February 26, 2001 - National Semiconductor Corporation (NYSE:NSM), furthering its technology leadership in the audio arena, today announced another first, the LM4867 Boomer? amplifier, the world's first truly noise-free 2.1W stereo amplifier with headphone mode. Featuring National's patent-pending technology, the LM4867 provides popless, clickless operation, meaning that there are no sound artifacts when the amplifier is turned on or off. This product is ideal for a number of portable audio systems, including notebook computers and PDAs, as well as desktop computer applications.
"Not only does the new circuit topology of the LM4867 eliminate unnecessary popping, clicking and general noise typically associated with Class AB amplifiers, but it also eliminates the need for expensive headphone output coupling capacitors, providing significant cost and space savings to the customer," said Steve Kaufman, marketing manager for National's audio amplifier product group. "The LM4867 offers the market's only completely noise-free solution in a small package at a competitive price."
National's LM4867 is a dual bridge-connected audio power amplifier which, when connected to a 5V supply, will deliver 2.1W to a 4 Ohm load or 2.4W to a 3 Ohm load with less than 1.0% THD+N. The LM4867 uses patent-pending technology to eliminate all traces of clicks and pops when the supply voltage is first applied. The amplifier also has a headphone mode sense input pin, which is used to switch the amplifiers from bridge to single-ended mode for driving headphones.
A new circuit topology in the LM4867 eliminates headphone output coupling capacitors, and a MUX control pin allows selection between the two sets of stereo input signals. The MUX control can also be used to select between two different customer-specified closed-loop responses.
In order to simplify audio system design, National's LM4867 Boomer amplifier combines dual bridge speaker amplifiers and stereo headphone amplifiers in one package. The LM4867 also features an externally controlled power-saving micropower shutdown mode, a stereo headphone amplifier mode and thermal shutdown protection. The LM4867 will be shown at the Intel Developer Forum from February 26 - March 1, 2001 in National Semiconductor's Booth #809 at the San Jose Convention Center in San Jose, California.
Pricing and Availability
The LM4867 is available now in LLP, TSSOP and exposed-DAP TSSOP packaging. The LM4867 is priced at $1.55 in the LLP package, $1.45 in the TSSOP package, and at $1.68 in the exposed-DAP TSSOP package, all in 1000-unit quantities. For more information on the LM4867, visit National's World Wide Web site at
http://www.national.com/pf/LM/LM4867.html, or contact National's Design Support Group at
1-800-272-9959. For more information on National Semiconductor's audio products, visit http://www.national.com/appinfo/audio/. To view a high-resolution downloadable photo of the LM4867, visit National's photo gallery at http://www.national.com/company/pressroom/gallery/audio.html.
About National Semiconductor
National Semiconductor is the premier analog company driving the information age. Combining real-world analog and state-of-the-art digital technology, the company is focused on the fast growing markets for wireless handsets; information appliances; information infrastructure; and display, imaging and human interface technologies. With headquarters in Santa Clara, California, National reported sales of $2.1 billion for its last fiscal year and has about 10,500 employees worldwide. Additional company and product information is available on the World Wide Web at www.national.com.
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