Product category: Analogue and Mixed Signal ICs
News Release from: National Semiconductor | Subject: LME49811 and LME49830
Edited by the Electronicstalk Editorial Team on 17 January 2008
Audio power amp ICs cut distortion
Highly integrated single-chip devices accelerate the design of high-end consumer and professional audio applications.
National Semiconductor has extended its high-fidelity LME audio amplifier family with the introduction of a pair of 200V mono audio power amplifier input stages that deliver industry-leading low distortion performance and reduce design time These highly integrated single-chip devices accelerate the design of high-end consumer and professional audio applications that span powered studio monitors and subwoofers, audio/visual (AV) receivers, commercial sound reinforcement, automotive after-market audio, professional mixers, distributed audio and guitar amplifiers
This article was originally published on Electronicstalk on 5 Jan 2001 at 8.00am (UK)
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The LME49811 and LME49830 offer scalable output power based on supply voltage and output device count.
With these devices, designers can use the same base circuit design to create multiple power-level solutions up to 1kW amplifiers, just by scaling the output stage devices to accommodate for more power dissipation and current drive.
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When implemented in a complete power amplifier design, the LME49811's total harmonic distortion plus noise (THD+N) is a remarkably low 0.00035%, and the LME49830's THD+N is 0.0006%.
The LME49811 and LME49830 contain all the essential circuitry required for a high-quality, high-performance power amplifier input stage.
They save board space and design time by replacing more than 25 discrete components (many of which must be hand selected and matched by the audio system designer) in high-power audio amplifiers.
This enables designs with more channels and more power per square-inch of chassis space.
These devices also provide designers more time to differentiate their output stage and power supply design, as well as "tune" the amplifier's overall sound.
National's power amplifier input stages have achieved a new benchmark in integrated circuitry by enabling audio designers to easily create high-power systems, where previously only discrete designs could achieve this level of power and performance.
The LME49811 drives Darlington or bipolar power transistors in an amplifier's output stage.
It is a mono version of the LM4702 stereo driver, National's first power amplifier input stage for the high-performance audio market.
The LME49811 is capable of driving an output stage to deliver in excess of 500W single-ended into an 8ohm load.
The device can easily attain slew rates of 40V/us, while providing 9mA output drive current and 100uV output voltage noise.
The LME49811 also provides a wide operating voltage range of +/-20 to +/-100V, and its power supply rejection ratio (PSRR) is 115dB.
The LME49830 is optimised to drive a wide range of MOSFETs with standard and low threshold voltages.
It can drive an output stage in excess of 500W single-ended into an 8ohm load.
The device's 60mA output current capability increases design flexibility when selecting output stage configurations.
The LME49830 provides slew rates of 40V/us, PSRR of 115dB, output voltage noise of 41uV and a wide operating voltage range of +/-20 to +/-100V.
The LME49811 and LME49830 are both protected by a thermal shutdown feature.
National engineers developed these devices using the company's proprietary VIP3 process technology.
The high-voltage high-performance complementary bipolar technology, with vertically integrated NPN and PNP transistors, enables larger peak-to-peak output voltage swings that are well-suited for high-voltage requirements in high-end audio applications.
The LME49811 and LME49830 are available now in 15-lead TO-247 packages and both are priced at US $3.33 in 1000-unit quantities.
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