june 2011 doc id 018599 rev 2 1/5 5 EVALPM8803-FWD EVALPM8803-FWD: ieee802.3at compliant demonstration kit with synchronous active clamp forward poe converter features eee 802.3at compliant support for gigabit ethernet data pass-through for the ethernet data works with power supplied from ethernet lan cables or from local auxiliary sources successful ieee802.3at layer1 classification indicator single output 3.3 v/5 v 90+% converter efficiency board size 10x13 cm description the EVALPM8803-FWD is a demonstration board implementing an i eee802.3at compatible interface together with a self driven synchronous active clamp forward converter based on pm8803. the board is designed to work up to 30 w, and with minimal changes the output voltage can be selected either 5 v or 3.3 v. for sake of flexibility, alternative footprint have been foreseen tor the main component (mos, transformer, etc.). it is possible to connect auxiliary sources to one of the 2 jacks in the EVALPM8803-FWD like in real application design. in one case thanks to the pm8803 feature, preval ence of the auxiliary source can be guaranteed. three leds give indication of: ? the converter is running ? an external auxiliary source is connected to the board ? a type 2 pse is connected to the board. EVALPM8803-FWD www.st.com
schematic diagrams EVALPM8803-FWD 2/5 doc id 018599 rev 2 1 schematic diagrams figure 1. demonstration kit schematic: detail of the poe+ input section including data transformer, diode bridges, protection and optional cm choke ! - v 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 6 3 3 0 / % & 0 / % & 0 / % & 0 / % & 6 3 3 6 / 5 4 3 0 # h a s s i s # h a s s i s # h a s s i s # h a s s i s # h a s s i s # h a s s i s 2 4 . 2 4 . / p t i o n ! c t i v e " r i d g e . o t - o u n t e d / p t i o n ) n p u t # o m m o n - o d e & |