Isolation system with analog communication across an isolation barrier

• US 20010028320A1
• Filed: 02/15/2001
• Published: 10/11/2001
• Est. Priority Date: 02/17/2000
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Wilson, James, Prendergast, Colm J., Boyko, Daniel T., Josefsson, Olafur
• Granted Patent: US 7,110,531 B2
• Time in Patent Office: Days
• US Class Current: 341/110
• CPC Class Codes: H04B 2203/5483 using coupling circuits
• CPC Class Codes: H04B 2203/5491 using filtering and bypassing
• CPC Class Codes: H04B 3/23 using a replica of transmitted signal in the time domain, e.g. echo cancellers
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 27/0002 analog front ends; means for connecting modulators, demodulators or transceivers to a transmission line duplex arrangements H04L5/143
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04M 1/7385 Programmable or microprocessor-controlled
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data

Abstract

An isolation system with analog communication across an isolation barrier includes an isolation barrier circuit having at least one isolation element; a digital to analog circuit having an analog output connected to the isolation barrier and an input for receiving an input digital signal to be communicated across the isolation barrier; and an analog to digital circuit having an input coupled to the analog output of the isolation barrier circuit for providing a digital output signal.

Claims

1. An isolation system with analog communication across an isolation barrier comprising:

an isolation barrier circuit having at least one isolation element;

a digital to analog circuit having an analog output connected to the isolation barrier and an input for receiving an input digital signal to be communicated across the isolation barrier; and

an analog to digital circuit having an input coupled to the analog output of the isolation barrier circuit for providing a digital output signal.

2. The isolation system of

claim 1

in which said digital to analog circuit includes an encoder circuit responsive to said input digital signal to provide a digital signal, and a digital to analog converter responsive to said digital signal to provide to said isolation barrier said analog output signal.

3. The isolation system of

claim 1

in which said digital to analog circuit includes a digital to analog converter with an input for receiving said input digital signal and a modulation circuit responsive to said digital to analog converter for providing said analog output.

4. The isolation system of

claim 1

in which said analog to digital circuit includes an analog to digital converter responsive to said input analog signal from said isolation barrier to provide a digital signal, and a decoder circuit responsive to said digital signal to provide said digital output response.

5. The isolation system of

claim 1

in which said analog to digital circuit includes a demodulator circuit responsive to said input analog signal from said isolation barrier, and an analog to digital converter responsive to said analog signal to provide said digital output signal.

6. The isolation system of

claim 1

in which said analog to digital circuit includes an analog to digital converter.

7. The isolation system of

claim 1

in which said digital to analog circuit includes a digital to analog converter.

8. The isolation system of

claim 1

in which said digital to analog circuit includes a termination resistance connected with said isolation barrier.

9. The isolation system of

claim 1

in which said analog to digital circuit includes a termination resistance connected with said isolation barrier.

10. The isolation system of

claim 1

in which said isolation element includes a capacitance.

11. The isolation system of

claim 1

in which said isolation element includes a transformer.

12. The isolation system of

claim 1

in which said analog to digital circuit includes a common mode interference signal sensing circuit and a summing circuit for removing the common mode interference signal from the received analog signal from the isolation barrier.

13. The isolation system of

claim 1

in which said digital signal to be communicated across said isolation barrier includes data.

14. The isolation system of

claim 1

in which said digital signal to be communicated across said isolation barrier includes control information.

15. The isolation system of

claim 14

in which said digital signal to be communicated across said isolation barrier includes reference and calibration information.

16. The isolation system of

claim 1

in which said digital signal to be communicated across said isolation barrier includes data and control information.

17. The isolation system of

claim 2

in which the signal is a constant average signal.

18. The isolation system of

claim 3

in which the signal is a constant average signal.

19. The isolation system of

claim 4

in which the signal is a constant average signal.

20. The isolation system of

claim 5

in which the signal is a constant average signal.

21. A bi-directional isolation system with analog communication across an isolation barrier comprising:

an isolation barrier circuit having at least one isolation element;

a first digital to analog circuit having an analog output coupled to a first side of the isolation barrier and an input for receiving an input digital signal to be communicated across the isolation barrier;

a first analog to digital circuit having an input coupled to the first side of the isolation barrier circuit;

a second digital to analog circuit having an analog output coupled to a second side of the isolation barrier and an input for receiving an input digital signal to be communicated across the isolation barrier; and

a second analog to digital circuit having an input coupled to the second side of the isolation barrier circuit.

22. The bi-directional isolation system of

claim 21

in which the input digital signals are communicated simultaneously across the isolation barrier circuit.

23. The bi-directional isolation system of

claim 21

in which the input digital signals are communicated alternately across the isolation barrier circuit.

24. The bi-directional isolation system of

claim 21

further including at least one echo cancellation circuit for removing a local echo signal from the input of at least one of said first and second analog to digital circuits.