High power architecture for power over Ethernet

• US 7,299,368 B2
• Filed: 01/18/2005
• Issued: 11/20/2007
• Est. Priority Date: 10/16/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Microsemi Corp. - Analog Mixed Signal Group, Ltd. (Microchip Technology Incorporated)
• Inventors: Darshan, Yair, Ferentz, Alon, Korcharz, Dror, Peker, Arkadiy
• Primary Examiner(s): Perveen; Rehana
• Assistant Examiner(s): Brown; Michael J.
• Application Number:
  US11/036,063
• Publication Number:
  US 20050122140A1
• Time in Patent Office: 1,036 Days
• Field of Search: 713/300, 713/320, 713/340
• US Class Current: 713/300
• CPC Class Codes: H03B 1/00 Details
• CPC Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/40 Constructional details, e.g. power supply, mechanical construction or backplane
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities

Abstract

Power sourcing equipment providing a plurality of power sources for connection over communication cabling to a single powered device, the power sourcing equipment comprising: a first power source; a second power source; a control circuit; a current sensor adapted to monitor an output current of the first power source, the current sensor being operatively connected to the control circuit; and a voltage regulating means associated with one of the first power source and the second power source, the voltage regulating means being responsive to the control circuit, the control circuit being operative responsive to the monitored output current to operate the voltage regulating means so as to maintain the monitored output current within a pre-determined range.

Claims

1. A local area network adapted to supply power over a plurality of communication cabling paths, the local area network comprising:

a powered device;

a power sourcing equipment; and

a communication cabling comprising a plurality of twisted wire pairs connecting said power sourcing equipment to said powered device, said communication cabling providing a first power path comprising a first set of twisted wire pairs of said communication cabling and a second power path comprising a second set of twisted wire pairs of said communication cabling, said first set being different from said second set;

said power sourcing equipment comprising;

a control circuit;

a first power source responsive to said control circuit adapted to supply a first power to said powered device via said first power path; and

a second power source responsive to said control circuit adapted to supply a second power to said powered device via said second power path,

said control circuit being operative to;

supply said first power to said powered device from said first power source via said first power path;

contemporaneously with said supplied power from said first power source, supply said second power to said powered device from said second power source via said second power path; and

control said first power source such that a current component of said first power is maintained within a pre-determined range.

2. A local area network according to claim 1, wherein said pre-determined range is a pre-determined limit of the difference between said current component of said first power and a current component of said second power.

3. A local are network according to claim 1, wherein said pre-determined range is a pre-determined maximum, said maximum being less than a maximum allowable current from said first power source.

4. A local area network according to claim 1, further comprising a current sensing means associated with one of said first power source and said second power source, said current sensing means being operatively connected to said control circuit, said control circuit being operative responsive to said current sensing means.

5. A local area network according to claim 1, further comprising a voltage regulating means associated with one of said first power source and said second power source, said voltage regulating means being responsive to said control circuit, said control of said first power source being a result of said voltage regulating means.

6. A local area network according to claim 5, wherein said voltage regulating means comprises one of a linear regulator and a switching regulator.

7. A local area network according to claim 5, wherein said voltage regulating means comprises an FET acting as a linear regulator.

8. A local area network according to claim 1, further comprising an unbalance resistor associated with one of said first power path and said second power path.

9. A local area network according to claim 1, wherein said control circuit is further operative to control said second power source.

10. A local area network according to claim 1, wherein said power sourcing equipment is associated with midspan power insertion equipment.

11. A local area network according to claim 1, wherein said power sourcing equipment is associated with endpoint power insertion equipment.

12. A local area network according to claim 1, wherein said communication cabling is adapted for communicating data to and from said powered device according to at least one of 10 Base-T, 100 Base-T and 1000 Base-T.

13. A local area network according to claim 1, further comprising an under-voltage lockout circuit associated with said powered device, said under-voltage lockout circuit being operative to sense said supplied first power and said contemporaneously supplied second power, said under-voltage lockout circuit being further operative to enable power to said powered device responsive to said sensed supplied first power and said sensed contemporaneously supplied second power.

14. A local area network according to claim 1, wherein said powered device comprises one of:

a wireless access point;

a laptop computer;

a desk top computer;

a security camera having at least one of pan, tilt and zoom functionality; and

an entrance control device.

15. Power sourcing equipment providing a plurality of power sources for connection over communication cabling to a single powered device, the power sourcing equipment comprising:

a control circuit;

a first power source responsive to said control circuit operative to supply power to the single powered device over communication cabling;

a second power source responsive to said control circuit operative to supply power to the single power device over communication cabling contemporaneously with said supplied power of said first power source;

a current sensor adapted to monitor an output current of said first power source supplying said power to the single powered device, said current sensor being operatively connected to said control circuit; and

a voltage regulating means associated with one of said first power source and said second power source, said voltage regulating means being responsive to said control circuit,

said control circuit being operative responsive to said monitored output current to operate said voltage regulating means so as to maintain said monitored output current within a pre-determined range.

16. Power sourcing equipment according to claim 15, wherein said pre-determined range is a pre-determined limit of a difference between a current output of said first power source supplying said power to the single powered device and a current output of said second power source contemporaneously supplying said power to the single powered device.

17. Power sourcing equipment according to claim 15, wherein said pre-determined range is a pre-determined maximum, said maximum being less than a maximum allowed current output of said first power source.

18. Power sourcing equipment according to claim 15, wherein said voltage regulating means comprises one of a linear regulator and a switching regulator.

19. Power sourcing equipment according to claim 15, wherein said voltage regulating means comprises an FET acting as a linear regulator.

20. Power sourcing equipment according to claim 15, further comprising an unbalance resistor associated with one of said first power source and said second power source.

21. A method for sharing power providing to a powered device over communication cabling, the method comprising:

supplying a first power to a powered device over communication cabling via a first path;

monitoring a current of said supplied first power;

supplying a second power to said powered device over communication cabling via a second path contemporaneously with said supplied first power, said first path being different than said second path; and

regulating a voltage associated with one of said supplied first power and said supplied second power responsive to said monitored current so as to maintain said monitored current within a pre-determined range.

22. A method according to claim 21, wherein said pre-determined range is a pre-determined limit of a difference between said monitored current of said supplied first power and a current of said second power source.

23. A method according to claim 21, wherein said pre-determined range is a pre-determined maximum, said maximum being less than a maximum allowed current of said first supplied power.

24. A method according to claim 22, further comprising:

monitoring a current of said supplied second power, wherein said pre-determined range is a pre-determined limit of a difference between said monitored current of said supplied first power and said monitored current of said supplied second power.