TIDUFG0 November   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
  8. 2System Overview
    1. 2.1 Block Diagram
      1. 2.1.1 PCB Rogowski Coils
      2. 2.1.2 Integrator Stage
      3. 2.1.3 Input Stage
      4. 2.1.4 Differential Amplifier Stage
      5. 2.1.5 High-Bandwidth, Low-Noise Amplifier Stage
        1. 2.1.5.1 Hybrid Integrator
        2. 2.1.5.2 Band Pass Filter
        3. 2.1.5.3 Logarithmic Amplifier
    2. 2.2 Design Considerations
      1. 2.2.1 Component Selection
      2. 2.2.2 RC Component Selection
      3. 2.2.3 Gain Setting
    3. 2.3 Highlighted Products
      1. 2.3.1 INA333
      2. 2.3.2 TLV9002
      3. 2.3.3 LM2664
      4. 2.3.4 TLV2387
      5. 2.3.5 LOG300
      6. 2.3.6 TL081H
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
      1. 3.2.1 Metering Setup
        1. 3.2.1.1 Accurate Current Source
        2. 3.2.1.2 TIDA-010987
        3. 3.2.1.3 ADS131M08 Metrology Evaluation Module
        4. 3.2.1.4 GUI
      2. 3.2.2 5kHz to 50kHz Band Pass and Logarithmic Amplifier Test Setup
        1. 3.2.2.1 Oscilloscope
        2. 3.2.2.2 Function Generator
    3. 3.3 Test Results
      1. 3.3.1 No Load Conditions
        1. 3.3.1.1 Objective
        2. 3.3.1.2 Setup
        3. 3.3.1.3 Requirements
        4. 3.3.1.4 Results
      2. 3.3.2 Starting Load Test
        1. 3.3.2.1 Objective
        2. 3.3.2.2 Setup
        3. 3.3.2.3 Requirements
        4. 3.3.2.4 Results
      3. 3.3.3 Active Power Measurements
        1. 3.3.3.1 Objective
        2. 3.3.3.2 Setup
        3. 3.3.3.3 Requirements
        4. 3.3.3.4 Results
      4. 3.3.4 Variation of Power factor
        1. 3.3.4.1 Objective
        2. 3.3.4.2 Setup
        3. 3.3.4.3 Requirements
        4. 3.3.4.4 Results
      5. 3.3.5 Variation of Voltage Test
        1. 3.3.5.1 Objective
        2. 3.3.5.2 Setup
        3. 3.3.5.3 Requirements
        4. 3.3.5.4 Results
      6. 3.3.6 Variation of Frequency
        1. 3.3.6.1 Objective
        2. 3.3.6.2 Setup
        3. 3.3.6.3 Requirements
        4. 3.3.6.4 Results
      7. 3.3.7 Band Pass
        1. 3.3.7.1 Objective
        2. 3.3.7.2 Setup
        3. 3.3.7.3 Requirements
        4. 3.3.7.4 Results
      8. 3.3.8 Logarithmic Amplifier
        1. 3.3.8.1 Objective
        2. 3.3.8.2 Setup
        3. 3.3.8.3 Requirements
        4. 3.3.8.4 Results
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
      3. 4.1.3 PCB Layout Recommendations
        1. 4.1.3.1 Layout Prints
    2. 4.2 Tools
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author

2.2.1 Component Selection

System gain can be controlled at three different stages, the gain stage at the differential amplifier (INA333), the integrator stage after the amplifier stage, and the standalone integrator. Gain selection is highly influenced by the application.

Some applications require stepping down high amplitudes of current to a measurable value for protection purposes where the currents are greater than 1kA. For protection applications, where the precise measurements are crucial, the current is stepped down to the mV ranges where the gain amplifier amplifies the signal. The integrator (set to attenuate) attenuates all the noise in the system for precision measurements.

The design has multiple gain settings ranging from 1V/V to 1000V/V depending on the type and sensitivity of Rogowski coil where the integrator gain is set to unity gain for multiple component configurations.