TIDUF57 November   2023

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations {Required Topic}
    3. 2.3 Highlighted Products
      1. 2.3.1 LMG3624
  9. 3System Design Theory
    1. 3.1 Quasi-Resonant Operation
    2. 3.2 Transformer Design
    3. 3.3 GaN FET Switching Device
    4. 3.4 Current Sense Emulation Resistor
  10. 4Hardware, Testing Requirements, and Test Results
    1. 4.1 Required Hardware
      1. 4.1.1 Hardware
      2. 4.1.2 Testing Equipment
    2. 4.2 Test Setup
    3. 4.3 Test Results
      1. 4.3.1 Efficiency Results
      2. 4.3.2 Thermal Results
      3. 4.3.3 Switching Waveforms
      4. 4.3.4 Switching Transients
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support {Required Topic}
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author

2.1 Block Diagram

The reference design based on a low cost, high efficiency, and high density 65-W USB PD design including a QR flyback power stage, SR control , and USB PD control.

The QR flyback power stage is powered by the LMG3624, 170-mΩ GaN FET with integrated GaN FET and current sensing. The LMG3624 enables high-frequency operation, in which the transformer design is minimized. The integrated current sensing reduces the loss from traditional current shunt resistors, providing higher system efficiency and lower cost.

GUID-20231115-SS0I-SSVP-RSGH-9W34RQ3CC8F3-low.svg Figure 2-1 System Block Diagram of 65-W USB PD Reference Design