SNVS359E May   2005  – December 2014 LM5021

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operation Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Performance Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 PWM Comparator and Slope Compensation
      2. 7.3.2 Current Limit and Current Sense
      3. 7.3.3 Oscillator, Shutdown and Sync Capability
      4. 7.3.4 Gate Driver and Max Duty Cycle Limit
      5. 7.3.5 Soft-Start
      6. 7.3.6 Hiccup Mode Overload Current Limiting
      7. 7.3.7 Skip Cycle Operation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation With VIN Below 20 V
      2. 7.4.2 Operation in Soft Start
      3. 7.4.3 Operation Under Normal Conditions
      4. 7.4.4 Operation in Skip Cycle
      5. 7.4.5 Operation at Overload
      6. 7.4.6 Operation in Hiccup Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Startup Circuit
      2. 8.1.2 Relationship Between Input Capacitor CIN and VCC Capacitor CVCC
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Primary Bulk Capacitance
        2. 8.2.2.2 Transformer
        3. 8.2.2.3 Main Switch FET and Output Rectifier
        4. 8.2.2.4 Timing Resistor
        5. 8.2.2.5 Soft-Start Time
        6. 8.2.2.6 Current Sensing Network
          1. 8.2.2.6.1 Gate Drive Resistor
          2. 8.2.2.6.2 VCC Capacitor
          3. 8.2.2.6.3 Startup Circuit
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Trademarks
    2. 11.2 Electrostatic Discharge Caution
    3. 11.3 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

4 Revision History

Changes from D Revision (March 2013) to E Revision

  • Added, updated, or revised the following sections: Pin Configuration and Functions; Specifications; Detailed Description; Application and Implementation; Power Supply Recommendations; Layout; Device and Documentation Support; and Mechanical, Packaging, and Orderable InformationGo

Changes from C Revision (March 2013) to D Revision

  • Changed layout of National Data Sheet to TI formatGo