• State Resolved
  • Locked Locked
  • Replies 7 replies
  • Answers 2 answers
  • Subscribers 62 subscribers
  • Views 207 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.

UCC28C43-Q1: UCC28C43-Q1

Shritesh
Prodigy 205 points
Part Number: UCC28C43-Q1

Dear TI team,

I am using UCC28C43-Q1 IC for my Flyback converter application. I want to implement Enable/ Disable signal to Flyback converter.

In datasheet, it shows only MOSFET and Disable signal from micro-controller. I have few questions on this circuit:-

1. Only MOSFET is sufficient without gate driver or buffer ?

2. What is recommended MOSFET part  no. ?

3. What is the current and voltage rating of COMP pin?

4. Are there are any application where this is implemented ?

Thanks,
Shritesh

  • +1
    TI__Mastermind 44320 points

    Hi Shritesh,

    Let me try to answer your questions as follows:

    1. Only MOSFET is sufficient without gate driver or buffer ? *Yes. You can use any means to pull the comp pin to GND to disable the part. 

    2. What is recommended MOSFET part  no. ? *Any small transistor can work. 

    3. What is the current and voltage rating of COMP pin? *I would have to check with the design team, but this should be less than 1 mA. 

    4. Are there are any application where this is implemented ? *The new EVM using the UCC28C56 shows how Soft-start can be implemented by using a PNP transistor. I am not aware of any specific examples of this being used in an actual application but can check into it if you would like. 

  • 0 in reply to JCHK
    Prodigy 205 points

    Thanks a lot John for you quick reply.

    It will be very helpful if you can share specific application where disable/ enable is implemented. 

    Thanks,

    Shritesh

  • 0 in reply to Shritesh
    TI__Mastermind 44320 points

    HI Shritesh,

    I am checking into it. Since this is a generic PWM controller, it can be used as a boost, buck, flyback, forward, or SEPIC converter there are several use cases where I can see the desire to disable the controller. The only use case I imagine this is not used is the flyback as that is usually the first power rail to come up in any system. 

  • 0 in reply to JCHK
    Prodigy 205 points

    Hi John,

    I am designing Flyback controller for back up circuit where, Flyback will be operated for maximum one minute. Hence, I need to disable this converter once operation is over.

    Thanks,

    Shritesh

  • +1 in reply to Shritesh
    TI__Mastermind 44320 points

    HI Shritesh,

    I checked into this and there are many customers disabling the device for various reasons. I also confirmed that you can assume the pulldown current to be around 1mA. 

    Does this help to answer your question?

  • 0 in reply to JCHK
    Prodigy 205 points

    Thanks a lot John for your valuable support !

  • 0 in reply to Shritesh
    TI__Mastermind 44320 points

    HI Shritesh,

    You are most welcome!