SLUS829G August   2008  – February 2020 UCC2897A

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Diagram
  4. 4 Revision History
  5. 5 Device Options
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Detailed Pin Descriptions
        1. 8.3.1.1  RDEL
        2. 8.3.1.2  RON
        3. 8.3.1.3  ROFF
        4. 8.3.1.4  VREF
        5. 8.3.1.5  SYNC
        6. 8.3.1.6  GND
        7. 8.3.1.7  CS
        8. 8.3.1.8  RSLOPE
        9. 8.3.1.9  FB
        10. 8.3.1.10 SS/SD
        11. 8.3.1.11 PGND
        12. 8.3.1.12 AUX
        13. 8.3.1.13 OUT
        14. 8.3.1.14 VDD
        15. 8.3.1.15 LINEUV
        16. 8.3.1.16 VIN
        17. 8.3.1.17 LINEOV
      2. 8.3.2 JFET Control and UVLO
      3. 8.3.3 Line Undervoltage Protection
      4. 8.3.4 Line Overvoltage Protection
      5. 8.3.5 Pulse Skipping
      6. 8.3.6 Synchronization
      7. 8.3.7 Gate Drive Connection
      8. 8.3.8 Bootstrap Biasing
    4. 8.4 Device Functional Modes
  9. 9 Application 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 Oscillator
        2. 9.2.2.2 Soft Start
        3. 9.2.2.3 VDD Bypass Requirements
        4. 9.2.2.4 Delay Programming
        5. 9.2.2.5 Input Voltage Monitoring
        6. 9.2.2.6 Current Sense and Slope Compensation
      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 Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.3.7 Gate Drive Connection

The low-side P-channel gate-drive circuit involves a level shifter using a capacitor and a diode which ensures that the gate-drive amplitude of the auxiliary switch is independent of the actual duty-cycle of the converter.

Detailed analysis and design examples of these and many similar gate-drive solutions are given in Design and Application Guide for High Speed MOSFET Gate Drive Circuits, SLUP169.

UCC2897A low_side_SLUS829.gifFigure 24. Low-Side P-Channel