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Texas Instruments AFEx82H1 Low-Power Digital-to-Analog Converters

Texas Instruments AFEx82H1 Low-Power Digital-to-Analog Converters (DACs) are highly-integrated, high-accuracy, extremely low-power DACs with voltage-outputs designed for HART-enabled process control and industrial automation applications. The Texas Instruments AFEx82H1 devices include most components required to create a 4mA to 20mA, 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-to-digital converter (ADC). An external voltage-to-current conversion and power regulation are required to accommodate intrinsic and functional safety concerns.

The internal diagnostic of the ADC is multiplexed to several internal nodes, enabling an automatic self-health check. This check can detect 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, windowed watchdog timer, or CRC frame-error checking, the devices can optionally issue an interrupt, enter a user-specified fail-safe state, or both.

Features

  • Functional Safety-Capable
    • Documentation available to aid functional safety system design
  • Low quiescent current of 180µA (typical)
  • HART-compliant physical layer modem
    • Programmable amplitude of TX signals
    • RX demodulator and band-pass filter
  • 16-bit (AFE882H1) or 14-bit (AFE782H1) monotonic high-performance DAC
    • DAC output range: 0V to 2.5V
    • Digital DAC slew-rate control
    • 4LSB INL at 16 bits
    • 0.07% FSR (max) TUE from –40°C to +125°C
  • 12-bit 3.84kSPS ADC for advanced diagnostics
  • Integrated 1.25V reference at 10ppm/°C (max)
  • Internal 1.2288MHz oscillator with clock output
  • Digital interfaces
    • 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
  • –55°C to +125°C wide operating temperature

Applications

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

Functional Block Diagram

Block Diagram - Texas Instruments AFEx82H1 Low-Power Digital-to-Analog Converters

Related Development Tool

Texas Instruments AFE882H1EVM Evaluation Module

Configured to evaluate the AFE882H1 highly integrated, high-accuracy, and low-power 16-bit DAC.

Learn Moreabout Texas Instruments AFE882H1EVM Evaluation Module View Productsrelated to Texas Instruments AFE882H1EVM Evaluation Module
Published: 2024-04-11 | Updated: 2024-04-23