RoHS Compliance Information	Size in Kbytes	Date
LM3421 , LM3423 N-Channel Controllers for Constant Current LED Drivers	893 Kbytes	26-Jan-09	Download

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

Qty

$US each

LM3423MH

TSSOP EXP PAD

20

NOPB

1

260

RoHS

N/A

Full production

N/A

1K+

$1.75

rail of 73

NSUZXYTT LM3423 MH

6 weeks

N/A

LM3423MHX

TSSOP EXP PAD

20

NOPB

1

260

RoHS

N/A

Full production

N/A

1K+

$1.75

reel of 2500

NSUZXYTT LM3423 MH

6 weeks

N/A

LM3423MHBKBSTEV

LM3423 - Buck-Boost N-Channel Controllers for Constant Current LED Drivers

Full production

N/A

1+

$110.00

1

-

N/A

N/A

LM3423MHBSTEVAL

LM3423 - N-Channel Controllers for Constant Current LED Drivers from the PowerWise® Family

Full production

N/A

1+

$110.00

1

-

N/A

N/A

General Description

The LM3421/LM3423 devices are versatile high voltage LED driver controllers. With the capability to be configured in a Buck, Boost, Buck-Boost (Flyback), or SEPIC topology, and an input operating voltage rating of 75V, these controllers are ideal for illuminating LEDs in a very diverse, large family of applications.

Adjustable high-side current sense with a typical sense voltage of 100mV allows for tight regulation of the LED current with the highest efficiency possible. Output LED current regulation is based on peak current-mode control with predictive Off-Time Control. This method of control eases the design of loop compensation while providing inherent input voltage feed-forward compensation.

The LM3421/LM3423 include a high-voltage startup regulator that operates over a wide input range of 4.5V to 75V. The internal PWM controller is designed for adjustable switching frequencies of up to 2.0MHz, thus enabling compact solutions. Additional features include: “zero” current shutdown, precision reference, logic compatible DIM input suitable for fast PWM dimming, cycle-by-cycle current limit, and thermal shutdown.

The LM3423 also includes an LED output status flag, a fault flag, a programmable fault timer, and a logic input to select the polarity of the dimming output driver.

Application Notes

Title	Size in Kbytes	Date
AN-1907: Application Note 1907 LM3423 Buck-Boost Configuration Evaluation Board	879 Kbytes	8-Dec-08	Download
AN-1872: Application Note 1872 LM3423 Boost Evaluation Board	764 Kbytes	8-Dec-08	Download