LM3448 Datasheet, PDF (1/43 Pages) Texas Instruments – Phase Dimmable Offline LED Driver with Integrated FET

LM3448
www.ti.com
SNOSB51B – SEPTEMBER 2011 – REVISED NOVEMBER 2011
LM3448 Phase Dimmable Offline LED Driver with Integrated FET
Check for Samples: LM3448
FEATURES
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•23 Input phase angle dim decoder circuit for LED
dimming
• Integrated, vertical 600V MOSFET with
superior avalanche energy capability
• Application voltage range 85V_AC – 265V_AC
• Adjustable switching frequency
• Adaptive programmable off-time allows for
constant ripple current
• No 120Hz flicker possible
• Low quiescent current
• Thermal shutdown
• Low profile 16-pin Narrow SOIC package
• Wave solder capable
APPLICATIONS
• Retrofit TRIAC Dimming
• Solid State Lighting
• Industrial and Commercial Lighting
• Residential Lighting
DESCRIPTION
The LM3448 is an adaptive constant off-time AC/DC
buck (step-down) constant current LED regulator
designed to be compatible with TRIAC dimmers. The
LM3448 provides a constant current for illuminating
high power LEDs and includes a phase angle dim
decoder. The dim decoder allows wide range LED
dimming using standard forward and reverse phase
TRIAC dimmers. The integrated high-voltage and low
Rdson MOSFET reduces design complexity while
improving LED driver efficiency. The integrated and
patented architecture facilitates implementation of
small form factor LED drivers suitable for integrated
LED lamps with very low external component count.
The LM3448 also provides the flexibility required to
implement both isolated and non-isolated solutions
based on the Flyback, Buck or Buck-Boost topology
using either active or passive power factor correction
(Valley-Fill) circuits. Additional features include
thermal shutdown, current limit and V_CC under-
voltage lockout.
Typical LM3448 LED Driver Application Circuit
EMI
FILTER
TRIAC
AC
INPUT
LM3448
DIM
FLTR1
COFF
ASNS
FLTR2
VCC
GND
GND
ISNS
BLDR
SW
SW
SW
SW
+
+
BLDR
VCC
LED
LOAD
COFF
Figure 1. Typical Application Circuit
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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.
TRI-STATE is a trademark of Texas Instruments.
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All other trademarks are the property of their respective owners.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2011, Texas Instruments Incorporated