TIDUFE3 July   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 TPS7A03
      2. 2.3.2 REF35
      3. 2.3.3 TVS3301
      4. 2.3.4 OPA391
      5. 2.3.5 AFE881H1
      6. 2.3.6 AFE882H1
      7. 2.3.7 SN74LV8T165
      8. 2.3.8 TMUX1219
  9. 3System Design Theory
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Test Setup
    3. 4.3 Test Results
      1. 4.3.1 Linearity Tests
        1. 4.3.1.1 Linearity Tests Summary
      2. 4.3.2 Noise Tests and Current Histogram
        1. 4.3.2.1 Noise Tests and Current Histogram Summary
      3. 4.3.3 Step Response
        1. 4.3.3.1 Step Response Summary
      4. 4.3.4 Start-Up
      5. 4.3.5 MCU Current
        1. 4.3.5.1 MCU Current Summary
      6. 4.3.6 System Currents
        1. 4.3.6.1 Summary of System Currents
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
      3. 5.1.3 PCB Layout Recommendations
        1. 5.1.3.1 Layout Prints
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author

2.3.6 AFE882H1

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 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, 10ppm/°C voltage reference, and diagnostic analog-to- digital 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 self- health 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.