Detailed description

STEVAL-TSP009V2

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DocID027732 Rev 1

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Detailed description

The PM8803 evaluation board, STEVAL-TSP009V2, has been designed to cover a broad

range of Power over Ethernet (PoE) applications. The PM8803 is a highly integrated device

embedding an IEEE802.3af/at-compliant powered device (PD) interface together with a

PWM controller and support for auxiliary sources. Although the PM8803 can be configured

to work in several isolated topologies (self-driven or transformer gate-driven), the focus

here is on a high-efficiency isolated flyback converter topology with synchronous

rectification, 3.3 V output voltage with 6 A output current capability.

Auxiliary sources can be connected to the board on 2 different input connectors. One input

(AUX II) allows prevalence of the auxiliary sources with respect to the PoE, while the other

input (AUX I) allows the use of a wall adapter with voltage lower than the internal PoE

UVLO threshold, while still benefitting from the inherent inrush and DC current limit. The

possible configurations supported by the PM8803 evaluation board as options on the same

PCB are:



Input diode bridges; 4 possible options, including active bridges



Optional 4-pair detection circuit, to detect a high power PSE source



Optional booster circuit, to increase the max input current over 800 mA



Diode or synchronous rectification; 4 package options for diode and 3 package options

for MOSFET



Primary side snubber; 3 options including active clamp



Power transformer; 3 size options for transformer gate-driven solutions and 2 size

options for self-driven applications