Maxim Integrated MAX5981A / MAX5981B
PD Interface Controllers
Maxim Integrated MAX5981A / MAX5981B IEEE® 802.3af/at-Compliant, Powered Device (PD) Interface Controllers with Integrated Power MOSFET provide a complete interface for a PD to comply with the IEEE 802.3af/at standard in a power-over-ethernet (PoE) system. Maxim Integrated MAX5981 PD Interface Controllers provide the PD with a detection signature, a classification signature, and an integrated isolation power switch with inrush current control. MAX5981 supports a 2-Event classification method as specified in the IEEE 802.3at standard and provides a signal to indicate when probed by a Type 2 power sourcing equipment (PSE). This Maxim Integrated device detects the presence of a wall adapter power source connection and allows a smooth switch over from the PoE power source to the wall power adapter. Sleep mode and ultra-low power sleep mode features provide low power consumption while supporting Maintain Power Signature (MPS). MAX5891 PD Interface Controllers also feature an LED driver that is automatically activated during sleep mode. During sleep mode, the LED driver sources a periodic current (ILED) at 250Hz (MAX5981A) or 15.625kHz (MAX5981B).