Abstract: Increased cable length Power over Ethernet (PoE) systems are provided. Embodiments can be designed for compliance with IEEE 802.3af, IEEE 802.3at, or legacy PoE standards. Embodiments include PSE and PD designs enabled for increased length PoE. Embodiments include example modifications of IEEE 802.3af PSE system rules, including example modifications of PSE port voltage ranges to support IEEE 802.3af compliant PDs across increased cable lengths. Embodiments include example modifications of IEEE 802.3af PD system rules, including example modifications of PD port voltage ranges to enable current IEEE compliant PSEs to support increased cable length PoE. Embodiments include PDs having increased voltage process and/or added voltage protection circuitry to support increased length PoE. Modifications of PSE system rules and PD system rules can be performed independently of each others, so that modified PSEs can be made to work with existing PDs, or vice versa.

Abstract: In a Power over Ethernet (POE) system, a power source equipment (PSE) device configured to deliver power to one or more powered devices (PDs) over a plurality of Ethernet transmission lines. The PSE interface includes a multi-port transmission line connector capable connecting to multiple Ethernet transmission lines, and a power source equipment (PSE) controller module integrated with the multi-port transmission line connector. The PSE controller module is capable of high power operation beyond that specified by IEEE standard 802.3af™ for powered devices. More specifically, the PSE controller is configured to deliver over 15.4 Watts, and up to 36 Watts of power, to meet the needs of high powered devices such as IP Phones, and access points. Further, the PSE controllers can utilize, currently unused, class 4 of IEEE standard 802.3af™ to identify, initiate, and classify the high power operation mode.

Abstract: A new pulse width modulation return scheme in which the source of PWM FET is directly connected to the 48 Volt return and therefore Ids of PWM FET does not pass through the hot-swap FET which therefore significantly reduce the power dissipation on the die of PD chip.

Abstract: A system and method of analyzing a powered device (PD) in a Power-over-Ethernet (PoE) system are presented. The system includes an Ethernet interface having a physical layer (PHY) chip capable of providing a signal pulse in addition to physical layer 1 functions. The system further includes a pulse transformer, coupled to the PHY chip, capable of relaying the signal pulse provided by the PHY chip to the PD via the transmit line and a second PHY chip. The first PHY chip receives one or more return pulse signals from the PD, analyzes characteristics such as voltage and/or frequency of the return pulse signal(s), and determines attributes of the PD based on those characteristics. The attributes can include powered device validity and power classification. A method of supplying power to a PD is also presented.

Abstract: A system and method of classifying a high powered device (PD) with an increased current limit includes: connecting a voltage to the PD, measuring current through a classification resistor connected to the PD, and determining a PD classification signature based on the current according to classification steps such that a minimum classification step includes a minimum current of 0 mA and a maximum classification step includes a maximum current beyond a predetermined current limit. The system includes a PSE, voltage source, PD classification resistor, and PD voltage, connected to the P. An alternative embodiment further includes a discrete classification circuit and discrete classification resistor to be used to measure the current for classification purposes instead of the PD classification resistor when the PD and PD classification resistor do not support power classification under the classification scheme.

Abstract: A system and method for communicating information using Layer 1 from a powered device to power source equipment via Ethernet. In one embodiment, Layer 1 information such as power management, classification, temperature, and disconnect information is transmitted from a powered device to power source equipment using an AC signal that has a cycle defining a first time period during which the AC signal is turned on and a second time period during which the AC signal is turned off. A type of information being sent by the powered device can be determined based on characteristic on/off times of the AC signal cycle.

Abstract: A system and method for enabling communication between power source equipment and a powered device chip. In one embodiment, communication between the power source equipment and the powered device chip is enabled through a communication link established between the powered device chip and a host device on the powered device.

Abstract: In a Power over Ethernet (POE) system, a power source equipment (PSE) device configured to deliver power to one or more powered devices (PDs) over a plurality of Ethernet transmission lines. The PSE interface includes a multi-port transmission line connector capable connecting to multiple Ethernet transmission lines, and a power source equipment (PSE) controller module integrated with the multi-port transmission line connector. The PSE controller module is capable of semi-automatic mode and legacy detection of one or more of the PDs that are coupled to the Ethernet transmission lines. The PSE controller module includes a plurality of PSE controllers corresponding to the Ethernet transmission lines, including a master PSE controller and plurality of slave PSE controllers coupled to the master PSE controller. The master PSE controller controls the slave PSE controllers, so as to provide power management to said corresponding PD devices, without an external microcontroller.