Apparatus and method for multipoint detection in power-over-ethernet detection mode

• US 9,189,043 B2
• Filed: 03/22/2013
• Issued: 11/17/2015
• Est. Priority Date: 01/17/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Vorenkamp, Pieter, Woo, Agnes, Tammineedi, Anil, Fujimori, Ichiro, Chin, David, Perzow, John
• Primary Examiner(s): Berhane, Adolf
• Assistant Examiner(s): Mehari, Yemane
• Application Number:
  US13/849,391
• Publication Number:
  US 20130227313A1
• Time in Patent Office: 970 Days
• Field of Search: 323/266, 323/282, 323/901, 361/90, 363/49
• US Class Current: 1/1
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: H04B 3/44 Arrangements for feeding power to a repeater along the transmission line
• CPC Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 12/40045 Details regarding the feeding of energy to the node from the bus
• CPC Class Codes: H04L 25/02 Details ; arrangements for supplying electrical power along data transmission lines systems for transmitting signals via power distribution lines H04B3/54
• CPC Class Codes: Y10S 370/91 Carrier sense multiple access, e.g. ethernet, 10base-t

Abstract

Power over Ethernet (PoE) communication systems provide power and data communications over the same communications link, where a power source device (PSE) provides DC power to a powered device (PD). The DC power is transmitted simultaneously over the same communications medium with the high speed data from one node to the other node. The PSE controller measures the voltage, current, and temperature of the outgoing and incoming DC supply lines to characterize the power requirements of the PD. The PSE controller may detect and validate a compatible PD, determine a power classification signature for the validated PD, supply power to the PD, monitor the power, and reduce or remove the power from the PD when the power is no longer requested or required. If the PSE finds the PD to be non-compatible, the PSE can prevent the application of power to that PD device, protecting the PD from possible damage.

Claims

1. A Power Source Equipment (PSE) controller comprising:

a plurality of classification modules configured to provide a plurality of classification currents based on power requirements of a plurality of powered devices (PDs); and

a plurality of drivers, each driver from among the plurality of driver being configured to provide power to one of the plurality of PDs, to determine a temperature of a power delivery component, to deliver the power via the power delivery component based on a classification current associated with the one of the plurality of PDs, and to cease power delivery to a corresponding PD from among the plurality of PDs when the temperature exceeds a predetermined temperature.

2. The PSE controller of claim 1, wherein the power delivery component is a transistor, and wherein the classification current is applied to a gate of the transistor.

3. The PSE controller of claim 2, wherein the temperature is a p-type n-type (pn) junction temperature of the transistor.

4. The PSE controller of claim 1, further comprising:

a global thermal shutdown device (TSD) configured to measure a second temperature corresponding to the PSE controller; and

a digital section configured to instruct the plurality of drivers to cease power delivery to all of the plurality of PDs when the second temperature exceeds a second predetermined temperature.

5. The PSE controller of claim 4, wherein the digital section is further configured to receive a signal representative of temperatures of a plurality of power delivery components.

6. The PSE controller of claim 5, wherein the digital section is further configured to instruct the plurality of drivers to cease power delivery to all of the plurality of PDs when an average of the temperature and the second temperature exceeds a third predetermined temperature.

7. The PSE controller of claim 5, further comprising:

a multiplexer configured to multiplex the temperatures of the plurality of power delivery components to provide the signal.

8. A measurement and digital acquisition system, comprising:

a Power Source Equipment (PSE) controller configured to sample time division multiplexed measurements corresponding to a plurality of powered device (PD) ports over a plurality of sampling periods;

a finite state machine (FSM) configured to store the time divsion multiplexed measurements for each sampling period from among the plurality of sampling periods;

a data acquisition module configured to integrate the stored time division multiplexed measurements over the plurality of sampling periods to provide integrated measurements; and

a microcontroller configured to temperature compensate the integrated measurements utilizing a temperature derived from each of the plurality of PD ports.

9. The measurement and digital acquisition system of claim 8, wherein the data acquisition module is further configured to integrate the temperature compensated integrated measurements over a second plurality of sampling periods to remove noise from the temperature compensated measurements.

10. The measurement and digital acquisition system of claim 8, wherein the time division multiplexed measurements comprise:

current, voltage, and temperature measurements corresponding to each PD port from among the plurality of PD ports.

11. The measurement and digital acquisition system of claim 8, wherein the microcontroller is configured to temperature compensate the integrated measurements during a time period, and to derive the temperature from each of the plurality of PD ports during the time period.

12. The measurement and digital acquisition system of claim 8, wherein the PSE controller is further configured to monitor a maintain power signature (MPS) from each of the plurality of PD ports and to remove power to a PD when an MPS signal corresponding to the PD is absent for a time greater than a predetermined time period.

13. The measurement and digital acquisition system of claim 12, wherein the MPS includes a direct current (DC) component, the DC component being present when a DC current utilized by the PD is greater than a predetermined DC current over a second predetermined time period.

14. The measurement and digital acquisition system of claim 12, wherein the MPS includes an alternating current (AC) component, the AC component being present when an impedance at the PD is less than a predetermined impedance.

15. In a measurement and digital acquisition system, a method comprising:

sampling, by a Power Source Equipment (PSE) controller, a time division multiplexed measurement of current, voltage, and temperature corresponding to a plurality of powered device (PD) ports over a first plurality of sampling periods;

storing, by the PSE controller, the sampled multiplexed measurement of the current, the voltage, and the temperature for each sampling period from among the plurality of sampling periods;

integrating, by the PSE controller, the stored multiplexed measurement of the current, the voltage, and the temperature over the first plurality of sampling periods to provide integrated measurements;

temperature compensating, by the PSE controller, the integrated measurements utilizing a temperature derived from each of the plurality of PD ports; and

integrating, by the PSE controller, the temperature compensated integrated measurements over a second plurality of sampling periods to remove noise from the current, voltage, and temperature measurements.

16. The method of claim 15, farther comprising:

measuring the temperature of each of the plurality of PD ports during a time period, and wherein the temperature compensating comprises;

temperature compensating the integrated measurements during the time period.

17. The method of claim 15, further comprising:

monitoring a maintain power signature (MPS) from each of the plurality of PD ports; and

removing power to a PD if an MPS signal corresponding to the PD is absent for a time greater than a predetermined time period.

18. The method of claim 17, wherein the monitoring comprises:

monitoring a direct current (DC) component of the MPS, the DC component being present when a DC current utilized by the PD is greater than a predetermined DC current over a second predetermined time period.

19. The method of claim 17, wherein the monitoring comprises:

monitoring an alternating current (AC) component of the MPS, the AC component being present when an impedance at the PD port is less than a predetermined impedance.

20. The method of claim 19, further comprising:

applying, by the PSE controller, an AC signal to the PD; and

measuring, by the PSE controller, the impedance based on the AC signal.