SLUSDM7A April   2020  – May 2020 UCC21736-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Pin Configuration
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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-Related Certifications
    8. 6.8  Safety Limiting Values
    9. 6.9  Electrical Characteristics
    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 External Active Miller Clamp
    4. 7.4 Under Voltage Lockout (UVLO)
      1. 7.4.1 VCC UVLO
      2. 7.4.2 VDD UVLO
      3. 7.4.3 VEE UVLO
    5. 7.5 OC (Over Current) Protection
      1. 7.5.1 OC Protection with Soft Turn-OFF
    6. 7.6 ASC Protection
  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, VDD and VEE Undervoltage Lockout (UVLO)
      4. 8.3.4 Active Pulldown
      5. 8.3.5 Short Circuit Clamping
      6. 8.3.6 External Active Miller Clamp
      7. 8.3.7 Overcurrent and Short Circuit Protection
      8. 8.3.8 Fault (FLT, Reset and Enable (RST/EN)
      9. 8.3.9 ASC Protection and APWM Monitor
    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 External Active Miller Clamp
        7. 9.2.2.7 Overcurrent and Short Circuit Protection
          1. 9.2.2.7.1 Protection Based on Power Modules with Integrated SenseFET
          2. 9.2.2.7.2 Protection Based on Desaturation Circuit
          3. 9.2.2.7.3 Protection Based on Shunt Resistor in Power Loop
        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 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resource
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2.7.1 Protection Based on Power Modules with Integrated SenseFET

The overcurrent and short circuit protection function is suitable for the SiC MOSFET and IGBT modules with integrated SenseFET. The SenseFET scales down the main power loop current and outputs the current with a dedicated pin of the power module. With external high precision sensing resistor, the scaled down current can be measured and the main power loop current can be calculated. The value of the sensing resistor RS sets the protection threshold of the main current. For example, with a ratio of 1:N = 1:50000 of the integrated current mirror, by using the RS as 20Ω, the threshold protection current is:

Equation 10. UCC21736-Q1 eq-09-junction-temp-2.gif

The overcurrent and short circuit protection based on integrated SenseFET has high precision, as it is sensing the current directly. The accuracy of the method is related to two factors: the scaling down ratio of the main power loop current and the SenseFET, and the precision of the sensing resistor. Since the current is sensed from the SenseFET, which is isolated from the main power loop, and the current is scaled down significantly with much less dI/dt, the sensing loop has good noise immunity. To further improve the noise immunity, a low pass filter can be added. A 100pF to 10nF filter capacitor can be added. The delay time caused by the low pass filter should also be considered for the protection circuitry design.

UCC21736-Q1 OC-Protection-block-update.gifFigure 51. Overcurrent and Short Circuit Protection Based on IGBT Module with SenseFET