SNVS847F June   2012  – November 2017 LM34926

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 Operating Ratings
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    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  Control Overview
      2. 7.3.2  VCC Regulator
      3. 7.3.3  Regulation Comparator
      4. 7.3.4  Overvoltage Comparator
      5. 7.3.5  On-Time Generator
      6. 7.3.6  Current Limit
      7. 7.3.7  N-Channel Buck Switch and Driver
      8. 7.3.8  Synchronous Rectifier
      9. 7.3.9  Undervoltage Detector
      10. 7.3.10 Thermal Protection
      11. 7.3.11 Ripple Configuration
      12. 7.3.12 Soft Start
    4. 7.4 Device Functional Modes
  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  Custom Design With WEBENCH® Tools
        2. 8.2.2.2  Transformer Turns Ratio
        3. 8.2.2.3  Total IOUT
        4. 8.2.2.4  RFB1, RFB2
        5. 8.2.2.5  Frequency Selection
        6. 8.2.2.6  Transformer Selection
        7. 8.2.2.7  Primary Output Capacitor
        8. 8.2.2.8  Secondary Output Capacitor
        9. 8.2.2.9  Type III Feedback Ripple Circuit
        10. 8.2.2.10 Secondary Diode
        11. 8.2.2.11 VCC and Bootstrap Capacitor
        12. 8.2.2.12 Input Capacitor
        13. 8.2.2.13 UVLO Resistors
        14. 8.2.2.14 VCC Diode
      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 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Custom Design With WEBENCH® Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 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 E Revision (December 2014) to F Revision

  • Added WEBENCH links to the data sheetGo
  • Deleted lead temperature from the Absolute Maximum Ratings table Go
  • Changed TON vs VIN and RON in Typical Characteristics Go
  • Changed 14 V to 13 V in VCC Regulator section Go
  • Added Receiving Notification of Documentation Updates sectionGo

Changes from D Revision (December 2013) to E Revision

  • Added Pin Configuration and Functions section, Handling Rating table, Switching Characteristics table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section Go
  • CMS Request No.: C1411181Go
  • Changed Thermal Information tableGo
  • Changed Control Overview sectionGo
  • Changed Soft-Start Circuit, Isolated Fly-Buck Converter graphics.Go
  • Deleted Lowest Part Count Isolated Application Schematic Go

Changes from C Revision (December 2013) to D Revision

  • Added Thermal ParametersGo

Changes from B Revision (March 2013) to C Revision

  • Changed formatting to the TI standardGo
  • Changed minimum operating input voltage from 9 V to 7.5 V in Features, Typical Application, Pin Descriptions, Recommended Operating Ratings Go
  • Added Absolute Maximum Junction TemperatureGo

Changes from A Revision (March 2013) to B Revision

  • Added SW to RTN (100 ns transient) in Absolute Maximum Ratings Go

Changes from * Revision (March 2013) to A Revision

  • Changed layout of National Data Sheet to the TI standardsGo