Analog isolation system with digital communication across a capacitive barrier

Claim 2

An isolation barrier for conveying an electrical signal from a transmitting circuit to a receiving circuit while electrically isolating the transmitting circuit from the receiving circuit, comprising: an isolation capacitor; a synchronous analog-to-digital converter having an input connected to the transmitting circuit for receiving the electrical signal to be transmitted across the barrier, and an output connected to a first side of the isolation capacitor for providing a synchronous digital signal to the isolation capacitor; a synchronous digital-to-analog converter having an input connected to a second side of the isolation capacitor for receiving the synchronous digital signal therefrom, and having an output connected to the receiving circuit for providing an analog signal thereto; and a power supply having an input connected to the second side of the isolation capacitor to receive the synchronous digital signal therefrom, the power supply comprising a rectifier circuit for providing a DC voltage derived from energy contained in the synchronous digital signal.

Claim 5

A bidirectional isolation barrier for conveying analog data signals between a powered circuit and an isolated circuit while electrically isolating the powered circuit from the isolated circuit, the barrier comprising: a first isolation capacitor; a powered-side signal processing system comprising: a first synchronous analog-to-digital converter having an input connected to the powered circuit for receiving an analog data signal to be transmitted across the barrier in a first direction, and an output connected to a first side of the isolation capacitor for providing a synchronous digital signal to the isolation capacitor, and a first synchronous digital-to-analog converter having an input connected to said first side of the isolation capacitor for receiving synchronous digital signals therefrom when data signals are transmitted in a second direction from the isolated circuit to the powered circuit, and having an output connected to the powered circuit for providing analog signals thereto; and an isolated-side signal processing system comprising: a second synchronous digital-to-analog converter having an input connected to a second side of the isolation capacitor for receiving a synchronous digital signal therefrom when the data signals are transmitted in said first direction, and having an output connected to the isolated circuit for providing a reconstructed analog data signal thereto, and a second synchronous analog-to-digital converter having an input connected to the isolated circuit for receiving an analog data signal to be transmitted across the barrier in said second direction to the powered circuit, and an output connected to the second side of the isolation capacitor for conveying a synchronous digital signal corresponding to said analog data signal to the isolation capacitor, and a power supply circuit having an input connected to the first isolation capacitor to receive the synchronous digital signal, the power supply comprising a rectifier circuit for providing a DC voltage signal.

Claim 6

A bidirectional isolation barrier for conveying analog data signals between a powered circuit and an isolated circuit while electrically isolating the powered circuit from the isolated circuit, the barrier comprising: a first isolation capacitor; a powered-side signal processing system comprising: a first synchronous analog-to-digital converter having an input connected to the powered circuit for receiving an analog data signal to be transmitted across the barrier in a first direction, and an output connected to a first side of the isolation capacitor for providing a synchronous digital signal to the isolation capacitor, and a first synchronous digital-to-analog converter having an input connected to said first side of the isolation capacitor for receiving synchronous digital signals therefrom when data signals are transmitted in a second direction from the isolated circuit to the powered circuit, and having an output connected to the powered circuit for providing analog signals thereto; and an isolated-side signal processing system comprising: a second synchronous digital-to-analog converter having an input connected to a second side of the isolation capacitor for receiving a synchronous digital signal therefrom when the data signals are transmitted in said first direction, and having an output connected to the isolated circuit for providing a reconstructed analog data signal thereto, and a second synchronous analog-to-digital converter having an input connected to the isolated circuit for receiving an analog data signal to be transmitted across the barrier in said second direction to the powered circuit, and an output connected to the second side of the isolation capacitor for conveying a synchronous digital signal corresponding to said analog data signal to the isolation capacitor, and a power supply circuit having an input connected to the first isolation capacitor to receive the synchronous digital signal, the power supply comprising a rectifier circuit for providing a DC voltage signal.

