Texas Instruments LM3448

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 phaseTRIAC 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 VCC under voltage lockout.

Features

• Input phase angle dim decoder circuit for LED dimming
• Integrated, vertical 600V MOSFET with superior avalanche energy capability
• Application voltage range 85VAC – 265VAC
• 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

Typical applications

• Residential Lighting
• Solid State Lighting
• Industrial Lighting
• Commercial Lighting

More information

• Datasheet
• IC product information