AFEX82H1中文資料德州儀器數(shù)據(jù)手冊(cè)PDF規(guī)格書

1 Features

? Functional Safety-Capable

– Documentation available to aid functional safety

system design

? Low quiescent current: 180 μA (typical)

? HART?-compliant physical layer modem

– Programmable amplitude of TX signals

– RX demodulator and band-pass filter

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

– DAC output range: 0 V to 2.5 V

– Digital DAC slew-rate control

– 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 (max)

? Internal 1.2288-MHz oscillator with clock output

? Digital interface

– Serial peripheral interface (SPI): Shared bus for

both DAC and HART

– Universal asynchronous receiver-transmitter

(UART): Shared bus for both DAC and HART

– Both: SPI for DAC and UART for HART

? Fault detection: CRC bit error checking, windowed

watchdog timer, diagnostic ADC

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

2 Applications

? Process control and industrial automation

? PLC or DCS I/O modules

? 3-wire and 4-wire transmitters

? 4-mA to 20-mA loop-powered applications

3 Description

The 16-bit AFE882H1 and 14-bit AFE782H1

(AFEx82H1) are highly-integrated, high-accuracy,

extremely low-power DACs with voltage-outputs

designed for HART-enabled process control and

industrial automation applications.

The AFEx82H1 devices include most of the

components required to design a 4?mA to 20?mA,

3?wire or 4-wire sensor transmitter or analog output

module. In addition to the highly accurate DAC, these

devices include a HART?-compliant FSK modem, 10-

ppm/°C voltage reference, and diagnostic analog-todigital

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 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

user-specified fail-safe state, or both.