Texas Instruments AN-1521 POEPHYTEREV-E User Manual Download Page 1

User's Guide

SNOA476C – October 2006 – Revised April 2013

AN-1521 POEPHYTEREV-I / -E Evaluation Board

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Introduction

The POEPHYTEREV-I/-E evaluation board is a seamless design demonstrating Texas Instruments
LM5072 PoE product (capable of up to 24W) and DP83848I (single port 10/100Mb/s) Ethernet PHYTER®
product. While both the LM5072 and the DP83848 Ethernet PHY device have many advanced and
enticing features, this specific board is designed to demonstrate a subset of those features, specifically
Power over Ethernet. Two versions of this board are available. The –I version has an RJ-45 connector that
with integrated Ethernet magnetics. The –E version has discrete RJ-45 connector and Ethernet magnetics.
The schematics of the board are available with this kit for duplication into an end application product.

For additional features of the PoE and PHY devices, individual device evaluation boards are separately
available. For detailed information about the complete functions and features of the LM5072 or DP83848
devices, refer to the relevant data sheets. For applications where IEEE 802.3af must be complied with and
the power level is below 12.95W, refer to AN-1455 LM5072 Evaluation Board (

SNVA154

). For detailed

information about the Ethernet PHYTER® circuit, refer to AN-1469 PHYTER® Design & Layout Guide
(

SNLA079

).

This evaluation kit contains:

POEPHYTEREV-I or –E Evaluation board

Printed copy of this User's Guide

Board schematic

End User Licensing Agreement (EULA)

2

Scope of Applications

The POEPHYTEREV-I/-E evaluation kit (EK) is designed for high power PD (PoE terminology - Powered
Device) applications in which the maximum power exceeds the IEEE 802.3af’s 12.95W limit. The
evaluation board features TI™’s DP83848 10/100 Mb/s PHYTER® Ethernet Physical Layer Transceiver,
so any equipment that provides a standard IEEE 802.3, Clause 22 MII DTE interface; e.g.
SmartBits/Netcom box, is required as a data source for the Ethernet device. The LM5072 is a 100V, high
power PoE PD and PWM controller. The evaluation board is capable of operating with both PoE and
auxiliary (AUX) power sources. The dc-dc converter stage of the power supply is implemented in the
versatile flyback converter topology.

3

Important Note on Circuit Board Versions

There are two versions of PCBs being built, which can be identified by the PCB serial number printed
along the left edge of the top side the circuit board. One version is labelled 551012916-001 Rev A, the
other 551013040-001 Rev A. The first version cannot modify the 3.3V output to higher voltages because it
is directly connected to the PHY through inner layers. It is modified on the second version such that higher
output voltage can be produced without damaging the PHY circuit. The factory default output setting for
both versions is 3.3V. Contact TI on support to modify the latter version to other output voltage.

In the following, descriptions apply to both versions of the circuit boards unless specifically indicated.

TI is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.

1

SNOA476C – October 2006 – Revised April 2013

AN-1521 POEPHYTEREV-I / -E Evaluation Board

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Copyright © 2006–2013, Texas Instruments Incorporated

Summary of Contents for AN-1521 POEPHYTEREV-E

Page 1: ...ion kit EK is designed for high power PD PoE terminology Powered Device applications in which the maximum power exceeds the IEEE 802 3af s 12 95W limit The evaluation board features TI s DP83848 10 10...

Page 2: ...oltage ranges PoE input voltage range 39 to 57V AUX input voltage range 22 to 57V Measured maximum efficiency DC to DC converter efficiency 90 at 6A Overall efficiency including the input diode bridge...

Page 3: ...1h The board may be set to PHY Address 03h by adding jumper J3 Table 1 Table of Jumpers 1 Jumper Name Function J1 MII Male Connector MII interface J2 MII Header Alternative connection for MII signals...

Page 4: ...oper cable at such power levels may violate safety regulations and may cause damage 7 A Note about PoE Input Potentials PoE applications are typically 48V systems in which the notations GND and 48V no...

Page 5: ...tic Part 1 The Ethernet Circuit Figure 2 Evaluation Board Schematic Part 2 RJ45 connectors and Ethernet Magentics 5 SNOA476C October 2006 Revised April 2013 AN 1521 POEPHYTEREV I E Evaluation Board Su...

