TIDUFE9 August   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
    2. 1.2 Electricity Meters
    3. 1.3 Circuit Breakers
    4. 1.4 EV Chargers
    5. 1.5 Protection and Relay
    6. 1.6 Rogowski Coil-Based Current Sensor
      1. 1.6.1 Principle
      2. 1.6.2 Rogowski Coil Types
      3. 1.6.3 Integration Methods
      4. 1.6.4 Rogowski Coil Selection
  8. 2System Overview
    1. 2.1 Block Diagram
      1. 2.1.1 Differential Gain Amplifier
      2. 2.1.2 High-Pass Filter
      3. 2.1.3 Low-Pass Filter
      4. 2.1.4 Active Integrator
    2. 2.2 Design Considerations
      1. 2.2.1 Components Selection
        1. 2.2.1.1 RC Component Selection
        2. 2.2.1.2 RG Selection for Gain Setting
    3. 2.3 Highlighted Products
      1. 2.3.1 INA828
      2. 2.3.2 TLV9001
      3. 2.3.3 LM27762
  9. 3System Design Theory
    1. 3.1 Schematics to Layout
      1. 3.1.1 Rogowski Input Connectors
      2. 3.1.2 Gain Setting Resistor Chain
      3. 3.1.3 Gain Amplifier and High-Pass Filter Stage
      4. 3.1.4 Active Integrator Stage
      5. 3.1.5 Output Stage
      6. 3.1.6 Power Supply
  10. 4Hardware, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Test Setup
      1. 4.2.1 Full System Block Diagram
      2. 4.2.2 Test System
      3. 4.2.3 Rogowski Coil
      4. 4.2.4 TIDA-010986
      5. 4.2.5 ADS131M08 Metrology Evaluation Module
      6. 4.2.6 GUI
        1. 4.2.6.1 Getting Started
          1. 4.2.6.1.1 PCB Rogowski Coil Setup
          2. 4.2.6.1.2 TIDA-010986 Connectors
            1. 4.2.6.1.2.1 Input Terminal Block
            2. 4.2.6.1.2.2 Power Connection
            3. 4.2.6.1.2.3 Output Connections
          3. 4.2.6.1.3 ADS131M08 Metrology Evaluation Module Connectors
    3. 4.3 Test Results
      1. 4.3.1 Functional Test
      2. 4.3.2 Accuracy Measurements
        1. 4.3.2.1 No Load Conditions
          1. 4.3.2.1.1 Objective
          2. 4.3.2.1.2 Setup
          3. 4.3.2.1.3 Requirements
          4. 4.3.2.1.4 Results
        2. 4.3.2.2 Initial Load Operation Test
          1. 4.3.2.2.1 Objective
          2. 4.3.2.2.2 Setup
          3. 4.3.2.2.3 Requirements
          4. 4.3.2.2.4 Results
        3. 4.3.2.3 Accuracy Test at Different Load Conditions
          1. 4.3.2.3.1 Objective
          2. 4.3.2.3.2 Setup
          3. 4.3.2.3.3 Requirements
          4. 4.3.2.3.4 Results
        4. 4.3.2.4 Variation of Power Factor Test
          1. 4.3.2.4.1 Objective
          2. 4.3.2.4.2 Setup
          3. 4.3.2.4.3 Requirements
          4. 4.3.2.4.4 Results
        5. 4.3.2.5 Variation of Voltage Test
          1. 4.3.2.5.1 Objective
          2. 4.3.2.5.2 Setup
          3. 4.3.2.5.3 Requirements
          4. 4.3.2.5.4 Results
        6. 4.3.2.6 Variation of Frequency Test
          1. 4.3.2.6.1 Objective
          2. 4.3.2.6.2 Setup
          3. 4.3.2.6.3 Requirements
          4. 4.3.2.6.4 Results
        7. 4.3.2.7 Phase Sequence Reversal Test
          1. 4.3.2.7.1 Objective
          2. 4.3.2.7.2 Setup
          3. 4.3.2.7.3 Requirements
          4. 4.3.2.7.4 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 Layout Prints
    2. 5.2 Tools
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5.     Trademarks
  12. 6About the Author

2.2.1.1 RC Component Selection

This design targets low phase error, low noise, fast settling, and precision measurements. To target low phase error < 3 degrees, an RC time constant of < 30ms is selected. A 100kΩ resistor and 0.3μF capacitor are selected to get 30ms of settling time for the integrator. Select an integrator capacitor with low (< ±5%) tolerance and lower temperature drift. C0G/NP0 capacitors have good frequency response and temperature stability. The resistors used in the design have a ±0.1% tolerance and are thin film material to improve accuracy, repeatability, and does not introduce additional noise to the system.