TIDUEX8 September   2020

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 TPS23730
      2. 2.2.2 TLV431
    3. 2.3 System Design Theory
      1. 2.3.1 IEEE802.3bt Introduction
  8. 3Hardware, Testing Requirements, and Test Results
    1. 3.1 Required Hardware
      1. 3.1.1 Hardware
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
      2. 3.2.2 Test Results
        1. 3.2.2.1 Efficiency
        2. 3.2.2.2 Control Loop Gain/Stability
        3. 3.2.2.3 Load Transient
        4. 3.2.2.4 Input and Output Ripple
        5. 3.2.2.5 Switching Waveforms
        6. 3.2.2.6 Start Up Response
        7. 3.2.2.7 Soft-Stop Response
        8. 3.2.2.8 Output Short Circuit Response
        9. 3.2.2.9 Thermal Performance
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout Recommendations
      1. 4.3.1 Layout Prints
    4. 4.4 Altium Project
    5. 4.5 Gerber Files
    6. 4.6 Assembly Drawings
  10. 5Related Documentation
    1. 5.1 Trademarks
  11. 6Terminology
  12. 7About the Author

3.2.2.5 Switching Waveforms

Figure 3-8 shows the VDS voltage of secondary parallel MOSFET (Q6) and Figure 3-9 shows the primary synchronous MOSFET (Q8) at a 10 A load. The input voltage is 48-V. Figure 3-10 shows the VDS and Vgs voltage of primary switching MOSFET (Q11) and Figure 3-11 shows the VDS and Vgs voltage across the primary synchronous MOSFET (Q10) at a 10 A load.

GUID-5459BA3B-A035-4360-8716-CABFBEAA0E0C-low.jpgFigure 3-8 Secondary Parallel MOSFET Voltage, 10-A Load, 50 V-div, 1 µs-div
GUID-DE9DF67A-D556-46A6-8383-A6B65F8DBB69-low.jpgFigure 3-10 Primary MOSFET Voltage, 10-A Load, 50 V-div, 1 µs-DIV
GUID-F1C77326-F734-4BAB-9AA2-C67344392395-low.jpgFigure 3-9 Secondary Series MOSFET Voltage, 10-A Load, 50 V-div, 1 µs-div
GUID-DC747140-FA58-4306-B622-1D5487EDFC0D-low.jpgFigure 3-11 Primary Synchronous MOSFET Voltage, 10-A Load, 50 V-div, 1 µs-DIV