DAC is integrated to save times, cost and board space
Texas Instruments has introduced the 16-bit DAC8775, which operates from a single, wide 12- to 36V power rail. It uses an integrated buck/boost converter to generate all of the required internal power supplies to save designers time, cost and significant board space, claims Texas Instruments.
The four-channel DAC8775 addresses the trend in I/O modules to include more channels in a smaller space in factory automation and process control equipment. This produces a challenge in managing power dissipation in a small form factor. By combining a 4.0 to 20mA current and voltage driver with a precision reference and a buck/boost converter, the DAC8775 enables a total system footprint that is up to 25 per cent smaller than the nearest competing device, claims Texas Instruments. It can also deliver advanced diagnostic capabilities, says the company.
The DAC8775’s on-chip diagnostic features include smart alarms that monitor open load, short circuit, over-temperature, cyclic redundancy check (CRC), watchdog timer and compliance voltage. Designers can choose pre-set actions that help detect faults early to facilitate reliable system operation.
An auto-learn feature calculates the load impedance on the 4.0 to 20mA loop and clamps the power supply to enable faster settling time. Total unadjusted error of 0.1 per cent full-scale range (FSR) operates over an extended industrial temperature range of -40 to 125 degree C. The high DC performance of the DAC8775 reduces the need for system calibration, saving manufacturing costs compared to a discrete solution, says Texas Instruments.
The DAC8775 dynamically adjusts the generated supply based on the current load on the current loop. This creates an efficient system with well-controlled thermal performance, allowing more channels in a smaller space.
A four-channel analogue output module reference design is also offered. It demonstrates the DAC8775 and the LM5166 high-efficiency synchronous buck converter that dissipates less than 1.0W of power in factory-automation implementations.
The DAC8775 is available now in a 10 x 10mm QFN package.