External AC-DC Coupling for Communication Interfaces

• US 20100246648A1
• Filed: 02/12/2010
• Published: 09/30/2010
• Est. Priority Date: 02/12/2009
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rocamora, David Gimenez, Hurwitz, Jonathan Ephraim David
• Granted Patent: US 8,232,666 B2
• Time in Patent Office: Days
• US Class Current: 375/222
• CPC Class Codes: H04B 2203/5483 using coupling circuits
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: H04B 3/56 Circuits for coupling, blocking, or by-passing of signals
• CPC Class Codes: H04M 11/066 Telephone sets adapted for data transmision
• CPC Class Codes: Y10S 307/01 Data transmitted over power lines

Abstract

A power line communication device comprises a plurality of transformers in series. These transformers are used to increase the voltage of a digitally encoded signal in a stepwise fashion prior to being coupled into a power line. While a transmit path includes at least a first transformer and a second transformer in series, a receive path may include only one of these two transformers. For example a receive path may include only the first transformer, or include the first transformer and a third transformer. The net ratio of voltage increase and decrease may be different in the transmit and receive paths. Additionally, the communication interface can be disposed within an AC/DC converter or distributed among an AC/DC converter and an appliance attached thereto.

Claims

1. A system comprising:

an appliance including a modem configured to send and receive digitally encoded signals;

an AC/DC converter disposed external to the appliance and including

an AC to DC module configured to convert AC line voltage of a power line to one or more DC voltages, and

signal coupling circuitry comprising a first transformer and configured to receive the digitally encoded signals from the appliance and to couple the digitally encoded signals into the power line; and

cabling including

one or more first conductors configured to convey the one or more DC voltages between the AC/DC converter and the appliance, and

one or more second conductors configured to convey the digitally encoded signals between the appliance and the AC/DC converter.

2. The system of claim 1, wherein the appliance comprises a portable electronic device.

3. The system of claim 1, further comprising a filter in electrical communication between the AC to DC module and the power line and configured to protect the signal coupling circuitry from noise produced by the AC to DC module.

4. The system of claim 3, wherein the filter comprises a capacitor.

5. The system of claim 1, wherein the signal coupling circuitry further comprises a signal conditioner in electrical communication between the first transformer and the one or more second conductors.

6. The system of claim 1, wherein the signal coupling circuitry further comprises an over-voltage protection device.

7. The system of claim 1, wherein the signal coupling circuitry further comprises a coupling capacitor.

8. The system of claim 1, wherein the AC/DC converter further comprises a zero crossing circuitry configured to generate a timing signal from the AC line voltage.

9. The system of claim 8, wherein the signal coupling circuitry further comprises a second transformer configured to increase the peak-to-peak voltage of digitally encoded signals received from the appliance.

10. The system of claim 8, further comprising one or more third conductors configured to convey the timing signal to the appliance.

11. The system of claim 1, wherein the signal coupling circuitry further comprises a pair of transformers in parallel electrical communication between the power line and the AC to DC module.

12. The system of claim 1, wherein the cabling is integral with the AC/DC converter.

13. The system of claim 1, wherein the cabling is external to, and detachable from, the appliance.

14. A system comprising:

an AC/DC converter comprising

means for converting AC line voltage of a power line to one or more DC voltages, and

means for receiving digitally encoded signals and coupling the digitally encoded signals into the power line; and

means for conveying the one or more DC voltages between the AC/DC converter and an external appliance, and

means for conveying the digitally encoded signals between the external appliance and the AC/DC converter.

15. The system of claim 14, further comprising the appliance.

16. The system of claim 15, wherein the appliance includes a modem configured to send and receive the digitally encoded signals.

17. The system of claim 14, wherein the AC/DC converter further comprises means for generating a timing signal from the AC line voltage.

18. A method comprising:

receiving a digitally encoded signal from a power line, using an AC/DC converter that includes signal coupling circuitry;

decoupling the digitally encoded signal from an AC voltage of the power line, within the AC/DC converter using the signal coupling circuitry;

communicating the decoupled digitally encoded signal from the AC/DC converter to an appliance using a conductor external to the appliance; and

receiving the decoupled digitally encoded signal at the appliance.

19. A method comprising:

generating a digitally encoded signal within an appliance;

passing the digitally encoded signal through a first transformer;

communicating the digitally encoded signal from the appliance to an external AC/DC converter;

passing the digitally encoded signal through a second transformer, the second transformer being disposed within the external AC/DC converter; and

coupling the digitally encoded signal into a power line using the AC/DC converter.

20. The method of claim 19, wherein the first transformer is a component of the appliance.