Datasheet

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1 Related Documentation From Texas Instruments
2 Introduction
3 Setup
3.1 Input / Output Connector Descriptions
3.1.1 J1 – Data Port Output
Related Documentation From Texas Instruments
• TPS2376-H data sheet (SLVS646 )
• UCC3809-2 data sheet (SLUS166 )
• TPS2375 data sheet (SLVS525 )
• TPS2384 data sheet (SLUS634 )
• Application report, High Power PoE Using TPS2375/77-1 (SLVA225 )
• Application report, Achieving High Efficiency with a Multi-Output CCM Flyback Supply Using
Self-Driven Synchronous Rectifiers (SLUP204 )
• Application report, Reference Design: Isolated 50W Flyback Converter Using the UCC3809 Primary
Side Controller (SLUU096 ).
Traditionally, PoE has followed the standard IEEE 802.3af for specifying PD design and performance that
includes a maximum power allotment of 15.4 W per port by the PSE. Due to resistive losses in the CAT5
cable, the effective power to the PD input is limited to approximately 13 W. Additionally, most applications
require a power supply after the PD input that further reduces the system efficiency and limits actual
power to the load to approximately 11 W. As the drive for more complex end equipment increases, many
end equipment types requires more power than the IEEE 802.3af standard allows. This evaluation board
demonstrates how a PD can deliver up to 25 W to the load, and can be interfaced to any PSE that follows
detection and classification procedures defined by the IEEE 802.3af standard. For details on PD
operation, read the Application Information section in the datasheet for the TPS2375, IEEE 802.3af PoE
Powered Device Controllers (SLVS525 ). For details on PSE operation, read the Application Information
section in the data sheet for the TPS2384, Quad Integrated Power Sourcing Equipment Power Manager
(SLUS634 ).
Note that from a system-level perspective, the amount of power that can be delivered to the load is
dependent on both the PD and PSE. This evaluation board is intended to demonstrate how a PD can
deliver 25 W to the load. Because this PD evaluation board is intended for power levels greater than what
the IEEE 802.3af specification allows, a PSE designed to meet only the IEEE 802.3af standard will not be
able to source enough power, because it will go into current limit once the port current goes higher than
350 mA. For additional details, read the application report, High Power PoE Using TPS2375/77-1
(SLVA225 ).
The DC/DC power supply used in this evaluation board uses a Continuous Conduction Mode
Synchronous Flyback topology using the UCC3809-2 Economy Primary Side Controller. For details on this
topology, see the application reports, Achieving High Efficiency with a Multi-Output CCM Flyback Supply
Using Self-Driven Synchronous Rectifiers (SLUP204 ) and, Reference Design: Isolated 50 W Flyback
Converter Using the UCC3809 Primary Side Controller (SLUU096 ). For details on the UCC3809, see the
data sheet (SLUS166 ).
This section describes the jumpers and connectors on the TPS2376HEVM EVM as well as how to
properly connect, setup, and use TPS2376HEVM.
J1 is the RJ-45 adapter jack for the Data Port output for Ethernet data transmission. CAT5 cable can be
connected here to transmit Gigabit Ethernet data; however, this is beyond the scope of this reference
design and does not have any bearing on the PoE functionality. For PoE operation, J1 is not used.
TPS2376HEVM 2 SLVU197B – March 2007 – Revised September 2007
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