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

9.2.2.3 FLT, RDY, and RST/EN Pin Circuitry

Both FLT and RDY pin are open-drain output. The RST/EN pin has a 50-kΩ internal pulldown resistor, so the driver is in OFF status if the RST/EN pin is not pulled up externally. A 5 kΩ resistor can be used as pullup resistor for the FLT, RDY and RST/EN pins.

To improve the noise immunity due to the parasitic coupling and common mode noise, low pass filters can be added between the FLT, RDY and RST/EN pins and the microcontroller. A filter capacitor between 100 pF to 300 pF can be added.

GUID-BB76DD75-1902-4871-A327-6EBCDA8D39B0-low.gifFigure 9-3 FLT, RDY, and RST/EN Pins Circuitry