SNOSDB7 December   2020 LM74500-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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. 7 Typical Characteristics
  8. 8 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
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Conduction Mode
  9. 9 Application and Implementation
    1. 9.1 Reverse Battery Protection for Automotive Body Control Module Applications
    2. 9.2 Reverse Polarity Protection
    3. 9.3 Application Information
      1. 9.3.1 Typical Application
        1. 9.3.1.1 Design Requirements
        2. 9.3.1.2 Detailed Design Procedure
          1. 9.3.1.2.1 Design Considerations
          2. 9.3.1.2.2 MOSFET Selection
          3. 9.3.1.2.3 Charge Pump VCAP, Input and Output Capacitance
        3. 9.3.1.3 Selection of TVS Diodes for 12-V Battery Protection Applications
        4. 9.3.1.4 Selection of TVS Diodes and MOSFET for 24-V Battery Protection Applications
        5. 9.3.1.5 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.1 Overview

The LM74500-Q1 controller has all the features necessary to implement an efficient and fast reverse polarity protection circuit. This easy to use reverse polarity protection controller is paired with an external N-channel MOSFET to replace other reverse polarity schemes such as a P-channel MOSFET. An internal charge pump is used to drive the external N-Channel MOSFET to a maximum gate drive voltage of approximately 15 V. An enable pin, EN is available to place the LM74500-Q1 in shutdown mode disabling the N-Channel MOSFET and minimizing the quiescent current.