SLUSD77C August   2020  – January 2024 UCC21732

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Power Ratings
    6. 5.6  Insulation Specifications
    7. 5.7  Safety-Related Certifications
    8. 5.8  Safety Limiting Values
    9. 5.9  Electrical Characteristics
    10. 5.10 Switching Characteristics
    11. 5.11 Insulation Characteristics Curves
    12. 5.12 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Propagation Delay
      1. 6.1.1 Regular Turn-OFF
    2. 6.2 Input Deglitch Filter
    3. 6.3 Active Miller Clamp
      1. 6.3.1 External Active Miller Clamp
    4. 6.4 Under Voltage Lockout (UVLO)
      1. 6.4.1 VCC UVLO
      2. 6.4.2 VDD UVLO
    5. 6.5 OC (Over Current) Protection
      1. 6.5.1 OC Protection with 2-Level Turn-OFF
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Power Supply
      2. 7.3.2  Driver Stage
      3. 7.3.3  VCC and VDD Undervoltage Lockout (UVLO)
      4. 7.3.4  Active Pulldown
      5. 7.3.5  Short Circuit Clamping
      6. 7.3.6  External Active Miller Clamp
      7. 7.3.7  Overcurrent and Short Circuit Protection
      8. 7.3.8  2-Level Turn-Off
      9. 7.3.9  Fault ( FLT, Reset and Enable ( RST/EN)
      10. 7.3.10 Isolated Analog to PWM Signal Function
    4. 7.4 Device Functional Modes
  9. 8 Applications 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 Input Filters for IN+, IN- and RST/EN
        2. 8.2.2.2 PWM Interlock of IN+ and IN-
        3. 8.2.2.3 FLT, RDY and RST/EN Pin Circuitry
        4. 8.2.2.4 RST/EN Pin Control
        5. 8.2.2.5 Turn-On and Turn-Off Gate Resistors
        6. 8.2.2.6 External Active Miller Clamp
        7. 8.2.2.7 Overcurrent and Short Circuit Protection
          1. 8.2.2.7.1 Protection Based on Power Modules with Integrated SenseFET
          2. 8.2.2.7.2 Protection Based on Desaturation Circuit
          3. 8.2.2.7.3 Protection Based on Shunt Resistor in Power Loop
        8. 8.2.2.8 Isolated Analog Signal Sensing
          1. 8.2.2.8.1 Isolated Temperature Sensing
          2. 8.2.2.8.2 Isolated DC Bus Voltage Sensing
        9. 8.2.2.9 Higher Output Current Using an External Current Buffer
  10. 9 Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.8 2-Level Turn-Off

The UCC21732 initiates a fast 2-level turn-off when the overcurrent and short circuit protection is triggered. When the overcurrent and short circuit fault happens, the power power semiconductor transits from the linear region to the saturation region very fast. The channel current is controlled by the gate voltage. By pulling down the gate voltage to a mid-voltage level V2LOFF and stay for a fixed time t2LOFF, the channel current can be limited to a much lower level, which significantly reduces the energy dissipation during the fault event. After t2LOFF, the driver continues to pull down the gate voltage by the soft turn off current ITL3 until it reaches VEE. With dI/dt of the channel current is controlled by the gate voltage and decreasing in a soft manner, thus the overshoot of the power semiconductor is limited and prevents the overvoltage breakdown. The timing diagram of 2-level turn-off shows in Figure 6-10.

GUID-20231215-SS0I-S2MV-JXZ2-LQNWGD8HWLHB-low.png Figure 7-6 2-Level Turn-Off