JAJSAY1E March   2008  – October 2017 LM2854

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      代表的なアプリケーション回路
  4. 4 改訂履歴
  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 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  Switching Frequency
      2. 7.3.2  Enable
      3. 7.3.3  Soft-Start
      4. 7.3.4  Tracking
      5. 7.3.5  Pre-Biased Start-up Capability
      6. 7.3.6  Feedback Voltage Accuracy
      7. 7.3.7  Positive Current Limit
      8. 7.3.8  Negative Current Limit
      9. 7.3.9  Overtemperature Protection
      10. 7.3.10 Loop Compensation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Soft-Start and Track Mode
      3. 7.4.3 Normal Operating 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 Input Filter Capacitor
        2. 8.2.2.2 AVIN Filtering Components
        3. 8.2.2.3 Soft-Start Capacitor
        4. 8.2.2.4 Tracking - Equal Soft-Start Time
        5. 8.2.2.5 Tracking - Equal Slew Rates
        6. 8.2.2.6 Enable and UVLO
        7. 8.2.2.7 Output Voltage Setting
        8. 8.2.2.8 Compensation Component Selection
        9. 8.2.2.9 Filter Inductor and Output Capacitor Selection
      3. 8.2.3 Application Curves
      4. 8.2.4 System Examples
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 ドキュメントのサポート
      1. 11.1.1 関連資料
    2. 11.2 商標
    3. 11.3 静電気放電に関する注意事項
    4. 11.4 Glossary
  12. 12メカニカル、パッケージ、および注文情報

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

7.3.4 Tracking

The LM2854 can track the output of a master power supply during soft-start by connecting a resistor divider to the SS pin. In this way, the output voltage slew rate of the LM2854 will be controlled by a master supply for loads that require precise sequencing. When the tracking function is used, a small value soft-start capacitor can be connected to the SS pin to alleviate output voltage overshoot when recovering from a current limit fault.

LM2854 30052857.gifFigure 14. Simplified Schematic Showing Use of Tracking