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

Abstract

Protecting power semiconductors like SiC MOSFETs and IGBTs from damage due to oversaturation is critical in power electronics design. When these devices perform beyond their intended operating region, excessive power dissipation can lead to thermal stress and failure.

Desaturation (DESAT) protection circuits offer cost-effective protection by monitoring the voltage across the semiconductor and shutting it down during an overcurrent event. This article explores how DESAT protection works, key circuit components, and how to design a DESAT circuit with the TPSI3133 isolated switch driver.