Features • VIN operating range of 3V to 15V • Thin SOT23-6 package • 1.6MHz switching frequency • 300mΩ NMOS switch • 40nA shutdown current at VIN = 5V • EN/DIM input for enabling and PWM dimming of LEDs • Internally compensated current-mode control • Cycle-by-cycle current limit • Input voltage UVLO • Over-current protection • Thermal shutdown Description Integrated with a 1A power switch, the LM3405 is a current-mode control switching buck regulator 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 LM3405 utilizes current-mode control and internal compensation offering ease of use and predictable, high performance regulation over a wide range of operating conditions. 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. Applications • LED Driver • Constant Current Source • Industrial Lighting • LED Flashlights

Also Recommended LM3405A▲ Extended Input Voltage Range Up To 22V redraw to make it compact MY BRIEFCASE                                       Click any "Briefcase" icon to add an item

Typical Application click for larger image redraw to make it compact	Block Diagram click for larger image Simplified Internal Block Diagram, add IF and VOUT
Typical Performance click for larger image Efficiency vs. LED Current for Vin = 5V

Datasheet

Title		Size	Date	Other Language
	LM3405 1.6MHz, 1A Constant Current Buck Regulator for Powering LEDs	486 Kbytes	16-Feb-07	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-1590: Application Note 1590 LM3405 Demo Board	475 Kbytes	19-Mar-07
	AN-1644: Application Note 1644 Powering and Dimming High-Brightness LEDs with the LM3405 Constant-Current Buck Regulator	174 Kbytes	17-Jan-08

More Application Notes

Title		Size	Date	Other Language
	AN-103: Application Note 103 LM340 Series Three Terminal Positive Regulators	421 Kbytes	3-Oct-02
	AN-1545: Application Note 1545 LM3404/LM3404HV Evaluation Board	665 Kbytes	14-Aug-09	中文
	AN-1839: Application Note 1839 LM3402/LM3404 Fast Dimming and True Constant LED Current Evaluation Board	678 Kbytes	10-Dec-08	中文
	AN-1500: Application Note 1500 LM3402/02HV Demo Board	29977 Kbytes	5-Jun-07	中文
	AN-1899: Application Note 1899 LM3405A eMSOP Evaluation Board	442 Kbytes	6-Jul-09	中文
	AN-1585: Application Note 1585 LM3402 and LM3404 High Power PSOP-8 Evaluation Board	493 Kbytes	4-Oct-07
	AN-1192: Application Note 1192 Overture™ Series High Power Solutions	548 Kbytes	15-Jun-04
	AN-1982: Application Note 1982 Small, Wide Input Voltage Range LM2842 Keeps LEDs Cool	63 Kbytes	15-Jul-09
	AN-1657: Application Note 1657 LM3401 Demo Board	891 Kbytes	29-Jul-08	中文
	AN-127: Application Note 127 LM143 Monolithic High Voltage Operational Amplifier Applications	441 Kbytes	2-May-04
	AN-298: Application Note 298 Isolation Techniques for Signal Conditioning	379 Kbytes	2-Oct-02
	AN-182: Application Note 182 Improving Power Supply Reliability with IC Power Regulators	27 Kbytes	3-Oct-02
	AN-1763: Application Note 1763 LM3407 Evaluation Board Reference Design	421 Kbytes	21-Jan-09	中文
	AN-181: Application Note 181 3-Terminal Regulator Is Adjustable	165 Kbytes	1-May-04
	AN-1853: Application Note 1853 COT Drivers Control LED Ripple Current	158 Kbytes	23-Sep-08
	AN-1954: Application Note 1954 LM3409 Demonstration Board	762 Kbytes	20-Nov-09	中文
	AN-1750: Application Note 1750 LM3406 Evaluation Board	481 Kbytes	9-Sep-08
	AN-1685: Application Note 1685 LM3405A Demo Board	907 Kbytes	19-Oct-07	中文
	AN-1148: Application Note 1148 Linear Regulators: Theory Of Operation and Compensation	200 Kbytes	10-May-04	日本語 中文
	AN-1529: Application Note 1529 LM3430 Evaluation Board	2770 Kbytes	21-Aug-07	中文

Design Tools

Title	Size	Date
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Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM3405XMK	PVIP050	0	9960	0	0	855000	5	242608584
LM3405XMKX	PVIP050	0	9960	0	0	855000	5	242608584

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.

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