Multiple current limits for power over ethernet controller

• US 7,567,579 B2
• Filed: 10/26/2006
• Issued: 07/28/2009
• Est. Priority Date: 08/02/1999
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Microsemi Corp. - Analog Mixed Signal Group, Ltd. (Microchip Technology Incorporated)
• Inventors: Cohen, Shimon, Ohana, Eli, Barnea, Nadav, Ferentz, Alon, Korcharz, Dror
• Primary Examiner(s): Pham; Chi H.
• Assistant Examiner(s): Hyun; Soon D.
• Application Number:
  US11/552,995
• Publication Number:
  US 20070121929A1
• Time in Patent Office: 1,006 Days
• Field of Search: None
• US Class Current: 370/401
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: H02G 3/00 Installations of electric cables or lines or protective tubing therefor in or on buildings, equivalent structures or vehicles installations of bus-bars H02G5/00; overhead installations H02G7/00; installations in or on the ground H02G9/00
• CPC Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 12/44 Star or tree networks
• CPC Class Codes: H04L 69/323 in the physical layer [OSI layer 1]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A power over Ethernet controller comprising: a control circuitry; at least one powering port, each of the at least one powering port comprising a unique means for controlling a switch associated therewith; and at least one current limiter, each of the at least one current limiter being associated with a unique one of the at least one powering port, each of the at least one current limiter being operable to limit the current through the controlled switch to a particular one of a plurality of values, each of the values being in excess of 100 mA, the particular value being selected responsive to the control circuitry.

Claims

1. A power over Ethernet controller comprising:

a control circuitry;

at least one powering port, each of said at least one powering port comprising a unique means for controlling a switch associated therewith; and

at least one current limiter, each of said at least one current limiter being associated with a unique one of said at least one powering port, each of said at least one current limiter arranged to limit the current through the controlled switch to a particular one of a settable plurality of values, each of said plurality values being in excess of 100 mA, said particular value being set responsive to said control circuitry.

2. A power over Ethernet controller according to claim 1, wherein said at least one powering port comprises a plurality of powering ports and said control circuitry is arranged to limit the current through each of the current limiters associated with said plurality of powering ports to a single one of said settable plurality of values.

3. A power over Ethernet controller according to claim 1, wherein said at least one powering port comprises a plurality of powering ports comprising a first group and a second group, and said control circuitry is arranged to set said current limiters associated with said first group to a first value, and to set said current limiters associated with said second group to a second value, said first value being different than said second value.

4. A power over Ethernet controller according to claim 1, wherein said particular value is responsive to classification of a powered device connected to said powering port.

5. A power over Ethernet controller according to claim 1, wherein each of said unique means for controlling a switch is responsive to said control circuitry, and wherein said control circuitry is arranged to:

detect a powered device connected to a particular one of said at least one powering port;

set the current limiter associated with said particular powering port to a first one of said plurality of values;

operate said unique means for controlling a switch associated with said particular powering port to power the detected powered device; and

responsive to information transmitted by the detected powered device, set the current limiter associated with said particular powering port to a second one of said plurality of values.

6. A power over Ethernet controller according to claim 1, wherein each of said unique means for controlling a switch represents a unique output of said control circuitry.

7. A power over Ethernet controller according to claim 6, wherein each of said at least one powering port further comprises an electronically controlled switch responsive to said unique means for controlling a switch.

8. A power over Ethernet controller according to claim 1, wherein said control circuitry comprises a plurality of registers, each of said plurality of registers comprising a digital value associated with one of said plurality of values.

9. A power over Ethernet controller according to claim 8, further comprising a digital to analog converter arranged to convert one of said digital values in said plurality of registers to an analog value, each of said current limiters limiting said current to said settable particular value responsive to said analog value.

10. A power over Ethernet controller according to claim 8, further comprising:

a plurality of digital to analog converters, each of said plurality of digital to analog converters being associated with a particular one of said plurality of registers and arranged to convert said digital value to an analog value; and

a multiplexer responsive to said control circuitry,

said multiplexer in communication with the output of each of said plurality of digital to analog converters and responsive to an output of said control circuitry to connect one of said analog values to one of said plurality of current limiters thereby setting said current limiter to said particular value.

