National Semiconductor Introduces Industry's First High-side Dual LED Flash Driver

PowerWise Synchronous Boost Converter Enables Thermally Optimized Flash System in Portable Devices

SANTA CLARA, Calif., June 29 /PRNewswire-FirstCall/ -- National Semiconductor Corp. (NYSE: NSM) today introduced the industry's first high-side light-emitting diode (LED) driver that enables dual LED operation for the camera flash function in portable, battery-powered multimedia devices. The LM3554, a member of National's PowerWise(R) energy-efficient product family, drives one or two high-current LEDs for flash applications in handheld devices such as mobile phones, smartphones and portable scanners.

Traditional LED flash drivers sink current from a single high-current LED back into the driver resulting in significant heat dissipation into the driver IC and reduced system reliability. The LM3554's dual LED, high-side current-drive architecture sources regulate current into two LEDs with cathodes connected directly to the ground. This ground connection provides more effective thermal dissipation while minimizing routing complexity and protecting sensitive circuitry. Due to nonlinearity of LED light output versus LED current, the dual LED architecture consumes less power for the same light output as a single LED. In addition, monitoring pins enable detection of other high current demands in the system, adaptively throttling the LED current to avoid drawing excessive battery current, which can cause faults or harm the system.

The LM3554 is offered in a 16-pin micro SMD package. A complete boost converter solution for LED flash using National's LM3554 measures less than 23 mm squared.

Technical Features of National's LM3554 LED Driver

National's LM3554 flash LED driver is a fixed-frequency, step-up DC-DC converter with two regulated current sources capable of driving loads up to 1.2A from a single-cell Li-Ion battery.

The LM3554 drives the LEDs in a high-power flash mode for still photography or a low-power torch mode for video recording. To configure the driver, designers can adjust the flash current levels and timer durations via an I2C compatible interface. The LM3554 features built-in time-out protection to protect the flash LEDs in case of a fault condition.

National's LM3554 features an adjustable switch current limit for the use of small inductors with low saturation currents. The voltage mode offers a 5V rail, which can be used for backlight LEDs and audio amplifier supplies. One or more high-current LEDs can be driven either in a high-power flash mode or a lower-power torch mode controlled by either an internal register or the strobe and TX pins. A GPIO pin adds a separate hardware control resource to the system. The hardware reset pin offers full control over the device in the case of I2C communication failure. Additional features include internal soft-start to eliminate large in-rush currents during start-up and fast switching frequency, allowing for the use of small external components.

For more information on the LM3554 or to order samples or an evaluation board, visit http://www.national.com/pf/LM/LM3554.html.

Availability and Pricing

National's LM3554 is available now and is priced at $2.32 in 1,000-unit quantities. More information about National's LED drivers is available at http://www.national.com/led.

About National Semiconductor

National Semiconductor is a leader in analog power management technology. Its products include easy-to-use integrated circuits, PowerWise products that enable more energy-efficient systems, and SolarMagic products which improve the energy output of solar arrays. The company celebrates its 50th anniversary this year. Headquartered in Santa Clara, Calif., National reported sales of $1.46 billion for fiscal 2009. Additional information is available at www.national.com.

National Semiconductor and PowerWise are registered trademarks of National Semiconductor Corporation. All other trademarks are the property of their respective owners.

    Media Contact
    Gayle Bullock
    National Semiconductor
    (408) 721-2033
    gayle.bullock@nsc.com

    Reader Information
    Design Support Group
    National Semiconductor
    (800) 272-9959
    www.national.com

Web site: http://www.national.com/

Featured Video
Editorial
Jobs
Mechanical Engineer for PTEC Solutions at Fremont, California
Upcoming Events
RAPID + TCT 2024 at Anaheim Convention Center Anaheim CA - Jun 25 - 27, 2024
IMTS 2024 – The International Manufacturing Technology Show at McCormick Place 2301 S Lake Shore Dr Chicago IL - Sep 9 - 14, 2024
FABTECH Orlando 2024 at Orange County Convention Center Orlando FL - Oct 15 - 17, 2024
TIMTOS 2025 at Nangang Exhibition Center Hall 1 & 2 (TaiNEX 1 & 2) TWTC Hall Taipei Taiwan - Mar 3 - 8, 2025



© 2024 Internet Business Systems, Inc.
670 Aberdeen Way, Milpitas, CA 95035
+1 (408) 882-6554 — Contact Us, or visit our other sites:
AECCafe - Architectural Design and Engineering EDACafe - Electronic Design Automation GISCafe - Geographical Information Services TechJobsCafe - Technical Jobs and Resumes ShareCG - Share Computer Graphic (CG) Animation, 3D Art and 3D Models
  Privacy PolicyAdvertise