Method and Apparatus for Communicating Between Devices Having No Common Electrical Ground

• US 20070242757A1
• Filed: 03/01/2007
• Published: 10/18/2007
• Est. Priority Date: 04/18/2006
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: 2Wire, Inc. (CommScope Holding Company, Inc.)
• Inventors: Henderson, Michael, Schley-May, James T.
• Granted Patent: US 7,526,034 B2
• Time in Patent Office: Days
• US Class Current: 375/257
• CPC Class Codes: H04L 25/0268 with modulation and subsequent demodulation
• CPC Class Codes: H04L 25/0284 Arrangements to ensure DC-balance
• CPC Class Codes: H04L 25/03828 Arrangements for spectral shaping; Arrangements for providing signals with specified spectral properties partial response systems H04L25/497
• CPC Class Codes: H04L 25/4915 using pattern inversion or substitution H04L25/4908 takes precedence

Abstract

Various methods, apparatuses, and systems are described in which devices having no common electrical ground communicate. In at least certain embodiments, an apparatus includes a transformer block to communicate a plurality of data signals and a synchronous clock signal between a first device with a first ground reference and a second device with a second ground reference over a data communication link. The first device sends the plurality of data signals to a modulator block having one or more Boolean logic gates that receive each data signal in combination with the synchronous clock signal. The modulator block sends a plurality of modulated data signals corresponding to the plurality of data signals to the transformer block. The transformer block sends the plurality of modulated data signals and the synchronous clock signal to the second device to provide the data communication link between devices having different ground references.

Claims

1. An apparatus comprising:

a transformer block having output and input ports to communicate a plurality of data signals and a synchronous clock signal between a first device with a first voltage ground reference and a second device with a second voltage ground reference over a data communication link, where the first device to send the plurality of data signals to one or more input ports of a modulator block having one or more Boolean logic gates to receive each data signal in combination with the synchronous clock signal and the one or more output ports of the modulator block to send a plurality of modulated data signals corresponding to the plurality of data signals to the input ports of the transformer block, and wherein the one or more output ports of the transformer block to send the plurality of modulated data signals and the synchronous clock signal to the second device to provide the data communication link between devices having different voltage ground references.

2. The apparatus of claim 1, further comprising:

input ports of a demodulator block to receive at least one of the modulated data signals and the synchronous clock signal from the transformer block; and

output ports of the demodulator block to send at least one demodulated data signal to a third device, wherein the demodulated data signal restores a format of a data signal that originated from the first device.

3. The apparatus of claim 1, wherein each Boolean logic gate in the modulator block is an XOR gate that is coupled to clock delay logic to receive each data signal.

4. The apparatus of claim 1, wherein the plurality of data signals have a frequency approximately equal to the frequency of the synchronous clock signal.

5. The apparatus of claim 1, wherein the transformer block comprises a plurality of common pulse transformers.

6. The apparatus of claim 1, wherein the demodulator block comprises an edge-triggered master/slave flip-flop for each data signal to be demodulated.

7. The apparatus of claim 1, wherein the modulated data signals sent to the transformer block are non-inverted for half of a clock cycle and inverted for the remaining half of the clock cycle.

8. The apparatus of claim 1, wherein each transformer has a first output port coupled to a voltage bias block and a second output port coupled to at least one of the second device or the demodulator block.

9. The apparatus of claim 1, wherein each transformer has a first output coupled to a resistive divider and a second output coupled to a receiving device with single ended logic.

10. The apparatus of claim 2, wherein asynchronous data signals are sent between the first and third device via the data communication link.

11. A system comprising:

a network interface device (NID) coupled to a digital subscriber loop access multiplexer, the NID located outside a building;

an input port of the NID coupled to receive a power signal from a power supply unit located inside the building, the power supply unit provides isolated DC power to the NID via a first and a second phone line located in the building, wherein the NID also includes;

logic coupled to a plurality of isolation transformers;

a subscriber line interface circuit (SLIC) coupled to one or more isolation transformers of the plurality of isolation transformers and one of the first or second phone line; and

the plurality of isolation transformers having output and input ports to communicate a corresponding plurality of data signals and a synchronous clock signal between the logic having a first voltage ground reference and the SLIC having a second voltage ground reference over a data communication link.

12. The system of claim 11 wherein the logic to send the plurality of data signals to a modulator block having a Boolean logic gate to receive each data signal in combination with the synchronous clock signal.

13. The system of claim 12, wherein the modulator block further comprises output ports to send a plurality of modulated data signals to the input ports of the plurality of isolation transformers.

14. The system of claim 13, wherein the output ports of the plurality of isolation transformers to send the plurality of modulated data signals and the synchronous clock signal to the SLIC.

15. The system of claim 11, further comprising:

input ports of a demodulator block to receive at least one modulated data signal and the synchronous clock signal from the transformer block, output ports of the demodulator block to send at least one demodulated data signal to a third device, wherein the demodulated data signal restores a data signal that originated from the first device.

16. The system of claim 11, wherein each transformer has a first output and a second output coupled to a receiving device with differential logic.

17. A method comprising:

sending a plurality of data signals from a first device and a synchronous clock signal to a modulator block having a Boolean logic gate for each data signal;

sending a plurality of modulated data signals from the modulator block to a transformer block which also receives the synchronous clock signal; and

sending the plurality of modulated data signals and the synchronous clock signal from the transformer block to a second device with the first and second devices have no common electrical ground.

18. The method of claim 17, further comprising:

sending at least one modulated data signal and the synchronous clock signal from the transformer block to a demodulator block; and

sending at least one demodulated data signal from the demodulator block to a third device with the first and third devices having no common electrical ground, wherein the demodulated data signal restores a data signal that originated from the first device.

19. An apparatus, comprising:

means for sending a plurality of data signals from a first device and a synchronous clock signal to a modulator block having a Boolean logic gate for each data signal;

means for sending a plurality of modulated data signals from the modulator block to a transformer block which also receives the synchronous clock signal, and

means for sending the plurality of modulated data signals and the synchronous clock signal from the transformer block to a second device with the first and second devices having no common electrical ground.

20. The apparatus of claim 19, further comprising:

means for sending at least one modulated data signal and the synchronous clock signal from the transformer block to a demodulator block; and

means for sending at least one demodulated data signal from the demodulator block to a third device with the first and third devices having no common electrical ground, wherein the demodulated data signal restores a data signal that originated from the first device.