Isolation system with analog communication across an isolation barrier

• US 7,110,531 B2
• Filed: 02/15/2001
• Issued: 09/19/2006
• Est. Priority Date: 02/17/2000
• Status: Expired due to Term

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Wilson, James, Prendergast, Colm J., Boyko, Daniel T., Josefsson, Olafur
• Primary Examiner(s): Tsang, Fan
• Assistant Examiner(s): SINGH, RAMNANDAN P
• Application Number:
  US09/784,827
• Publication Number:
  US 20010028320A1
• Time in Patent Office: 2,042 Days
• Field of Search: 375/261, 375/222, 375/38, 375/5, 375/8, 379/99, 379/98, 379/97, 379/93, 37939901-41304
• US Class Current: 379/399.01
• 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 configured to provide a constant average analog output signal to the isolation barrier and having an input for receiving an input digital signal to be communicated across the isolation barrier, said digital to analog circuit including a digital to analog converter with an input for receiving said input digital signal and an analog modulation circuit responsive to said digital to analog converter for providing said constant average analog output signal; 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 analog to digital circuit includes an analog 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.

3. The isolation system of claim 1 in which said isolation element includes a capacitance.

4. The isolation system of claim 1 in which said isolation element includes a transformer.