AFE78101RRUR

Analog Front End (AFE) Overview

The AFE78101RRUR is a 14-bit low-power digital-to-analog converter (DAC) with voltage output, designed for sensor-transmitter applications. It integrates a 1.25-V reference and a diagnostic ADC. The device operates from supplies as low as 1.71 V with a maximum quiescent current of 210 µA. Key electrical parameters include a typical INL of ±2 LSB, TUE of 0.07% FSR (-40°C to +125°C), and a 12-bit diagnostic ADC sampling at 3.84 kSPS. It supports SPI and UART interfaces, features an internal 1.2288-MHz oscillator, and functions within a temperature range of -55°C to +125°C.

Analog Front End (AFE) Feature Summary

• 14-bit monotonic DAC with 0.07% max TUE over extended temperature
• Integrated 1.25-V reference with 10 ppm/°C drift
• 12-bit diagnostic ADC for self-health checks at 3.84 kSPS
• Low quiescent current: 170 µA typical

Analog Front End (AFE) Applications

• 2-wire transmitters
• 4-mA to 20-mA loop-powered applications
• Process control and industrial automation
• Smart transmitters
• PLC or DCS I/O modules

Analog Front End (AFE) Procurement Notes

Verify the specific suffix RRUR corresponds to the UQFN 24-pin package when ordering. Confirm functional safety documentation availability if required for system design. Ensure external components meet intrinsic safety requirements for loop-powered configurations.

Analog Front End (AFE) Selection Notes

Select AFE78101 for 14-bit resolution needs; choose AFE88101 for 16-bit precision. Both share identical pinouts and features. Verify supply voltage compatibility, as internal LDO operation depends on PVDD levels above or below 2.7 V.

Analog Front End (AFE) Part Context

Part of the AFEx8101 family, which includes the AFE88101 (16-bit). Designed specifically for highly integrated, high-accuracy, extremely low-power DAC solutions in sensor-transmitter designs.

Analog Front End (AFE) Replacement Considerations

AFE88101RRUR offers 16-bit resolution with similar packaging and feature sets. Direct substitution requires verifying resolution requirements and potential calibration adjustments.

Analog Front End (AFE) FAQ

How does the internal LDO operate based on supply voltage?

When PVDD is between 2.7 V and 5.5 V, the internal LDO activates to generate VDD internally. For PVDD between 1.71 V and 1.89 V, the LDO is disabled, requiring an external supply on the VDD pin.

What fault detection mechanisms are included?

The device includes CRC bit error checking, a windowed watchdog timer, and a diagnostic ADC that monitors internal bias sources, power regulators, voltage references, DAC outputs, die temperature, and optional external voltage sources.

What is the alarm response behavior upon fault detection?

Upon detecting a fault via the diagnostic ADC, CRC errors, or watchdog timer, the device can issue an interrupt and enter a fail-safe state corresponding to standard NAMUR output values or user-specified custom values.