LM3509 Datasheet, PDF (1/30 Pages) National Semiconductor (TI) – OLED Displays with Dual Current Sinks and I2C Compatible Brightness Control

LM3509
www.ti.com
SNVS495D – FEBRUARY 2007 – REVISED MAY 2013
LM3509 High Efficiency Boost for White LED's and/or OLED Displays with Dual Current
Sinks and I²C Compatible Brightness Control
Check for Samples: LM3509
FEATURES
1
•2 Integrated OLED Display Power Supply and
LED Driver
• Drives up to 10 LED’s at 30mA
• Drives up to 5 LED’s at 20mA and Delivers up
to 21V at 40mA
• Over 90% Efficient
• 32 Exponential Dimming Steps
• 0.15% Accurate Current Matching Between
Strings
• Internal Soft-Start Limits Inrush Current
• True Shutdown Isolation for LED’s
• 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
APPLICATIONS
• Dual Display LCD Backlighting for Portable
Applications
• Large Format LCD Backlighting
• OLED Panel Power Supply
DESCRIPTION
The LM3509 current mode boost converter offers two
separate outputs. The first output (MAIN) is a
constant current sink for driving series white LED’s.
The second output (SUB/FB) is configurable as a
constant current sink for series white LED bias, or as
a feedback pin to set a constant output voltage for
powering OLED panels.
Typical Application Circuits
10 PH
2.7V to 5.5V
C_IN
1 PF
10 k: _{10 k:}
SW
IN
OVP
LM3509
VIO
SCL
SDA
MAIN
SUB/FB
RESET/GPIO SET
GND
30 mA per string
C_OUT
1 PF
R_SET
8 k:
Dual White LED Bias Supply
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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