Phase Dimmable LED Drivers

NEW LM3450 Phase Dimmable LED Driver

National's LM3450 phase dimmable LED driver integrates active power factor correction and phase dimming decoding, and is ideal for dimmable LED fixture applications with output powers between 10W and 100W and accepts universal input voltages. The LM3450 features unique dynamic hold circuitry which allows for excellent dimming performance and an analog adjust pin to allow for differentiated features such as thermal foldback, interface to sensors, or dimmer range adjust.

LM3450 Key Features:

• Active power factor correction IC with phase dimmer decoder
• Unique dynamic hold circuitry allows for high performance, smooth, linear dimming without flicker
• 70:1 PWM decoded from phase dimmer
• Up to 100W output power
• Programmable dimming range
• Analog adjust pin allows for interface to sensors, thermal foldback, analog dimming, or dimmer range adjust
• TSSOP-16 package
• Over-voltage protection
• Feedback short circuit protection
• Compatible with both forward phase (TRIAC) and reverse phase dimmers
• Target Applications: Dimmable LED fixtures, 10W-100W output power
• 120VAC & 230VAC evaluation boards available

See all high-brightness LED drivers as parametric table

LM3445 TRIAC Dimmable LED Driver

The industry-leading LM3445 TRIAC dimmable offline LED driver solution is perfect for any application where an LED driver must interface to a standard triac wall dimmer. National's new TRIAC dimmable LED driver delivers a wide, uniform dimming range free of flicker, best-in-class dimming performance, and high efficiency—all while maintaining ENERGY STAR® power factor requirements in a typical application.
Conventional TRIAC dimmers are designed to interface to a resistive load (halogen or incandescent bulb), while today's LED driver solutions interfaced to a standard wall dimmer produce 120 Hz flicker of the LED and/or do not allow 100:1 dimming. National's LM3445 LED driver decodes the TRIAC chopped waveform and translates the signal to dim the LEDs, to achieve a full, wide dimming range, without flicker.

LM3445 Key Features:

• Application voltage range from 80 VAC to 270 VAC
• Angle detector/decoder enables wide (100:1) full range dimming
• Integrated 300Ω bleeder resistor to ensure proper TRIAC signal decoding
• Patent-Pending control architecture allows for constant ripple current which extends the life of the LEDs
• Scalable output current up to and greater than 1A
• Master/Slave control for uniform dimming across multi-channel applications
• Ideal dimming solution for MR16 & PAR20, PAR25, PAR30, PAR38 LED bulbs

Video: Learn more about Triac Dimming
and LM3445 LED Driver

Easy To Use

The LM3445 LED driver enables a direct replacement of incandescent or halogen lamp systems that are currently interfaced to a TRIAC dimmer without having to change the original infrastructure or sacrifice performance. In addition, the LM3445 and other switching controller (switcher) constant-current LED drivers are available in WEBENCH® LED Architect to allow for easy and quick design in.

Full Range Dimming Capability

The LM3445 LED driver offers 100:1 full range dimming capability, going from full light to nearly imperceptible light in a continuous range without being extinguished, and maintains a constant current to large strings of LEDs driven in series off of a standard line voltage.

Uniform Dimming Without Flicker

The LM3445 LED driver allows master-slave operation control in multi-chip solutions which enables a single TRIAC dimmer to control multiple strings of LEDs with smooth consistent dimming, free of flicker.

LM3445 TRIAC Dimmable LED Driver Design Resources

• LM3445 Product Folder
• RD-172 - LM3445 Off-Line TRIAC Dimmer LED Driver Reference Design
• RD-185 - 230 VAC Off-line TRIAC Dimmer Retrofit with 6 LEDs Reference Design
• LM3445 Eval Boards
• Power Designer #126 - Dimming Techniques for Switched-Mode LED Drivers (article)
• Fundamentals of LED Dimming Webinar at EETimes techonline (35 mins, registration required)

Video: Watch the Arrow Electronics
evaluation of the LM3445