SNOU206 October   2024 LMG2640

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5.   5
  6. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
    5. 1.5 General TI High Voltage Evaluation User Safety Guidelines
      1. 1.5.1 Safety and Precautions
  7. 2Hardware
    1. 2.1 LMG2640EVM-090 Daughter Card
      1. 2.1.1 Test Points
      2. 2.1.2 Integrated Current Sensing
      3. 2.1.3 Enable Pin
      4. 2.1.4 FAULT
      5. 2.1.5 Power Pins
      6. 2.1.6 Heat Sink
    2. 2.2 Motherboard
      1. 2.2.1 Bias Supply
      2. 2.2.2 PWM Input
      3. 2.2.3 Fault Protection
    3. 2.3 Recommended Footprint
    4. 2.4 Test Equipment
    5. 2.5 Test Procedure When Paired With LMG342X-BB-EVM
      1. 2.5.1 Setup
      2. 2.5.2 Start-Up and Operating Procedure
      3. 2.5.3 Test Results
      4. 2.5.4 Shutdown Procedure
      5. 2.5.5 Additional Operating Notes
  8. 3Hardware Design Files
    1. 3.1 LMG2640EVM-090 Schematic
    2. 3.2 Motherboard Schematic
    3. 3.3 PCB Layout
    4. 3.4 Bill of Materials
  9. 4Additional Information
    1. 4.1 Trademarks
  10. 5Related Documentation

2.1.2 Integrated Current Sensing

The current-sense emulation function creates a scaled replica of the GaN power FET positive drain current at the output of the CS pin. The current-sense emulation gain, GCSE, is 0.616mA output from the CS pin, ICS, for every 1A passing into the drain of the low-side GaN power FET, ID.

A 162 Ohm resistor connected to AGND sets the output conversion ratio which can be monitored on an oscilloscope. In addition to the LMG2640 Integrated 650V GaN Half Bridge data sheet, see the Maximize System Efficiency With Integrated Current Sensing From TI GaN application brief, which describes the function of the CS pin and how to manipulate the output resistor for system-level control.