SLUSCM5A August   2017  – February 2018 UCC24612

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Flyback with High-Side SR
      2.      Flyback with Low-Side SR
  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 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Power Management
      2. 7.3.2 Synchronous Rectifier Control
      3. 7.3.3 Adaptive Blanking Time
        1. 7.3.3.1 Turn-On Blanking Timer (Minimum On Time)
        2. 7.3.3.2 Turn-Off Blanking Timer
        3. 7.3.3.3 SR Turn-on Re-arm
      4. 7.3.4 Gate Voltage Clamping
      5. 7.3.5 Standby Mode
    4. 7.4 Device Functional Modes
      1. 7.4.1 UVLO Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Run Mode
  8. 8 Application 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 SR MOSFET Selection
        2. 8.2.2.2 Bypass Capacitor Selection
        3. 8.2.2.3 Snubber design
        4. 8.2.2.4 High-Side Operation
      3. 8.2.3 Application Curves
        1. 8.2.3.1 Steady State Testing Low-Side Configuration
        2. 8.2.3.2 Steady State Testing High-Side Configuration
  9. 9 Power Supply Recommendations
  10. 10PCB Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Community Resources
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.3 Adaptive Blanking Time

In power converters, the sensed the voltage across the SR is often noisy, caused by the parasitic ringing. This parasitic ringing is often associated with the SR and the primary-side switch turning on and off. Blanking time is used to deal with the parasitic ringing to prevent SR false turn on and off. Figure 19 shows more realistic waveforms and the internal control timing which accommodates them.

UCC24612 DCMRing.gifFigure 19. Parasitic Ringing Associated with DCM Operation