TIDUEX5 October   2020

 

  1.   Description
  2.   Resources
  3.   Applications
  4.   Features
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Ideal Diode Design Overview
      2. 2.2.2 Current Sensing Amplifier Design Overview
      3. 2.2.3 OR Gate Design Overview
      4. 2.2.4 MOSFET Selection
        1. 2.2.4.1 Blocking MOSFET
        2. 2.2.4.2 Hot-Swap MOSFET
      5. 2.2.5 TVS Input Diode Selection
      6. 2.2.6 Inrush Current
    3. 2.3 Highlighted Products
      1. 2.3.1 LM74810-Q1
      2. 2.3.2 INA302-Q1
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
      1. 3.1.1 Getting Started
      2. 3.1.2 Testing and Results
        1. 3.1.2.1 Over-Voltage Protection Cut-Off Mode
        2. 3.1.2.2 Over-Voltage Protection Clamping-Mode
        3. 3.1.2.3 ISO7637-2 Pulse 1
        4. 3.1.2.4 Overcurrent Protection
        5. 3.1.2.5 Load Dump
        6. 3.1.2.6 Cold Crank, Warm Start, and Cold Start
          1. 3.1.2.6.1 Cold Crank
          2. 3.1.2.6.2 Warm Start
          3. 3.1.2.6.3 Cold Start
        7. 3.1.2.7 Standby Current
        8. 3.1.2.8 Currency Sense Accuracy
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks

3.1.2.5 Load Dump

Suppressed load dump testing was done with a 35 V max transient pulse. The load dump transient is shown in the yellow trace in Figure 3-7.

GUID-20200710-SS0I-J8DQ-LCRB-0GWN9SGQ8NDZ-low.png Figure 3-7 Suppressed Load Dump Test

Over-voltage protection is triggered by the LM74810 device when input is higher than the 18.2 V threshold that is set. The blue trace shows the output voltage where it decreases as the HGATE driven MOSFETs is turned off to protect any components downstream from the high voltage at the input. Once the high voltage transient ends, the MOSFETs will turn on again as shown in Figure 3-7. Load dump test demonstrates the inrush limiting feature by the LM74810 device as the inrush current is limited to roughly to 15A. The green trace is the output current delivered to e-load.