LM3405A - 1.6MHz, 1A Constant Current Buck LED Driver with Internal Compensation in Tiny SOT23 and eMSOP Package from the PowerWise® Family
Datasheet Packaging Samples & Pricing Eval. Boards Reliability Reference Designs Application Notes Knowledge Base

Features
VIN operating range of 3V to 22V
Drives up to 5 High-Brightness LEDs in series at 1A
Thin SOT23-6 package & eMSOP8 with exposed DAP
1.6MHz switching frequency
EN/DIM input for enabling and PWM dimming of LEDs
300mΩ NMOS switch
40nA shutdown current at VIN = 5V
Internally compensated current-mode control
Cycle-by-cycle current limit
Input voltage UVLO
Over-current protection
Thermal shutdown

General Description


The LM3405A is a 1A constant current buck LED driver designed to provide a simple, high efficiency solution for driving high power LEDs. More...


Applications


LED Driver
Constant Current Source
Industrial Lighting
LED Flashlights
LED Lightbulbs
  Typical Application
click for larger image

Series zener diode from Vin

ParametersValues
Topology Buck
Input Min Voltage 3 Volt
Input Max Voltage 22 Volt
Output Range 0.2V to 20V
Output Current 1000 mA
Efficiency (peak) 92 %
Output Min 0.2 Volt
Output Max 20 Volt
Adjustable Output Yes
On/Off Pin Yes
Error Flag No
Switching Frequency 1600 kHz
Adj Switch Frequency No
Sync Pin No
Step-Down Yes
Step-Up No
Inverting No
Flyback No
RegType Switching Regulator
Temperature Min -40 deg C
Temperature Max 125 deg C
Feedback Voltage 0.2 Volt
Automotive Yes
PowerWise Yes


Typical Performance


click for larger image

Efficiency vs. LED Current for Vin = 12V, 1 and 2 LEDs
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LM3405A

 
3.00 <=
V in Lower
 V
 
<=
V in Upper
 V
 
<= 22.00
Ambient Temperature  °C <= 100


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Additional Resources
Application Notes


Block Diagram


click for larger image

temporary

Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM3405A 1.6MHz, 1A Constant Current Buck LED Driver with Internal Compensation in Tiny SOT23 and eMSOP Package 516
Kbytes
23-Oct-08 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
LM3405AXMKETSOT6NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now
1K+$1.10reel
of
250
SSEB
XTT
6 weeksN/A
LM3405AXMKTSOT6NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now
1K+$1.10reel
of
1000
SSEB
XTT
6 weeksN/A
LM3405AXMKXTSOT6NOPB1260RoHS N/A Full productionN/A
 
Buy Now
1K+$1.10reel
of
3000
SSEB
XTT
6 weeksN/A
LM3405AXMYMINI SOIC EXP PAD8NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now
1K+$1.20reel
of
1000
ZXTT
SVSA
6 weeksN/A
LM3405AXMYXMINI SOIC EXP PAD8NOPB1260RoHS N/A Full productionN/A
 
Buy Now
1K+$1.20reel
of
3500
ZXTT
SVSA
6 weeksN/A
LM3405AEVAL1.6MHz, 1A Constant Current Buck LED Driver with Internal Compensation in Tiny SOT-23 PackageFull productionN/A
 
Buy Now
1+$45.001-
8 weeksN/A
LM3405AXMYEVALLM3405AXMY - 1.6 MHz, 1A Constant Current Buck LED Driver with Internal Compensation in eMSOP PackageFull productionN/A
 
Buy Now
1+$55.001-
8 weeksN/A

General Description


The LM3405A is a 1A constant current buck LED driver designed to provide a simple, high efficiency solution for driving high power LEDs. With a 0.205V reference voltage feedback control to minimize power dissipation, an external resistor sets the current as needed for driving various types of LEDs. Switching frequency is internally set to 1.6MHz, allowing small surface mount inductors and capacitors to be used. The LM3405A utilizes current-mode control and internal compensation offering ease of use and predictable, high performance regulation over a wide range of operating conditions. With a maximum input voltage of 22V, it can drive up to 5 High-Brightness LEDs in series at 1A forward current, with the single LED forward voltage of approximately 3.7V. Additional features include user accessible EN/DIM pin for enabling and PWM dimming of LEDs, thermal shutdown, cycle-by-cycle current limit and over-current protection.

Reliability Metrics


Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM3405AXMKPVIP05009960008550005242608584
LM3405AXMKEPVIP05009960008550005242608584
LM3405AXMKXPVIP05009960008550005242608584
LM3405AXMYPVIP05009960008550005242608584
LM3405AXMYXPVIP05009960008550005242608584

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.



Reference Designs
RD-148 - LM3405A Reference Design for MR16 LED Bulb, 600mA

Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1685: Application Note 1685 LM3405A Demo Board 907
Kbytes
19-Oct-07 Download
AN-1685 (Chinese): Application Note 1685 LM3405A Demo Board
478 Kbytes  
AN-1899: Application Note 1899 LM3405A eMSOP Evaluation Board 442
Kbytes
6-Jul-09 Download
AN-1899 (Chinese): Application Note 1899 LM3405A eMSOP Evaluation Board
289 Kbytes  

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More Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1644: Application Note 1644 Powering and Dimming High-Brightness LEDs with the LM3405 Constant-Current Buck Regulator 174
Kbytes
17-Jan-08 Download
AN-1590: Application Note 1590 LM3405 Demo Board 475
Kbytes
19-Mar-07 Download

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

[Information as of 7-Nov-2009]