Method to control current imbalance between differential pairs providing a DC power feed

• US 20060218418A1
• Filed: 08/23/2005
• Published: 09/28/2006
• Est. Priority Date: 03/28/2005
• Status: Active Grant

• Current Assignee: Kinetic Technologies International Holdings LP
• Original Assignee: Akros Silicon, Inc. (Kinetic Technologies Incorporated)
• Inventors: Ghoshal, Sajol, Camagna, John R.
• Granted Patent: US 7,500,116 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• 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

Abstract

The present invention provides a method to at least partially power an Ethernet device from a plurality of balanced network power signals received through a network connection. This involves attaching the network device to the network, wherein network signals are received and contain both power signals and/or data signals. These network signals may be passed through surge protection and power-conditioning circuitry wherein the output of these circuits may be provided to a power absorbing circuit. This power absorbing circuit may separate the communication signal and power signal from the network signal. The communication signal may be passed to a network physical layer while the power signal may be passed to a power distribution module. Additionally, because certain embodiments may provide multiple pairs of network power signals to the power absorbing circuit, the current or power associated with each power signal must be sensed and balanced. This may be done with an active control circuit. The balanced power signals may then be supplied from the power absorbing circuit to the network-attached device in order to at least partially power the network-attached device.

Claims

1. A method to at least partially power an Ethernet network device, with a plurality of power signals fed through an Ethernet network connection, comprising:

physically coupling the Ethernet network device to the Ethernet network;

receiving an Ethernet signal from the Ethernet network, wherein the Ethernet signal comprises the plurality of power signals and/or data signal(s);

passing the Ethernet signal to an integrated circuit (IC) wherein the IC comprises;

an Ethernet physical layer (PHY) module;

a power management module; and

a direct connection module;

separating with the direct connection module, the data signal from the Ethernet signal, wherein the data signal is passed to the Ethernet PHY module of the IC;

separating with the direct connection module, the plurality of power signals from the Ethernet signal;

sensing a current associated with each power signal of the plurality of power signals;

balancing the plurality of power signals with an active control circuit and based on the sensed current associated with each power signal of the plurality of power signals, wherein the balanced plurality of power signal are passed to the power management module; and

at least partially powering the Ethernet network device from the plurality of balanced power signal.

2. The method of claim 1, wherein the sensed current of each of the balanced power signals is equal.

3. The method of claim 1, wherein the balancing the plurality of power signals with an active control circuit results in each sensed current not exceeding a reference current.

4. The method of claim 1, wherein:

an RJ45 connector physically couples the Ethernet network device to the Ethernet network, and wherein the RJ45 connector couples to twisted pairs that further comprise conductors 1 and 2;

3 and 6;

4 and 5; and

7 and 8; and

a switching/rectifying circuit that receives the power signal utilizing conductors 1, 2, 3, and 6; and

conductors 4, 5, 7, and 8.

5. The method of claim 4, wherein the balancing the plurality of power signals with an active control circuit results in each sensed current not exceeding a predetermined current associated with twisted pair.

6. The method of claim 1, wherein each of the plurality of power signals does not exceed 57 volts.

7. The method of claim 1, wherein the Ethernet PHY module is operable to implement 10 Mbps, 100 Mbps and/or 1 Gbps physical layer functions.

8. The method of claim 1, wherein the IC further comprises an Ethernet media access controller (MAC) wherein the Ethernet PHY and Ethernet MAC are operable to implement hardware layers of an Ethernet protocol stack.

9. The method of claim 1, wherein the Ethernet network device comprises at least one device selected from the group consisting of:

a voice over internet protocol (VoIP) telephone;

an Ethernet router;

an Ethernet switch;

a printer;

a data server;

an Ethernet enabled camera;

a wireless access point;

a playback device;

a portable computing device;

a personal data assistant;

a wireless terminal;

a graphics display; and

an audio interface.

10. The method of claim 1, wherein the plurality of power signals is IEEE 802.3af compliant.

11. The method of claim 1, wherein comprising supplying the power signal to the Ethernet network from a power sourcing equipment (PSE), and wherein the PSE is operable to determine if the Ethernet network device is IEEE 802.3af compliant.

12. The method of claim 1, wherein the direct connection module further comprises a power device controller.

13. The method of claim 1, wherein separating with the direct connection module, the data signal from the Ethernet signal utilizes direct current (DC) blocking capacitors that couple the Ethernet PHY module to the Ethernet signal.

14. The method of claim 1, wherein balancing the plurality of power signals with the active control circuit further comprises actively balancing currents associated within a twisted pair, wherein the twisted pairs are operable to conduct power signal(s).

15. The method of claim 1, wherein balancing the plurality of power signals with the active control circuit further comprises:

actively controlling the current passed within a twisted pair.

16. An Ethernet network device operable to receive a plurality of power signals and data signals through a coupled Ethernet network, comprising:

an Ethernet network connector operable to physically couple the Ethernet network device to the Ethernet network, wherein the Ethernet network connector receives four twisted pairs that carry the plurality of power signals, wherein the plurality of power signals comprise a first power signal and a second power signal;

an integrated circuit (IC) operably coupled to the Ethernet network connector, wherein the IC comprises;

an Ethernet physical layer (PHY) module;

a power management module; and

a direct connection module operable coupled to the Ethernet network connector, wherein the direct connection module is operable to;

pass the received data signal(s) to the Ethernet PHY;

sense a current associated with each twisted pair;

actively balance the current associated with each twisted pair; and

pass the received plurality of power signals to the power management module, wherein the power management module is operable to at least partially power the Ethernet network device from the received plurality of power signals.

17. The Ethernet network device of claim 16, wherein:

the Ethernet network connectors comprises an RJ45 connector; and

the four twisted pairs comprise conductors 1 and 2;

3 and 6;

4 and 5; and

7 and 8;

the first power signal utilizing conductors 1, 2, 3, and 6; and

the second power signal utilizing conductors 4, 5, 7, and 8.

18. The Ethernet network device of claim 16, wherein the first power signal and second power signal each do not exceed about 17 watts.

19. The Ethernet network device of claim 16, wherein the received power signal does not exceed 57 volts.

20. The Ethernet network device of claim 16, wherein the Ethernet PHY module is operable to implement 10 Mbps, 100 Mbps and/or 1 Gbps physical layer functions.

21. The Ethernet network device of claim 16, wherein the IC further comprises an Ethernet media access controller (MAC) wherein the Ethernet PHY and Ethernet MAC are operable to implement hardware layers of an Ethernet protocol stack.

22. The Ethernet network device of claim 16, wherein the Ethernet network device comprises at least one device selected from the group consisting of:

a voice over internet protocol (VoIP) telephone;

an Ethernet router;

an Ethernet switch;

a printer;

a data server;

an Ethernet enabled camera;

a wireless access point;

a playback device;

a portable computing device;

a personal data assistant;

a wireless terminal;

a graphics display; and

an audio interface.

23. The Ethernet network device of claim 16, wherein the received power signals are IEEE 802.3af compliant.

24. The Ethernet network device of claim 16, wherein the plurality of power signals are provided to the Ethernet network from a power sourcing equipment (PSE), and wherein the PSE is operable to determine if the Ethernet network device is IEEE 802.3af compliant.

25. The Ethernet network device of claim 16, wherein the direct connection module further comprises a power device controller.

26. The Ethernet network device of claim 16, wherein direct current (DC) blocking capacitors couple the Ethernet PHY module to the received signal.