SNOSD17G October   2017  – December 2020 LM74700-Q1

PRODMIX  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  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. Typical Characteristics
  8. Parameter Measurement Information
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Input Voltage
      2. 9.3.2 Charge Pump
      3. 9.3.3 Gate Driver
      4. 9.3.4 Enable
    4. 9.4 Device Functional Modes
      1. 9.4.1 Shutdown Mode
      2. 9.4.2 Conduction Mode
        1. 9.4.2.1 Regulated Conduction Mode
        2. 9.4.2.2 Full Conduction Mode
        3. 9.4.2.3 Reverse Current Protection Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Typical Application
        1. 10.1.1.1 Design Requirements
        2. 10.1.1.2 Detailed Design Procedure
          1. 10.1.1.2.1 Design Considerations
          2. 10.1.1.2.2 MOSFET Selection
          3. 10.1.1.2.3 Charge Pump VCAP, input and output capacitance
        3. 10.1.1.3 Selection of TVS Diodes for 12-V Battery Protection Applications
        4. 10.1.1.4 Selection of TVS Diodes and MOSFET for 24-V Battery Protection Applications
        5. 10.1.1.5 Application Curves
    2. 10.2 OR-ing Application Configuration
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Receiving Notification of Documentation Updates
    2. 13.2 Support Resources
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Layout Guidelines

  • Connect ANODE, GATE and CATHODE pins of LM74700-Q1 close to the MOSFET's SOURCE, GATE and DRAIN pins.
  • The high current path of for this solution is through the MOSFET, therefore it is important to use thick traces for source and drain of the MOSFET to minimize resistive losses.
  • The charge pump capacitor across VCAP and ANODE pins must be kept away from the MOSFET to lower the thermal effects on the capacitance value.
  • The Gate pin of the LM74700-Q1 must be connected to the MOSFET gate with short trace. Avoid excessively thin and long trace to the Gate Drive.
  • Keep the GATE pin close to the MOSFET to avoid increase in MOSFET turn-off delay due to trace resistance.
  • Obtaining acceptable performance with alternate layout schemes is possible, however the layout shown in the Layout Example is intended as a guideline and to produce good results.