TIDUFI7 May   2026

 

  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 ADS125H18
      2. 2.3.2 MSPM0G5117
      3. 2.3.3 TXE8116
      4. 2.3.4 ISO6441
      5. 2.3.5 LM5180
      6. 2.3.6 UCC33420
      7. 2.3.7 TPS7A2050
      8. 2.3.8 TLV709A33
  9. 3System Design Theory
    1. 3.1 Power Supply
      1. 3.1.1 24V Input Power Path
      2. 3.1.2 USB Power Path
      3. 3.1.3 Non-isolated MCU Power
      4. 3.1.4 Isolated ADC and Peripheral Power
    2. 3.2 Analog Input Ports
      1. 3.2.1 Analog Input Port and Protection
      2. 3.2.2 Voltage and Current Mode Selection
      3. 3.2.3 Current Measurement Path
      4. 3.2.4 Voltage Measurement Path
      5. 3.2.5 Channel Configuration
    3. 3.3 Digital Control and Data Acquisition Subsystem
      1. 3.3.1 Microcontroller Platform
      2. 3.3.2 Precision ADC
      3. 3.3.3 Shared SPI Bus and Chip-Select Forwarding
      4. 3.3.4 I/O Expander
      5. 3.3.5 Optional External Reference
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
      1. 4.1.1 PCB Overview
      2. 4.1.2 Connector Description
        1. 4.1.2.1 Power Connectors
        2. 4.1.2.2 Input Connectors
    2. 4.2 Test Setup and Test Results
      1. 4.2.1 ADS125H18 General Configuration
      2. 4.2.2 Offset Test
        1. 4.2.2.1 Test Setup
        2. 4.2.2.2 Test Results
          1. 4.2.2.2.1 Voltage Input Mode
          2. 4.2.2.2.2 Current Input Mode
      3. 4.2.3 System Accuracy Error and Noise Performance Test
        1. 4.2.3.1 Calculation Method
        2. 4.2.3.2 Test Setup
        3. 4.2.3.3 Test Results
          1. 4.2.3.3.1 Voltage Input Mode
          2. 4.2.3.3.2 Current Input Mode
      4. 4.2.4 Input Protection Test
        1. 4.2.4.1 Test Setup
        2. 4.2.4.2 Test Results
  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
      1. 5.2.1 Tools
      2. 5.2.2 Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5.     Trademarks
  12. 6Revision History
  13. 7About the Author

2.3.4 ISO6441

The ISO6441 is a reinforced, quad‑channel digital isolator that provides galvanic isolation for three forward and one reverse unidirectional channels. The device uses a silicon‑dioxide (SiO₂) insulation barrier to achieve high isolation ratings and high common‑mode transient immunity, improving robustness in noisy industrial environments.

In this design, the ISO6441 provides galvanic isolation for the digital communication path between the controller and the isolated analog input domain. Combined with the shared SPI architecture, the ISO6441 helps reduce isolated channel count and external components while maintaining robust isolated communication.