PRODUCT DATASHEET
AAT2861
TM
ChargePump
Backlight/Flash LED Driver and Multiple LDO Lighting Management Unit
General Description
Features
The AAT2861 is a highly integrated charge pump-based
lighting management unit (LMU) offering eight LED
channels with three linear regulators optimized for sin-
gle-cell lithium-ion/polymer systems. The charge pump
provides power for all LED outputs; multiple backlight
and flash LED configurations are available. The backlight
LED outputs can be programmed up to 31mA each and
the flash LED output current can be programmed up to
600mA total. AnalogicTech’s AS2Cwire™ (Advanced
Simple Serial Control™) single-wire interface is used to
enable, disable, and set the current to one of 32 levels
for the backlight and one of 16 levels for the flash. A
programmable safety timer and separate flash control
input are included for easy flash control. Backlight cur-
rent matching is better than 3% for uniform display
brightness, and flash current matching is better than 5%
for uniform power dissipation.
• Input Voltage Range: 2.7V to 5.5V
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AS2Cwire Serial Interface
Tri-Mode Charge Pump
Drives up to Eight LEDs (Backlight/Flash)
Programmable Backlight Current Settings
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31mA Maximum Current per Channel
32 Linear Current Settings
Independent Main/Sub Settings
Programmable Fade-In and Fade-Out
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Programmable Flash Current
600mA Total Flash Current
16 Linear Current Settings
1- or 2-Channel Configuration
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1MHz Switching Frequency
Automatic Soft-Start
Three Linear Low Dropout Regulators
300mA Output Current
150mV Dropout
Programmable Output Voltage from 1.2V to 3.3V
Output Auto-Discharge for Fast Shutdown
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The AAT2861 also offers three high-performance low-
noise MicroPower™ LDO linear regulators. The regulators
output voltages are set through the AS2Cwire serial
interface. Each LDO can supply up to 300mA load cur-
rent and ground-pin current is only 80μA, making the
AAT2861 ideal for battery-operated applications.
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Built-In Thermal Protection
Automatic Soft Start
-40°C to +85°C Temperature Range
TQFN34-24 Package
The AAT2861 is available in a Pb-free, space-saving
TQFN34-24 package and operates over the -40°C to
+85°C ambient temperature range.
Applications
• Camera Enabled Mobile Devices
• Digital Still Cameras
• Multimedia Mobile Phones
Typical Application
CF1
1µF
CF2
1µF
WLEDs
OSRAM LW M673
or equivalent
C1+ C1- C2+ C2-
IN OUT
VOUT
Flash LEDs
Lumiled LXCL-PWF1
VBAT
3.6V
CIN
2.2µF
COUT
2.2µF
or equivalent
AAT2861-x
IN
BL1
BL2
BL3
BL4
BL5
BL6
EN/SET
FL_EN
EN/SET
FL_EN
EN_ LDOA
EN_ LDOA
BL7/FL2
FL1
EN_LDOB/C
EN_LDOB/C
VLDOA
at 300mA
CLDOA
LDOA
LDOB
VLDOB
at 300mA
CLDOB
2.2µF
2.2µF
VLDOC
at 300mA
CLDOC
2.2µF
LDOC
PGND
AGND
w w w . a n a l o g i c t e c h . c o m
2861.2009.02.1.2
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