TRIAC

+

+

BLDR

ASNS

ISNS

DIM

COFF

GND

VCC

FLTR1

GND

FLTR2

LM3448

SW

SW

SW

SW

BLDR

VCC

LED

LOAD

AC

INPUT

EMI

FILTER

COFF

LM3448

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SNOSB51B – SEPTEMBER 2011 – REVISED NOVEMBER 2011

LM3448 Phase Dimmable Offline LED Driver with Integrated FET

Check for Samples: LM3448

1

FEATURES

DESCRIPTION

The LM3448 is an adaptive constant off-time AC/DC

23

•

Input phase angle dim decoder circuit for LED

buck (step-down) constant current LED regulator

dimming

designed to be compatible with TRIAC dimmers. The

•

Integrated, vertical 600V MOSFET with

LM3448 provides a constant current for illuminating

superior avalanche energy capability

high power LEDs and includes a phase angle dim

decoder. The dim decoder allows wide range LED

•

dimming using standard forward and reverse phase

•

Adjustable switching frequency

TRIAC dimmers. The integrated high-voltage and low

•

Adaptive programmable off-time allows for

Rdson MOSFET reduces design complexity while

constant ripple current

improving LED driver efficiency. The integrated and

patented architecture facilitates implementation of

•

No 120Hz flicker possible

small form factor LED drivers suitable for integrated

•

Low quiescent current

LED lamps with very low external component count.

•

Thermal shutdown

The LM3448 also provides the flexibility required to

•

Low profile 16-pin Narrow SOIC package

implement both isolated and non-isolated solutions

based on the Flyback, Buck or Buck-Boost topology

•

Wave solder capable

using either active or passive power factor correction

(Valley-Fill)

circuits.

Additional

features

include

APPLICATIONS

•

Retrofit TRIAC Dimming

voltage lockout.

•

Solid State Lighting

•

Industrial and Commercial Lighting

•

Residential Lighting

Typical LM3448 LED Driver Application Circuit

Figure 1. Typical Application Circuit

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

TRI-STATE is a trademark of Texas Instruments.

3

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2011, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.