SLUSEM9A September   2022  – June 2024 UCC21755-Q1

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 Limiting Values
    8. 5.8  Electrical Characteristics
    9. 5.9  Switching Characteristics
    10. 5.10 Insulation Characteristics Curves
    11. 5.11 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Propagation Delay
      1. 6.1.1 Non-Inverting and Inverting Propagation Delay
    2. 6.2 Input Deglitch Filter
    3. 6.3 Active Miller Clamp
      1. 6.3.1 Internal On-Chip Active Miller Clamp
    4. 6.4 Undervoltage Lockout (UVLO)
      1. 6.4.1 VCC UVLO
      2. 6.4.2 VDD UVLO
    5. 6.5 Desaturation (DESAT) Protection
      1. 6.5.1 DESAT Protection with Soft 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  Internal Active Miller Clamp
      7. 7.3.7  Desaturation (DESAT) Protection
      8. 7.3.8  Soft 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 Overcurrent and Short Circuit Protection
        7. 8.2.2.7 Isolated Analog Signal Sensing
          1. 8.2.2.7.1 Isolated Temperature Sensing
          2. 8.2.2.7.2 Isolated DC Bus Voltage Sensing
        8. 8.2.2.8 Higher Output Current Using an External Current Buffer
      3. 8.2.3 Application Curves
  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 Device Support
      1. 11.1.1 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

7.3.3 VCC and VDD Undervoltage Lockout (UVLO)

The device implements the internal UVLO protection feature for both input and output power supplies VCC and VDD. When the supply voltage is lower than the threshold voltage, the driver output is held as LOW. The output only goes HIGH when both VCC and VDD are out of the UVLO status. The UVLO protection feature not only reduces the power consumption of the driver itself during low power supply voltage condition, but also increases the efficiency of the power stage. For SiC MOSFET and IGBT, the on-resistance reduces while the gate-source voltage or gate-emitter voltage increases. If the power semiconductor is turned on with a low VDD value, the conduction loss increases significantly and can lead to a thermal issue and efficiency reduction of the power stage. The device implements 12-V threshold voltage of VDD UVLO, with 800-mV hysteresis. This threshold voltage is suitable for both SiC MOSFET and IGBT.

The UVLO protection block features with hysteresis and deglitch filter, which help to improve the noise immunity of the power supply. During the turn on and turn off switching transient, the driver sources and sinks a peak transient current from the power supply, which can result in sudden voltage drop of the power supply. With hysteresis and UVLO deglitch filter, the internal UVLO protection block will ignore small noises during the normal switching transients.

The timing diagrams of the UVLO feature of VCC and VDD are shown in Figure 6-8, and Figure 6-9. The RDY pin on the input side is used to indicate the power good condition. The RDY pin is open drain. During UVLO condition, the RDY pin is held in low status and connected to GND. Normally the pin is pulled up externally to VCC to indicate the power good. The AIN-APWM function stops working during the UVLO status. The APWM pin on the input side will be held LOW.