• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 321 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

TPS23881: Power components selection

CSD19538Q3A: PSE Mosfet Protection

d_zero
Genius 4660 points
Part Number: CSD19538Q3A
Other Parts Discussed in Thread: TIDA-00290, PMP20588, TIDA-01411

Dear All,

there a numerus different design from TI on how to protect PSE mosfet, which one is the most recommended one?

1) No protection eg:  PMP20588, TPS23861EVM-613 (TIDA-00290), SLVUB84B

2) Protection with Schottky diode eg. : slva233a (STPS1H100),  TIDA-01411 (10MQ100NTRPBF)

3) Protection with TVS diode eg. : TIDA-01411 (CD143A-SR70)

4) Protection with standard diode eg. : slva233a (STTH102)

How to choose the diode for protection?

Best Regards,

David.

  • 0
    TI__Mastermind 32125 points

    Hello David,

    Thanks for the inquiry. Protection for the FET is dependent on the application and requirements. Please keep in mind, that you must avoid overvoltage stress from drain-to-source (BVDSS or avalanche breakdown) and gate-to-source (abs max VGS). TI rates our FETs for single pulse avalanche although this condition should be avoided. We do not rate our devices for repetitive avalanche. I am going to pass this onto our PoE apps team to get their input as well.

    Best Regards,

    John Wallace

    TI FET Applications

  • 0
    TI__Genius 15655 points

    David,

    Please review this app note for surge protection. Thanks.

    Best regards,

    Penny

  • 0 in reply to Penny Xu
    Genius 4660 points

    Dear Penny,

    we revived the document multiple times, there are no written guidelines in the document or am i missing something?

    There is only a Schottky diode in the schematic TIDA-01411 (10MQ100NTRPBF), and i saw this before asking the question, what is the logic to choose the protection for PSE mosfet?

    Best Regards,

    David.

  • +1 in reply to d_zero
    TI__Genius 15655 points

    David,

    Please refer to TIDA-01411 and there's a section in design guide on how to choose the protection components.  We need multiple protection components to protect the PSE port during surge. Thanks. 

    Best regards,

    Penny