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National Semiconductor’s New Stereo Headphone Amplifier Doubles Audio Playback Time for Portable Devices

PowerWise Class G Amplifier Provides Industry’s Lowest Power Consumption

Apr 6, 2009

April 6, 2009 – A new PowerWise® stereo headphone amplifier from National Semiconductor Corp. (NYSE:NSM) draws only 0.9 mA (typical) of quiescent current to double the audio playback time of smart phones, full-featured mobile phones and portable music players.

The LM48824’s Class G architecture significantly increases audio (MP3, mobile TV, etc.) playback time with its adaptive power supply approach that enables very low supply rails, which doubles the power-efficiency compared to typical Class AB headphone amplifiers. Additionally, the LM48824’s output noise created by ground mismatches is improved through common-mode sensing that corrects for differences between the amplifier ground and the headphone return terminal.

Key Technical Features – LM48824 Class G Stereo Headphone Amplifier
The LM48824 is offered in an ultra-small, 16-bump, 1.7 mm by 1.7 mm, 0.4 mm-pitch micro SMD package. It features National’s ground-referenced architecture, which saves space and minimizes system cost by eliminating the need for bulky and expensive DC blocking capacitors. The LM48824 includes a 32-step I2C compatible volume control with mute and delivers 37 mW per channel into a 16-Ohm load with less than one percent total harmonic distortion plus noise (THD+N) at 3.6V.

The LM48824’s high power supply rejection ratio (PSRR) of 105 dB at 217 Hz enables the device to operate in noisy environments without additional power supply conditioning. Its high-output impedance mode allows the LM48824’s outputs to be driven by an external source without degrading the signal.

Pricing and Availability
Available now, the LM48824 is priced at $1.06 each in 1,000-unit quantities.For more information, or to order samples and an evaluation board, visit http://www.national.com/pf/LM/LM48824.html.

Note to editors: To view a high-resolution downloadable photo of this product, visit National's photo gallery.

About National’s Audio Portfolio
National Semiconductor has been a leading provider of audio solutions for more than 30 years and offers a wide range of products in its Boomer®, Overture® and high-performance audio lines. National works with every major handset maker in the world and is the leading provider of analog audio solutions for the cell phone market. The company's line of Boomer audio amplifiers and subsystems enhance and enrich the entire range of sound – from voice, ring sounds and music – that can be amplified in mobile phones and other portable equipment. National manufactures Class AB and Class D speaker amplifiers, headphone amplifiers and audio subsystems for many applications ranging from portable devices to high-power, high-fidelity audio systems. The company offers its higher-power Overture amplifiers for mid-performance consumer applications, and National’s new high-performance series brings dramatically improved sound quality to high-fidelity consumer and professional audio equipment. For more information on National’s audio products, visit http://www.national.com/audio.

About National Semiconductor
National Semiconductor creates energy-efficient analog and mixed-signal semiconductors. Its PowerWise® products enable systems that consume less power, extend battery life and generate less heat. Headquartered in Santa Clara, Calif., National reported sales of $1.89 billion for fiscal 2008 which ended May 25, 2008. Additional company and product information is available at www.national.com.