16-bit DAC allows single isolator data transmission
8/17/2011 7:59 AM EDT
National Semiconductor Corp. introduced a 16-bit digital-to-analog converter (DAC) featuring a single-wire interface and 4-to-20 mA current loop drive that simplifies the design of smart transmitters used in industrial two-wire sensor systems.
The highly integrated DAC161P997 reduces component count and cost in factory and building automation control systems by enabling the use of a single isolation component to cross the isolation boundary. For sensing and detecting applications where galvanic isolation is not required, National’s DAC161P997 interfaces directly to a microcontroller.
Its delta-sigma DAC offers 16-bit accuracy with a minimal temperature coefficient of 29 ppm and long-term output current drift of 90 ppm, while consuming less than 190 µA of supply current. The DAC161P997's loop drive interfaces to a highway addressable remote transducer (HART) modulator, allowing injection of FSK-modulated digital data into the 4-to-20 mA current loop. The DAC operates over the -40ºC to 125ºC extended industrial temperature range.
- Single-wire interface: enables higher system accuracy compared to discrete PWM implementations, and lower system cost compared to 4-wire SPI solution
- Low power operation: 190 µA enables total system power consumption below 30 mW or 3.5 mA
- User programmable start up conditions and data rate auto detect: allows system configuration for trade-off between update-rate vs. power consumption
- Error detection and reporting: multiple error conditions detected automatically, providing higher system reliability
Pricing and Availability
Offered in a 16-pin, 4 mm by 4 mm LLP package, the DAC161P997 is available now and priced at $4 in 1,000-unit quantities.
Datasheet: Click here.