UCC24612: For forward converter

Hello TQ,

I have talked to some of my colleagues about this to see what their thoughts were on using the UCC24612 in a forwarded converter.

The UCC24612 controls the gate drive by the SR FET’s Vds voltage. The FET turns on when the Vds voltage is less than VTHVGON and will turn off when Vds > VTHVGOFF. The turnoff threshold (VTHVGOFF) is roughly -10 mv. In a continuous conduction mode forwarded converter there is always current present in the output filter inductor. This current is most likely going to be large enough to prevent the SR FET from turning off when the converter goes from freewheeling to delivering energy. This could result in shoot through and could result in SR FET damage.

Have you considered using gate drive transformers or self-driven SR FETs from the transformer? One of these options might be a better solution for driving SR FETs in a forwarded converter.

Regards,

Mike