Analog Devices introduced the first 1 mega sample per second (MSPS) 16-bit successive-approximation register (SAR) analog-to-digital converter (ADC). This level of performance is unmatched in the industry and has raised the bar in terms of speed and precision for SAR converters, which comprise the majority of the ADC market. SAR converters are widely considered the most cost-effective technology for applications that require very precise digital modeling of analog signals.

The conversion rate of the AD7671 is twice that of what was previously available on the market and uses 115 milliwatts --half the power used by other 16-bit SAR converters. Many applications benefit from this faster response time. For example, optical switches can direct information packages more quickly, and data acquisition systems can respond faster to external stimuli and better perform key functions, such as moderating temperatures.

The AD7671 has no data latency, and it operates at three different speeds, including 1 MSPS for asynchronous sampling applications, 800 kSPS 'normal' mode, and an 'impulse' mode, in which power consumption varies with throughput. This low-power device uses a single 5 V power supply and typically dissipates only 115 mW, even less in the impulse mode. The device also offers a power-down mode to further extend battery life.

The AD7671's flexibility makes it easy for the devices to interface with the rest of the circuit. It accommodates variable input ranges by offering bipolar/unipolar inputs. It also offers calibration and error correction circuits, an internal clock, and both 8- or 16-bit and two-wire serial interfaces.

Analog Devices Inc., One Technology Way, PO Box 9106, Norwood, MA 02062-9106; Phone: 781- 329-4700.

The need for signal processing is bursting at the seams because of the need to convert the real world analog to digital and all the crunching it takes. Analog Devices has focused on the $1 billion ADC market and zeroed in on the successive approximation register (SAR) architecture because it is the sweet spot in ADC market - with about 50% of the sales. Why so popular? Simple, SARs have no latency, can be multiplexed, offer accuracy, and speed not provided in combination by the sigma delta, pipeline or flash type ADCs.

The SAR architecture is a good match for the data acquisition and optical fiber applications. These are the apps that have a control loop that require some form of adjustment during operation. For example, with optical fibers you may need to switch the light from one fiber to another or move a mirror to tune the laser for pumping in more light to amplify a signal. For these control loops you cannot have latencies so you need a SAR converter because they are very accurate (16-bits) and they have to be as fast as possible.

The Analog Device 1 MSPS AD7671 is appropriate for these applications and can also be multiplexed so that it can replace of two 500 kSPS converters. This means that it takes up less space, and uses less power - 150 mw .

More established applications like process control and the medical world - they want to shrink board space because they may need to add more sensors, but in the same box size. Other applications for the AD7671 include: wired communications (MEMS switches, optical MUX), Test and Measurement, instrumentation, scanners, Electromagnetic prospecting, space cameras, atomic microscopes, and blood analyzers. For data acquisition applications, the faster you can acquire information the better the product. Some examples would be data acquisition cards, network analyzers, or data loggers.

With its compact, 9x9 mm 48-lead LQFP (low-profile quad flat pack) package, the AD7671 saves board space, is pin compatible with the ADI PulSAR family of 16-bit SAR converters, and is specified to operate from -40 to +85 degrees Celsius.

You can find a data sheet for the AD7671 here.

The AD7671 Pulsar ADC is priced at $25 in 10,000-piece quantities. Evaluation boards and production quantities are now available.

The AD7671 Pulsar converter doubles performance for a variety of high-precision applications, including medical instrumentation, spectrum analyzers, data acquisition systems, scanners, wired communications, and fiber optic networking equipment.