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

2.3.1 INA333

The INA333 device is a low-power, precision instrumentation amplifier offering excellent accuracy. The versatile three-operational amplifier design, small size, and low power make the device an excellent choice for a wide range of portable applications. A single external resistor sets any gain from 1 to 1000. The INA333 is designed to use an industry standard gain equation: G = 1 + (100kΩ / RG). The INA333 device provides very low offset voltage (25μV, G ≥ 100), excellent offset voltage drift (0.1μV/°C, G ≥ 100), and high common-mode rejection (100dB at G ≥ 10). The device operates with power supplies as low as 1.8V (±0.9V) and quiescent current is only 50μA, making the device appropriate for battery-operated systems. Using autocalibration techniques to provide excellent precision over the extended industrial temperature range, the INA333 device also offers exceptionally low noise density (50nV/√Hz) that extends down to DC.