AAT3143 View Datasheet(PDF) - Advanced Analogic Technologies
Part Name
Description
MFG CO.
AAT3143
Advanced Analogic Technologies
'AAT3143' PDF : 10 Pages View PDF
PRODUCT DATASHEET
AAT3143
ChargePumpM High Efficiency 1X/1.5X/2X Charge Pump with PWM Control for White LED Applications
General Description
The AAT3143 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
AAT3143 can deliver current levels up to 80mA to drive
white LEDs connected to the four current source outputs
from a 2.7V to 5.5V input. The current source outputs
may source up to 20mA each and 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) makes the
AAT3143 ideally suited for small battery-powered appli-
cations.
Output current, and therefore brightness, is controlled
via externally applied Pulse Width Modulation (PWM)
control. Typically, PWM frequencies of up to 50kHz can
be applied.
The AAT3143 has a thermal management system to pro-
tect the device in the event of a short-circuit condition at
the voltage output pin. Built-in soft-start circuitry pre-
vents excessive inrush current during startup. A high
charge pump switching frequency allows the use of very
small external capacitors. A low current shutdown fea-
ture disconnects the load from VIN and reduces quiescent
current to less than 1µA.
The AAT3143 is available in a Pb-free, space-saving,
2.85x3.0mm 12-pin TSOPJW package.
Features
• Input Voltage Range: 2.7V to 5.5V
• PWM Brightness Control
• Tri-Mode 1X, 1.5X, and 2X Charge Pump for Maximum
Efficiency and VF Coverage
• Drives Four Low- or High-VF Type LEDs
• Up to 20mA LED Current per Channel
• No Inductors
• 1MHz Switching Frequency
• Small Application Circuit
• AutoBias™ Technology
• IQ <1µA in Shutdown
• 2.85x3.0mm TSOPJW-12 Package
Applications
• Programmable Current Sources
• White LED Backlighting
• White Photo Flash for Digital Still Cameras
Typical Application
2.7V to 5.5V
IN
CIN
1µF
C1+
C1
C1-
1µF
C2+
C2
C2-
1µF
AAT3143 CP
D1
COUT
1µF
PWM/EN
D2
EN/PWM
D3
D4
GND
D4 D3 D2 D1
3143.2009.06.1.1
www.analogictech.com
1
Share Link: 