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

3.1.2 USB Power Path

For evaluation and bench testing, the board can also be powered from the 5V USB input. In this mode, VUSB powers the UCC33420 isolated DC/DC module (U12), which generates the isolated 5V5_ISO_USB rail.

C41 and C42 provide input decoupling, while C43 and C44 filter the isolated output and support load transients. In the current configuration, this path provides approximately 1.5W of isolated output power.

TIDA-010988 Schematic of USB Power Path Figure 3-2 Schematic of USB Power Path