Date: 19/10/2006

National Semiconductor's LM340X series can drive 1W to 5W rated LEDs for illumination applications

As LED illumination market is growing faster, National releases set of new LED drivers to take on high current load of high-brightness LEDs. They provide constant current and low feedback voltage to minimize power dissipation.

LM3402 can drive 525 mA of current, designed for 1W LEDs. Basically a buck regulator with peak efficiency of 95%. The output voltage can be varied for dimming the LED through Pulse Width Modulation.
I/P Voltage range is 6V to 42 V, but LM3402HV can work up to 75V
Package: 8pin mini SOIC
Availability: Now in samples and in production volumes.
Price: LM3402 -- $1.35
LM3402H-- $1.65
in 1K order quantity

LM3404 is same as LM3402 except for the current rating 0f 1.2 A and designed for 3W and 5W LEDs.
Package: 8 pin narrow SOIC
Availability: Now in samples and production volumes in November.