TPS23750EVM-108: POE 3.3V @ 3A, 36 ~ 57Vin

The HPA108 evaluation module implements an IEEE 802.3af-compliant class-3 power interface and a 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 provided on this EVM is a 3.3-V isolated design using a synchronous flyback topology; however, the BOM shows how to build 3.3-V or 5-V isolated and non-isolated variants. In addition, the EVM provides footprints for a simple diode and an associated snubber to implement a nonsynchronous flyback converter. 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.