SNOSDC2B September   2021  – July 2022 LM74721-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 Reverse Battery Protection (A, C, GATE)
        1. 8.3.1.1 Input TVS Less Operation: VDS Clamp
      2. 8.3.2 Load Disconnect Switch Control (PD)
      3. 8.3.3 Overvoltage Protection and Battery Voltage Sensing (VSNS, SW, OV)
      4. 8.3.4 Boost Regulator
    4. 8.4 Shutdown Mode
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical 12-V Reverse Battery Protection Application
      1. 9.2.1 Design Requirements for 12-V Battery Protection
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Boost Converter Components (C2, C3, L1)
        2. 9.2.2.2 Input and Output Capacitance
        3. 9.2.2.3 Hold-Up Capacitance
        4. 9.2.2.4 MOSFET Selection: Q1
      3. 9.2.3 Application Curves
    3. 9.3 What to Do and What Not to Do
  10. 10Power Supply Recommendations
    1. 10.1 Transient Protection
  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

Package Options

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

9.2.2.1 Boost Converter Components (C2, C3, L1)

Place a minimum of a 1-µF capacitor across drain of the FET to GND (C2) and across CAP pin of LM74721-Q1 to drain of the FET (C3). Use a 100-µH inductor (L1) with saturation current rating > 175 mA. Example: XPL2010-104ML from coil craft.