TIDUFF4 October   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
      1. 1.1.1 General TI High Voltage Evaluation User Safety Guidelines
        1. 1.1.1.1 Safety and Precautions
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 GaN Power Stage
      2. 2.2.2 Inductor
      3. 2.2.3 Controller
      4. 2.2.4 Cooling
        1. 2.2.4.1 Heat Sink Placement
        2. 2.2.4.2 Via Placement
        3. 2.2.4.3 Copper Block
    3. 2.3 Highlighted Products
      1. 2.3.1 LMG3100R017
      2. 2.3.2 UCD3138A
      3. 2.3.3 TPSM365R6V5
      4. 2.3.4 TMP61
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Software Requirements
    3. 3.3 Test Setup
    4. 3.4 Test 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 Power Loop Optimization
        2. 4.1.3.2 Return Current Through Output Power Ground
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author

2.2.4 Cooling

One of the major aspects of this design is to dissipate heat efficiently through a heat sink and fan. This design uses the Z35-12.7B heat sink from Alpha Novatech, which has approximately 2.2°C/W thermal resistance at 200 linear feet per minute (LFM) air flow. The design also uses a 1mm-thick thermal interface material (TIM) with 6W/m-K thermal conductivity. Using a thinner TIM can improve heat dissipation, provided there is enough distance between the heat sink and the LMG3100R017 exposed GaN die and capacitors for electrical isolation.