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.
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.