SNOU191 January   2022 LM74502-Q1 , LM74502H-Q1

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Features
    2. 1.2 Applications
  3. 2Description
    1. 2.1 Input Power and Load (J1/J5 and J2/J6, J7/J11 and J8/J12)
    2. 2.2 Two Back-to-Back Connected MOSFETs (Q1/Q2–Q3/Q4 and Q6/Q7–Q8/Q9)
    3. 2.3 Output Slew Rate Control (R1 and C1)
    4. 2.4 Output Schottky Diode (D4, D10) and LED Indication (D6, D12)
    5. 2.5 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 Turn-ON with EN
    4. 5.4 Inrush Current Control
    5. 5.5 Overvoltage Response
    6. 5.6 Reverse Polarity Protection
  7. 6Board Layout and Bill of Materials
    1. 6.1 Board Layout
    2. 6.2 Bill of Materials

1 Introduction

TI's LM74502-Q1 Evaluation module, LM74502Q1EVM, is a two-channel EVM that helps designers evaluate the operation and performance of the LM74502-Q1 in channel 1 and LM74502H-Q1 in channel 2 respectively. This evaluation module demonstrates how LM74502-Q1 drives external back-to-back connected N-channel MOSFETs to realize reverse polarity protection and load disconnect feature in case of overvoltage and undervoltage events. LM74502-Q1 has a gate drive strength of 60 μA, which makes it suitable for use in applications that need inherent inrush current control. On the other hand, LM74502H-Q1 has a faster gate drive of 11-mA peak, which makes it suitable for applications which need fast turn-on and turn-off of external MOSFET switch. With the enable pin low during the standby mode, both the external MOSFETs and controller is off and draws a very low 1 μA of current.