11. A power over Ethernet controller according to claim 1, wherein said control circuitry is arranged to:

obtain data indicative of the total available power;

detect a first powered device connected to a first one of said at least one powering port;

set the current limiter associated with said first powering port to a first one of said plurality of values;

operate said unique means for controlling a switch associated with said first powering port to power the detected first powered device;

determine an available power, said available power being responsive to said obtained data indicative of the total available power and one of the power being drawn by said powered device connected said first powering port and the power allocated to said powered device connected to said first powering port;

detect a second powered device connected to a second one of said at least one powering port;

set the current limiter of said second powering port to a value consonant with said determined available power; and

operate said unique means for controlling a switch associated with said second powering port to power the detected second powered device.

12. A power over Ethernet controller according to claim 11, wherein said determined available power thereby prevents overload of said total available power.

13. A method of powering over communication cabling, the method comprising:

providing a plurality of current limit values, each of said provided current limit values being in excess of 100 mA;

providing at least one powering port, each of said provided at least one powering port having associated therewith a current limiter limiting the current flowing through said powering port to a settable one of said plurality of current limit values; and

setting said associated current limiter of each of said provided at least one powering port to a particular one of said provided plurality of current limit values by a control circuitry.

14. A method according to claim 13, wherein said provided at least one powering port comprises a plurality of powering ports, and said setting of said associated current limiter of each of said provided plurality of powering ports is to a single one of said plurality of values.

15. A method according to claim 13, wherein said provided at least one powering port comprises a plurality of powering ports comprising a first group and a second group, and said setting of said current limiter associated with said first group is to a first value, and said setting of said current limiter associated with said second group is to a second value, said first value being different than said second value.

16. A method according to claim 13, further comprising:

detecting a powered device connected to a particular one of said provided at least one powering port; and

classifying the detected powered device to determine a maximum current draw,

wherein said setting of said current limiter associated with said particular one of said provided plurality of ports is responsive to said classifying.

17. A method according to claim 13, wherein said setting of said associated current limiter is to a first one of said plurality of values, the method further comprising:

detecting a powered device connected to a particular one of said provided at least one powering port;

powering the powered device;

receiving information transmitted by said powered device, said information being associated with powering requirements of the powered device; and

setting said associated current limiter of said provided particular powering port to a second one of said provided plurality of current limit values responsive to said received information.

18. A method according to claim 13, further comprising storing each of said provided plurality of values is stored in a unique register.

19. A method according to claim 18, further comprising converting said stored value to an analog value.

20. A method according to claim 13, wherein said setting of said associated at least one current limiter is to a first one of said plurality of values, the method further comprising:

obtaining data indicative of the total available power;

detecting a first powered device connected to a first one of said provided at least one powering port;

powering the detected first powered device;

determining an available power, said available power being responsive to said obtained data indicative of the total available power and one of the power being drawn by said detected first powered device and the power allocated to said detected first powered device;

detecting a second powered device connected to a second one of said provided at least one powering port;

setting the current limiter associated with said second powering port to a limit consonant with said determined available power; and

powering the detected second powered device.

21. A method according to claim 20, wherein said determined available value prevents overload of the total available power.

22. A power over Ethernet controller supporting a plurality of powering ports, the power over Ethernet controller comprising:

a control circuitry;

a plurality of powering ports, each of said plurality of powering ports comprising a switch responsive to said control circuitry; and

a plurality of current limiters, each of said plurality of current limiters associated with a unique one of said powering ports, each of said plurality of current limiters arranged to limit the current through said switch to a settable one of a plurality of values, each of said values being in excess of 100 mA, said particular value being set responsive to said control circuitry.

23. A power over Ethernet controller comprising:

a control circuitry;

a powering port comprising a switch responsive to said control circuitry; and

a current limiter arranged to limit the current through the switch to a settable one of a plurality of values, each of said values being in excess of 100 mA, said one of said plurality of values being set responsive to said control circuitry.

24. A power over Ethernet controller comprising:

a control circuitry;

a powering port comprising a means for controlling a switch associated therewith; and

a current limiter arranged to limit the current through the controlled switch to a settable value responsive to said control circuitry,

said control circuitry arranged to detect a powered device connected to said at least one powering port, classify the power requirements of the detected powered device and set the current limiter to a particular value responsive to said classified power requirements.