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UCC28180: device restart issue

FRANK1
Expert 8575 points
Part Number: UCC28180


Hi Sir,

A customer has a design issue on UCC28180.

can you share your valuable suggestion?

When I use ucc28180 for DC boost control chip application,
I found that under the condition of load in the front section of power supply,
there will be automatic shutdown at the moment of load, and then restart，

I also monitored, ucc28180 trigger protection only current loop open circuit ISOP,
but voltage loop open circuit OLP, VCC under voltage UVLO, icompp, all did not trigger,
Please find my attached pictures.
green is vboost voltage, blue is input, yellow is icompp,
the green waveform after turning off is hardware under voltage protection.



Thanks a lot.

  • 0
    TI__Genius 9140 points

    Hi Frank,

    at the icomp pin there is a resistor between Icomp to ground, why do you add this resistor? It is not recommended to add the resistor here.

    for your OCP issue, can you lower the current sense resistor to aviod the ocp protection?

    Btw, the schematic you captured is unclear ,please use "insert" to add the schematic in the post.

  • 0 in reply to David Huang33
    TI__Expert 8575 points

    Hi David,

    We've tried, and we've also paralleled an 18m Ω ,the results did not change.

    Any other suggestion?

    Thanks a lot.

  • +1 in reply to FRANK1
    TI__Genius 9140 points

    Hi Frank,

    it is better to have the CS signal and PFC inductor current and Icomp together to see what is happening at this moment.

    Per your description, only CS pin triggers ISOP protection, we need to confirm whether it really have a real current through the CS pin to trigger it. And isop is a protection for Isense pin open loop. I do not think the controller can trigger ISOP,. in most chance it is PCL protection.