We used UCC28250 as the full bridge controller in a non-isolated DC/DC converter. Input voltage is 70Vdc, output voltage is 5.72Vdc.
Normal primary MOSFET on time is 1.5us, abnormal primary MOSFET on time can be 3us.
Pls check the waveform as below,
Once there’s short on output, the duty will be changed from 1.5us to 3us within one cycle. Which will lead it? How to limit the max duty cycle?