TIDUFC8 July   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Introduction
      2. 2.2.2 Basic Operation Principles and ZVS Requirements
    3. 2.3 Highlighted Products
      1. 2.3.1 UCC27288
      2. 2.3.2 UCC23513
      3. 2.3.3 TMS320F2800137
      4. 2.3.4 TLV9062
      5. 2.3.5 INA181
      6. 2.3.6 TPSM861252
      7. 2.3.7 AMC0311R
  9. 3System Design Theory
    1. 3.1 Design Theory
      1. 3.1.1 Resonant Tank Design
      2. 3.1.2 Full-Range ZVS Realization
      3. 3.1.3 Total Control Algorithm
      4. 3.1.4 Resonant Tank RMS Current Analysis
    2. 3.2 Hardware Design Theory
      1. 3.2.1 Resonant Capacitors
      2. 3.2.2 Power Stage
      3. 3.2.3 Voltage Sensing
      4. 3.2.4 Current Sensing
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Software Requirements
      1. 4.2.1 Simulation
    3. 4.3 Test Setup
    4. 4.4 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
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author

2.3.5 INA181

The INA181, INA2181, and INA4181 (INAx181) current sense amplifiers are designed for cost-optimized applications. These devices are part of a family of bidirectional, current-sense amplifiers (also called current-shunt monitors) that sense voltage drops across current-sense resistors at common-mode voltages from –0.2V to +26V, independent of the supply voltage. The INAx181 family integrates a matched resistor gain network in four, fixed-gain device options: 20V/V, 50V/V, 100V/V, or 200V/V. This matched gain resistor network minimizes gain error and reduces the temperature drift.

These devices operate from a single 2.7V to 5.5V power supply. The single-channel INA181 draws a maximum supply current of 260µA; whereas, the dual-channel INA2181 draws a maximum supply current of 500µA, and the quad-channel INA4181 draws a maximum supply current of 900µA.

The INA181 is available in both the 6-pin, SOT-23 and SC70 packages. The INA2181 is available in 10-pin, VSSOP and WSON packages. The INA4181 is available in a 20-pin, TSSOP package. All device options are specified over the extended operating temperature range of –40°C to +125°C.