SNVS846G June   2012  – November 2017 LM34925

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 Conditions
    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 Application Circuit: 20-V to 95-V Input and 10-V, 100-mA Output Isolated Fly-Buck Converter
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Transformer Turns Ratio
          2. 8.2.1.2.2  Total IOUT
          3. 8.2.1.2.3  RFB1, RFB2
          4. 8.2.1.2.4  Frequency Selection
          5. 8.2.1.2.5  Transformer Selection
          6. 8.2.1.2.6  Primary Output Capacitor
          7. 8.2.1.2.7  Secondary Output Capacitor
          8. 8.2.1.2.8  Type III Feedback Ripple Circuit
          9. 8.2.1.2.9  Secondary Diode
          10. 8.2.1.2.10 VCC and Bootstrap Capacitor
          11. 8.2.1.2.11 Input Capacitor
          12. 8.2.1.2.12 UVLO Resistors
          13. 8.2.1.2.13 VCC Diode
      2. 8.2.2 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 Documentation Support
      1. 11.1.1 Related Documentation
    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

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

4 Revision History

Changes from F Revision (November 2014) to G Revision

  • Deleted lead temperature and related footnote from Abs Max tableGo
  • Changed /moved Storage temp from Handling ratings to Absolute Maximum Ratings, changed Handling ratings title to ESD ratingsGo
  • Changed 14 V to 13 V in the VCC Regulator section Go

Changes from E Revision (December 2013) to F 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
  • Changed Thermal Information tableGo
  • Changed TON vs VIN and RON in Typical Characteristics Go
  • Changed Control Overview section, Ripple Configuration tableGo
  • Changed Soft-Start Circuit, Isolated Fly-Buck Converter graphics.Go

Changes from D Revision (December 2013) to E Revision

  • Added Thermal ParametersGo

Changes from C Revision (September 2013) to D Revision

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

Changes from B Revision (September, 2013) to C Revision

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

Changes from A Revision (February 2013) to B Revision

  • Changed layout of National Data Sheet to TI formatGo