New Family of LED Drivers to Power High-Brightness LEDs
Optimized for Industrial and Automotive LED Applications, New Family Provides Constant Current Through LEDs and Features Low Feedback Voltage to Minimize Power Dissipation
National Semiconductor have released a new family of light-emitting diode (LED) drivers designed to power the new generation of 1W to 5W, high-brightness LEDs found in automotive, industrial and general illumination applications.
National's LM3402, LM3404 and LM3405 LED drivers offer the wider input voltage range required by this fast-growing market segment.
In addition, National's new LED drivers provide a constant current to regulate the LED brightness and low feedback voltage to minimize power dissipation.
“National already offers a wide portfolio of LED drivers designed for low-power portable applications such as those in cell phones and PDAs,” said Mal Humphrey, product line director for the Power Management Group at National Semiconductor. “This new family of products extends that portfolio, using our higher voltage and current capabilities to address the high-brightness LED market as well.” “Today's feature-rich portable electronics need more efficient power management to maintain peak performance at all power levels,” said Peter Henry, vice president of National Semiconductor's Portable Power Products Group. “The LM3670 and LM3671 accomplish this by combining a tiny solution size with the highest efficiency and longest stand-by times to offer the most effective buck regulator solution for portable power solutions.”
Optimized for 1W LEDs, National offers two versions of the LM3402 LED driver that provide wide input voltage ranges of either 6V to 42V or 6V to 75V. For 3W and 5W LEDs, the LM3404 and LM3405 have additional output current drive capability.
Technical Features of the LED Drivers
The LM3402 is a compact, constant-current buck regulator with up to 95 percent efficiency that drives up to 525 mA of current. Offered in an 8-pin mini SOIC package, the LM3402 has an enable pin that also can be used for dimming via pulse-width modulation (PWM) inputs and a reduced feedback of 0.2V for current sensing. The LM3402's input voltage ranges from 6V to 42V. For higher input voltages, the LM3402HV offers the same features and a 6V-to-75V voltage range.
The company's Web site address is www.ti.com
[Reprinted with kind permission from National Semiconductor]