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UCC28061: UCC28061

lev nemets1
Intellectual 465 points
Part Number: UCC28061

Hello,

WE would like to use UCC28061 in our mainstream products as this is only controller currently available on the market .

But we found a problem. During start-up with low line voltage (90Vrms) even at very low load (5W) , the inductor current can jump (depending on which part of sinusoidal voltage the start occurs ) 

to extremely high level (40A and more). We found this is to be due to the input EMI filter having differential mode chokes. We tried to simulate this circuit using SIMPLIS simulation model for UCC28054, downloaded from TI. Simulation shows the same problem. Could you, please, help to solve this problem

Regards

Lev

  • 0
    TI__Genius 9140 points

    hello Lev:

    thanks for your interest in UCC28061.

    do you have the current spike waveform or simulation waveform to share? You can also test the controller's GDA/GDB together as a reference of the current spike.

    what we need to confirm is whether during the current spike there is GDA/GDB pulse output from the controller.

    if no pulse, I guess it is the inrush current for the PFC bus cap charge when we add the main voltage to the power supply.

    And usually the current is limited by the NTC in the input filter circuit.