JAJSLG5 december   2022 LM7481

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Charge Pump
      2. 8.3.2 Dual Gate Control (DGATE, HGATE)
        1. 8.3.2.1 Reverse Battery Protection (A, C, DGATE)
        2. 8.3.2.2 Load Disconnect Switch Control (HGATE, OUT)
      3. 8.3.3 Overvoltage Protection and Battery Voltage sensing (VSNS, SW, OV)
      4. 8.3.4 Low Iq Shutdown and Undervoltage Lockout (EN/UVLO)
    4. 8.4 Device Functional Modes
    5. 8.5 Application Examples
      1. 8.5.1 Redundant Supply OR-ing With Inrush Current Limiting, Overvoltage Protection and ON/OFF Control
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical 12-V Reverse Battery Protection Application
      1. 9.2.1 Design Requirements for 12-V Battery Protection
      2. 9.2.2 Automotive Reverse Battery Protection
      3. 9.2.3 Detailed Design Procedure
        1. 9.2.3.1 Design Considerations
        2. 9.2.3.2 Charge Pump Capacitance VCAP
        3. 9.2.3.3 Input and Output Capacitance
        4. 9.2.3.4 Hold-up Capacitance
        5. 9.2.3.5 Overvoltage Protection and Battery Monitor
      4. 9.2.4 MOSFET Selection: Blocking MOSFET Q1
      5. 9.2.5 MOSFET Selection: Hot-Swap MOSFET Q2
      6. 9.2.6 TVS selection
      7. 9.2.7 Application Curves
    3. 9.3 Do's and Don'ts
    4. 9.4 Power Supply Recommendations
      1. 9.4.1 Transient Protection
      2. 9.4.2 TVS Selection for 12-V Battery Systems
      3. 9.4.3 TVS Selection for 24-V Battery Systems
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 ドキュメントの更新通知を受け取る方法
    2. 10.2 サポート・リソース
    3. 10.3 Trademarks
    4. 10.4 静電気放電に関する注意事項
    5. 10.5 用語集
  12. 11Mechanical, 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

9.2.2 Automotive Reverse Battery Protection

The LM74810 feature two separate gate control and driver outputs (DGATE and HGATE) to drive back to back N-channel MOSFETs. This enables LM74810 to provide comprehensive immunity with robust system protection during various automotive transient tests as per ISO 7637-2 and ISO 16750-2 standard as well as other automotive OEM standards. For more information, see the Automotive EMC-compliant reverse-battery protection with ideal-diode controllers article.

LM74810 gate drive output DGATE controls MOSFET Q1 to provide reverse battery protection and true reverse current blocking functionality. HGATE controls MOSFET Q2 to turn off the power path during input overvoltage condition. Resistor network R1, R2 and R3 connected to OV and SW can be configured for overvoltage protection and also for battery monitoring under normal operating conditions as well as reverse battery conditions. Bi-directional TVS D1 clamps the automotive transient input voltages on the 12-V battery, both positive and negative transients, to voltage levels safe for MOSFET Q1 and LM74810.

Fast reverse current blocking response and quick reverse recovery enables LM74810 to turn ON/OFF MOSFET Q1 during AC super imposed input and provide active rectification of the AC input superimposed on DC battery voltage. Fast reverse current blocking response of LM74810 helps to turn off MOSFET Q1 during negative transients inputs and input micro short interruption conditions where input can fall to 0-V for short duration.