Leading a market transition to higher-performance data conversion solutions, Cirrus Logic Inc. announced the industry's highest performance 16-bit, delta-sigma, analog-to-digital converters (ADCs), the Crystal CS5180 and CS5181.

Capable of distinguishing and measuring very small analog signals in the presence of much larger signals, the new Crystal ADCs provide the most accurate digital representation of an input signal available today. These new mixed-signal chips enable high-precision data acquisition for demanding applications such as active and passive sonar, vibration and noise analysis, PC- based laboratories, automated test equipment, high-sample rate audio, and process and industrial control systems.

According to Cirrus Logic, the new 16-bit data converters coincide with a market shift to the use of 16-bit microcontrollers and DSPs in industrial applications. With the cost efficiencies of 16-bit controllers, and an increased demand for open, real-time operating systems such as Windows CE, Cirrus Logic expects that non-PC applications will soon be taking advantage of 16-bit converter performance.

With a 93 dB signal to noise ratio (SNR) ý at least 6 dB higher than competitive solutions -- these devices provide the highest accuracy of any 16-bit ADC available. This performance is enhanced by variable output rates of 8 kHz to 400 kHz (CS5180) and 625 kHz (CS5181), allowing the new ADCs to be tailored to the specific signal bandwidth of a given application.

"Although designers are used to the limits of 12-bit data converters today, we expect that the price and performance advantages of 16-bit solutions will transform the market by the year 2000, " said Eric Broockman, general manager of Cirrus Logic's Crystal division. "And while there are other high-speed data converters on the market, the new Crystal chips are the industry's most accurate and the first to approach true 16-bit performance."

Additional Performance Highlights

The new ADCs offer several features designed to minimize development time and lower system cost and complexity. For example, by integrating low-pass and anti-alias filtering onto one linear phase digital filter and including an on-chip reference, each of the new entries minimizes the number of components needed for data acquisition. This provides higher performance for a lower overall system cost and footprint compared to alternative solutions.

Another value-added feature is the chip's auto-calibration at start-up. Automatic calibration of on-chip digital gain and offset at start-up guarantees the highest performance and eliminates the need for user intervention. The device can also be synchronized with an external signal to remove the need for intensive DSP phase correction algorithms in multi-channel systems.

For applications that require special digital filter algorithms, such as modems, the CS5180/81 converters allow users to process the delta-sigma modulators output bit-stream in a separate user-defined, application-specific filter. This gives designers the flexibility and control to design the highest performance solution quickly with the lowest development cost.

Superior Technical Support

Achieving analog precision in the presence of noisy high-speed digital circuitry requires specialized skills in PC-board layout. To avert tricky mixed-signal design pitfalls, Cirrus Logic offers a unique Design Evaluation Service free of charge to assist customers with schematic and layout review before they commit their board-level designs to manufacturing. This popular technical support program has proven to prevent costly design iterations.

Cirrus' Crystal division has produced audio and conversion parts that have become an extremely significant force in the PC market; the company has taken a good percentage of the market from much larger operations and it is holding on to its position. The movement into more industrial markets is certainly a logical one with the performances its parts have been producing but it is a major change in both the players the company will meet and in the way that non-PC partners behave in the market. By making this part an Editor's Choice I am saying that I think it can and will make it into some of those new markets. Every design win that the company makes in such areas as ATE and control systems -- the ones where I think they are most likely to find success -- will go directly to the bottom line and take away sales from the larger competitors. It will be interesting to watch if this is something the company continues to chase.

I love the 93-dB signal-to-noise ratio and the work they have done to bring essential parts of the data acquisition process on-chip. The auto-calibration feature will considerably widen the capture area of non-analog designers to allow them to feel more comfortable with the circuits they are working on, while the application-specific digital filter will save considerable off-chip processing in some less day-to-day applications involving strange non-linearities or coding.

The price premium/differential between a 400 and a 625-kHz part seems a bit high. The two parts are currently sampling with production in January 1999. They are priced at $12.50 for the CS5180 and $17.00 for the CS5181, both for 1000-piece lots.