The TPS23881 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 TPS23881 improves on the TPS23880 with reduced current sense resistors, more accurate programmable power limiting, capacitance measurement and the ability to operate from ROM (see Device Comparison Table). The TPS23881 is also compatible with TIs FirmPSE system firmware, which provides a fully configurable solution for controlling multiple TPS23881 devices in systems offering up to 48-ports of 4-pair PoE power.
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 90 W to upwards of 125 W. The 200-mΩ current sense resistor and external FET architecture allow designs to balance size, efficiency, thermal and solution cost requirements.