Date: 06/12/2010

Dimmable LED driver for 10 Watt to 100 Watt LED lamps

National Semiconductor Corp. has introduced a new LED driver with phase-based dimming performance for high-brightness light-emitting diode (LED) applications. The LM3450 LED driver integrates active power factor correction (PFC) and phase dimming decoding to provide uniform, flicker-free illumination across a wide, programmable dimming range. LM3450 is designed to drive LED lamps in phase dimmable, 10 Watt to 100 Watt LED based lighting fixtures.

National says current dimmable LED drivers in the market do not always meet the minimum current requirement for forward phase or TRIAC-based dimmers, causing the dimmer to shut off or "misfire" during operation resulting in flicker, particularly at very low dimming levels. So the designer is forced to avoid burning lamps at low level of dimming.

National Semiconductor's LM3450 LED driver integrates hold circuitry to dynamically adjust the current through the phase dimmer and coupled with a programmable, intelligent dimming decoder enables full dimming range. The LM3450 LED driver also provides active power factor correction meeting Energy Star standards.

The phase dimming decoder uses programmable mapping from input to output to increase design flexibility. It also features a dynamic filter and variable sampling rate for a fast, smooth response to dimmer movement.
Other benefits include an analog adjust input to allow for differentiation such as thermal foldback, interface to sensors or dimmer range adjustability.

The LM3450 can be implemented in either single stage or two stage configurations. The single stage configuration yields the smallest footprint and allows for the highest efficiency when converting from the AC mains voltage. The two stage configuration provides improved dimming performance and better noise immunity.

Price: Each $1.85 in 1K pieces
Availability: Now
Package: TSSOP

Editorial product rating: ** (Average Plus)