TMI7302A

TMI7302A provides a complete interface for a  powered device (PD) to comply with the IEEE®  802.3af standard in a Power-over-Ethernet (PoE)  system. TMI7302A provides the PD with a  detection signature, classification signature, and  an integrated isolation power switch with inrush  current control. During the inrush period,  TMI7302A limit the current to less than 150mA  before switching to the higher current limit (400mA  to 500mA) when the isolation power MOSFET is  fully enhanced. The device features an input UVLO  with wide hysteresis and long deglitch time to  compensate for twisted-pair cable resistive drop  and to assure glitch-free transition during poweron/-off conditions. TMI7302A can withstand up to  100V at the input. TMI7302A also provides a  power-good (PG) signal, two- step current limit and  fold-back, over temperature protection, and di/dt  limit. TMI7302A automatically generates the necessary  pulsed current to maintain the PSE power. An  external resistor is used to enable this functionality  and to program the MPS pulsed current amplitude.