SW

IN

OVP

MAIN

SUB/FB

SCL

SDA

GND

VIO

SET

LM3509

Dual White LED Bias Supply

10 PH

1 PF

1 PF

30 mA per string

8 k:

2.7V to 5.5V

10 k:

10 k:

RESET/GPIO

LM3509

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SNVS495D – FEBRUARY 2007 – REVISED MAY 2013

LM3509 High Efficiency Boost for White LED's and/or OLED Displays with Dual Current

Check for Samples: LM3509

1

FEATURES

APPLICATIONS

2

•

Integrated OLED Display Power Supply and

•

Dual Display LCD Backlighting for Portable

LED Driver

Applications

•

Drives up to 10 LED’s at 30mA

•

Large Format LCD Backlighting

•

Drives up to 5 LED’s at 20mA and Delivers up

•

OLED Panel Power Supply

to 21V at 40mA

DESCRIPTION

•

Over 90% Efficient

The LM3509 current mode boost converter offers two

•

32 Exponential Dimming Steps

separate outputs. The first output (MAIN) is a

•

0.15% Accurate Current Matching Between

constant current sink for driving series white LED’s.

Strings

The second output (SUB/FB) is configurable as a

constant current sink for series white LED bias, or as

•

Internal Soft-Start Limits Inrush Current

a feedback pin to set a constant output voltage for

•

True Shutdown Isolation for LED’s

powering OLED panels.

•

Wide 2.7V to 5.5V Input Voltage Range

•

21V Over-Voltage Protection

•

1.27MHz Fixed Frequency Operation

•

Low Profile 10-Pin WSON Package (3mm x

3mm x 0.8mm)

•

General Purpose I/O

•

Active Low Hardware Reset

Typical Application Circuits

1

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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

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PRODUCTION DATA information is current as of publication date.

Copyright © 2007–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.