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. Introduction
  3. Reverse Battery Protection
    1. 2.1 Reverse Battery Protection with Schottky Diode
  4. ORing Power Supplies
  5. 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. 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. 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. 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. ORing Power Supplies with Ideal Diode Controllers
  10. Integrated Ideal Diode Solution
  11. 10Summary
  12. 11References
  13. 12Revision History

Very Low Quiescent Current

For battery-operated electronic systems in automotive applications, battery supply remains on even when ignition is off, to support features like remote key entry and security which are required even in ignition-off state. To maximize battery life, there is a need for power protection solutions to provide robust reverse protection while maintaining low supply current.

In an automotive system, the low IQ during sleep mode/ignition off state is generally achieved by following approaches:

  1. An external IGN connection is commonly found in redundant supply input-based ECU designs. Such a design uses extra wiring to the ECU.
  2. An internal control signal from micro controller is used to pull EN low to disable the device. If the digital and power sections of the design are far apart or on separate boards, this signal becomes prone to noise and unknown state, making the overall operation unreliable.

LM7472x-Q1 devices enable <35uA quiescent current without dependency on MCU EN control signal or an external signal through a wire, making the device more suitable in comparison.