LM3431 - 3-Channel Constant Current LED Driver with Integrated Boost Controller from the PowerWise® Family

Datasheet Packaging Samples & Pricing Eval. Boards Reliability Design Tools Reference Designs Application Notes Knowledge Base

Features
LM3431Q/LM3431AQ are Automotive Grade products that are AEC-Q100 grade 1 qualified (-40°C to 125°C operating junction temperature)
3-channel programmable LED current
High accuracy linear current regulation
Analog and digital PWM dimming control
Up to 25kHz dimming frequency
>100:1 contrast ratio
Integrated Boost controller
5V-36V input voltage range
Adjustable switching frequency up to 1MHz
LED short and open protection
Selectable fault shutdown or automatic restart
Programmable fault delay
Programmable cycle by cycle current limit
Output Over Voltage Protection
No Audible Noise
Enable pin
LED Over-Temperature shutdown input
Thermal Shutdown
TSSOP-28 exposed pad package

General Description


The LM3431 is a 3-channel linear current controller combined with a boost switching controller ideal for driving LED backlight panels in space critical applications. More...


Applications


Automotive Infotainment Displays
Small to Medium Format Displays
  Typical Application
*click for larger image


Parametric Table     expand
Parametric Table    collapse
Topology boost controller / current regulator
Input Min Voltage 5 Volt
Input Max Voltage 37 Volt
Output Range Vin to 40V+
Efficiency (peak) 88 %
Topology boost controller / current regulator
Input Min Voltage 5 Volt
Input Max Voltage 37 Volt
Output Range Vin to 40V+
Efficiency (peak) 88 %
Special Features 3-channel current controller, LED fault protection
Adjustable Output Yes
On/Off Pin Yes
Error Flag Yes
Switching Frequency 1000 kHz
Adj Switch Frequency Yes
Sync Pin No
Step-Down No
Step-Up Yes
Inverting No
Flyback No
RegType Switching Controller
Temperature Min -40 deg C
Temperature Max 125 deg C
Feedback Voltage 1.71 Volt
Automotive Selection Guide Yes
PowerWise Yes
View Using Catalog


Typical Performance


*click for larger image


  WEBENCH Live Simulation!
LED WEBENCH® Designer

LM3431

 
5.00 <=
V in Lower
 V
 
<=
V in Upper
 V
 
<= 34.00
Ambient Temperature  °C <= 100


What are WEBENCH® tools?


Additional Resources
Design Tools (see below)

Application Notes (see below)


Block Diagram


click for larger image



Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM3431/LM3431A/LM3431Q/LM3431AQ 3-Channel Constant Current LED Driver with Integrated Boost Controller 591 Kbytes 10-Mar-09 Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.


Package Availability, Models, Samples & Pricing
Part NumberPackageFactory Lead TimeModelsSamples &
Electronic
Orders
Budgetary PricingStd
Pack
Size
Package
Marking
Format
TypePinsSpec.MSL
Rating
Peak
Reflow
RoHS
Report
CAD
Symbols
WeeksQtyQty$US each
LM3431EVALEvaluation Board for the 3-Channel Constant Current LED Driver with Integrated Boost ControllerFull productionN/A
 
Buy Now
1+$90.001-
8 weeksN/A
LM3431AMHTSSOP EXP PAD28NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now
1K+$2.05rail
of
48
NSUZXYTT
LM3431AMH
6 weeksN/A
LM3431AQMHTSSOP EXP PAD28NOPB1260RoHS N/A Full productionN/A
Samples1K+$2.20rail
of
48
NSUZXYTT
LM3431
AQMH
6 weeksN/A
LM3431MHTSSOP EXP PAD28NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now
1K+$1.95rail
of
48
NSUZXYTT
LM3431MH
6 weeksN/A
LM3431QMHTSSOP EXP PAD28NOPB1260RoHS N/A Full productionN/A
Samples1K+$2.10rail
of
48
NSUZXYTT
LM3431
QMH
6 weeksN/A
LM3431AMHXTSSOP EXP PAD28NOPB1260RoHS N/A Full productionN/A
 
