• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 62 subscribers
  • Views 557 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.

LM5022 SEPIC on PMP9334 schematic

KIYOSHI NARISAWA1
Expert 1510 points
Other Parts Discussed in Thread: PMP, LM5022

Dear TI

Custoer has question for PMP schematic on below URL.

http://www.ti.com/lit/df/snvr397/snvr397.pdf

There are diodes of D103and Z1 in 1st trans side and they are DNP.

 Customer would like to know what case are Z1 and D103 needed and what case not needed.

 

I'm sorry I don't have enough knowledge for that.

 

Thank you and best regards

K.Narisawa

 

  • 0
    TI__Mastermind 49317 points
    Hello Kiyoshi-san,
    The diode and zener are used to limit and clamp the drain-source voltage spike of the main MOSFET. This is needed based on the transformer leakage inductance and the amount of stored parasitic energy that transfers to the MOSFET output capacitance during MOSFET turn-off. You can examine your Vds waveform to see if this is needed. In this case, the 1000V MOSFET likely offers ample margin.
    Regards,Tim
  • 0 in reply to Timothy Hegarty
    Expert 1510 points

    Hi Tim-san,

    Thank you for your quick response.

    I understood and feedback to customer.

    And also I'm asking to other E2E for LM5022 flyback type too.

    But I can't open E2E on web due to customer's schematic.

    Can you help to review customer's scheatic too?

    If you can, please send below mail and then I'll send customer's schematic soon.

    narisawa-k@clv.macnica.co.jp

    Thank you and best Reagrds

    K.Narisawa