SLVAG18 April   2025 TPSI3100 , TPSI3100-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Why DESAT Protection Is Needed
    1. 1.1 Key Considerations for DESAT Protection
  5. 2Key DESAT Circuit Components
    1. 2.1 Circuit Startup Behavior
  6. 3Design Example
    1. 3.1 Design Requirements
    2. 3.2 Threshold Equations
    3. 3.3 Given Parameters
    4. 3.4 Inserting Given Parameters into Equations
    5. 3.5 Solving Equations for Unknowns
    6. 3.6 Selecting Resistances to Satisfy Equations
    7. 3.7 Determining Blanking Capacitance
    8. 3.8 Final Component Values
    9. 3.9 Lab Testing
  7. 4Closing

2 Key DESAT Circuit Components

  1. Blocking diode: Protects the circuit from high voltage while the IGBT/SiC MOSFET is off.
  2. Current limiting resistor (RLIM) to limit diode forward current.
  3. DESAT threshold detection (RDIV1, RDIV2): Defines the voltage threshold for detecting oversaturation.
  4. Blanking capacitance (CBLK): Filters noise and prevents false triggering. While blanking capacitance helps avoid false positives, it may also extend stress time on the IGBT/SiC MOSFET during overcurrent events.