SLVSHI9A March   2025  – September 2025 TPS7H5020-SEP , TPS7H5020-SP

PRODMIX  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Quality Conformance Inspection
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Input Voltage (VIN) and VLDO
      2. 7.3.2  Driver Input Voltage (PVIN)
      3. 7.3.3  Start-Up
      4. 7.3.4  Enable and Undervoltage Lockout (UVLO)
      5. 7.3.5  Voltage Reference
      6. 7.3.6  Error Amplifier
      7. 7.3.7  Output Voltage Programming
      8. 7.3.8  Soft Start (SS)
      9. 7.3.9  Switching Frequency and External Synchronization
        1. 7.3.9.1 Internal Oscillator Mode
        2. 7.3.9.2 External Synchronization Mode
          1. 7.3.9.2.1 External Synchronization with TPS7H5021
      10. 7.3.10 Duty Cycle Limit
      11. 7.3.11 Minimum On-Time and Off-Time
      12. 7.3.12 Pulse Skipping
      13. 7.3.13 Leading Edge Blank Time
      14. 7.3.14 Current Sense and PWM Generation (CS_ILIM)
      15. 7.3.15 Gate Driver Output
      16. 7.3.16 Unpowered Voltage Clamp
      17. 7.3.17 Sourcing Driver Return (OUTH_REF)
      18. 7.3.18 Slope Compensation (RSC)
      19. 7.3.19 Frequency Compensation
      20. 7.3.20 Thermal Shutdown
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Switching Frequency
        2. 8.2.2.2  Output Voltage Programming Resistor Selection
        3. 8.2.2.3  Driver PVIN Configuration
        4. 8.2.2.4  Soft-Start Capacitor Selection
        5. 8.2.2.5  Transformer Design
        6. 8.2.2.6  Primary Power Switch Selection
        7. 8.2.2.7  Output Diode Selection
        8. 8.2.2.8  RCD Clamp
        9. 8.2.2.9  Output Capacitance Selection
        10. 8.2.2.10 Current Sense Resistor
        11. 8.2.2.11 Frequency Compensation Component Selection
      3. 8.2.3 Application Curves
      4. 8.2.4 Boost Converter
      5. 8.2.5 Feedback Isolation Using ISOS510
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.2.2.1 Switching Frequency

The flyback converter was designed to operate at a switching frequency of 500kHz. For space-grade converter designs, the benefits of GaN power devices over silicon counterparts are readily apparent at this switching frequency. Using Equation 31, the required RT resistor for the desired frequency can be determined. Note that the value of fSW is in kHz and RT is giving in kΩ.

Equation 31. RT=112390fSW-14.2
Equation 32. RT=112390500-14.2=210.5kΩ

A standard resistor value of 210kΩ is good for the design. A slightly lower value of 205kΩ was used due to availability.