Hi,

I want to design 100 W flyback converter. Input voltage 30-50 V output voltage 300-350 V . While input voltage is 20-25 V, switching pulse is corruption and HF transformer has noise. What is the reason of this? I added switching pulse below.

 

More information needed. Post your complete schematic.

 

https://www.onsemi.com/pub/Collateral/AN-4137.pdf.pdf

http://www.ti.com/lit/an/slua086/slua086.pdf

https://www.st.com/resource/en/application_note/cd00004190.pdf

https://micro.rohm.com/en/techweb/knowledge/acdc/acdc_pwm/acdc_pwm01/940/

https://www.eenewspower.com/content/step-step-optimised-flyback-design

https://coefs.uncc.edu/mnoras/files/2013/03/Transformer-and-Inductor-Design-Handbook_Chapter_13.pdf


Regards, Dana.