SLUSFA0 September   2023 UCC21738-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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  Switching Characteristics
    10. 6.10 Insulation Characteristics Curves
    11. 6.11 Typical Characteristics
  8. 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 Undervoltage Lockout (UVLO)
      1. 7.4.1 VCC UVLO
      2. 7.4.2 VDD UVLO
    5. 7.5 Overcurrent (OC) Protection
      1. 7.5.1 OC Protection with Soft Turn-OFF
    6. 7.6 ASC Support
  9. 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  External Active Miller Clamp
      7. 8.3.7  Overcurrent and Short Circuit Protection
      8. 8.3.8  Soft Turn-off
      9. 8.3.9  Fault (FLT), Reset, and Enable (RST/EN)
      10. 8.3.10 ASC Support and APWM Monitor
    4. 8.4 Device Functional Modes
  10. 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
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  13. 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
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2.2 PWM Interlock of IN+ and IN-

The UCC21738-Q1 features a PWM interlock for the IN+ and IN- pins, which can be used to prevent a phase leg shoot-through issue. As shown in Table 8-1, the output is logic low while both IN+ and IN- are logic high. When only IN+ is used, IN- can be tied to GND. To utilize the PWM interlock function, the PWM signal of the other switch in the phase leg can be sent to the IN- pin. As shown in Figure 9-2, PWM_T is the PWM signal to the top-side switch, and PWM_B is the PWM signal to the bottom-side switch. For the top-side gate driver, the PWM_T signal is given to the IN+ pin, while the PWM_B signal is given to the IN- pin; for the bottom-side gate driver, the PWM_B signal is given to the IN+ pin, while PWM_T signal is given to the IN- pin. When both PWM_T and PWM_B signals are high, the outputs of both gate drivers are logic low to prevent the shoot-through condition.

GUID-DD8C6A92-7E75-4DAE-B66C-1E544E9F0A60-low.gifFigure 9-2 PWM Interlock for a Half Bridge