SLUSD78C February   2019  – January 2023 UCC21750

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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  Power Ratings
    6. 6.6  Insulation Specifications
    7. 6.7  Safety Limiting Values
    8. 6.8  Electrical Characteristics
    9. 6.9  Safety-Related Certifications
    10. 6.10 Switching Characteristics
    11. 6.11 Insulation Characteristics Curves
    12. 6.12 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Propagation Delay
      1. 7.1.1 Regular Turn-OFF
    2. 7.2 Input Deglitch Filter
    3. 7.3 Active Miller Clamp
      1. 7.3.1 Internal On-chip Active Miller Clamp
    4. 7.4 Undervoltage Lockout (UVLO)
      1. 7.4.1 VCC UVLO
      2. 7.4.2 VDD UVLO
    5. 7.5 Desaturation (DESAT) Protection
      1. 7.5.1 DESAT Protection with Soft Turn-OFF
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Power Supply
      2. 8.3.2  Driver Stage
      3. 8.3.3  VCC and VDD Undervoltage Lockout (UVLO)
      4. 8.3.4  Active Pulldown
      5. 8.3.5  Short Circuit Clamping
      6. 8.3.6  Internal Active Miller Clamp
      7. 8.3.7  Desaturation (DESAT) Protection
      8. 8.3.8  Soft Turn-Off
      9. 8.3.9  Fault (FLT, Reset, and Enable (RST/EN)
      10. 8.3.10 Isolated Analog to PWM Signal Function
    4. 8.4 Device Functional Modes
  9. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Input Filters for IN+, IN–, and RST/EN
        2. 9.2.2.2 PWM Interlock of IN+ and IN–
        3. 9.2.2.3 FLT, RDY, and RST/EN Pin Circuitry
        4. 9.2.2.4 RST/EN Pin Control
        5. 9.2.2.5 Turn-On and Turn-Off Gate Resistors
        6. 9.2.2.6 Overcurrent and Short Circuit Protection
        7. 9.2.2.7 Isolated Analog Signal Sensing
          1. 9.2.2.7.1 Isolated Temperature Sensing
          2. 9.2.2.7.2 Isolated DC Bus Voltage Sensing
        8. 9.2.2.8 Higher Output Current Using an External Current Buffer
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

9.2.2.6 Overcurrent and Short Circuit Protection

A standard desaturation circuit can be applied to the DESAT pin. If the voltage of the DESAT pin is higher than the threshold VDESAT, the soft turn-off is initiated. A fault is reported to the input side to DSP/MCU. The output is held to LOW after the fault is detected, and can only be reset by the RST/EN pin. The state-of-art overcurrent and short circuit detection time helps to ensure a short shutdown time for SiC MOSFET and IGBT.

If DESAT pin is not in use, it must be tied to COM to avoid overcurrent fault false triggering.

  • TI recommends fast reverse recovery high voltage diode in the desaturation circuit. A resistor is recommended in series with the high voltage diode to limit the inrush current.
  • Ti recommends a Schottky diode from COM to DESAT to prevent driver damage caused by negative voltage.
  • TI recommends a Zener diode from COM to DESAT to prevent driver damage caused by positive voltage.