SNOU187 September   2021

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Features
    2. 1.2 Applications
  3. 2Description
    1. 2.1 Input Power and Load (J2, J6 and J3, J7):
    2. 2.2 Enable Control (J5):
    3. 2.3 Two Back-to-Back Connected MOSFETs (Q1 and Q2):
    4. 2.4 Output Slew Rate Control (R5 and C5):
    5. 2.5 Output Schottky Diode (D3) and LED Indication:
    6. 2.6 TVS Selection for 12-V Battery Protection:
    7. 2.7 Test Points:
  4. 3Schematic
  5. 4Test Equipment Requirements
    1. 4.1 Power Supplies
    2. 4.2 Meters
    3. 4.3 Oscilloscope
    4. 4.4 Loads
  6. 5Test Setup and Results
    1. 5.1 Initial Setup
    2. 5.2 Power Up
    3. 5.3 Enable Control
    4. 5.4 Hot-Plug and Disable Using EN
    5. 5.5 Inrush Current Control
    6. 5.6 Load Response
  7. 6Board Layout and Bill of Materials
    1. 6.1 Board Layout
    2. 6.2 Bill of Materials

2.2 Enable Control (J5):

Enable control is usually used by external MCU or controller to turn off LM74721-Q1 and cut off the power path. Setting 1-2 on J5 enables the controller and 2-3 disables the controller. TI recommends to connect the EN to external MCU or to test point 1-2 for uninterrupted performance during negative transient tests.