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TPS564201: ISO 7637-2 pulses, TVS Diode selection and secondary protection?

Pradeep Mohan
Intellectual 725 points
Part Number: TPS564201
Other Parts Discussed in Thread: TPS54340, LMR23630

Hello TI,

considering the TPS564201 has a limited input voltage range, would you have any recommendations as to what kinds of protection should be implemented to withstand the ISO 7637-2 pulses? Should I choose a TVS diode with reverse stand off voltage of 12V (intended Vin) even though the clamping voltage is lower? Or would you recommended two TVS diodes in parallel with different ratings?

Any suggestions/application notes would be appreciated.

  • 0
    TI__Expert 3480 points
    Here is a blog. It is related to TVS. Also it uses smart diode to avoid load dump in automotive applications.
    e2e.ti.com/.../selecting-tvs-diodes-for-reverse-polarity-in-automotive 7637-2 pulses&tisearch=Search-EN-Everything
  • 0 in reply to Gavin Wang (Zejing)
    Intellectual 725 points
    Hello Gavin,

    thanks for your tip. However, the biggest problem I have is the with the 17V volt maximum Vin of the TPS564201. The supply voltage is 12V. If I choose a bidirectional TVS diode with a slightly higher standoff voltage of say 14V, the clamping voltage of the TVS diode is around 23V.

    Can the TPS564201 simply handle these extra volts or do I use a Zener diode to regulate the clamped 23V to the absolute maximum allowed Vin of the TPS5654201?
  • 0 in reply to Pradeep Mohan
    TI__Expert 3480 points
    What is output voltage, load current and switching frequency ? I recommend to use LMR140x0-Q series which can withstand the standard.
  • 0 in reply to Gavin Wang (Zejing)
    Intellectual 725 points
    Hello Gavin,

    thanks again for your response. Vout 3.8V, I out 3A minimum, switching frequency currently in the 560kHz range. More important is the feature of Light Load Efficiency (Eco Mode) since we required minimal current consumption during no load. Also transient response should be good, which is why I chose the DCAP control mode over the Current Control Mode convertors. However I realize now the DCAP convertors do not have the wide Vin range that current control mode convertors do.

    1. Why the LMR140x0-Q series?
    2. Is the difference between the LM and TPS family that the FET is external to TPS and internal in the LM series?

    Thanks again for your help Gavin!
  • 0 in reply to Pradeep Mohan
    TI__Expert 3480 points
    1. LMR140x0-Q series is wide Vin. It has lower cost and you can use it in your application. TPS564201 can't cover your wide Vin.
    2. What is the meaning of I out 3A minimum? What is the maximum value?
  • 0 in reply to Gavin Wang (Zejing)
    Intellectual 725 points

    Hello Gavin,

    thanks again for your response.

    Apologies if my previous message was not clear enough. What I meant was why the LMR140x0-Q series and not the TPS or other families. I've narrowed my search down to this list.

    I see the TPS54340 is also a viable option. Am I correct in assuming that this one needs more external components (for compensation) than the LM Simple Switcher families of convertors?

    If EMC, BOM Cost, PCB footprint and low current consumption were all important factors for my final design, would I go with the LM series or the TPS series?

    The LMR23630 also seems to be a viable option with a much lower factory lead time. 

    To answer you other question, I meant that we need at least an Iout of 3A, or greater. Sorry I didn't phrase that better.

    Once again thanks for your support.

  • 0 in reply to Pradeep Mohan
    TI__Expert 3480 points
    Right, TPS54340 needs more external components (for compensation) than the LMR140x0-Q series. The LMR23630 has higher cost. Considering the BOM cost, the LMR140x0-Q series is the best choice.