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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
1F
FLASH
CTRL
1F
white LED
RSET
10F
TypicalApplicationCircuit
Applications
Features