AAT3169 Datasheet, PDF (1/14 Pages) Advanced Analogic Technologies – High Efficiency 1X/1.5X/2X Charge Pump for White LED Applications

General Description
The AAT3169 is a low noise, constant frequency
charge pump DC/DC converter that uses a tri-mode
load switch (1X), fractional (1.5X), and doubling
(2X) conversion to maximize efficiency for white
LED applications. The AAT3169 is capable of driv-
ing six LEDs for a total of 180mA from a 2.7V to
5.5V input. The current sinks may be operated indi-
vidually or in parallel for driving higher current LEDs.
A low external parts count (two 1µF flying capacitors
and two small 1µF capacitors at VIN and VOUT)
make this part ideally suited for small, battery-pow-
ered applications.
AnalogicTech's AS²Cwire™ (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 115µA. For optimized efficiency,
low-current settings require only 65µA of house-
keeping current.
Each output of the AAT3169 is equipped with built-
in protection for V_OUT short-circuit and auto-disable
for load short-circuit conditions. Built-in soft-start
circuitry prevents excessive inrush current during
start-up. A low-current shutdown feature discon-
nects the load from V_IN and reduces quiescent cur-
rent to less than 1µA.
The AAT3169 is available in a Pb-free, space-sav-
ing, thermally-enhanced 16-pin 3x4mm TDFN or
4x4mm QFN package.
Typical Application
AAT3169
High Efficiency 1X/1.5X/2X Charge
Pump for White LED Applications
Features
ChargePump^™
• V_IN Range: 2.7V to 5.5V
• Fully Programmable Current with Single Wire
— 16-Step Logarithmic Scale
— 20/30/15mA Max Current
— Four Low-Current Settings Down to 115µA
— Low I_Q (65µA) for Single-Channel, Low-
Current Mode
• Tri-Mode 1X, 1.5X, and 2X Charge Pump for
Maximum Efficiency and V_F Coverage
• Drives Up to Six LEDs
• Individual Main-Sub (5-1) Group Control
• No Inductors, Low Noise Operation
• 1MHz Constant Switching Frequency
• Small Application Circuit
• Built-In Thermal Protection
• Built-In Auto-Disable for Open Circuit
• Automatic Soft Start
• I_Q <1µA in Shutdown
• Thermally-Enhanced TDFN34-16 or
QFN44-16 Package
Applications
• Color (RGB) Lighting
• Programmable Current Sink
• White LED Backlighting
• White Photo Flash for Digital Still Cameras
C1+
C2+
C1
1μF
C1-
C2-
2.7V to 5.5V
EN/SET
VIN
VOUT
C_IN
1μF
AAT3169
GND
D1
D2
EN/SET
D3
D4
D5
D6
C2
1μF
D1 D2 D3 D4 D5
D6
COUT
1μF
3169.2006.04.1.0
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