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.