1 Features

? Functional Safety-Capable

– Documentation available to aid functional safety

system design: AFE88101, AFE78101

? Low quiescent current: 170 μA (typ)

? 16-bit or 14-bit monotonic high-performance DAC

– 1.8-V supply: 0.15 V to 1.25 V, 0.2 V to 1.0 V

– 5-V supply: 0.3 V to 2.5 V, 0.4 V to 2.0 V

– 4-LSB INL at 16 bits

– 0.07 FSR (max) TUE from –40°C to +125°C

? 12-bit 3.84-kSPS ADC for advanced diagnostics

? Integrated 1.25-V reference at 10 ppm/°C

? Internal 1.2288-MHz oscillator with clock output

? Digital interfaces:

– Serial peripheral interface (SPI)

– Universal asynchronous receiver-transmitter

(UART)

? Fault detection: CRC bit error checking, windowed

watchdog timer, diagnostic ADC

? Wide operating temperature: –55°C to +125°C

2 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

3 Description

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 sensortransmitter

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 analogto-

digital converter (ADC). To accommodate intrinsic

and functional-safety concerns, external voltage-tocurrent

conversion and power regulation are required.

The internal diagnostic ADC is multiplexed to

several internal nodes that enable an automatic selfhealth

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.