MAX5971A,pdf datasheet (Single

The MAX5971A is a single-port, power-sourcing equipment
(PSE) power controller designed for use in IEEE®
802.3af/at-compliant PSE. This device provides powered
device (PD) discovery, classification, current limit, and
DC and AC load-disconnect detections. The MAX5971A
operates automatically without the need for any software
programming and features an integrated power MOSFET
and sense resistor. The device also supports new Class 5
and 2-event classification for detection and classification
of high-power PDs. The MAX5971A provides up to 40W
to a single port (Class 5 enabled) and still provides highcapacitance
detection for legacy PDs.
The MAX5971A provides input undervoltage lockout
(UVLO), input overvoltage lockout, overtemperature
detection, output voltage slew-rate limit during startup,
and LED status indication.