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National Semiconductor Enables High-Fidelity Stereo Voice Output in Microphone Applications

Two New Amplifiers Use Digital Voice Technology to Dramatically Improve Microphone Sound Quality in Handsets and Other Portable, Wireless Applications

Mar 14, 2005

CTIA, NEW ORLEANS, LA - March 14, 2005 - National Semiconductor Corporation (NYSE:NSM) today introduced two new amplifiers that put high-fidelity sound quality directly inside electret condenser microphones (ECMs).  Previously, the large size and high cost associated with this effort kept manufacturers from implementing digital voice technology in wireless products.  National overcame the size-and-cost barrier with the LMV1024 and LMV1026 by putting the digital modulation and gain inside the microphone to dramatically improve sound quality.  By integrating several components and simplifying routing, National's "digital voice-in-a-mic" technology produces superior sound quality, reduces overall system cost and enables the smallest possible form factor.

“With mixed-signal capability so small that it fits inside existing ECMs, National’s LMV1024 and LMV1026 amplifiers provide 20 KHz CD-quality stereo sound, which has never before been achieved in this form factor,” said Erroll Dietz, vice president of National Semiconductor’s Amplifier products group.  “By integrating the sigma-delta codec, the amplifier, regulator and several filter components inside the existing 6 mm ECM, National reduces the size of the overall solution and provides simplified system design for the customer.”

National Continues to Revolutionize Amplifier Technology
The introduction of National’s LMV1024 and LMV1026 amplifiers with digital voice technology follows the company’s successful portfolio of analog “amp-in-a-mic” products, the LMV1012 and LMV1032.  These products transformed the market by replacing the decades-old junction field effect transistor (JFET), dramatically improving audio performance and sensitivity in 2- and 3-wire ECMs.  Integrating digital output at the microphone is the second step in National’s strategy of enabling the world’s first 4-wire ECM with built-in gain and sigma-delta modulation to deliver the best possible audio fidelity.  Applications using this technology are microphones in mobile handsets, PDAs and other portable, wireless applications.  For more information on National’s microphone amplifier technology, visit http://www.national.com/appinfo/amps/microphone.html

LMV1024 and LMV1026
National designed the LMV1024 and LMV1026 by integrating the amplifier and sigma-delta modulator inside an ECM.  These next-generation microphone amplifiers produce an over-sampled single bit stream that connects directly to a DSP in a digital audio system.  These amplifiers allow the user the flexibility of adjusting clock frequency ranging between 1 to 3.25 MHz. 

The LMV1024and LMV1026 are designed for very robust signal-to-noise ratio (SNR) and acoustic audio sensing.  The output of an ECM eliminates sensitive, low-level analog signals that form the output of a conventional JFET ECM.  System design routing and layout is simplified due to integration of external components.  The analog-to-digital conversion of the LMV1024/26 enables customers to design high-performance stereo microphone subsystems. 

National's LMV1024 and LMV1026 amplifiers will be shown in National's booth #6645 at the CTIA tradeshow in New Orleans, Louisiana, from March 14-16.

About National’s Amplifier Portfolio
National Semiconductor, a leader in high-performance amplifiers and comparators, offers a complete portfolio of op amps ranging from building-block chips to application specific standard products (ASSPs), including precision, high-speed, low-power and low-voltage amplifiers. The company has a long history of innovation, including the first low-voltage op amp, the "amp-in-a-mic,” and the world's fastest laser diode driver.  National ships more than 500 million operational amplifiers per year.

National also has led the industry in packaging technology with the introduction of revolutionary Silicon Dust™ and micro SMD packaging technologies. In addition, National's patented VIP10 process technology enables it to create the industry's broadest suite of high-performance op amps available today.   For more information on National’s amplifier products, visit http://www.amplifiers.national.com.

Pricing and Availability
Sampling now in limited quantities, the LMV1024 and LMV1026 are offered in 6-bump micro SMD packages.  The LMV1024 and LMV1026 are each priced at $0.81 in 1,000-unit quantities.  More information on the LMV1024 is available at http://www.national.com/pf/LM/LMV1024.html
and more information on the LMV1026 is available at http://www.national.com/pf/LM/LMV1026.html.  A large selection of amplifiers is supported by National’s Amplifiers Made SimpleSM WEBENCH® online design tool.  To explore these solutions, visit http://webench.national.com.  To learn more about designing with amplifiers, visit National’s library of online seminars

Note to editors: To view a high-resolution downloadable photo of these 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.