LM3551 - 1A White LED Driver with Flash Timeout Protection from the PowerWise® Family

Datasheet Packaging Samples & Pricing Eval. Boards Reliability Application Notes Knowledge Base

Features
•Up to 1A total drive current
•Flash timeout protection
•Independent Torch/Flash/Shutdown modes
•LED disconnect in shutdown
•Programmable soft-start limits inrush current
•Over-voltage protection
•Wide voltage range 2.7 to 5.5V
•1.25MHz constant switching frequency
•Small, low profile package, non-pullback LLP14 (4mm x 4mm)

General Description

The LM3551 and LM3552 are fixed frequency, current mode step-up DC/DC converters with two integrated NFETs that can be used for precision LED brightness control. More...


Applications

•White LED Camera Flash
•White LED Torch (Flashlight)
•DSC (Digital Still Camera) Flash
•Cellular Camera Phone Flash
•PDA Camera Flash
•Camcorder Torch (Flashlight) lamp
  Typical Application
click for larger image


Parametric Table     expand
Parametric Table    collapse
Regulated LEDs 1
Total LED Current 1000 mA
Boost Type Inductive
Switching Frequency 1250 kHz
Efficiency (peak) 93 %
Regulated LEDs 1
Total LED Current 1000 mA
Boost Type Inductive
Switching Frequency 1250 kHz
Efficiency (peak) 93 %
Input Min Voltage 2.7 Volt
Input Max Voltage 5.5 Volt
LED Configuration Series
Current Matching Perfect
OutputMax Voltage 20 Volt
Supply Current 1.47 mA
Switching Type PWM
Special Features Up to 4 LEDs, Flash LED driver, timeout protection, active low enable
PWM BrightCtrl Yes
Analog-V BrightCtrl No
Ambient Light Compensation No
RGB-LED No
Temperature Min -40 deg C
Temperature Max 85 deg C
RegType WhiteLED Driver
PowerWise Yes
View Using Catalog


Typical Performance

click for larger image


  Also Recommended
LM2750Low Noise Regulator Switched Capacitor Boost Regulator
LM2753High Power Switched Capacitor Voltage Converter/Flash LED Driver
LM3224High Power Step-Up PWM DC/DC Converter

Additional Resources

Application Notes (see below)


Block Diagram

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Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM3551/LM3552 1A White LED Driver with Flash Timeout Protection 756 Kbytes 28-Feb-06 View Online
Download

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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
LM3552SDEV1A White LED Driver with Flash Timeout ProtectionFull productionN/A
 
Buy Now 		1+$113.001-
6 weeksN/A
LM3551SDLLP14NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.19reel
of
1000		NS
UZXYTT
L3551SD
8 weeks500
LM3551SDXLLP14NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.19reel
of
4500		NS
UZXYTT
L3551SD
8 weeksN/A

General Description

The LM3551 and LM3552 are fixed frequency, current mode step-up DC/DC converters with two integrated NFETs that can be used for precision LED brightness control. The devices are capable of driving loads up to 1A from a single-cell Li-Ion battery.

The LM3551 and LM3552 can drive one or more high current flash LEDs either in a high power Flash mode or a lower power Torch mode using the TORCH/FLASH pin. A programmable Timeout function on the FTO pin forces the internal NFETs to turn off after a certain user defined time. An external SD pin (LM3551) or EN pin (LM3552) is available to put the device into low power shutdown mode. During shutdown, the feedback resistors and the load are disconnected from the input to avoid leakage current paths to ground.

User programmable soft-start circuitry has been integrated to eliminate large inrush currents at start-up. Over-voltage protection circuitry and a 1.25MHz switching frequency allow for the use of small, low-cost output capacitors with lower voltage ratings.

The LM3551 and LM3552 are available in a low profile 14 pin LLP package.

Reliability Metrics

Part Number Process EFR Reject EFR Sample Size PPM * LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM3551SDABCD1500282800029740002843880620
LM3551SDXABCD1500282800029740002843880620

Note: The Early Failure Rates were calculated as point estimates. 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.


More Application Notes

TitleSize in Kbytes Date Click link below to Download
AN-1495: Application Note 1495 LM3552 White LED Flash Driver Evaluation Board 626 Kbytes 27-Sep-06 Download
AN-1495 (Chinese): Application Note 1495 LM3552 White LED Flash Driver Evaluation Board
 208 Kbytes  
AN-1780: Application Note 1780 LM3553 1.2A Dual Flash LED Driver System with I2C Compatible Interface 1427 Kbytes 12-Mar-08 Download

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

[Information as of 20-Nov-2008]