Page 6: ...connection pins for the 3 3V output JE4 and JE5 of are the high potential pins J13 a regular RJ45 connector on the E version board for PoE input and data link UE13 Bel Stewart Integrated RJ45 connect...

Page 7: ...ectronic load It is not recommended to use additional filter capacitors greater than 20 F total across the output port as the extra capacitance will alter the feedback loop properties and may cause in...

Page 8: ...er application If the proper response is not observed during both detection and classification modes check the connections closely If no current is flowing it is likely that the set of conductors feed...

Page 9: ...RE2D in parallel to achieve a low cost AUX inrush limiter and transient protection Otherwise the unlimited inrush currents can wear on board traces connector contacts and various board components as...

Page 10: ...p regulator output thus shutting off the startup regulator and reducing the power dissipation inside the IC Given the low current limit value 15 mA nominal of the high voltage startup regulator the VC...

Page 11: ...e and directly enters full power application mode Horizontal Resolution 50 ms div Trace 1 PoE input voltage across the VIN and VEE pins 20V div Trace 2 Voltage across the RTN and VEE pins namely the v...

Page 12: ...ET 3 Because linear current limiting is accomplished by driving the MOSET into the saturation region the drain voltage RTN pin rises When it reaches 2 5V with respect to VEE power good is de asserted...

Page 13: ...ent Limit under 48V PoE Input and Output Dead Short Condition Figure 9 shows key waveforms of over current protection by the hot swap MOSFET s dc current limit The PoE input voltage is at 38V The inpu...

Page 14: ...e Figure 10 shows the step load response at Vin equal to 48V The load current changes in step between 1A and 7A Horizontal Resolution 0 5 ms div Trace 1 Load current step changes between 1A and 7A 2A...

Page 15: ...l 5 mA div Figure 11 PoE Input Current Ripples under Full Load Horizontal Resolution 5 s div Trace 1 The AUX input current ripples AC coupled 10 mA div Trace 2 The FFT of Trace 1 showing the peak valu...

Page 16: ...r U6 along with a Syfer 1808JA250102MCTPY2 or equivalent for CE12 and CE13 24 Bill of Materials Table 2 Part 1 PoE Circuit BOM 1 ITEM PART NUMBER DESCRIPTION VALUE BR1 CBR1 D020S DIODE BRIDGE SMDIP CE...

Page 17: ...S DUAL SCHOTTKY SOT 23 DIODE INC DE4 CMHD4448 DIODE SOD123 CENTRAL 125 mA 75V DE5 NU DE6 CMR1U 01M DIODE SMA CENTRAL 1A 100V DE7 NU P1 PJ 102A POWER JACK JE4 NU JE5 3104 2 00 01 00 00 080 POST MILL MA...

Page 18: ...OR 21 0 k RE22 NU RE23 CRCW08051582F RESISTOR 15 8 k RE25 CRCW12060R47F RESISTOR 0 47 Ohm RE26 NU RE28 CRCW08050R0J RESISTOR 332 Ohm RE29 CRCW12062492F RESISTOR 24 9 k RE34 CRCW08050R0J RESISTOR 0 Ohm...

Page 19: ...F 50V C49 CAPACITOR CER CC0603 KEMET E Board 8 pF 50V ONLY C50 CAPACITOR CER CC0603 KEMET E Board 8 pF 50V ONLY C53 CAPACITOR CER CC0603 KEMET E Board 8 pF 50V ONLY C54 CAPACITOR CER CC0603 KEMET E B...

Page 20: ...ISTOR 220 Ohm R28 CRCW08051501F RESISTOR 1 5 k R29 CRCW06032201F RESISTOR 2 2 k R30 CRCW060324871F RESISTOR 4 87 k R31 CRCW06032201F RESISTOR 2 2 k R32 CRCW06032201F RESISTOR 2 2 k R33 CRCW060349R9J R...

Page 21: ...OILCRAFT E BOARD ONLY U8 NU U9 NU U10 NU UE13 0838 1X1T W6 CONNECTOR INTEGRATED WITH ETHERNET TRANSFORMER BEL STEWARD I BOARD ONLY Y1 FOXSLF 250F 20 CRYSTAL HC49 US 25 MHz 21 SNOA476C October 2006 Rev...

Page 22: ...sponsible for compliance with all legal regulatory and safety related requirements concerning its products and any use of TI components in its applications notwithstanding any applications related inf...

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