1 Features

1• IEEE 802.3at Quad Port PSE controller

– Auto Detect, classification

– Auto Turn-On and disconnect

– Efficient 255-mΩ sense resistor

• Pin-Out enables Two-Layer PCB

• Kelvin Current Sensing

• 4-Point detection

• Automatic mode – as shipped

– No External terminal setting required

– No Initial I2C communication required

• Semi-Automatic mode – set by I2C command

– Continuous Identification and Classification

– Meets IEEE 400-ms TPON specification

– Fast-Port shutdown input

– Operates best when used in conjunction with

system reference code

http://www.ti.com/product/TPS23861/toolssoftw

are

• Optional I2C control and monitoring

• –40°C to 125°C Temperature range

• TSSOP 28 Package 9.8 mm x 6.6 mm

2 Applications

• Ethernet switches and routers

• Surveillance NVR and DVRs

• Residential gateways

• PoE Pass-Through systems

• Wireless backhaul

3 Description

The TPS23861 is an easy-to-use, flexible,

IEEE802.3at PSE solution. As shipped, it

automatically manages four 802.3at ports without the

need for any external control.

The TPS23861 automatically detects Powered

Devices (PDs) that have a valid signature, determines

power requirements according to classification and

applies power. Two-event classification is supported

for type-2 PDs. The TPS23861 supports DC

disconnection and the external FET architecture

allows designers to balance size, efficiency and

solution cost requirements.

The unique pin-out enables 2-layer PCB designs via

logical grouping and clear upper and lower

differentiation of I2C and power pins. This delivers

best-in-class thermal performance, Kelvin accuracy

and low-build cost.

In addition to automatic operation, the TPS23861

supports Semi-Auto Mode via I2C control for precision

monitoring and intelligent power management.

Compliance with the 400-ms TPON specification is

ensured whether in semi-automatic or automatic

mode.