SLUUD80 December   2024 LM74681

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5.   5
  6. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Device Information
  7. 2Hardware
    1. 2.1 Test Points and Connectors
    2. 2.2 Test Equipment and Setup
      1. 2.2.1 Power Supplies
      2. 2.2.2 Meters
      3. 2.2.3 Oscilloscope
      4. 2.2.4 Loads
    3. 2.3 Test Setup and Procedures
      1. 2.3.1 UVLO Functionality
      2. 2.3.2 Polarity Agnostic Startup
  8. 3Hardware Design Files
    1. 3.1 Schematic
    2. 3.2 PCB Layouts
    3. 3.3 Bill of Materials (BOM)
  9. 4Additional Information
    1.     Trademarks

2.3.2 Polarity Agnostic Startup

Use the following instructions to verify the startup behavior of LM74681.

  1. Set the input supply voltage to 48V and current limit of 3A
  2. Make sure the J2 jumper setting is set to 2-3.
  3. Plug the positive end of power supply to J1 and negative end to J2.
  4. Turn ON the power supply and observe the behavior of TG1-IN1, BG1, and OUTP.
  5. Turn OFF the power supply and reverse the connection on J1 and J2.
  6. Turn ON the power supply and observe the behavior of TG2-IN2 and BG2 with OUTP same as step 4.
LM74681 LM74681 Forward Connection Startup Figure 2-4 LM74681 Forward Connection Startup
LM74681 LM74681 Reverse Connection Startup Figure 2-5 LM74681 Reverse Connection Startup