JAJSI67 November   2019 TPS7A52

ADVANCE INFORMATION for pre-production products; subject to change without notice.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      RFコンポーネントの電源
      2.      デジタル負荷の電源
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Voltage Regulation Features
        1. 8.3.1.1 DC Regulation
        2. 8.3.1.2 AC and Transient Response
      2. 8.3.2 System Start-Up Features
        1. 8.3.2.1 Programmable Soft Start (NR/SS Pin)
        2. 8.3.2.2 Internal Sequencing
          1. 8.3.2.2.1 Enable (EN)
          2. 8.3.2.2.2 Undervoltage Lockout (UVLO) Control
          3. 8.3.2.2.3 Active Discharge
        3. 8.3.2.3 Power-Good Output (PG)
      3. 8.3.3 Internal Protection Features
        1. 8.3.3.1 Foldback Current Limit (ICL)
        2. 8.3.3.2 Thermal Protection (Tsd)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Regulation
      2. 8.4.2 Disabled
      3. 8.4.3 Current Limit Operation
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1  Recommended Capacitor Types
        1. 9.1.1.1 Input and Output Capacitor Requirements (CIN and COUT)
        2. 9.1.1.2 Noise-Reduction and Soft-Start Capacitor (CNR/SS)
        3. 9.1.1.3 Feed-Forward Capacitor (CFF)
      2. 9.1.2  Soft Start and Inrush Current
      3. 9.1.3  Optimizing Noise and PSRR
      4. 9.1.4  Charge Pump Noise
      5. 9.1.5  Current Sharing
      6. 9.1.6  Adjustable Operation
      7. 9.1.7  Power-Good Operation
      8. 9.1.8  Undervoltage Lockout (UVLO) Operation
      9. 9.1.9  Dropout Voltage (VDO)
      10. 9.1.10 Device Behavior During Transition From Dropout Into Regulation
      11. 9.1.11 Load Transient Response
      12. 9.1.12 Reverse Current Protection Considerations
      13. 9.1.13 Power Dissipation (PD)
      14. 9.1.14 Estimating Junction Temperature
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Board Layout
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 デバイス・サポート
      1. 12.1.1 開発サポート
        1. 12.1.1.1 リファレンス・デザイン
      2. 12.1.2 デバイスの項目表記
    2. 12.2 ドキュメントのサポート
      1. 12.2.1 関連資料
    3. 12.3 ドキュメントの更新通知を受け取る方法
    4. 12.4 コミュニティ・リソース
    5. 12.5 商標
    6. 12.6 静電気放電に関する注意事項
    7. 12.7 Glossary
  13. 13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

9.1.12 Reverse Current Protection Considerations

As with most LDOs, this device can be damaged by excessive reverse current.

Conditions where excessive reverse current can occur are outlined in this section, all of which can exceed the absolute maximum rating of VOUT > VIN + 0.3 V:

  • If the device has a large COUT, then the input supply collapses quickly and the load current becomes very small
  • The output is biased when the input supply is not established
  • The output is biased above the input supply

If an excessive reverse current flow is expected in the application, then external protection must be used to protect the device. Figure 8 shows one approach of protecting the device.

TPS7A52 ai_reverse_current_soln_sbvs267.gifFigure 8. Example Circuit for Reverse Current Protection Using a Schottky Diode