March 30, 1999 - National Semiconductor Corporation® (NYSE: NSM), co-author of the Audio Codec '97 common architecture standard for PC audio devices, today reached another milestone in its codec roadmap with the introduction of the LM4549 AC'97 Rev2.1 audio codec, which includes sample rate conversion (SRC) and provides a critical building block in the development of National’s system-on-a-chip solutions.
"The demand for high quality sound for both desktop and notebook computers is what is driving National to develop leading edge audio solutions, such as the LM4549 AC'97 Rev2.1 codec," said Suneil Parulekar, product line director of National’s audio and amplifier division. "With the introduction of this product, we will be one of the first manufacturers to provide a codec that is both AC'97 Rev2.1 and PC98/99 compliant, and will allow our customers to offer an unparalleled audio experience to consumers."
Applications and Markets
The LM4549 is designed for the general PC market and extends National's audio strategy by interfacing with its Boomer amplifier line and other audio chips. The introduction of the LM4549 allows National to provide its customers with a complete audio solution for a range of products, enabling significant performance gains and improved efficiency.
Features and Benefits
The LM4549 is ideal for PC applications that require SRC, and features a high-performance built-in SRC with 1Hz resolution for offloading CPU bandwidth that complies with the AC'97 Rev2.1/PC98/99 specifications. For increased battery life, which is key for portable devices, the LM4549 operates at a digital voltage range of 3.0V to 5.0V and an analog voltage of 4.2V to 5.0V. The LM4549 AC'97 also features a multiple codec option and analog 3-D for maximum audio performance. The LM4549 achieves impressive analog performance with only .01 percent total harmonic distortion plus noise (THD+N) and over a 97dB signal-to-noise ratio.
About AC'97
The AC'97 standard, defined by a consortium of ADI, Creative Labs, Intel, National Semiconductor and Yamaha, was first announced in May 1996. Reversing the trend toward integration of analog and digital audio circuitry on a single chip, AC'97 calls for two separate chips – one mixed-signal, the other purely digital. Significantly higher levels of performance and design flexibility are made possible by separating the mixed-signal and digital sections. For example, placing analog inputs and outputs physically close to audio connectors minimizes unwanted coupling of noisy digital system signals. Similarly, separation of the digital audio controller from the analog codec allows significant improvements in signal-to-noise ratio.
Price and Availability
The LM4549, housed in a 48-pin TQFP (thin quad flatpack), is priced at $3.50 in quantities of 1000. It will be available in production quantities in May 1999.
National Semiconductor provides system-on-a-chip solutions for the information age. Combining real-world analog and state-of the-art digital technology, the company's chips lead many sectors of the personal computer, communications and consumer markets. With headquarters in Santa Clara, Calif., National has annual sales of approximately $2.5 billion and 11,500 employees worldwide. Additional company and product information is available on the World Wide Web at www.national.com.
