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AAT3120 Datasheet, PDF (1/14 Pages) Advanced Analogic Technologies – 3-Channel Charge Pump For White LED Applications | |||
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General Description
The AAT3120 is a low noise, constant frequency
charge pump DC/DC converter that uses fractional
(1.5X) conversion to improve efficiency for white
LED applications. The device can be used to pro-
duce eight current levels up to 20mA per channel
for up to three channels. 1X load switch mode is
also built-in to improve efficiency at low current set-
tings. Low external parts count (two 1µF flying
capacitors and two small 1µF capacitors at VIN and
OUT) makes the AAT3120 ideally suited for small
battery-powered applications.
AnalogicTech's S2Cwire⢠(Simple Serial Controlâ¢)
serial digital input is used to enable, disable, and
set current for each LED at eight different levels.
The AAT3120 has a thermal management system
to protect the device in the event of a short-circuit
condition at the output pin. Built-in soft-start circuit-
ry prevents excessive inrush current during start-
up. A high charge pump switching frequency
enables the use of very small external capacitors.
A low current shutdown feature disconnects the
load from VIN and reduces quiescent current to less
than 1µA. The AAT3120 is available in the very
small Pb-free 12-pin TSOPJW package.
Typical Application
AAT3120
3-Channel Charge Pump
For White LED Applications
Features
ChargePumpâ¢
⢠VIN Range: 2.7V to 5.5V
⢠Fractional Charge Pump Mode
⢠Drives Low-VF and High-VF Type LEDs
⢠Up to Three LED Outputs
â Single Wire Programming
â Eight Regulated Current Settings
â Max 20mA per Channel
⢠Low Noise Constant Frequency Operation
⢠No Inductors
⢠1MHz Switching Frequency
⢠Small Application Circuit
⢠Automatic Soft-Start
⢠IQ <1µA in Shutdown
⢠12-Pin TSOPJW Package
Applications
⢠Color (RGB) Lighting
⢠Programmable Current Source
⢠White LED Backlighting
⢠White Photo Flash for DSCs
VBATTERY
VIN
C1+
CIN
1µF
C OUT
1µF
EN/SET
VOUT
C1-
C2+
AAT3120
C2-
D1
EN/SET
D2
D3
GND
C1
1µF
C2
1µF
D3
D2
D1
3120.2005.11.1.1
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