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National Semiconductor Expands High-Fidelity Family with New Rail-to-Rail and Current Feedback Operational Amplifiers

36V Current Feedback Op Amp Provides High Slew Rate, Extended Bandwidth

5V Rail-to-Rail Input and Output Op Amp Breaks High-Fidelity, Low-Voltage Performance Barrier

Oct 1, 2007

October 1, 2007 – Further expanding its high-fidelity operational amplifier family, National Semiconductor Corporation (NYSE: NSM) today introduced a 5V rail-to-rail input and output (RRIO) and a 36V current feedback operational amplifier (op amp). The LME49721 RRIO op amp’s combined specifications provide the high-fidelity performance and signal conditioning required by high-end portable devices and applications where supply rails are limited to lower voltages. The LME49713 current feedback op amp delivers ultra-low distortion, low noise, extended bandwidth past 190 MHz and fast settling times down to 50 nanoseconds.

Both op amps join a family of high-performance, high-fidelity op amps that includes the award-winning LM4562, which set a new industry standard with 0.00003 percent total harmonic distortion plus noise (THD+N).
National’s dual 5V LME49721 RRIO op amp maximizes signal integrity by allowing the input signal and output signals to swing within 20 mV of either rail. Its low 4.0 nV/sqrt Hz input referred noise density and 0.0018 percent THD+N make it well-suited for lower-voltage supply-rail applications (plus or minus 1.1V to plus or minus 2.5V) such as 5V digital-to-analog converters (DACs), portable audio devices, signal conditioning, data acquisition, process control and test equipment.

The single LME49713 current feedback op amp features 1.9 nV/sqrt Hz input noise density, THD+N of 0.00008 percent and 150-Ohm output drive. Its 1900 V/us slew rate ensures accurate bandwidth and high dynamic range for all signal conditioning applications, including crosspoint switchers, multimedia broadcast systems, HDTV-compatible systems, line drivers and distribution amplifiers.

Key Technical Features and Benefits
The LME49721 provides output current capability up to 100 mA. It is unity-gain stable over a wide supply range of plus or minus 1.1V to 2.75V, with power-supply rejection rate (PSRR) of more than 100 db and a typical low input bias current of 40 fA. The output stage of the LME49721 can swing to within 20 mV of either power supply voltage when driving 2-kiloOhm loads or to within 30 mV when driving 600-Ohm loads. To ensure high dynamic range, it has a slew rate of 8.5 V/us while allowing the input signal to drive to the rails.

The LME49713 is unity-gain stable over a wide supply range of plus or minus 5V to 18V. Over this supply range, the LME49713 input circuitry maintains a PSRR of more than 100 db and a common-mode rejection rate (CMRR) of 88 dB. The settling time to within 0.1% is 50 nSec for a 10V step.

National at Audio Engineering Society Convention
National is demonstrating its latest high-performance products in booth 744 of the 123rd International Audio Engineering Society Convention in New York City from Oct. 5 through Oct. 8. On Mon., Oct. 8, the company’s experts will lead a series of one-hour free technical seminars focused on new technologies, high-performance power amplifiers and signal-path circuit performance. To register, visit www.national.com/rsvp/audioseminar

Pricing and Availability
The LME49721 is available now in an 8-lead SOIC package and is priced at $1.50 each in 1,000-unit quantities. The LME49713’s 8-lead, narrow-body SOIC package is priced at $2.49 each in 1,000-unit quantities. More information, easy-to-order samples and evaluation boards are available at
http://www.national.com/pf/LM/LME49713.html and http://www.national.com/pf/LM/LME49721.html.

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://audio.national.com

About National Semiconductor
National Semiconductor, the industry's premier analog company, creates high-value analog devices and subsystems. National's leading-edge products include power management circuits, display drivers, audio and operational amplifiers, interface products and data conversion solutions. National's key analog markets include wireless handsets, displays, communications infrastructure, medical, automotive, industrial, and test and measurement applications. Headquartered in Santa Clara, Calif., National reported sales of $1.93 billion for fiscal 2007, which ended May 27, 2007. Additional company and product information is available at www.national.com