Si34061

Si3406x Family Data Sheet Fully-Integrated IEEE 802.3-Compliant POE+ PD Interface and High-Efficiency Switching Regulators with Sleep, Wake, and LED Drive The Si3406x family integrates all power management and control functions required in a Power-over-Ethernet Plus (PoE+) powered device (PD) application. These devices convert the high voltage supplied over the 10/100/1000BASE-T Ethernet connection to a regulated, low-voltage output supply. The optimized architecture of this device family minimizes the solution footprint and external BOM cost and enables the use of low-cost external components while maintaining high performance. The Si3406x family integrates the required diode bridges and transient surge suppressor, thus enabling direct connection of the IC to the Ethernet RJ-45 connector. The switching power FET and all associated functions are also integrated. The integrated, current mode controlled switching regulator supports isolated or non-isolated flyback and buck converter topologies. The switching frequency for the regulator is tunable with a simple external resistor value to help avoid unwanted harmonics for better emissions control. A synchronous driver is provided to optionally drive a secondary side FET to improve efficiency of power conversion. Connection to the PSE switch is maintained during sleep by an optional automated maintain-power-signature (MPS) signal. These devices fully support the IEEE 802.3at specification for the cases of single or two event clas...