Abstract: A semi-active bridge for furnishing voltage of a correct polarity to a powered device in a Power over Ethernet (PoE) network is disclosed. In one or more implementations, the semi-active bridge includes a diode having an anode portion and a cathode portion. The anode portion of the diode is connected to an input terminal, and the cathode portion of the diode is connected to an output terminal. The semi-active bridge also includes an active transistor device having a source region and a drain region. The drain region of the active transistor device is connected to the input terminal, and the source region of the active transistor device is connected to the output terminal.

Abstract: A method for detecting and classifying powered devices in power over Ethernet/non-power over Ethernet applications is described. In one or more implementations, the method includes deactivating a non-power over Ethernet component for a predetermined time period. The method also includes activating an isolation switch of a powered device after the predetermined time period has elapsed since no characteristic impedance associated with the powered device has been detected.

Abstract: A system for controlling the operation of isolation transistors in high power Power over Ethernet (PoE) networks to achieve greater power delivery to a load is disclosed. In one or more implementations, the system includes a first power over Ethernet (PoE) powered device controller configured to control power supply to a load, and a second PoE powered device controller coupled to the load and to the first PoE powered device controller. The second PoE powered device controller is connected to the first PoE powered device controller using a shared connection interface and is configured to control power supply to the load. The shared connection interface is configured to synchronize the first PoE powered device controller and the second PoE powered device controller to deliver power at least substantially contemporaneously to the load.

Abstract: A method is disclosed to at least partially prevent back powering of power sourcing equipment. In one or more implementations, the method includes detecting a magnitude of current through a current sensor, such as a transistor and/or a resistor. The active FET bridge is configured to rectify input power supplied by power sourcing equipment to a power over Ethernet (PoE) powered device. The method also includes causing the transistor to transition from a closed configuration to an open configuration to at least substantially prevent current flow through the transistor when the magnitude of current is below a predefined threshold to at least substantially prevent back powering of the PSE.

Abstract: A system for sinking maintain power signature (MPS) current to a rectifier bridge from a powered device (PD) controller in a Power over Ethernet (PoE) network is disclosed. In one or more implementations, the system includes a rectifier bridge configured to electrically connect to Power over Ethernet power sourcing equipment for receiving power from the power sourcing equipment. The system also includes a powered device controller operatively connected to the rectifier bridge and configured to control power supplied to a load. The load is configured to receive power from the power sourcing equipment and a second power source. The powered device controller is configured to source maintain power signature current to the power sourcing equipment using an input of the rectifier bridge when the second power source is furnishing power to the load.

Abstract: A method is disclosed to at least partially prevent back powering of power sourcing equipment. In one or more implementations, the method includes detecting a magnitude of current through a current sensor, such as a transistor and/or a resistor. The active FET bridge is configured to rectify input power supplied by power sourcing equipment to a power over Ethernet (PoE) powered device. The method also includes causing the transistor to transition from a closed configuration to an open configuration to at least substantially prevent current flow through the transistor when the magnitude of current is below a predefined threshold to at least substantially prevent back powering of the PSE.

Abstract: A system for sinking maintain power signature (MPS) current to a rectifier bridge from a powered device (PD) controller in a Power over Ethernet (PoE) network is disclosed. In one or more implementations, the system includes a rectifier bridge configured to electrically connect to Power over Ethernet power sourcing equipment for receiving power from the power sourcing equipment. The system also includes a powered device controller operatively connected to the rectifier bridge and configured to control power supplied to a load. The load is configured to receive power from the power sourcing equipment and a second power source. The powered device controller is configured to source maintain power signature current to the power sourcing equipment using an input of the rectifier bridge when the second power source is furnishing power to the load.

Abstract: A system for controlling the operation of isolation transistors in high power Power over Ethernet (PoE) networks to achieve greater power delivery to a load is disclosed. In one or more implementations, the system includes a first power over Ethernet (PoE) powered device controller configured to control power supply to a load, and a second PoE powered device controller coupled to the load and to the first PoE powered device controller. The second PoE powered device controller is connected to the first PoE powered device controller using a shared connection interface and is configured to control power supply to the load. The shared connection interface is configured to synchronize the first PoE powered device controller and the second PoE powered device controller to deliver power at least substantially contemporaneously to the load.

Abstract: Modulating current of an integrated circuit for signal transmission. The invention may be used in a network device to signal its presence or continued presence to a network router, mid span, hub, or switch, and/or to identify its characteristics or class to control whether and/or what power is applied to the applicable network lines to fully power the network device. Use of the invention in a network environment allows use of certain lines as low voltage signal communication lines for certain network devices, and use of the same lines and/or of different lines for powering other network devices from the same lines at voltages that would damage devices intended for low voltage communication.