Crystal Semiconductor Raises Digital Audio Standard: Announces 120-dB, 96-kHz A/D Converter; Cirrus Logic's Crystal Semiconductor Products Division Develops Record Breaking Analog-to-Digital Converter.

AUSTIN, Texas--(BUSINESS WIRE)--July 14, 1997--Cirrus Logic Inc. (NASDAQ:CRUS) and its Crystal Semiconductor Products Division today introduced the first audio analog-to-digital converter (ADC) to break the 120-dB dynamic range barrier.

The CS5396 is also the first 24-bit ADC to support the emerging 96-kHz sampling rate requirement for professional audio systems.

The new device's high-dynamic range and doubled sampling rate, combined with its 24-bit resolution and negligible distortion, will enable digital signal processing (DSP) based systems to match and exceed the performance of high-end analog audio systems. This performance makes it ideal for use in digital mixing consoles, multi-track recorders, CD and DVD mastering systems, and professional digital audio tape (DAT) players.

Third Generation Delta-Sigma Technology

The CS5396 achieves the high-dynamic range using a proprietary delta-sigma modulator. "The 120-dB dynamic range requires 7th-order noise-shaping," explains Eric Broockman, vice president and general manager of Cirrus Logic's Crystal Semiconductor Products Division.

"However, overcoming the instabilities of high-order modulators presents a difficult challenge. Cirrus Logic, through its Crystal Semiconductor Products Division, is the only company that has stabilized a 7th-order modulator."

The company employs a patented calibration technique which yields greater than 105-dB total harmonic distortion plus noise (THD+N), the lowest total harmonic distortion achieved in any converter to date.

96-kHz Sampling Mode

96-kHz sampling improves sound perception, according to research. "Studies have shown that although audio information beyond 20-kHz cannot be heard, this high frequency information affects the perception of what you do hear," says Rupert Neve, founder of the Neve Group of Companies. Current 48-kHz sampling systems provide a flat noise floor only out to 20-kHz. In 96-kHz mode, the CS5396 provides a flat noise floor all the way to 40-kHz.

24-Bit Resolution and Psychoacoustic Noise Shaping

Most current sound systems record digital sound only at 16-bits or 18-bits, but the CS5396 samples sound with 24-bit resolution. Thus, using a fully programmable psychoacoustic filter, the CS5396 can shape 24-bit sampled sound so that it can be represented with only 16-, 18- or 20-bits.

This filtering technique maintains the sound quality of 24-bit resolution in critical listening regions while it pushes quanitization noise to less critical frequencies.

Psychoacoustic noise shaping allows current systems to take advantage of the CS5396's high performance without having to change the data storage component of the system. This key new feature is a first to be included in an audio A/D converter.

Backward Compatible Decimation Mode

To enable backward compatible communication with existing digital audio equipment, the CS5396 digital filter uses a technique known as decimation.

The decimation technique converts the 96-kHz digital audio data to 48-kHz for transmission over industry-standard Sony/Philips Digital Interface Format (S/PDIF) protocol, which supports sound sampling rates up to 50-kHz only. This unique decimation capability provides a compatibility bridge for new 96-kHz audio equipment in an existing 48-kHz environment.

For applications requiring only 48-kHz sample rates, system designers can choose the CS5394 24-bit audio A/D converter. This device offers 117-dB dynamic range and 103 -dB THD+N, and is pin-compatible with the CS5396 device.

Pricing and Availability

The CS5394 and CS5396 come in a space-saving 28-pin SOIC package. Production quantities of the CS5394 and the CS5396 are priced at less than $20.00 and $26.00 respectively in thousands. Samples and production quantities of both products are available now.

Crystal Semiconductor Products Division

The Crystal Semiconductor Products Division of Cirrus Logic designs, manufactures, and markets advanced analog and digital integrated circuits for data acquisition, consumer/professional audio and video and imaging applications. The Crystal brand is recognized for providing high-performance mixed-signal and DSP solutions for consumer and industrial markets.

Cirrus Logic Inc.

Cirrus Logic is a leading manufacturer of advanced integrated circuits for personal computing, communications, mass storage, consumer and industrial markets. The company's "systems in silicon" add high value and software richness to major brands worldwide.

With a focus on innovating microperipheral chip solutions that make the human interface with electronics more natural and exciting, Cirrus Logic is committed to technology leadership in the Interactive Age. -0-

Cirrus Logic news releases may be obtained by fax by dialing 800/359-6414, or by dialing 510/249-4200 from outside the United States, or via the Internet on the world wide web at http://www.cirrus.com/

CONTACT: Cirrus Logic, Inc.

Crystal Semiconductor Products Division

Editorial: Jo-Dee Benson, 512/912-3823

[e-mail]

Reader: Tom Stein, 512/912-3113

[e-mail]