SLVUBU5A May   2020  – December 2020 LM7481-Q1

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Features
    2. 1.2 Applications
  3. 2Description
    1. 2.1  Input Power and Load (J1/J3 and J2/J4):
    2. 2.2  Enable Control (J5):
    3. 2.3  Over Voltage Protection (J6):
    4. 2.4  Input Voltage Monitor (J10 and VIN_MON):
    5. 2.5  Two Back-Back Connected MOSFETs (Q1/Q3 and Q2/Q4):
    6. 2.6  Output Slew Rate Control (R2 and C4):
    7. 2.7  Output Schottky Diode (D2) and LED Indication:
    8. 2.8  TVS Selection for 12-V Battery Protection:
    9. 2.9  TVS Selection for 24-V Battery Protection:
    10. 2.10 RC Input Snubber Option (R7 and C15):
    11. 2.11 Optional LC Filter at the Output (L2 and C11):
    12. 2.12 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 Over Voltage Protection
    4. 5.4 Enable Control
    5. 5.5 Input Reverse Polarity
    6. 5.6 Load Transient Response
  7. 6EVM Board Layout and Bill of Materials
    1. 6.1 EVM Board Layout
    2. 6.2 Bill of Materials
  8. 7Revision History

2.8 TVS Selection for 12-V Battery Protection:

A single TVS such as 600-W SMBJ33CA can be used along with a 60-V rated MOSFET for automotive transient protection requirements on a 12-V battery, but in this EVM, Q1 and Q2 are 40-V rated. To protect the 40-V rated MOSFET, D3 and D4 are used and D1 is not populated on board. For detailed information on TVS selection, refer to the data sheet of LM74810-Q1.