PRODUCT DATASHEET
AAT2861
ChargePump
TM
Backlight/Flash LED Driver and Multiple LDO Lighting Management Unit
Features
• Input Voltage Range: 2.7V to 5.5V
• AS
2
Cwire Serial Interface
• Tri-Mode Charge Pump
▪
Drives up to Eight LEDs (Backlight/Flash)
• Programmable Backlight Current Settings
▪
31mA Maximum Current per Channel
▪
32 Linear Current Settings
▪
Independent Main/Sub Settings
▪
Programmable Fade-In and Fade-Out
• Programmable Flash Current
▪
600mA Total Flash Current
▪
16 Linear Current Settings
▪
1- or 2-Channel Configuration
• 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
• Built-In Thermal Protection
• Automatic Soft Start
• -40°C to +85°C Temperature Range
• TQFN34-24 Package
General Description
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 AS
2
Cwire™ (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.
The AAT2861 also offers three high-performance low-
noise MicroPower™ LDO linear regulators. The regulators
output voltages are set through the AS
2
Cwire 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.
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
C1+
IN
V
BAT
3.6V
C
IN
2.2µF
IN
EN/SET
FL_EN
EN_ LDOA
EN_ LDOB/C
BL1
BL2
BL3
BL4
FL_EN
BL5
BL6
EN_ LDOA
BL7/FL2
FL1
EN_LDOB/C
EN/SET
LDOA
LDOB
LDOC
AGND
PGND
CF2
1µF
C2-
OUT
C1- C2+
WLEDs
OSRAM LW M673
or equivalent
V
OUT
C
OUT
2.2µF
Flash LEDs
Lumiled LXCL-PWF1
or equivalent
AAT2861-x
V
LDOC
at 300mA
C
LDOC
2.2µF
V
LDOB
at 300mA
C
LDOB
2.2µF
V
LDOA
at 300mA
C
LDOA
2.2µF
2861.2009.02.1.2
www.analogictech.com
1
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
