AFE78201RRUT

Analog Front End (AFE) Overview

The AFE78201RRUT is a 14-bit digital-to-analog converter (DAC) from Texas Instruments, packaged in a 24-pin UQFN (RRU). It features a 0V to 2.5V output range with a maximum total unadjusted error of 0.07% FSR across the –40°C to +125°C temperature range. The device integrates a 1.25V voltage reference with 10ppm/°C drift and a 12-bit diagnostic ADC operating at 3.84kSPS. Quiescent current is typically 170µA. Digital interfaces include SPI and UART, supported by fault detection mechanisms such as CRC checking and a windowed watchdog timer.

Analog Front End (AFE) Feature Summary

• 14-bit monotonic DAC with 0.07% max TUE (-40°C to +125°C)
• Integrated 1.25V reference (10ppm/°C) and 12-bit diagnostic ADC
• Low quiescent current: 170µA typical, 210µA maximum
• SPI and UART digital interfaces with CRC and watchdog fault detection

Analog Front End (AFE) Applications

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

Analog Front End (AFE) Procurement Notes

Verify the RRU suffix confirms the 24-pin UQFN package (4.00mm × 4.00mm). Confirm functional safety documentation availability if required for system design. Ensure external voltage-to-current conversion components are included in the design, as the device requires them for loop-powered applications.

Analog Front End (AFE) Selection Notes

Select the AFE78201 over the AFE88201 when 14-bit resolution is sufficient, as it offers identical integration but lower cost. Verify that the 0V to 2.5V output range meets application requirements. Ensure the PCB layout accommodates the 24-pin UQFN package and provides adequate thermal dissipation given the 103.1°C/W junction-to-ambient resistance.

Analog Front End (AFE) Part Context

The AFE78201 belongs to the AFEx8201 family, which also includes the 16-bit AFE88201. Both devices share the same pinout, package, and peripheral integrations, differing only in DAC resolution. This family is designed for low-power industrial analog output modules requiring high accuracy and built-in diagnostics.

Analog Front End (AFE) Replacement Considerations

The AFE88201 is a pin-compatible alternative offering 16-bit resolution instead of 14-bit. No other direct substitutes are documented in the provided datasheet.

Analog Front End (AFE) FAQ

What is the maximum total unadjusted error (TUE) for the AFE78201?

The maximum TUE is 0.07% FSR from –40°C to +125°C.

Does the AFE78201 support both SPI and UART interfaces?

Yes, the device supports both Serial Peripheral Interface (SPI) and Universal Asynchronous Receiver-Transmitter (UART) digital interfaces.

What is the purpose of the internal diagnostic ADC?

The 12-bit diagnostic ADC enables automatic self-health checks by monitoring internal nodes such as bias sources, power regulators, voltage references, DAC output, and die temperature to detect errors or malfunctions.