypicalApplicationCircuit

TheSC635isahigh-currentchargepumpdesignedspe-

cificallyforusewithwhiteLEDsusedincameraflashap-

plications.Onlytwosmallbucketcapacitorsarerequired

todeveloptheoutputdrive,providingalowEMIsolution

comparedtoinductiveboostregulators.

TheSC635hastwomodesofoperation:Flashmodeand

Spotlightmode.InFlashmode,theSC635iscapableof

delivering 200mA to a high-intensity LED during image

capture.InSpotlightmodetheSC635outputs40%ofthe

Flashmodecurrentforgeneralpurposelightingorstatus

indication.

AnexternalresistorisconnectedinserieswiththeLEDto

setthecurrent.InFlashmode,thisresistorcandissipate

upto50mW,reducingthepowerdissipationrequirement

oftheSC635.Theflashinput(FLASH)overridesthecon-

trolinput(CTRL)tomakesuretheflashfunctionisacti-

vatedwhencalledfor.

ThethermallyefficientMLPD-10packageandceramicby-

passandbucketcapacitorsmaketheSC635ahighout-

putcurrentdriverthatrequiresminimalPCBarea.

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MobileCameraPhones

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DigitalCameras

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PDAswithBuilt-inCameras

VBAT

SC635

VIN

1

C2-

2

C2+

10

C1-

4

C1+

8

VOUT

9

FLASH

5

CTRL

7

GND

3

ISET

6

1µF

1µF

FLASH

CTRL

1µF

white LED

RSET

10µF

TypicalApplicationCircuit

Applications

Features