Rev1.0

Preliminary and all contents are subject to change without prior notice.

© Seaward Electronics, Inc., • www.seawardinc.com • Page

2

9/4/2012

SE3505

1.9A Fixed Frequency White LED Driver

Typical Application

(1)

8 series LED application

General Description

The SE3505 is a step-up converter designed

for driving up to 8 series white LEDs for

backlighting application. The SE3505 uses

current

mode,

fixed

frequency

architecture to regulate the LED current, which

is set through an external current sense

resistor. Its low 300mV feedback voltage

reduces power loss and improves efficiency.

The OV pin monitors the output voltage and

turns off the converter if an over-voltage

condition is present due to an open circuit

condition. The SE3505 includes under-voltage

lockout, current limiting and thermal shutdown

protection preventing damage in the event of

an output overload. The driver is available in

small 6-pin SOT-23 package.

Features



2.5V to 5.5V operating input voltage range



Drives up to 8 series White LEDs



1.2MHz Fixed Switching Frequency



Wide range for PWM dimming (200Hz to

200KHz)



Internal 1.9A switching current limit



Over Voltage Protection (OVP)



Internal Soft-start Function



Current

limit

and

Thermal

shutdown

protection



Under voltage Lockout



Available in the 6-pin SOT-23 Package

Applications



Camera Flash White LED



Mobile Phone, Smart Phone LED Backlight



PDA

LED Backlight



Digital Still Cameras



Camcorder