Power over Ethernet system and method for detecting disconnection of a device
AssigneeTexas Instruments Incorporated
InventorsJean Picard, Barry Jon Male
Life of this patent
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Abstract
A detection system to detect disconnection of a powered device from a link of a power over Ethernet system is disclosed. The detection system can include closed-loop control configured to supply a predetermined test current to an electrically conductive path that includes at least a portion of the link via which the powered device is connectable for receiving power. A detector is configured to monitor the closed-loop control, the loop detector providing a disconnect signal if the closed-loop control is outside of expected operating parameters, thereby indicating that the powered device has been disconnected from the link.
Claims19
A detection system to detect disconnection of a powered device from a link of a power over Ethernet system, the detection system comprising:
- closed-loop control configured to supply a predetermined test current to an electrically conductive path that includes at least a portion of the link via which the powered device is connectable for receiving power, wherein the closed-loop control further comprises:
- a transistor coupled to provide the test current to the link;
- and
- a driver coupled to drive the transistor with a drive voltage based on a control signal,
- wherein a comparator is configured to compare the drive voltage with a threshold voltage and
- configured to monitor the closed-loop control and to provide a disconnect signal if the closed-loop control is outside of expected operating parameters, thereby indicating that the powered device has been disconnected from the link.
A power over Ethernet system comprising:
- power sourcing equipment configured to supply power to at least one port;
- a powered device coupled to a respective one of the at least one port via an electrically conductive link for receiving power;
- a disconnect detection system coupled to the electrically conductive link, the disconnect detection system comprising:
- closed-loop control configured to supply a test current to the electrically conductive link, wherein the closed-loop control further comprises:
- a transistor coupled to provide the test current to the link;
- and
- a driver coupled to drive the transistor with a drive voltage based on a control signal,
- wherein a comparator is configured to compare the drive voltage with a threshold voltage and
- configured to provide a disconnect signal in response to detecting an open loop condition in the closed-loop control indicative of the powered device being disconnected from the electrically conductive link.
A method for detecting that a powered device has disconnected from a link of a power over Ethernet system, the method comprising:
- generating a control signal as part of a closed-loop control for delivering a test current to the link to which the powered device is connected;
- driving a transistor with a drive voltage based on the control signal;
- comparing the drive voltage with a threshold voltage for detecting an open loop condition;
- and
- asserting a disconnect signal in response to detecting an open loop condition in the closed-loop control.
Dependencies are inferred from the claim text.