Phase Dimmable Offline Led Driver With Integrated Fet
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 in- cludes 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 architec- ture facilitates implementation of small form factor LED drivers suitable for integrated LED lamps with very low exter- nal component count. The LM3448 also provides the flexibility required to implement both isolated and non-isolated solu- tions 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.