Type-4, four-pair, 8-channel PoE PSE controller with autonomous mode

The TPS23881B is an 8-channel power sourcing equipment (PSE) controller engineered to insert power onto Ethernet cables in accordance with the IEEE 802.3bt standard. The eight individual power channels can be configured in any combination of 2-Pair (1-channel) or 4-Pair (2-channels) PoE Ports. The PSE controller can detect powered devices (PDs) that have a valid signature, complete mutual identification, and apply power.

The TPS23881B improves on the TPS2388

with reduced current sense resistors, selectable Autonomous operation, SRAM

programmability, programmable power limiting, capacitance measurement, and

compatibility with TI’s FirmPSE system firmware (see Device Comparison Table).

Programmable SRAM enables

in-field firmware upgradability over

I2C to ensure IEEE compliance and

interoperability with the latest PoE enabled

devices. Dedicated per port ADCs provide

continuous port current monitoring and the ability

to perform parallel classification measurements

for faster port turn on times. A ±2.5% accurate

programmable port power limit provides the ability

to expand the maximum power sourced from 90W to

upwards of 125W. The 200mΩ current sense resistor and external

FET architecture allow designs to balance size,

efficiency, thermal and solution cost

requirements.