Thanks for your updates.
The AC coupling makes sense that ch1 has negative Vds. So there is no 8 kHz at Vout actually?
These two pdfs have information for ACF closed control loop design:
Part Number: TPS23754 Other Parts Discussed in Thread: PMP10288 Hi~ TI expert
I've test a board using TPS23754. And shemetic is same with reference design PMP10288.
If the auxiliary voltage is entered, it is working but does not operate when the PoE…
At 3.3V the efficiencies will be low given the voltage difference between 3.3V and 48V. Therefore typically you'll see an active clamp forward design to save on efficiency as shown in below link. This would be the most optimized solution. …