Tool/software:
Dear Texas Instruments Team,
we are using the UCC33420 power supply IC in our actual design. The UCC33420 is connected with 22u in parallel to 2n2 at the input and output as well. These values are used as recommended in the datasheet. Although, we are struggling with radiated emissions according to IEC61000-6-4 in the frequency range of 30MHz to 1GHz. Especially the the switching frequency of 76MHz and multiple of the switching frequency causes peaks in the spectrum. If the output voltage is analysed in detail burst modulation could be recognized on the ripple voltage.
So the question is, do we need an additional filter for the output voltage to suppress the HF disturbance and how does the filter could be look like?
Can you propose an filter design for that proplem?
Thanks in advance for your support.
With best regards,
Thomas
