• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 239 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.

LM25117 FBpin Open

K.Hamamoto
Guru 12155 points
Other Parts Discussed in Thread: LM25117

Hi

Our customer evaluates LM25117 on their board and they found unknown operation when they opened the FB pin.

The operation stops when the FB pin is open. Is there any OVP?

The customer would like to know that mechanism.

Regards,

Koji Hamamoto

  • 0
    TI__Mastermind 46081 points

    Hi Hamamoto-san

    What are the FB and COMP pin voltages when the switching stops? 

    Regards,

    EL

  • 0 in reply to EricLee
    Guru 12155 points
    Hi Eric-san

    Thank you for your support as always.

    I talked with the customer about this issue.
    I explained the FB is Hi-z pin. The duty will be max if the FB is over 0.8V. And the low side fet will be turn off if the FB is below 0.8V.
    However we can not know how much is the voltage of FB pin when the FB is opened because of Hi-z.

    They understand that explanation. Please close this.
    (I have another question from the customer about LM25117. I will post new one.)

    Regards,
    Koji Hamamoto