National Semiconductor listed high brightness LED constant current buck regulator with maximum drive efficiency of 95%

National Semiconductor (National Semiconductor) listed the constant current buck regulator with high brightness LED. Including 1W LED with "LM3402", 3W LED "LM3404" and 5W LED "LM3405" a total of 3 models. These new products reduce the power loss by reducing the reference voltage. From general purpose to industrial and automotive applications, for a variety of LED lighting.

LM3402 can output maximum 525mA drive current. Maximum drive efficiency up to 95%. Enable terminal with adjustable brightness through PWM input. The reference voltage for current sensing is 0.2V. The input voltage range is from 6 to 42V. The model also includes the same performance, the input voltage range of 6 ~ 75V "LM3402HV".

LM3404 and LM3402 have the same function, can output the maximum 1.2A drive current. Like LM3402, the model also includes an input voltage range of 6 to 75V "LM3404HV". LM3404 and LM3404HV are able to drive 3W and 5W with 700mA and 1A currents by LED.

LM3405 can output maximum 1A drive current. The model also includes an internal set of switching frequencies of 550kHz "LM3405Y" and 1.6MHz "LM3405X"". Input voltage range of 3 ~ 22V, with internal compensation function. Enable/DIM terminal with PWM brightness adjustment.

LM3402 has begun mass production. 8 pin Mini SOIC package. 1000 bulk purchase price of $1.35, LM3402HV $1.65. LM3404 has begun to supply samples, scheduled to start production in November 2006. 8 pin SOIC NARROW package. LM3405 is scheduled to begin in November to supply samples, in January 2007 began mass production. With 8 pin Mini SOIC package and a 6 pin Thin SOT23 package.