ZHCSNL2A February   2022  – May 2022 LM74502-Q1 , LM74502H-Q1

PRODUCTION DATA  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and 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
    6. 7.6 Switching Characteristics
    7. 7.7 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Input Voltage (VS)
      2. 9.3.2 Charge Pump (VCAP)
      3. 9.3.3 Gate Driver (GATE an SRC)
        1. 9.3.3.1 Inrush Current Control
      4. 9.3.4 Enable and Undervoltage Lockout (EN/UVLO)
      5. 9.3.5 Overvoltage Protection (OV)
    4. 9.4 Device Functional Modes
      1. 9.4.1 Shutdown Mode
      2. 9.4.2 Conduction Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Design Considerations
        2. 10.2.2.2 MOSFET Selection
        3. 10.2.2.3 Overvoltage Protection
        4. 10.2.2.4 Charge Pump VCAP, Input and Output Capacitance
      3. 10.2.3 Selection of TVS Diodes for 12-V Battery Protection Applications
      4. 10.2.4 Selection of TVS Diodes and MOSFET for 24-V Battery Protection Applications
      5. 10.2.5 Application Curves
    3. 10.3 Surge Stopper Using LM74502-Q1, LM74502H-Q1
      1. 10.3.1 VS Capacitance, Resistor R1 and Zener Clamp (DZ)
      2. 10.3.2 Overvoltage Protection
      3. 10.3.3 MOSFET Selection
    4. 10.4 Fast Turn-On and Turn-Off High Side Switch Driver Using LM74502H-Q1
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 接收文档更新通知
    2. 13.2 支持资源
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 术语表
  14. 14Mechanical, Packaging, and Orderable Information

封装选项

请参考 PDF 数据表获取器件具体的封装图。

机械数据 (封装 | 引脚)
  • DDF|8
散热焊盘机械数据 (封装 | 引脚)
订购信息

9.3.3 Gate Driver (GATE an SRC)

The gate driver is used to control the external N-Channel MOSFET by setting the appropriate GATE to SRC voltage.

Before the gate driver is enabled following three conditions must be achieved:

  • The EN/UVLO pin voltage must be greater than the specified input high voltage.
  • The VCAP to VS voltage must be greater than the undervoltage lockout voltage.
  • The VS voltage must be greater than VS POR Rising threshold.
If the above conditions are not achieved, then the GATE pin is internally connected to the SRC pin, assuring that the external MOSFET is disabled. After these conditions are achieved the gate driver operates in the conduction mode enhancing the external MOSFET completely.

The controller offers two gate drive variants. LM74502-Q1 with typical peak gate drive strength of 60 μA is suitable to achieve smooth start-up with inherent inrush current control due to its lower gate drive strength.

LM74502H-Q1 with its 11-mA typical peak gate drive strength is suitable for applications which need faster turn-on such as load switch applications.

LM74502-Q1, LM74502H-Q1 SRC pin is capable of handling negative voltage which also makes it suitable for load disconnect switch applications with loads which are inductive in nature.