AT1313 Datasheet, PDF (1/12 Pages) Aimtron Technology – High Efficiency, Constant Current White-LED Driver

Feature
•Operating Voltage:2.5V~5.5V
•High Operating Frequency: 1.4MHz
•High Output Voltage: Up to 18V
•Shutdown Current <1µA
•18V Output Over-voltage protection
•Digital Dimming Control.
•Built-in Cycle-by Cycle Current-limiting.
•Built-in Soft-Start Function.
•0.2V Low Reference Voltage
•Tiny SOT-26 Package
Application
• LED Module
• Compact Back Light Module
• Constant Current Source

Block Diagram
VIN
AT1313
High Efficiency, Constant Current
White-LED Driver
Description
The AT1313 step-up converter drives white LEDs
with a constant current to provide backlight in cell
phones, PDAs, and other hand-held devices. It
features allowing series connection of the white
LEDs so that the LED currents are identical for
uniform brightness. An enable input can be pulsed
repeatedly to adjust LED’s brightness. The fast 1.4
MHz current-mode PWM control allows for smaller
capacitor and inductor. Fault condition protection
uses cycle-by-cycle current limiting to sense
maximum inductor current, thermal protection and
over-voltage protection. Also included soft-start
eliminates inrush current during start-up. The 0.2V
low reference voltage minimized the power loss
across the current-setting resistor.
The AT1313 is available in 6-pin SOT-26 packages
LX
VREF
ON/OFF
0.2V
EN
Control
Logic / PWM
VBG
Soft-Start
Dimming
1.23V
Control
VREF
CTL
+
FB
-
N
Control Logic
OVP
18V
VBG
+
-
Overvoltage
Protection
Current Limit
1.2A
+
-
CTL
GND
Aimtron reserves the right without notice to change this circuitry and specifications.
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: [phone] Fax: [phone]
WWW: http://www.aimtron.com.tw
10/31/2006 REV:2.0
Email:[e-mail]
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