AAT3164 Datasheet, PDF (1/14 Pages) Advanced Analogic Technologies – High Efficiency 1X/1.5X/2X Charge Pump for Six-Channel White LED Applications

AAT3164
High Efficiency 1X/1.5X/2X Charge Pump for
Six-Channel White LED Applications
General Description
Features
ChargePump^™
The AAT3164 is a low noise, constant frequency
charge pump DC/DC converter that uses a tri-
mode load switch (1X), fractional (1.5X), and dou-
bling (2X) conversion to maximize efficiency for
white LED applications. The device is capable of
driving up to six channels of LEDs at up to 30mA
per channel from a 2.7V to 5.5V input. The current
sinks may be operated individually or in parallel for
driving higher-current LEDs. A low external parts
count (two 1µF flying capacitors and two small 1µF
capacitors at IN and OUT) makes this part ideally
suited for small, battery-powered applications.
AnalogicTech's patented single-wire Simple Serial
Control™ (S²Cwire™) serial digital input is used to
enable, disable, and set current for each LED with
16 levels from a maximum of 40mA down to 50µA.
The maximum current level is programmed via an
external resistor. To save power, the low-current
mode supply current can be programmed as low
as 70µA.
Each output of the AAT3164 is equipped with built-
in protection for V_OUT short-circuit and auto-disable
for LED 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 AAT3164 is available in a Pb-free, space-saving,
ultra-thin (3x4x0.75mm), thermally-enhanced 16-pin
TDFN package.
• V_IN Range: 2.7V to 5.5V
• Tri-Mode (1X/1.5X/2X) Charge Pump Operation
— Maximizes Efficiency and LED V_F
Coverage
— 1MHz Constant Switching Frequency
— No Inductors, Low Noise Operation
• Drives Six Channels of LEDs up to 30mA/
Channel
— User-Programmable R_SET Sets Maximum
LED Current
— Excellent LED Channel-to-Channel
Current Match
• Digitally Programmable LED Current with
Single-Wire S²Cwire Interface
— 16 Current Levels From I_{LED_MAX} to 50µA
• Low I_Q (70µA) for Low Current Mode Operation
• True Load Disconnect in Shutdown; I_Q < 1µA
• Built-In Thermal Protection
• Built-In Auto-Disable for Open LED Circuit
• Automatic Soft-Start Minimizes Inrush Startup
Current
• Small 3x4mm TDFN34-16 Package
Applications
• Color (RGB) Lighting
• Programmable Current Sinks
• White LED Backlighting
• White Photo Flash for Digital Still Cameras
Typical Application
Li-Ion
Battery
C_IN
VNOM = 3.6V
1µF
EN/SET
26.1K
1%
1µF
1µF
C1+ C1- C2+ C2-
IN
OUT
AAT 3164
GND
D1
EN/SET
D2
D3
D4
RSET
D5
D6
COUT
D1 D2 D3 D4 D5 D6
1µF
OSRAM
LW M67C
3164.2006.07.1.0
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