UCC2897A: Can I use PMP9720 active clamping using UCC2897A for AC-DC power converter.

UCC2897A has included features that make this controller more useful for telecom voltage range (36V<VIN<72V). For off-line active clamp design, you can consider UCC2894, otherwise if you are firm on UCC2897A use, you need to bypass the internal 110V JEFET startup. Also, the AUX output from UCC2897A is intended to drive a p-channel clamp MOSFET which is mostly used for low-side clamp applications. For off-line active clamp applications, a N-channel, high-side clamp MOSFET is usually preferred. Refer to "Active Clamp Transformer Reset: High Side or Low Side?" As long as you are ok to bypass the internal 100V startup and you can find a P-channel MOSFET to meet your design/cost needs, UCC2897A can be used for off-line applications.

Steve

so with ucc2897a bypassing 110vjefet  and Low side active clamping with p channel , is it possible to make offline? 

Yes, PMP22495 shows an example of UCC2897A used in an off-line application but this ref design is using a high-side clamp (N-channel clamp MOSFET)

Steve

Yes

Thank you so much for giving clearity on whether we can use active clamp with p channel in offline applications