National Semiconductor Launches Phase-Dimmable LED Driver

National Semiconductor has introduced a new LED driver for high-brightness LEDs (HB LED) applications. The LM3450 LED driver integrates phase-dimming decoding and active power factor correction over a broad range of programmable dimming to offer an even, flicker-free dimming.

The LM3450 LED driver is part of the PowerWise product line and is suitable for phase-dimmable 10-100 W LED fixtures. The LED driver incorporates hold circuitry to fine-tune the current dynamically via the phase dimmer. The combination of an intelligent, programmable dimming decoder and the dynamic hold circuitry enables consistent, even lighting over the entire dimming range.

The active power factor correction aids in maintaining a high power factor that fulfills the commercial and residential Energy Star standards. The LM3450 maintains an improved power factor at the input level and regulates a precise output. In order to dim the LEDs, the phase dimming decoder deduces and remaps the phase angle into a pulse width modulation output of 500 Hz. These features facilitate the implementation of a phase-dimmable off-line driver for loads of 10-100 W.