SNOSD87A July   2021  – February 2022 LM74501-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. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  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 Enable
      4. 8.3.4 Gate Driver
      5. 8.3.5 SW (Battery Voltage Monitoring)
      6. 8.3.6 Gate Discharge Timer
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Full Conduction Mode
      3. 8.4.3 VDS Clamp
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Reverse Battery Protection
    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 Gate Discharge Timer Capacitor Selection (CT)
        4. 9.2.2.4 Charge Pump VCAP, Input and Output Capacitance
      3. 9.2.3 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 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

3 Description

The LM74501-Q1 operates in conjunction with an external N-channel MOSFET as a low loss reverse polarity protection solution. The device supports wide supply input range of 3.2 V to 65 V. 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 –18 V. The LM74501-Q1 does not have reverse current blocking functionality and is suitable for input reverse polarity protection of loads that can potentially deliver energy back to the input supply such as automotive body control module motor loads.

The LM74501-Q1 controller provides a charge pump gate drive for an external N-channel MOSFET. The LM74501-Q1 has a unique integrated feature that allows systems to meet automotive ISO7637 pulse 1 transient requirements without an additional TVS Diode (TVS less). The LM74501-Q1 features an integrated switch to enable battery voltage monitoring with an external resistor divider. With the enable pin low, the controller is off and draws only around 1 µA of current, thus offering low system current when put into sleep mode.

Device Information
PART NUMBERPACKAGE(1)BODY SIZE (NOM)
LM74501-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-20210920-SS0I-3HZX-VDBK-JXLGLKC76SXF-low.gifLM74501-Q1 Typical Application Schematic for Automotive Battery Reverse Polarity Protection
GUID-20210915-SS0I-90FH-FBLN-G6N3LMJKMNB2-low.pngTVS Less ISO7637-2 Pulse 1 Operation