**Part Number:**UCC28019A

Hi,

In fact, I have used the UCC28019A for an AC/DC board that should operate from 100V 50/60 Hz to 265V 50/60 Hz, everything is working fine for me. In the case of 265V, I reached a power of 1200 W for an output voltage of 400V with a perfect power factor 0.99 and with a good current form. Also in the 100V case, I reached 400W with a good power factor and a good current form. The problem for me is that I want to reach 550 W in the case of 100V. But here is the problem:

When I reach 420W, with a 100V/50Hz as an example for the input voltage, I notice that at each half cycle there is a resonance that remains for 5ms in the input current, I also hear a sound coming from the boost inductor (this inductor has a maximum rms current of 8A). My question is how can I get rid of this resonance and maintain a good sinusoidal shape of the input current. Here are the critical components used for compensation of the UCC28019A:

Vcomp components: Rvcomp=25.5kR Cvcomp=10uF , Cvcomp_p=0.68uF.

Icomp components: Cicomp= 1300pF.

Rsense=0.03 R

- I have tried to add a 100 kR resistor in series with the Cicomp capacitor and I noticed a little filtering of the resonance but it still remain in the current form. I have also tried to use a resistor of 1.2MR and a capacitor Cicomp of 820 pF but the problem of the resonance still remain. So I hope that I can solve this problem with your help and support.

And thank you in advance.