LM5025A: LM5025A is ACF(Active-Clamp-Forward) topology controller, is it possible to use in a flyback application?

Hello Mike,
It is not possible to do this because of the timing relationship between the main gate drive and the clamp gate drive.
With a forward converter, the clamp is turn on when the main switch is turned off.
The clamp switch remains on until the next clock cycle when the main switch turns on again.
The LM5025A allows for some time delay here but the relationship is fairly fixed.
With a flyback converter, the main switch turns off and the secondary delivers power to the load.
If the clamp is active during the main switch OFF time then the secondary winding will not be able to deliver the full stored power to the load.
I think what will happen is that some power is returned to the DC source and some power to the secondary.
In any case there will be a conflict in the timing of the clamp signal and your performance will suffer.
For active clamp flyback applications TI makes the UCC28780 which is the best part to consider in your application.

Regards
John