JAJSOY6A May   2023  – December 2023 LM74703-Q1 , LM74704-Q1

PRODUCTION DATA  

  1.   1
  2. 特長
  3. アプリケーション
  4. 概要
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. 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. Parameter Measurement Information
  9. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input Voltage
      2. 8.3.2 Charge Pump
      3. 8.3.3 Gate Driver
      4. 8.3.4 Enable
      5. 8.3.5 FET Status Indication (FETGOOD)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Conduction Mode
        1. 8.4.2.1 Regulated Conduction Mode
        2. 8.4.2.2 Full Conduction Mode
        3. 8.4.2.3 Reverse Current Protection Mode
  10. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Design Considerations
        2. 9.2.2.2 MOSFET Selection
        3. 9.2.2.3 Charge Pump VCAP, Input and Output Capacitance
        4. 9.2.2.4 Selection of TVS Diodes for 12-V Battery Protection Applications
        5. 9.2.2.5 Selection of TVS Diodes and MOSFET for 24-V Battery Protection Applications
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 ドキュメントの更新通知を受け取る方法
    3. 10.3 サポート・リソース
    4. 10.4 Trademarks
    5. 10.5 静電気放電に関する注意事項
    6. 10.6 用語集
  12. 11Revision History
  13. 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

Overview

The LM74703-Q1 and LM74704-Q1 ideal diode controllers have all the features necessary to implement an efficient and fast reverse polarity protection circuit. The devices can be used in an ORing configuration while minimizing the number of external components. This easy-to-use ideal diode controller is paired with an external N-channel MOSFET to replace other reverse polarity schemes like a P-channel MOSFET or a Schottky diode. An internal charge pump drives the external N-Channel MOSFET to a maximum gate-to-source drive voltage of approximately 12 V. The voltage drop across the MOSFET is continuously monitored between the ANODE and CATHODE pins, and the GATE to ANODE pin voltages are adjusted as needed to regulate the forward voltage drop at 20 mV. This closed-loop regulation scheme enables graceful turn off of the MOSFET during a reverse current event and provides zero DC reverse current flow. A fast reverse current condition is detected when the voltage across the ANODE and CATHODE pins reduces below –11 mV. This behavior connects the GATE pin internally to the ANODE pin, turning off the external N-channel MOSFET, and using the body diode to block any of the reverse current. An enable pin, EN, is available to place the LM74703-Q1 in shutdown mode, disabling the N-Channel MOSFET and minimizing the quiescent current.

LM74703-Q1 and LM74704-Q1 offer an external FET health monitoring feature with the FETGOOD pin. The device monitors for external FET drain-to-source short or open condition during power-up and pulls the FETGOOD pin low in case the external FET fault condition is diagnosed.

For automotive applications like automotive lighting, camera modules that are typically exterior facing require low conducted and radiated emissions in the frequency band ranging up to few Gigahertz (GHz). LM74703-Q1 and LM74704-Q1 offer low emissions in high-frequency band, making these devices a good candidate for applications where emissions in high-frequency band are a key consideration.