1 Features
• IEEE 802.3bt PSE solution for PoE 2 Type 3 or
Type 4 power over ethernet applications
• Eight independent PSE channels
• Resistor selectable autonomous operation
– No external MCU required
• Compatible with TI's FirmPSE system firmware
• SRAM Programmable memory
• Programmable power limiting accuracy ±2.5%
• 200mΩ current sense resistor
• Legacy PD capacitance measurement
• Selectable 2-pair or 4-pair port power allocations
– 15.4W, 30W, 45W, 60W, 75W or 90W
• Single and dual signature PD compatibility
• Dedicated 14-bit integrating current ADC per port
– Noise immune MPS for DC disconnect
– 2% current sensing accuracy
• 1- or 3-bit fast port shutdown input
• Auto-class discovery and power measurement
• Inrush and operational foldback protection
• Flexible processor controlled operating modes
– Auto, semi auto and manual / diagnostic
• Per port voltage monitoring and telemetry
• –40°C to +125°C temperature operation
• Ultra Low Alpha (ULA) packaging (TPS23881B1A)

2 Applications
• Video recorder (NVR, DVR, and so forth)
• Small business switch
• Campus and branch switches

3 Description
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.