ADI's precision DACs suit industrial process control apps

Analog Devices Inc. (ADI) has unveiled new precision DACs that significantly improve the reliability of industrial process control applications in harsh factory environments, including those operating under extreme temperatures or high compliance voltages.

The offering includes four 12bit to 16bit single-channel DACs that integrate user-programmable current source and voltage output, making them suited for factory process control, distributed control, and smart transmitter systems. By eliminating the need for bulky discrete analogue circuitry and mechanical pin-strapped configurations, the DACs reduce board space by as much as 70 percent compared to competing solutions, enabling system design engineers to deliver more cost- and space-efficient industrial equipment.

"Our newest DACs provide a compact and intelligently integrated solution for 4- to 20mA transmitters and analogue I/O systems, meeting the growing demand for feature-rich, highly reliable programmable automation controllers," said Mike Britchfield, product line director, precision data converters, ADI. "These devices offer industrial designers a high-performance, 16bit control system that provides excellent drift and stability specifications, while reducing system inaccuracies and cost by eliminating multi-temperature factory calibration sequences."

The new products, which include the AD5422, AD5420, AD5412, and AD5410, leverage the technological advancements enabled by ADI's iCMOS industrial process technology, allowing them to achieve the high voltages needed by industrial applications. The AD5422 single-channel 16-bit DAC operates from a single 12- to 48V supply, or dual ?12- to ?24V supplies. The output configuration is software selectable from options of 5-, 10-, ?5 and ?10V in voltage mode and 4- to 20mA, 0 to 20mA and 0 to 24mA in current mode. All output spans include an additional over-range setting.

The AD5422 achieves an accuracy level of 0.1 percent total unadjusted error while operating in voltage or current mode and includes a precision 5ppm/?C internal reference. Internal fault detection circuitry provides hardware and software indication of line faults, such as opens or shorts in cable wiring or remotely located loads. The device also integrates an over-temperature indicator.

To sense output voltage, the AD5422 includes a buffered voltage output with force and sense capability that can compensate for series protection resistors and field-wiring resistance. The on-chip programmable precision output amplifier allows rail-to-rail output swing to be achieved, maximizing dynamic range and enabling the device to deliver the performance needed in a wide variety of industrial applications. Analog outputs can drive capacitive loads up to 1uF and inductive loads up to 1H.

The AD5412 is a pin-compatible, single-channel 12bit current source and voltage output DAC. The AD5420 (16bit) and AD5410 (12bit) operate in current source mode only. With a single 12- to 60V supply, their output configuration is software selectable from 4- to 20mA, 0 to 20mA and 0 to 24mA options.

The new DACs incorporate a 30MHz SPI, power-on reset and hardware CLR and CLR-select functionality for output control. Each device is fully specified over the industrial temperature range.

All of the devices are housed in 24-lead TSSOP and 40-lead LFCSP packages. Sample units are now available.