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器件描述：Six-Channel White LED Backlight Charge Pump with Flash
器件厂商：ANALOGICTECH [Advanced Analogic Technologies]
厂商主页：http://www.analogictech.com/
文件大小：581.92KB
文件页数：16
PDF阅读：AAT2803ISK-4.5-T1.pdf (点击阅读器件资料)
摘要：
AAT2803
Six-Channel White LED Backlight
Charge Pump with Flash
2803.2006.04.1.5 1
ChargePump
?
General Description
The AAT2803 is a dual charge pump designed to sup-
port both white LED backlight and flash applications
for systems operating with lithium-ion/polymer batter-
ies. The backlight charge pump is capable of driving
up to six LEDs at a total of 180mA. The current sinks
may be operated in group or in parallel for driving
higher current LEDs. To maximize power efficiency,
the charge pump operates in 1X, 1.5X, or 2X mode,
where the mode of operation is automatically select-
ed by comparing the forward voltage of each LED
with the input voltage. AnalogicTech's AS
2
Cwire?
(Advanced Simple Serial Control?) serial digital input
is used to enable, disable, and set current for each
LED with a 16-level logarithmic scale plus four low-
current settings down to 50μA for optimized efficien-
cy, with a low housekeeping current of only 50μA.
The flash charge pump is a charge pump doubler
with a regulated output voltage. It is designed to
deliver 120mA of continuous current and up to
300mA of pulsed current. It has an independent
enable pin for improved power savings.
The AAT2803 is equipped with built-in protection,
short-circuit, and auto-disable for load short-circuit
condition. Built-in soft-start circuitry prevents exces-
sive inrush current during start-up. A low-current
shutdown feature disconnects the load from V
IN
and
reduces quiescent current to less than 1μA.
The AAT2803 is available in a Pb-free, space-saving,
thermally enhanced 24-pin 4x4mm QFN package
and is rated over the -40°C to +85°C temperature
range.
Features
?V
IN
Range: 2.7V to 5.5V
? Dual Charge Pump:
— Flash: Charge Pump Doubler
— Backlight: Tri-Mode Charge Pump
? Backlight Charge Pump:
— Programmable Current With Single GPIO
— 16 Current Steps
— 15/20/30mA Max Current
— Four Low Current Settings
— Individual Main/Sub-Group Control
— Low I
Q
(50μA) for Low-Current Mode
— Drives Six Channels of LEDs
? Flash Charge Pump:
— Regulated V
OUT_FL
4.5/5.0 Volts
— Up to 300mA of Current for Flash
? 1MHz Constant Switching Frequency
? Independent Backlight/Flash Control
? Built-In Thermal Protection
? Built-In Auto-Disable for Open Circuit
? Automatic Soft Start
?I
Q
<1μA in Shutdown
? Available in QFN44-24 Package
Applications
? Color (RGB) Lighting
? Programmable Current Sink
? White LED Backlighting
? White Photo Flash for Digital Still Cameras
Typical Application
AAT2 8 0 3
C
IN
1 ? F
V
IN
C1
1 ? F
D2
GN D
B a ckl i g h t
C2
1 ? F
C3
1 ? F
C2
+
C
OU T
1 ? F
E NFL
E N/SET
VIN
EN _ F L
Fl a s h
EN / SET
C2
-
C1
+
C1
-
C3
+
C3
-
VOUT
D3 D2 D1D4D5D6
D1
D3
D4
D5
D6
C
OU T
1 ? F
相关器件：AAT2803
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