Slow diode in Innoswitch flyback RCD clamp
Posted by: treez
on
Hi,
In DER726, on page 6 schem it shows a slow diode in the RCD clamp........this is not a good idea with gan fet in the innoswitch. This is because Gan fets dont have the anti parallel internal diode.
As you know, the slow diode is used to "backflow" current out of the rcd capacitor, and through the pri to the sec, thus recoverign some of the clamp energy....but during that backflow time, the slow diode will eventually turn off...and the leakage inductor current will then need to flow in the primary fet's diode in order to "discharge"...but with innoswitch it cannot do this as there is no diode in the Gan package.
Please confirm that DER-726 is wrong as stated?
Hi treez,
You could measure a diode drop across drain to source pin of InnoSwitch. That's the only information I could share with you. Regarding the details as to why it has diode drop is something I could not share publicly.
Regards,
Jedidiah