• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 1041 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.

LM5026: What is the use of SYNC Pin in LM5026

Aneesh TS
Expert 1735 points
Part Number: LM5026

Dear friends,

can anybody please explain me the need of synchronization in power supply?. Why power supply units need to synchronize?.

Regards

Aneesh

  • 0
    TI__Mastermind 34465 points
    Hello Aneesh,
    The benefits of synchronising multiple supplies include reduced EMI, lower risk of inter-modulation due to beat frequencies, ripple reduction and timing optimization in pre and post regulator stages. This is discussed in detail in TI Power Tips 73 :
    www.eetimes.com/author.asp

    Regards
    John
  • 0 in reply to John Griffin1
    Expert 1735 points

    Hi John ,

    I have the following doubts regarding synchronization

    1. ripple will be low when two power supplies operate in 180 degree out of phase right?. But when two power supply synchronize ,it will be in same phase and ripple will be high. Correct me if i am wrong.

    2. When two power supply in synchronize it will operate in same phase and it will draw the inrush current at same time. so the resulting inrush current will be huge right?.

    Regards

    Aneesh

  • 0 in reply to Aneesh TS
    TI__Mastermind 34465 points

    Hello Anesh,

    Answers to your questions

    1. Ripple will not be high. In the worst case there is no ripple reduction.
    However in the case of a pre-regulator that is supplying power to a post regulator, the post regulator can be synchronised so that it is taking power from the pre-regulator output capacitors at the time that the pre-regulator is supplying power to its output capacitors. This will minimize the ripple on these capacitors.

    2.No. Soft start is used to minimise inrush at startup

    Regards

    John

  • 0 in reply to John Griffin1
    Expert 1735 points
    Hi John ,

    still my doubts not cleared
    1. So in synchronization there will not be any ripple reduction right?.
    2. If we don't have any soft start then synchronizing power supply will create bad impact right?

    Regards
    Aneesh