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National Semiconductor’s Boomer Audio Amplifier Improves RF Suppression in Wireless Notebooks and Other Portable Devices

New Audio Amp Provides Cleaner Sound in Wireless Applications that Integrate WiFi Features

Apr 25, 2005

April 25, 2005 - National Semiconductor Corporation (NYSE:NSM) today introduced a new Boomer® audio amplifier that features innovative internal circuitry that suppresses RF signals from passing through the amplifier.  This is important because certain types of RF signals can create distracting noise that is heard through the speaker.  National’s LM4884 is designed to suppress strong RF signals and produce clean sound in notebook computers enabled with WiFi/802.11, GSM cards or modems.  The device also suppresses RF noise generated by cell phones or other wireless devices operating in close proximity to the notebook computer.

"Notebook designers and notebook users value audio solutions that not only sound great but can also help solve system problems,” said Mike Polacek, vice president of National Semiconductor’s Audio group.  “With our LM4884 Boomer audio amplifier, designers and consumers can enjoy high-quality audio output even in noisy wireless environments which are typical today.  National’s device provides up to a 28dB improvement in RF suppression over previous designs on the market.  Reducing RF issues will shorten design time and ensure high-quality audio performance for notebook PCs and portable electronic devices.” 

Innovative Audio
In addition to RF suppression circuitry, National’s LM4884 Boomer audio amplifier offers four flexible gain selections from 6dB to 21.6dB, using a two-bit gain select.  When operating on a single 5V supply, it delivers 1.2W, 1.9W or 2.1W (typical) of output power to an 8 Ohm, 4 Ohm or 3 Ohm bridge-tied load (BTL), respectively. The LM4884 delivers high-quality output power from a surface-mount package, requires few external components, has an active-low micropower shutdown mode input and provides thermal shutdown protection.

About National’s Audio Portfolio
National Semiconductor works with every major handset maker in the world and is the leading provider of audio amplifier systems for the cell phone market.  The company’s line of Boomer audio amplifiers enhances and enriches the entire range of sound – from voice to ring sounds and music – that can be amplified in a mobile phone.  National manufactures Class AB and Class D mono and stereo speaker amplifiers, mono and stereo headphone amplifiers, and audio subsystems for desktop and notebook computers, multimedia displays and portable electronic devices.  The company also offers its higher-power Overture® amplifiers for consumer stereo and home theater systems.  For more information on National’s audio products, visit http://audio.national.com

Understanding Notebook Systems
National Semiconductor offers a diverse analog product portfolio to surround current and next-generation notebook CPUs, chipsets and memory. National provides all the analog technology a computing system needs for excellent audio, display and video performance with faster, easier connectivity and increased battery life.  Using this system-level approach, National is partnering with customers to re-define system partitions that create unique features for their products.  More information on National’s notebook system is available at solutions.national.com.

Pricing and Availability
Available now in a 20-pin exposed-DAP TSSOP package, the LM4884 is priced at $1.40 in 1,000-unit quantities.  Lead-free package options are also available. More information on the LM4884 is available at http://www.national.com/pf/LM/LM4884.html
. A large selection of audio amplifiers is supported by National’s WEBENCH® online design tool.  To explore these solutions, visit http://webench.national.com.  To learn about high-performance audio amplifiers for portable applications, visit National’s library of online seminars.

Note to editors: To view a high-resolution downloadable photo of the new products, visit National's photo gallery

About National Semiconductor
National Semiconductor, the industry's premier analog company, creates high-performance analog devices and subsystems.  National's leading-edge products include power management circuits, display drivers, audio and operational amplifiers, communication interface products and data conversion solutions. National's key markets include wireless handsets, displays, PCs and laptops.  The company's analog products are also optimized for numerous applications in a variety of electronics markets, including medical, automotive, industrial, and test and measurement.  Headquartered in Santa Clara, California, National reported sales of $1.98 billion for fiscal 2004, which ended May 30, 2004.  Additional company and product information is available at www.national.com