Texas Instruments TPS23881 8-Channel Power-Over Ethernet PSE

Texas Instruments TPS23881 8-Channel Power-Over Ethernet PSE is a power-sourcing equipment (PSE) controller engineered to insert power into Ethernet cables per 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-channel) PoE Ports. The PSE controller can detect powered devices (PDs) that have a valid signature, determine the power requirements of the devices according to their classification, 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. The TPS23881 is also compatible with TI’s 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.

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 can 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.

Features

IEEE 802.3bt PSE solution for Type 3 or Type 4 PoE applications
Eight independent PSE channels
Resistor-selectable autonomous operation
- No external MCU is 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 (TPS23881A)