• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 63 subscribers
  • Views 46 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.

TPS7H5005-SEP: Isolated Error Amplifier

Kamden Sarkey
Prodigy 50 points
Part Number: TPS7H5005-SEP

Tool/software:

Hello,

I am designing an isolated power supply using this controller.  I currently have my controller placed on the primary side of the isolation barrier and was wondering if I was to use an external isolated error amplifier rather than the error amplifier built in to the controller, if I would be able to just connect the output of this to the comp pin of the TPS7H5005-SEP. My biggest concern is the SS pin will now be bypassed.  Would soft start lose functionality if I used the external error amplifier then? If so, what would be the best approach to obtain the analog voltage feedback from the secondary side to the controller while maintaining the ability to soft start the supply? Currently optocoupler is not an option due to environment constraints. 

Thank you,
Kamden

  • +1
    TI__Mastermind 28495 points

    Hey Kamden,

    "Would soft start lose functionality if I used the external error amplifier then?"

    Yes

    "If so, what would be the best approach to obtain the analog voltage feedback from the secondary side to the controller while maintaining the ability to soft start the supply?"

    That depends on how you plan to implement the isolated feedback, though any method that slows down the rise of the error signal into the controller will help.
    How fast the COMP rises will effectively determine the SS time, though the actual SS time will be a function of where the COMP will want to settle to and the slope of that rise time.

    Thanks,
    Daniel