• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 100 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.

UCC29002: Start up issue

Rock Shao
Expert 2820 points
Part Number: UCC29002

Hi,

My customer used the UCC29002 in parallel with two 1000W power supplies, and there has been a start-up issue.

Because the start-up time of the two sets of power supplies is different, it will cause the OPP condition.
Is there any solution to reduce this problem?

Schematic

Set up

C2, C3 Vcc start-up time

C1, output current

input 100V, 42A full load start-up

input 230V, 42A full load start-up

Thank you very much for your time and consideration.

  • 0
    TI__Genius 9140 points

    Hi Rock,

    thanks for your interest in UCC29002.

    Please double confirm which version you are using in this application. UCC29002 or UCC29002-1?

    the difference between the two version is that UCC29002 has Start up and adjust logic block which has faster start up than UCC29002-1, so possible output voltage overshoots possible at start up.

    in your application, during start up, if there is no cycle by cycle protection for over power protection, then a constant current loop should be added to solve the issue that one module output total system current during start up.

    hope this help you.

  • 0 in reply to David Huang33
    Expert 2820 points

    My customer used UCC29002 when no-load can be turned on, but it will be turned off immediately on one side. When the load reaches a certain level, the slave will turn on by itself. No-load to full load will sometimes jump off unilaterally, resulting in the start of the group of power supplies will OPP.

  • 0 in reply to Rock Shao
    TI__Genius 9140 points

    Hi Rock,

    I did not see the fault on the UCC29002 circuit.

    as I mentioned in the post, there should be a current limitation or we called constant current loop in this application.

    do you have a full schematic for me to do further analysis?