Electronically implemented dynamic start up method for ports with inrush current limiting functionality

• US 7,406,614 B2
• Filed: 12/23/2004
• Issued: 07/29/2008
• Est. Priority Date: 12/23/2004
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.), DENSO Corporation
• Original Assignee: Microsemi Corp. - Analog Mixed Signal Group, Ltd. (Microchip Technology Incorporated)
• Inventors: Elkayam, Shimon, Peleg, Amir, Barnea, Nadav
• Primary Examiner(s): Patel; Nitin C
• Application Number:
  US11/019,275
• Publication Number:
  US 20060143488A1
• Time in Patent Office: 1,314 Days
• Field of Search: 713/320
• US Class Current: 713/320
• CPC Class Codes: H04L 12/10 Current supply arrangements

Abstract

A power over Ethernet controller comprising: control circuitry; at least one temperature sensor operatively connected to the control circuitry; and a plurality of electronically controlled switches responsive to the control circuit, each of the electronically controlled switches enabling power to a respective port and having associated therewith inrush current limiting functionality, the control circuit being operative to input at least one temperature indication from the at least one temperature sensor; operate at least one of the plurality of electronically controlled switches thereby enabling power to a first port; and delay a time period dependent on the at least one temperature indication, whereby operation of a second of the plurality of electronically controlled switches to enable power to a second port is permitted only after the delayed time period.

Claims

1. A power over Ethernet controller comprising:

control circuitry;

at least one temperature sensor operatively connected to said control circuitry; and

a plurality of electronically controlled switches responsive to said control circuit, each of said electronically controlled switches enabling power to a respective port and having associated therewith inrush current limiting functionality,

said control circuit being operative to input at least one temperature indication from said at least one temperature sensor;

operate at least one of said plurality of electronically controlled switches thereby enabling power to a first port; and

delay a time period dependent on said at least one temperature indication, whereby operation of a second of said plurality of electronically controlled switches to enable power to a second port is permitted only after said delayed time period.

2. A power over Ethernet controller according to claim 1, wherein said plurality of electronically controlled switches comprise one of a FET, a bipolar transistor and a power MOSFET.

3. A power over Ethernet controller according to claim 1, wherein said control circuit is further operable to compare said at least one temperature indication with a maximum, and only in the event said at least one temperature indication does not exceed said maximum to operate said at least one of said plurality of switches to enable power to said first port.

4. A power over Ethernet controller according to claim 1, wherein said control circuitry and said electronically controlled switches comprise a single integrated circuit.

5. A power over Ethernet controller according to claim 1, wherein said at least one temperature sensor comprises a plurality of temperature sensors and said at least one temperature indication comprises a plurality of temperature indications each from a unique one of said plurality of temperature sensors, said time period being dependent on a function of said plurality of temperature indications.

6. A power over Ethernet controller according to claim 5, wherein said function comprises an average of said plurality of temperature indications.

7. A power over Ethernet controller according to claim 5, wherein said function comprises one of a weighted average of said plurality of temperature indications and a maximum of said plurality of temperature indications.

8. A power over Ethernet controller according to claim 1, wherein said time period is further dependent on at least one of package type, die heat conduction parameters and the presence or absence of heat conductive adhesive.

9. An electronically implemented dynamic successive start up method for use with ports having a heat generating inrush current limiting functionality associated therewith, the method comprising:

inputting at least one indication of temperature;

comparing said at least one temperature indication with maximum;

activating, only in an event said temperature indication does not exceed said maximum, power to a first port having associated therewith the heat generating inrush current limiting funtionality; and

delaying a time period dependent on said at least one indication of temperature,

whereby activating power to a second port having associated therewith the heat generating inrush current limiting functionality is permitted only after said delayed time period.

10. A method according to claim 9, wherein said at least one indication of temperature comprises a plurality of indications of temperature, said time period being dependent on a function of said plurality of indications of temperature.

11. A method according to claim 10, wherein said function comprises one of an average, a weighted average and a maximum of said plurality of indications of temperature.

12. A method according to claim 9, wherein said time period is further dependent on at least one of package type, die heat conduction parameters and the presence or absence of heat conductive adhesive.

13. An electronically implemented dynamic successive start up method for use with ports each having a heat generating inrush current limiting functionality associated therewith, the method comprising:

inputting at least one indication of temperature;

comparing said at least one indication of temperature with a pre-determined maximum,

in the event that said at least one indication of temperature does not exceed said maximum, activating power to a first port;

having associated therewith the heat generating inrush current limiting funtionality; and

delaying a time period dependent on said at least one indication of temperature,

whereby activating power to a second port having associated therewith the heat generating inrush current limiting functionality is permitted only after said delayed time period.

14. A method according to claim 13, wherein said at least one indication of temperature comprises a plurality of indications of temperature, said time period being dependent on a function of said plurality of indications of temperature.

15. A method according to claim 14, wherein said function comprises one of an average, a weighted average and a maximum of said plurality of indications of temperature.

16. A method according to claim 13, wherein said time period is further dependent on at least one of package type, die heat conduction parameters and the presence or absence of heat conductive adhesive.

17. A power over Ethernet controller comprising:

control circuitry;

at least one temperature sensor operatively connected to said control circuitry; and

a plurality of electronically controlled switches responsive to said control circuit, each of said electronically controlled switches enabling power to a respective port and having associated therewith inrush current limiting functionality, said control circuit being operative to;

input at least one indication of temperature from said at least one temperature sensor;

operate at least one of said plurality of electronically controlled switches thereby enabling power to a first port; and

delay a time period dependent on a function of said at least one temperature indication and at least one of package type, die heat conduction parameters and the presence or absence of heat conductive adhesive,

whereby operation of a second of said plurality of electronically controlled switches to enable power to a second port is permitted only after said delayed time period.

18. A power over Ethernet controller according to claim 17, wherein said control circuit is further operable to compare said at least one temperature indications with a maximum, and only in the event said at least one temperature indication does not exceed said maximum to operate said at least one of said plurality of switches to enable power to said first port.

19. A power over Ethernet controller according to claim 17, wherein said control circuitry and said plurality of electronically controlled switches comprise a single integrated circuit.