UCC28740: No Voltage and current Regulation with Low Coss MOSFET

Hi Anand,

We are reviewing your query and will get back to you in a couple of days.

Thank you

Regards,

Harish

Hi Harish,

Thanks for the response, your early support is well appreciated. Looking forward to hear from you soon.

Regards,

Anand M

Hi Anand,

I think it would be good to compare the aux. winding waveform in both the cases in the first instance. The snubber might need to be redesigned for the new switch which might not be effective in reducing the switch node ringing and could potentially be causing a overvoltage/overcurrent fault causing the restart phenomenon.

Thank you

Regards,

Harish

Dear Harish,

Thank you for the reply. I have captured below waveform for both working and non working conditions:

With STP13NK60Z  MOSFET

--> VDS (yellow) & Vcs (blue) & VDD(pink)

--> VDS (yellow) & Vs pin (blue) & VDD(pink)

With IPP65R190CFD7A MOSFET

--> VDS (yellow) & Vcs (blue) & VDD(pink)                          (zoomed)

--> VDS (yellow) & Vs pin (blue) & VDD(pink)                          

                                                                                                          (Second pulse)

Let me know if you need any more information.

Regards,

Anand M

Hi Anand,

Thanks for sending the waveforms. I will go through them and let you know as discussed in the call earlier today.

Regards,

Harish

Hi Harish,

Yes, we can close this thread as we discussing over mail.

Thanks for the extended support and cooperation to resolve the issue. Appreciate it.

Regards,

Anand M

Thank you