MAX5995A Datasheet | Maxim Integrated

Description The MAX5995A/MAX5995B/MAX5995C provide a plete interface for a powered device (PD) to ply with the IEEE® 802.3af/at/bt standard in a Power-Over-Ethernet (Po E) system. The devices provide the PD with a detection signature, classification signature, and an integrated isolation power switch with startup inrush current control. During the startup period, the devices limit the current to 135m A (typ) before switching to the higher current limit (1800m A to 2400m A, typ) when the isolation power MOSFET is fully enhanced. The devices feature Multi-Event classification, Intelligent MPS (MAX5995B/MAX5995C), Autoclass (MAX5995C), and an input UVLO with wide hysteresis and long deglitch time to pensate for twisted-pair cable resistive drop and to assure glitch-free transition during power-on/-off conditions. The devices can withstand a maximum voltage of 100V at the input. The devices support a Multi-Event classification method, as specified in the IEEE 802.3bt standard, and provide a signal to indicate from Type 1 to Type 4 Power Sourcing Equipment (PSE). The devices can detect the presence of a wall adapter power source connection and allow a smooth switch-over from the Po E power source to the wall power adapter. The devices also provide a power-good (PG) signal, twostep current limit and foldback control, overtemperature protection. A sleep mode feature in the MAX5995A/ MAX5995B minimizes low power consumption while generating the Maintain Power Signature (MPS) to maintain PSE connection. An Ultra-Low-Power sleep mode feature in the MAX5995A/MAX5995B further reduces power consumption while still generating MPS current. The MAX5995B/MAX5995C provides Intelligent Maintain Power Signature (IMPS) feature to automatically enable MPS current by detecting the port current. The devices feature a LED driver that is activated during sleep mode, Ultra Low-Power sleep mode (MAX5995A/MAX5995B), and Intelligent MPS mode (MAX5995B/MAX5995C). Multi-Event indication feature...