JAJS177F November   2003  – February 2020 TPS2490 , TPS2491

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
  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 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  VCC
      2. 7.3.2  SENSE
      3. 7.3.3  GATE
      4. 7.3.4  OUT
      5. 7.3.5  EN
      6. 7.3.6  VREF
      7. 7.3.7  PROG
      8. 7.3.8  TIMER
      9. 7.3.9  PG
      10. 7.3.10 GND
    4. 7.4 Device Functional Modes
      1. 7.4.1 Board Plug-In ()
      2. 7.4.2 TIMER and PG Operation ()
      3. 7.4.3 Action of the Constant Power Engine ()
      4. 7.4.4 Response to a Hard Output Short ( and )
      5. 7.4.5 Automatic Restart ()
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Alternative Inrush Designs
        1. 8.1.1.1 Gate Capacitor (dV/dt) Control
        2. 8.1.1.2 PROG Inrush Control
      2. 8.1.2 Additional Design Considerations
        1. 8.1.2.1 Use of PG
        2. 8.1.2.2 Faults and Backplane Voltage Droop
        3. 8.1.2.3 Output Clamp Diode
        4. 8.1.2.4 Gate Clamp Diode
        5. 8.1.2.5 High Gate Capacitance Applications
        6. 8.1.2.6 Input Bypass
        7. 8.1.2.7 Output Short Circuit Measurements
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Select RSNS and CL setting
        2. 8.2.2.2 Selecting the Hot Swap FET(s)
        3. 8.2.2.3 Select Power Limit
        4. 8.2.2.4 Set Fault Timer
        5. 8.2.2.5 Check MOSFET SOA
        6. 8.2.2.6 Set Under-Voltage Threshold
        7. 8.2.2.7 Choose R5, and CIN
        8. 8.2.2.8 Input and Output Protection
        9. 8.2.2.9 Final Schematic and Component Values
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 PC Board Guidelines
      2. 10.1.2 System Considerations
    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 開発サポート
    2. 11.2 ドキュメントのサポート
      1. 11.2.1 関連資料
    3. 11.3 関連リンク
    4. 11.4 ドキュメントの更新通知を受け取る方法
    5. 11.5 コミュニティ・リソース
    6. 11.6 商標
    7. 11.7 静電気放電に関する注意事項
    8. 11.8 Glossary
  12. 12メカニカル、パッケージ、および注文情報

7.1 Overview

The inline protection functionality of the TPS2490 is designed to control the inrush current to the load upon insertion of a circuit card into a live backplane or other hot power source, thereby limiting the voltage sag on the backplane's supply voltage and the dV/dt of the voltage applied to the load. Effects on other circuits in the system are minimized, preventing possible unintended resets. A controlled shutdown when the circuit card is removed can also be implemented using the TPS2490.

In addition to a programmable current limit, the TPS2490 monitors and limits the maximum power dissipation in the series pass device to maintain operating within the device Safe Operating Area (SOA). Either current limiting or power limiting for an extended period of time results in the shutdown of the series pass device. In this event, the TPS2490 will latch off while the TPS2491 will retry an infinite number of timer to recover after the fault is removed. Programmable EN circuit shuts down the TPS2490 when the system input voltage falls below the desired operating range.