Hi,
i have been working on dcdc converter(design is similar to one present in your paper ''200-W Interleaved Forward Converter Design Review Using TI s UCC28221 PWM Controller'' ) while testing IC alone i get every value as mentioned in datasheet, once i connected entire circuit my output is zero because gate is not switching. Problem i found is Vref is zero.
In normal DC input condition, Vref should be 3.3V right? i'm getting value of 1.5V then instantly reduce to zero.
im attaching the schemaic of converter3WDCDC_VER0_SEPT2019_2.pdf