LM3509SDEV National Semiconductor, LM3509SDEV Datasheet

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LM3509SDEV

Manufacturer Part Number
LM3509SDEV
Description
BOARD EVALUATION FOR LM3509SD
Manufacturer
National Semiconductor
Series
PowerWise®r
Datasheets

Specifications of LM3509SDEV

Current - Output / Channel
40mA
Outputs And Type
2, Non-Isolated
Voltage - Output
21V
Features
Dimmable, I²C Interface
Voltage - Input
2.7 ~ 5.5V
Utilized Ic / Part
LM3509
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
© 2008 National Semiconductor Corporation
LM3509
High Efficiency Boost for White LED's and/or OLED
Displays with Dual Current Sinks and I
Brightness Control
General Description
The LM3509 current mode boost converter offers two sepa-
rate 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.
When configured as a dual output white LED bias supply, the
LM3509 adaptively regulates the supply voltage of the LED
strings to maximize efficiency and insure the current sinks re-
main in regulation. The maximum current per output is set via
a single external low power resistor. An I
face allows for independent adjustment of the LED current in
either output from 0 to max current in 32 exponential steps.
When configured as a white LED + OLED bias supply the
LM3509 can independently and simultaneously drive a string
of up to 5 white LED’s and deliver a constant output voltage
of up to 21V for OLED panels.
Output over-voltage protection shuts down the device if
V
voltage output capacitors. The LM3509 is offered in a small
10-pin thermally- enhanced LLP package and operates over
the -40°C to +85°C temperature range.
Typical Application Circuits
OUT
rises above 21V allowing for the use of small sized low
2
300043
C compatible inter-
Features
Applications
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 LLP Package (3mm x 3mm x 0.8mm)
General Purpose I/O
Active Low Hardware Reset
Dual Display LCD Backlighting for Portable Applications
Large Format LCD Backlighting
OLED Panel Power Supply
2
C Compatible
30004361
March 6, 2008
www.national.com

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LM3509SDEV Summary of contents

Page 1

... The LM3509 is offered in a small 10-pin thermally- enhanced LLP package and operates over the -40°C to +85°C temperature range. Typical Application Circuits © 2008 National Semiconductor Corporation Features ■ Integrated OLED Display Power Supply and LED Driver ■ ...

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www.national.com 2 30004301 ...

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Connection Diagram Ordering Information Order Number Package Type LM3509SD 10-Pin LLP LM3509SDX 10-Pin LLP Pin Descriptions/Functions Pin Name 1 MAIN Main Current Sink Input. 2 SUB/FB Secondary Current Sink Input or 1.25V Feedback Connection for Constant Voltage Output. 3 SET ...

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... Junction to Ambient Thermal -65ºC to +150º C Resistance (θ +300°C ESD Caution Notice National Semiconductor recommends that all integrated cir- 2.5kV cuits be handled with appropriate ESD precautions. Failure to observe proper ESD handling techniques can result in dam- age to the device. = 25°C and those in boldface type apply over the Operating Temperature Range ...

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... For guaranteed specifications and test conditions, see the Electrical Characteristics. Note 2: All voltages are with respect to the potential at the GND pin. Note 3: For detailed soldering specifications and information, please refer to National Semiconductor Application Note 1187: Leadless Lead frame Package (AN-1187). ...

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Typical Performance Characteristics Mode 2.2µF (OLED Mode), C OUT +25°C unless otherwise specified. SUB MAIN A 10 LED Efficiency Strings of 5LEDs) 6 LED Efficiency Strings ...

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OLED Efficiency vs I OUT 30004304 LED Line Regulation (UNI = '0') 30004359 OLED Line Regulation I = 60mA OLED 30004306 12V OLED Efficiency vs I OLED Line Regulation I = 60mA OLED OLED Load Regulation V = 18V ...

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OLED Load Regulation V = 12V OLED Over Voltage Limit vs. V Switching Frequency vs. V www.national.com Peak Current Limit vs. V 30004312 Switch On-Resistance vs 30004315 Maximum Duty Cycle vs 30004318 8 IN 30004314 IN ...

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Shutdown Current vs 30004320 LED Current Matching vs. CODE (Note 11) (UNI = '1 12kΩ -40°C to +85°C) SET A 30004322 LED Current vs CODE ( 12kΩ±0.05%) ...

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Start-Up Waveform (LED Mode) (2 × 5 LEDs, 30mA per string) Channel 1: SDA (5V/div) Channel 2: V (10V/div) OUT Channel 3: I (50mA/div) LED Channel 4: I (500mA/div) IN Time Base: 400µs/div Load Step (OLED Mode 18V, ...

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GPIO Functionality (GPIO Configured as OUTPUT, f Channel 2: GPIO (2V/div) Channel 3: SDA (2V/div) Channel 1:SCL (2V/div) Time Base: 40µs/div Ramp Rate Functionality (RMP1, RMP0 = '01') Channel 3: SDA (2V/div) Channel 1: I (10mA/div) MAIN Channel 4: I ...

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Block Diagram Operation Description The LM3509 Current Mode PWM boost converter operates from a 2.7V to 5.5V input and provides two regulated outputs for White LED and OLED display biasing. The first output, MAIN, provides a constant current of up ...

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In the instance when there are unequal numbers of LEDs or unequal currents from string to string, the string with the high- est voltage will be the regulation ...

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COMPATIBLE INTERFACE The LM3509 is controlled via an I START and STOP conditions classify the beginning and the end of the session. A START condition is defined as SDA transitioning from HIGH to LOW ...

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REGISTER DESCRIPTIONS There are 4, 8 bit registers within the LM3509 as detailed in Table 1. TABLE 1. LM3509 Register Descriptions Register Name General Purpose (GP) Brightness Main (BMAIN) Brightness Sub (BSUB) General Purpose I/O (GPIO) GENERAL PURPOSE REGISTER (GP) ...

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TABLE 3. Operational Truth Table UNI OLED ENM ENM ,ENS, or OLED high enables analog circuitry. BRIGHTNESS REGISTERS (BMAIN and BSUB) With the ...

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TABLE 4. I vs. Brightness Register Data LED BMAIN or BSUB Brightness Data 00000 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010 01011 01100 01101 01110 01111 FIGURE ILED_MAX BMAIN or BSUB Brightness Data ...

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BRIGHTNESS RATE OF CHANGE DESCRIPTION RMP0 and RMP1 control the rate of change of the LED cur- rent I and I in response to changes in BMAIN and / MAIN SUB/FB or BSUB. There are 4 user programmable LED current ...

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Application Information LED CURRENT SETTING/MAXIMUM LED CURRENT Connect a resistor (R ) from SET to GND to program the SET maximum LED current (I ) into MAIN or SUB/FB. The LED_MAX relationship is: SET LED_MAX where SET ...

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TABLE 7. Recommended Output Capacitors Manufacturer Part Number TDK C1608X5R1E105M Murata GRM39X5R105K25D53 TDK C2012X5R1E225M Murata GRM219R61E225KA12 INDUCTOR SELECTION The LM3509 is designed for use with a 10µH inductor, how- ever 22µH are suitable providing the output capacitor is in- creased ...

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... For more detailed instructions on mounting LLP packages, please refer to National Semiconductor Application Note AN-1187. The high switching frequencies and large peak currents make the PCB layout a critical part of the design. The proceeding steps must be followed to ensure stable operation and proper current source regulation ...

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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 10 Pin LLP For Ordering, Refer to Ordering Information Table NS Package Number SDA10A X1 = 3mm (±0.1mm 3mm (±0.1mm 0.8mm 22 ...

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Notes 23 www.national.com ...

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