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SC622A_09 Datasheet, PDF (1/23 Pages) Semtech Corporation – LED Light Management Unit Charge Pump, 400mA Flash LED,Dual LDOs,and I2C Interface | |||
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POWER MANAGEMENT
Features
 Input supply voltage range â 3.0V to 5.5V
 Charge pump modes â 1x, 1.5x and 2x
 Flash LED â 400mA max in flash mode, 250mA max
continuous for spotlight
 Two programmable 200mA low-noise LDO regulators
 Charge pump frequency â 250kHz
 I2C compatible interface â up to 400kHz
 External flash control pin to sync with camera
 Optional 1s flash time out
 Automatic sleep mode (flash off ) â I = 100μA
Q
 Low shutdown current â 0.1μA (typical)
 Ultra-thin package â 3mm x 3mm x 0.6mm
 Lead-free and halogen-free
 WEEE and RoHS compliant
Applications
 Cellular phone flash
 PDA flash
 Camera I/O and core power
SC622A
LED Light Management Unit
Charge Pump, 400mA Flash LED, Dual
LDOs, and I2C Interface
Description
The SC622A is a high efficiency charge pump LED driver
using Semtechâs proprietary mAhXLifeTM technology.
Performance is optimized for use in single-cell Li-ion
battery applications.
The charge pump provides continuous or bursted current
to a flash LED using a dedicated flash driver current sink.
The load and supply conditions determine whether the
charge pump operates in 1x, 1.5x, or 2x mode. A flash-
timeout feature disables the flash if active for longer than
1 second. The SC622A also provides two low-dropout,
low-noise linear regulators for powering a camera module
or other peripheral circuits.
The SC622A uses an I2C compatible serial interface. The
interface controls all functions of the device, including
flash current and two LDO voltage outputs. The flash/
spotlight output is triggered via either the I2C interface or
a dedicated pin.
In sleep mode, the device reduces quiescent current to
100μA while continuing to monitor the serial interface.
The two LDOs can be enabled when the device is in sleep
mode. Total current reduces to 0.1μA in shutdown.
Typical Application Circuit
VBAT
CIN
2.2μF
I2C Data
I2C Clock
Flash Control
Enable Control
CBYP
22nF
October 19, 2009
VIN
VOUT
SDA SC622A
SCL
FLEN
EN
COUT
4.7μF
FLASH
BYP
AGND
PGND
FL
LDO 1
LDO 2
C1+ C1- C2+ C2-
C1
2.2μF
C2
2.2μF
CLDO1
1μF
© 2009 Semtech Corporation
VLDO1 = 2.5V to 3.3V
VLDO2 = 1.5V to 1.8V
CLDO2
1μF
US Patents: 6,504,422; 6,794,926
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