The MAX5922A/B/C is a single-port networked power controller with integrated power MOSFETs that operates from a 32 V to 60 V power rail. The device is specially designed for power supply equipment (PSE) for powerover LAN applications and is fully compliant with the IEEE802.3af standard. The MAX5922 provides power device (PD) discovery, classification, current limiting, and other functions necessary for the IEEE 802.3af standard PSE. The MAX5922 is suitable for PSE functions in both switch/routers where power is delivered to the system via the signal pair to the load, and across the system where the power is delivered to the load via the spare wire pair. In midspan mode, the detection collision avoidance circuit (MAX5922A/C only) provides the necessary fallback timing to prevent fault detection that occurs when two different PSEs try to detect the same PD supply. The MAX5922B/C have a detect disable input that can be connected high to disable the detect/classify functions or low to enable them. The MAX5922 features a programmable undervoltage lockout (UVLO) internally that keeps the device shut down until the input voltage exceeds a certain threshold, set to 38V (MAX5922A) or 28V (MAX5922B/C). Upon successful discovery and classification of the PD, the MAX5922 enters start-up mode. During startup, the MAX5922 limits the output voltage and current slew rate, reducing EMI (electromagnetic interference). The MAX5922 integrates a 0.45Ω N-channel power MOSFET to provide efficient operation and simplified system design. The MAX5922 monitors and provides current limit protection to the load at all times. Programmable current limit uses an external current sense resistor. The MAX5922 features current-limited foldback and duty-cycle limiting during load faults and short-circuits to ensure robust operating conditions. Fault management, either allowing partial latching or automatic restart after a fault. The MAX5922 provides ZC and fault status signals to indicate output power is good, zero current fault, and other faults (overcurrent, overtemperature), respectively. The MAX5922 is available in a 28-pin TSSOP package and is rated over the extended -40°C to +85°C temperature range.