SYSTEM AND METHOD OF CLASSIFICATION IN POWER OVER ETHERNET SYSTEMS

• US 20080162973A1
• Filed: 12/31/2007
• Published: 07/03/2008
• Est. Priority Date: 06/22/2006
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Apfel, Russell J., Landry, D. Matthew
• Granted Patent: US 7,793,124 B2
• Time in Patent Office: Days
• US Class Current: 713/340
• CPC Class Codes: H04L 12/10 Current supply arrangements

Abstract

A power sourcing equipment (PSE) device is disclosed that includes an interface adapted to communicate with a powered device via wire pairs of a cable, a power supply circuit adapted to provide power to the interface, and device detection logic to detect the powered device coupled to the interface. The PSE device further includes power classification logic coupled to the interface and adapted to provide a power classification signal to the powered device. The power classification signal includes a first power classification signal and a second power classification signal to identify a power classification associated with the powered device. The power classification logic monitors the interface to detect a device classification response from the powered device and determines the power classification associated with the powered device based on the device classification response.

Claims

1. A power sourcing equipment (PSE) device comprising:

an interface adapted to communicate with a powered device via wire pairs of a cable;

a power supply circuit adapted to provide power to the interface;

device detection logic to detect the powered device coupled to the interface; and

power classification logic coupled to the interface and adapted to provide a power classification signal to the powered device, the power classification signal including a first power classification signal and a second power classification signal to identify a power classification associated with the powered device, the power classification logic to monitor the interface to detect a device classification response from the powered device and to determine the power classification associated with the powered device based on the device classification response.

2. The PSE device of claim 1, wherein the power classification logic comprises a signal generator to produce the first and second power classification signals.

3. The PSE device of claim 1, wherein the power classification logic includes a processor that is adapted to determine the power classification associated with the powered device based on the device classification response.

4. The PSE device of claim 1, wherein the first power classification signal and the second power classification signal are generated by superimposing a second signal onto a classification voltage pulse to vary a voltage level of the classification voltage pulse during a classification process.

5. The PSE device of claim 1, wherein the power classification logic is adapted to determine a first power classification when the powered device provides a first device classification response and to determine a second power classification when the powered device provides a second device classification response.

6. The PSE device of claim 1, further comprising a detection circuit adapted to receive the device classification response, wherein the device classification response comprises one of a voltage level, a current level, or any combination thereof.

7. The PSE device of claim 1, further comprising power supply logic adapted to provide a power supply to the powered device via the interface according to the power classification.

8. A method comprising:

receiving a classification signal at a powered device from a powered network, the classification signal including at least two classification signals;

selectively providing a device classification response signal in response to receiving the classification signal, the device classification response signal to identify a power classification associated with the powered device; and

receiving a power supply from the powered network according to the identified power classification.

9. The method of claim 8, further comprising detecting the at least two classification signals.

10. The method of claim 9, wherein selectively providing the device classification response signal comprises:

selectively providing a first device classification response signal in response to detecting a first classification signal of the at least two classification signals; and

selectively providing a second device classification response signal in response to detecting a second classification signal of the at least two classification signals.

11. The method of claim 9, wherein selectively providing the device classification response signal comprises turning off a current at the powered device after detecting one or more of the at least two classification signals.

12. The method of claim 8, wherein the powered network comprises a Power over Ethernet (PoE) network and wherein the powered device comprises a PoE-enabled device.

13. The method of claim 8, wherein the at least two classification signals includes a change in a voltage level of the classification signal during a power classification detection process.

14. The method of claim 8, further comprising deriving an operating power supply from the received power supply.

15. The method of claim 8, wherein the power classification has an associated power level that differs from power levels defined by a Power over Ethernet (PoE) Standard 802.3™

-2005, clause 33.

16. A method comprising:

detecting a powered device coupled to a network port of a power sourcing equipment (PSE) device during a powered device detection process;

transmitting a power classification signal to the powered device via the network port in response to detecting the powered device, the power classification signal including a first power classification signal and a second power classification signal;

monitoring the network port to detect a power classification response from the powered device in response to the power classification signal;

detecting a first power classification response from the powered device in response to the first power classification signal;

detecting a second power classification response from the powered device in response to the second power classification signal; and

determining a power classification associated with the powered device based on the first and second power classification responses.

17. The method of claim 16, further comprising providing a power supply to the powered device via the network port, the power supply including a power level corresponding to the power classification associated with the powered device.

18. The method of claim 16, wherein the first and second power classification signals are distinct signal elements.

19. The method of claim 16, further comprising adjusting a power budget at the PSE device according to the power classification associated with the powered device.

20. The method of claim 19, further comprising:

comparing an expected power consumption level associated with the power classification to an available power budget; and

providing a power supply associated with the power classification to the powered device when the expected power consumption level is less than the available power budget.

21. The method of claim 16, further comprising generating the first power classification signal and the second power classification signal.

22. The method of claim 16, wherein the first power classification response and the second power classification response are approximately equal.