SLVAE57B February   2021  – October 2021 LM5050-1 , LM5050-2 , LM5051 , LM66100 , LM74202-Q1 , LM74500-Q1 , LM74610-Q1 , LM74700-Q1 , LM74720-Q1 , LM74721-Q1 , LM74722-Q1 , LM7480-Q1 , LM7481-Q1 , LM76202-Q1 , SM74611 , TPS2410 , TPS2411 , TPS2412 , TPS2413 , TPS2419

 

  1.   Trademarks
  2. 1 Introduction
  3. 2 Reverse Battery Protection
    1. 2.1 Reverse Battery Protection with Schottky Diode
  4. 3 ORing Power Supplies
  5. 4 Reverse Battery Protection using MOSFETs
    1. 4.1 Reverse Battery Protection using P-Channel MOSFET
    2. 4.2 Input Short or supply interruption
    3. 4.3 Diode Rectification During Line Disturbance
    4. 4.4 Reverse Battery Protection using N-Channel MOSFET
  6. 5 Reverse Polarity Protection vs Reverse Current Blocking
    1. 5.1 Reverse Polarity Protection Controller vs. Ideal Diode Controller
    2. 5.2 Performance Comparison of P-Channel and Reverse Polarity Protection Controller Based Solution
  7. 6 What is an Ideal Diode Controller?
    1. 6.1 Linear Regulation Control Vs Hysteretic ON/OFF Control
    2. 6.2 Low Forward Conduction Loss
    3. 6.3 Fast Reverse Recovery
    4. 6.4 Very Low Shutdown Current
    5. 6.5 Fast Load Transient Response
    6. 6.6 Additional Features in Ideal Diode Controllers
      1. 6.6.1 Back-to-Back FET Driving Ideal Diode Controllers
      2. 6.6.2 Very Low Quiescent Current
      3. 6.6.3 TVSless Operation
  8. 7 Automotive Transient protection with Ideal Diode Controllers
    1. 7.1 LM74700-Q1 with N-Channel MOSFET
    2. 7.2 Static Reverse Polarity
    3. 7.3 Dynamic Reverse Polarity
    4. 7.4 Input Micro-Short
    5. 7.5 Diode Rectification of Supply Line disturbance
  9. 8 ORing Power Supplies with Ideal Diode Controllers
  10. 9 Integrated Ideal Diode Solution
  11. 10Summary
  12. 11References
  13. 12Revision History

7.2 Static Reverse Polarity

During maintenance of the car battery or jump start of the vehicle, the battery can be connected in reverse polarity during reinstallation. When the battery is connected with reversed polarity, the LM74700-Q1 remains turned off to protect the downstream circuits and components from damage. In Figure 7-2, output voltage remains protected when a reverse battery connection of -12 V is applied at its input.

GUID-BF752C8D-1159-4135-8304-CCD614D19BBD-low.gifFigure 7-2 LM74700-Q1 Response to Static Reverse Polarity