Buy Now
1K+$2.05reel
of
2500
NSUZXYTT
LM3431AMH
6 weeksN/A
LM3431AQMHXTSSOP EXP PAD28NOPB1260RoHS N/A Full productionN/A
 1K+$2.20reel
of
2500
NSUZXYTT
LM3431
AQMH
6 weeksN/A
LM3431MHXTSSOP EXP PAD28NOPB1260RoHS N/A Full productionN/A
 
Buy Now
1K+$1.95reel
of
2500
NSUZXYTT
LM3431MH
6 weeksN/A
LM3431QMHXTSSOP EXP PAD28NOPB1260RoHS N/A Full productionN/A
 1K+$2.10reel
of
2500
NSUZXYTT
LM3431
QMH
6 weeksN/A

General Description


The LM3431 is a 3-channel linear current controller combined with a boost switching controller ideal for driving LED backlight panels in space critical applications. The LM3431 drives 3 external NPN transistors or MOSFETs to deliver high accuracy constant current to 3 LED strings. Output current is adjustable to drive strings in excess of 200 mA. The LM3431 can be expanded to drive as many as 6 LED strings.

The boost controller drives an external NFET switch for step-up regulation from input voltages between 5V and 36V. The LM3431 features LED cathode feedback to minimize regulator headroom and optimize efficiency.

A DIM input pin controls LED brightness from analog or digital control signals. Dimming frequencies up to 25 kHz are possible with a contrast ratio of 100:1. Contrast ratios greater than 1000:1 are possible at lower dimming frequencies.

The LM3431 eliminates audible noise problems by maintaining constant output voltage regulation during LED dimming. Additional features include LED short and open protection, fault delay/error flag, cycle by cycle current limit, and thermal shutdown for both the IC and LED array. The enhanced LM3431A features reduced offset voltge for higher accuracy LED current.

Reliability Metrics


Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM3431AMHABCD15003152000373900011060951459
LM3431AMHXABCD15003152000373900011060951459
LM3431AQMHABCD15003152000373900011060951459
LM3431AQMHXABCD15003152000373900011060951459
LM3431MHABCD15003152000373900011060951459
LM3431MHXABCD15003152000373900011060951459
LM3431QMHABCD15003152000373900011060951459
LM3431QMHXABCD15003152000373900011060951459

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.


Design Tools


TitleSize in Kbytes Date Click link below to Download    
LM3431 Component Calculator 554 Kbytes 26-Nov-2007 View    

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Reference Designs
RD-169 - CCFL to LED Conversion Power Supply

Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1764: Application Note 1764 LM3431 Evaluation Board 588 Kbytes 10-Jan-08 Download
AN-1764 (Chinese): Application Note 1764 LM3431 Evaluation Board
983 Kbytes  

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More Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1679: Application Note 1679 LED Backlighting Solution with LM3430 and LM3432 2763 Kbytes 18-Sep-07 Download
AN-1937: Application Note 1937 LM3433 10A to 40A LED Driver Evaluation Board 1559 Kbytes 25-Mar-09 Download
AN-1907: Application Note 1907 LM3423 Buck-Boost Configuration Evaluation Board 879 Kbytes 8-Dec-08 Download
AN-1736: Application Note 1736 LM3433 HB LED Driver Evaluation Kit 1011 Kbytes 4-Feb-08 Download
AN-1793: Application Note 1793 LM3433 4A to 20A LED Driver Evaluation Board 701 Kbytes 25-Aug-08 Download
AN-1793 (Chinese): Application Note 1793 LM3433 4A to 20A LED Driver Evaluation Board
591 Kbytes  
AN-1529: Application Note 1529 LM3430 Evaluation Board 2770 Kbytes 21-Aug-07 Download
AN-1529 (Chinese): Application Note 1529 LM3430 Evaluation Board
789 Kbytes  

If you have trouble printing or viewing PDF file(s), see Printing Problems.

[Information as of 4-Jul-2009]