User's Guide
SLVU136A–July 2005–Revised January 2011
TPS23750 Buck-Converter Evaluation Board – HPA107
This user’s guide describes the function and operation of the HPA107 evaluation module (EVM). A
complete description, schematic, bill of materials, assembly drawing, and printed-circuit board artwork are
included.
Contents
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Introduction .................................................................................................................. 1
Specification, Schematic, and Bill of Materials .......................................................................... 2
Board Layout ................................................................................................................ 7
Using the EVM .............................................................................................................. 9
Related Documentation ................................................................................................... 10
List of Figures
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Typical 3.3-V PD End-to-End Efficiency .................................................................................
Typical 3.3-V DC/DC Converter Efficiency .............................................................................
Typical 5-V PD End-to-End Efficiency ...................................................................................
Typical 5-V DC/DC Converter Efficiency.................................................................................
Typical Setup ................................................................................................................
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4
9
List of Tables
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3
HPA107 Electrical Specification...........................................................................................
HPA107 Bill of Materials ...................................................................................................
EVM I/O Interfaces..........................................................................................................
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9
1
Introduction
The HPA107 evaluation module implements an IEEE 802.3af-compliant class-3 power interface and a
non-isolated DC/DC switching converter using the Texas Instruments TPS23750 powered device (PD)
controller in a typical power-over-Ethernet (PoE) configuration. The DC/DC converter is a 5-V output buck
converter with a BOM option for 3.3 V. A small prototype area is included on the printed-circuit board. The
EVM accepts a TPS23770 in place of the TPS23750 to support a PD with a legacy undervoltage lockout
(UVLO) threshold.
The EVM has separate LEDs that show when the DC/DC converter and the PoE interface are active. Test
points are provided at all critical nodes. Power to the EVM is provided over the spare or data lines in an
Ethernet cable or by an auxiliary source like a wall adapter.
PowerPad is a trademark of Texas Instruments.
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SLVU136A–July 2005–Revised January 2011
TPS23750 Buck-Converter Evaluation Board – HPA107
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