AFE78101

The 16-bit AFE88101 and 14-bit AFE78101 ( AFEx8101) are highly-integrated, high-accuracy, extremely low-power digital-to-analog converters (DACs) with voltage outputs designed for sensor-transmitter applications.

The AFEx8101 devices include most of the components required to design a 4‑mA to 20‑mA, 2‑wire (loop-powered) sensor transmitter. In addition to the highly accurate DAC, these devices include a 10‑ppm/°C voltage reference and a diagnostic analog-to-digital converter (ADC). To accommodate intrinsic and functional-safety concerns, external voltage-to-current conversion and power regulation are required.

The internal diagnostic ADC is multiplexed to several internal nodes that enable an automatic self-health check. This check is capable of detecting errors or malfunctions of the internal bias sources, power regulator, voltage reference, DAC output, die temperature, and optional external voltage source. If any fault is detected from the diagnostic ADC, CRC frame-error checking, or windowed watchdog timer, the devices can optionally issue an interrupt, enter a fail-safe state corresponding to a standard NAMUR output value or user-specified custom value, or both.

These devices operate from supplies as low as 1.71 V with a maximum quiescent current of 210 µA. The devices are specified over the temperature range of –40°C to +125°C, but are functional from –55°C to +125°C.