This application note presents a reference design for a high-efficiency, high-power PD (up to 60 W input) power converter based on an active-clamp forward topology with self-driven synchronous rectification using the PM8803 as the main controller.
This document presents a reference design for a high-efficiency, high-power Power over Ethernet (PoE) converter capable of handling up to 60 W input. The design utilizes the PM8803 controller, which is IEEE 802.3at compliant, combined with an external current booster to manage high input currents up to 1.4 A. The converter employs an active-clamp forward topology with self-driven synchronous rectification.
| Output voltage | 3.3 V |
|---|---|
| Output current | 18 A |
| Efficiency (DC-DC only) | 91 % |
| Overall efficiency | 88 % |
| Switching frequency | 220 kHz |
The maximum input voltage applied at the J3 connector is 57 V.
The operative input voltage range starts at 42 V.
The design manages higher input current up to 1.4 A using a current booster.