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

3 Description

The LM74500-Q1 is an automotive AEC Q100 qualified controller which operates in conjunction with an external N-channel MOSFET as a low loss reverse polarity protection solution. The wide supply input range of 3.2 V to 65 V allows control of many popular DC bus voltages such as 12-V, 24-V and 48-V automotive battery systems. The 3.2-V input voltage support is particularly well suited for severe cold crank requirements in automotive systems. The device can withstand and protect the loads from negative supply voltages down to –65 V. The LM74500-Q1 does not have reverse current blocking and is suitable for input reverse poalrity protection of loads that can potentially deliver energy back to the input supply such as automotive body control module motor loads.

The LM74500-Q1 controller provides a charge pump gate drive for an external N-channel MOSFET. The high voltage rating of LM74500-Q1 helps to simplify the system designs for automotive ISO7637 protection. With the enable pin low, the controller is off and draws approximately 1 µA of current thus offering low system current when put into sleep mode.

Device Information(1)
PART NUMBERPACKAGEBODY SIZE (NOM)
LM74500-Q1SOT-23 (8)2.90 mm × 1.60 mm
(1) For all available packages, see the orderable addendum at the end of the data sheet.
GUID-20200903-CA0I-88GT-8B56-M41LJFH2HNNF-low.gifLM74500-Q1 Typical Application Schematic
GUID-20201217-CA0I-J2W2-TLB8-NKBMJXSPFTBM-low.pngLM74500-Q1 Startup with –12-V Supply