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

10.1 Layout Guidelines

The printed circuit board (PCB) requires careful layout to minimize current loop areas and track lengths, especially when using single-sided PCBs.

  • Place a ceramic MLCC bypass capacitor as close as possible between VDD and VS, and between REG and VS.
  • Avoid connecting VD and VS sense points at locations where stray inductance is added to the SR MOSFET package inductance, as this will tend to turn off the SR prematurely.
  • Run a track from the VD pin directly to the MOSFET drain pad to avoid sensing voltage across the stray inductance in the SR drain current path.
  • Run a track from the VS pin directly to the MOSFET source pad to avoid sensing voltage across the stray inductance in the SR source current path. Because this trace shares both the gate driver path and the MOSFET voltage sensing path, it is recommended to make this trace as short as possible.
  • Run parallel tracks from VG and VS to the SR MOSFET. Include a series gate resistor between VG and SR MOSFET gate pin to dampen ringing if it is needed.