LM3405 - 1.6MHz 1A Constant Current Buck Regulator for Powering LEDs

LM3405 - 1.6MHz 1A Constant Current Buck Regulator for Powering LEDs from the PowerWise® Family

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

Features

•	V_IN operating range of 3V to 15V
•	Thin SOT23-6 package
•	1.6MHz switching frequency
•	300mΩ NMOS switch
•	40nA shutdown current at V_IN = 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

General 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. More...

Applications

•	LED Driver
•	Constant Current Source
•	Industrial Lighting
•	LED Flashlights

Typical Application

click for larger image

redraw to make it compact

Parameters Values

Topology Buck

Input Min Voltage 3 Volt

Input Max Voltage 15 Volt

Output Range 0.2V to 13.5V

Output Current 1000 mA

Efficiency (peak) 92 %

Output Min 0.2 Volt

Output Max 13.5 Volt

Adjustable Output Yes

On/Off Pin Yes

Error Flag No

Adj Switch Frequency No

Sync Pin No

Step-Down Yes

RegType Switching Regulator

Temperature Min -40 deg C

Temperature Max 125 deg C

Feedback Voltage 0.2 Volt

PowerWise Yes

Typical Performance

click for larger image

Efficiency vs. LED Current for Vin = 5V

Also Recommended

LM3405A▲

Extended Input Voltage Range Up To 22V

Additional Resources

Design Tools

Application Notes

Block Diagram

click for larger image

Simplified Internal Block Diagram, add IF and VOUT

Datasheet

RoHS Compliance Information	Size in Kbytes	Date
LM3405 1.6MHz, 1A Constant Current Buck Regulator for Powering LEDs	486 Kbytes	16-Feb-07	Download
LM3405 1.6MHz, 1A Constant Current Buck Regulator for Powering LEDs (Japanese)	757 Kbytes

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

Package Availability, Models, Samples & Pricing

Part Number

Package

Factory Lead Time

Models

Samples &
Electronic
Orders

Budgetary Pricing

Std
Pack
Size

Package
Marking
Format

Type

Pins

Spec.

MSL
Rating

Peak
Reflow

RoHS
Report

CAD
Symbols

Weeks

Qty

$US each

LM3405XEVAL

1.6MHz, 1A Constant Current Buck Regulator for Powering LEDs

Full production

N/A

$40.50

8 weeks

N/A

LM3405XMK

TSOT

NOPB

260

RoHS

Download

Full production

N/A

1K+

$1.05

reel
of
1000

SPNB
XTT

6 weeks

5000

LM3405XMKX

TSOT

NOPB

260

RoHS

Download

Full production

N/A

1K+

$1.05

reel
of
3000

SPNB
XTT

6 weeks

7500

General 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.

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.

For more information on Reliability Metrics, please click here.

Design Tools

Title	Size in Kbytes	Date
Article - Contact us for questions on this product			View

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

Application Notes

Title	Size in Kbytes	Date
AN-1590: Application Note 1590 LM3405 Demo Board	475 Kbytes	19-Mar-07	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

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

More Application Notes

Title	Size in Kbytes	Date
AN-103: Application Note 103 LM340 Series Three Terminal Positive Regulators	421 Kbytes	3-Oct-02	Download
AN-1545: Application Note 1545 LM3404/LM3404HV Evaluation Board	665 Kbytes	14-Aug-09	Download
AN-1545 (Chinese): Application Note 1545 LM3404/LM3404HV Evaluation Board	493 Kbytes
AN-1839: Application Note 1839 LM3402/LM3404 Fast Dimming and True Constant LED Current Evaluation Board	678 Kbytes	10-Dec-08	Download
AN-1839 (Chinese): Application Note 1839 LM3402/LM3404 Fast Dimming and True Constant LED Current Evaluation Board	746 Kbytes
AN-1500: Application Note 1500 LM3402/02HV Demo Board	29977 Kbytes	5-Jun-07	Download
AN-1500 (Chinese): Application Note 1500 LM3402/02HV Demo Board	531 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
AN-1585: Application Note 1585 LM3402 and LM3404 High Power PSOP-8 Evaluation Board	493 Kbytes	4-Oct-07	Download
AN-1192: Application Note 1192 Overture™ Series High Power Solutions	548 Kbytes	15-Jun-04	Download
AN-1982: Application Note 1982 Small, Wide Input Voltage Range LM2842 Keeps LEDs Cool	63 Kbytes	15-Jul-09	Download
AN-1657: Application Note 1657 LM3401 Demo Board	891 Kbytes	29-Jul-08	Download
AN-1657 (Chinese): Application Note 1657 LM3401 Demo Board	351 Kbytes
AN-127: Application Note 127 LM143 Monolithic High Voltage Operational Amplifier Applications	441 Kbytes	2-May-04	Download
AN-298: Application Note 298 Isolation Techniques for Signal Conditioning	379 Kbytes	2-Oct-02	Download
AN-182: Application Note 182 Improving Power Supply Reliability with IC Power Regulators	27 Kbytes	3-Oct-02	Download
AN-1763: Application Note 1763 LM3407 Evaluation Board Reference Design	421 Kbytes	21-Jan-09	Download
AN-1763 (Chinese): Application Note 1763 LM3407 Evaluation Board Reference Design	531 Kbytes
AN-181: Application Note 181 3-Terminal Regulator Is Adjustable	165 Kbytes	1-May-04	Download
AN-1853: Application Note 1853 COT Drivers Control LED Ripple Current	158 Kbytes	23-Sep-08	Download
AN-1954: Application Note 1954 LM3409 Demonstration Board	607 Kbytes	11-Jun-09	Download
AN-1954 (Chinese): Application Note 1954 LM3409 Demonstration Board	502 Kbytes
AN-1750: Application Note 1750 LM3406 Evaluation Board	481 Kbytes	9-Sep-08	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-1148: Application Note 1148 Linear Regulators: Theory Of Operation and Compensation	200 Kbytes	10-May-04	Download
AN-1148 (Japanese): Application Note 1148 Linear Regulators: Theory Of Operation and Compensation	216 Kbytes
AN-1148 (Chinese): Application Note 1148 Linear Regulators: Theory Of Operation and Compensation	396 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 7-Nov-2009]