austriamicrosystems announces new smartphone LCD backlight LED drivers with the industry's highest efficiency and smallest PCB area

The AS3674 and AS3490 inductive boost converters enable 90% peak efficiency and 60% reduction in PCB area

(PresseBox) ( Unterpremstaetten, Austria, )
austriamicrosystems (SIX: AMS), a leading global designer and manufacturer of high-performance analog ICs, has announced the AS3674 and AS3490 LED backlight drivers for smartphone LCD displays. These new LED drivers enable the industry's best application efficiency at a peak level of 90%, including the DC-DC converter and the current sources. With a PCB footprint of only 11.5 mm², and just four external components required, the AS3674 and AS3940 are well suited for smartphones and other mobile devices where space is at a premium.

The AS3674 backlight driver family complements austriamicrosystems' large portfolio of lighting management units which address backlight, smart light and ALS (ambient light sensing) processing inside a single IC. The AS3674 is a highly efficient 2 MHz DC-DC switch mode step-up converter controlling 5 current sources with each driving 2 LEDs in series. For added flexibility, the current for the LED channels can be set by an external resistor with a maximum of 25 mA per channel. The AS3490 incorporates the same functionality as the AS3674 but addresses only three LED channels.

A soft startup feature allows the AS3674 to be easily integrated into noise sensitive RF systems. The AS3674 is controlled by two enable inputs which can also serve as PWM inputs between 100 Hz and 800 Hz with 1:2000 dimming ratio. The 2 LED per channel configuration combined with the 2 MHz operating frequency of the converter allow the use of tiny external components such as a 4.7 AH coil and results in very high efficiency, up to 6% higher than the closest competitor.

"Today's smartphones are power hungry miniature computers that use large displays with significant power requirements," said Ronald Tingl, Senior Marketing Manager Illumination at austriamicrosystems. "Yet smartphone manufacturers are challenged to extend the battery capacity and shrink the overall size of the phone. The AS3674 addresses these 2 challenges by offering the industry's highest efficiency with the smallest PCB area. In fact the total PCB area required is 60% smaller than today's commonly used single string LED backlight solutions."

The AS3674 operates from a 2.5 to 5.5 V power supply and includes a number of safety features such as undervoltage lockout, overcurrent and over-temperature protection and LED testing. Both the AS3674 and AS3490 are housed in space saving 12-ball WL-CSP package (1.7 x 1.4 x 0.5 mm, 0.4 mm pitch).

For more information on the AS3674 and AS3490 please visit and

Price & availability:

Samples of the AS3674 and AS3490 are available now. Please contact austriamicrosystems for pricing.

austriamicrosystems is exhibiting together with TAOS at Mobile World Congress in Barcelona, Feb 27 - March 1, 2012. Our industry is redefining "mobile". No longer limited only to communications, mobile is now a force transforming our world in an unprecedented way. Mobile connects, entertains, informs and inspires us, ultimately changing how we live and who we are. Mobile World Congress is the global epicenter of this redefinition as our participants enable, lead and accelerate it. Talk to the experts for Display and Lighting Management, Hall 2, Space H02.
The publisher indicated in each case is solely responsible for the press releases above, the event or job offer displayed, and the image and sound material used (see company info when clicking on image/message title or company info right column). As a rule, the publisher is also the author of the press releases and the attached image, sound and information material.
The use of information published here for personal information and editorial processing is generally free of charge. Please clarify any copyright issues with the stated publisher before further use. In the event of publication, please send a specimen copy to