• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 63 subscribers
  • Views 1482 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

TLV62130A: FB pin gets opened

kura
Genius 4840 points
Part Number: TLV62130A

I found below description in datasheet P14.

 

"In case the FB pin gets opened, the device clamps the output voltage at the VOS pin internally to about 7.4 V."

 

When they use this part VIN:5V and FB pin gets opened,please let us know what voltage VOS and SW become.

 

regards,

  • 0
    TI__Guru**** 150830 points
    With a buck converter like this, Vout cannot go above Vin. The highest Vout will go is the 5V input voltage.
  • 0 in reply to Chris Glaser
    Genius 4840 points

    Chris-san

     

    Thank you for your reply.

    Could please advise us more.

     

    They consider to use TLV62130A like below in their system.

    Vin:5V

    Vout:3.78V

    R1:820kohms

    R2:220kohms

     

    Could you please let us know how IC behavior at following conditon.
    R1                R2                IC behavior

    open            open             Vout goes 5V

    open            220kohms          ?

    short            220kohms          ?

    820kohms     open                 ?

    820kohms     short                 ?

    open              short                 ?

    short              open                 ?

    regards,

  • 0 in reply to kura
    TI__Guru**** 150830 points
    If the FB pin is pulled above its 0.8V reference, the output will go high impedance. If FB is pulled below its 0.8V reference, the IC will try and drive the output higher (and enter 100% mode if necessary). If FB is connected to Vout, Vout will go to the 0.8V FB voltage.

    R1 R2 IC behavior
    open open unknown--FB is driven by noise
    open 220kohms Vout goes to Vin
    short 220kohms Vout goes to 0.8V
    820kohms open Vout goes to 0.8V
    820kohms short Vout goes to Vin
    open short Vout goes to Vin
    short open Vout goes to 0.8V
  • 0 in reply to Chris Glaser
    Genius 4840 points
    Chris-san

    Thank you for your reply.

    About following your comment.please advise us more.
    ---
    R1 R2 IC behavior
    open open unknown--FB is driven by noise
    ----

    IC behavior is unknow in this condition,but Vout cannot go above Vin because this is buck converter.

    Is my understanding correct.

    Regards,
  • 0 in reply to kura
    TI__Guru**** 150830 points
    Yes, this is correct.