Norwood, Mass. ï Raising the bar for high performance in consumer audio systems, Analog Devices Inc. today (January 24th) introduced a family of audio amplifiers that combine the space- and heat-saving advantages of Class-D amplification, with dramatic improvements in sound quality and reduced EMI (electro magnetic interference).
Featuring less than 0.005 percent THD+N (total harmonic distortion plus noise), and up to 2 - 40 W output power, the devices deliver an exceptional level of audio performance that no other single-chip Class-D device has been able to achieve. This unique combination of features resolves design challenges in consumer applications, such as HDTV and home theater systems, that demand high performance audio in the smallest possible space. EMI reduction prevents interference with other electronic equipment, a critical requirement in the design of car audio systems.
The AD199x Class-D amplifiers outperform competing PWM (pulse width modulation) based Class-D schemes, through the combination of a highly-integrated single-chip design featuring an internal sigma-delta modulator and a closed-loop sigma-delta architecture. Ultimately, this enables higher audio fidelity in half the board space, satisfying the demands of advanced electronics such as thin flat panel TVs and multichannel surround sound car stereos.
"New consumer electronics applications, especially advanced TVs, are designed as much for their aesthetic appeal as their audio/video performance. Class-D, with its inherent space and heat advantages, is a critical enabling technology in this revolution," said Dick Meaney, vice president of the precision converter group at Analog Devices, Inc. "Analog Devices' new audio amplifiers take Class-D technology to the next level without compromising audiophile sound quality. Leading the industry in high performance and EMI reduction, the devices are the best choice for audio amplification in the demanding car audio market."
Best-in-class Audio Fidelity and EMI Reduction
Analog Devices' AD199x Class-D audio amplifiers outperform competing devices on two key performance benchmarks: audio fidelity and EMI. These requirements were previously the most difficult to attain using Class-D architecture, but the AD199x amplifiers deliver audiophile sound quality (THD<0.005 percent; SNR>101 dB; PSRR>65 dB), while producing 30 percent less heat. The device's breakthrough performance is achieved through Analog Devices' closed-loop, mixed signal integration of 7th order sigma-delta modulator technology with high power output drive and bridge circuitry.
Radiated and conducted out-of-band RF emissions are minimized with Analog Devices' advanced modulation technique and closed-loop, sigma-delta architecture, enabling a significant reduction in EMI.
Designers have embraced Class-D integrated circuits as a solution to the challenge of building multi-channel high performance audio systems that fit into compact spaces with minimal heat dissipation. As a result, worldwide sales of Class-D products have grown 200 percent to almost $84 million in 2004. According to Forward Concepts, an industry analyst firm, the Class-D market will continue to increase—by up to 68 percent this year alone.
More About the AD199x Class-D Amplifier Family
The AD199x amplifiers, including the AD1990, AD1992, AD1994 and AD1996, are single-chip devices containing an integrated stereo modulator and stereo "bridge-tied" load (BTL) power stage. This compact design reduces board space and component requirements. Power levels range from stereo 4 W (8 W) to stereo 40 W (80 W). A modulator-only version of the device is also available. This, coupled with external high power FETs, enables very high power amplification (only limited by the power stage design).
The AD199x amplifiers can be integrated with other Analog Devices audio products, including ADCs (analog-to-digital converters), DACs (digital-to-analog converters) and CODECs, as well as SigmaDSP and SHARC audio processors.
Availability and Pricing
The AD199x Class-D amplifiers are now sampling, with full production quantities available in Q2 2005.
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Look here for product information on the AD1990.