Claim 7

A bidirectional isolation system for providing an isolated communication channel for data signals in a forward direction and in a reverse direction across an isolation barrier comprised of isolation elements, the system comprising: a powered system on a first side of the isolation barrier, the powered system comprising a powered analog to digital converter having a data input terminal and an output connected to a first driver circuit, the first driver circuit being connected to the isolation barrier for driving a forward direction digital signal across the isolation barrier; and an isolated system on a second side of the isolation barrier, the isolated system comprising an isolated analog to digital converter having a data input terminal and an output connected to a second driver circuit, the second driver circuit being connected to the isolation barrier for driving a reverse direction digital signal across the isolation barrier; wherein the forward direction digital signal and the reverse direction digital signal are both driven through the same isolation elements; and wherein the forward direction digital signal comprises at least one of said data signals multiplexed with a control signal.

Claim 8

A bidirectional isolation system for providing an isolated communication channel for data signals in a forward direction and in a reverse direction across an isolation barrier comprised of isolation elements, the system comprising: a powered system on a first side of the isolation barrier, the powered system comprising a powered analog to digital converter having a data input terminal and an output connected to a first driver circuit, the first driver circuit being connected to the isolation barrier for driving a forward direction digital signal across the isolation barrier; and an isolated system on a second side of the isolation barrier, the isolated system comprising an isolated analog to digital converter having a data input terminal and an output connected to a second driver circuit, the second driver circuit being connected to the isolation barrier for driving a reverse direction digital signal across the isolation barrier; wherein the forward direction digital signal and the reverse direction digital signal are both driven through the same isolation elements; and wherein the forward direction digital signal comprises at least one of said data signals multiplexed with a control signal.

Claim 9

A bidirectional isolation system for providing an isolated communication channel for data signals in a forward direction and in a reverse direction across an isolation barrier comprised of isolation elements, the system comprising: a powered system on a first side of the isolation barrier, the powered system comprising a powered analog to digital converter having a data input terminal and an output connected to a first driver circuit, the first driver circuit being connected to the isolation barrier for driving a forward direction digital signal across the isolation barrier; and an isolated system on a second side of the isolation barrier, the isolated system comprising an isolated analog to digital converter having a data input terminal and an output connected to a second driver circuit, the second driver circuit being connected to the isolation barrier for driving a reverse direction digital signal across the isolation barrier; wherein the forward direction digital signal and the reverse direction digital signal are both driven through the same isolation elements; and wherein the reverse direction digital signal comprises at least one of said data signals multiplexed with a control signal.

Claim 10

A bidirectional isolation system for providing an isolated communication channel for data signals in a forward direction and in a reverse direction across an isolation barrier comprised of isolation elements, the system comprising: a powered system on a first side of the isolation barrier, the powered system comprising a powered analog to digital converter having a data input terminal and an output connected to a first driver circuit, the first driver circuit being connected to the isolation barrier for driving a forward direction digital signal across the isolation barrier; and an isolated system on a second side of the isolation barrier, the isolated system comprising an isolated analog to digital converter having a data input terminal and an output connected to a second driver circuit, the second driver circuit being connected to the isolation barrier for driving a reverse direction digital signal across the isolation barrier; wherein the forward direction digital signal and the reverse direction digital signal are both driven through the same isolation elements; and wherein the reverse direction digital signal comprises at least one of said data signals multiplexed with a control signal.

Claim 11

An isolation system for providing a digital communication channel for data signals and control signals, the isolation system comprising: an isolation barrier; an analog to digital converter connected to receive the data signals having an output for providing digitized data signals; a multiplexer located on one side of the isolation barrier and connected to receive the digitized data signals and the control signals and providing a multiplexed digital signal that is connected to the isolation barrier; a demultiplexer located on the other side of the isolation barrier and connected to receive the multiplexed digital signal from the isolation barrier, the demultiplexer having a digitized data signal output and a control signal output; and a digital to analog converter having an input connected to the digitized data signal output and an analog output terminal.

Claim 12

An isolation system for providing a digital communication channel for data signals and control signals, the isolation system comprising: an isolation barrier; an analog to digital converter connected to receive the data signals having an output for providing digitized data signals; a multiplexer located on one side of the isolation barrier and connected to receive the digitized data signals and the control signals and providing a multiplexed digital signal that is connected to the isolation barrier; a demultiplexer located on the other side of the isolation barrier and connected to receive the multiplexed digital signal from the isolation barrier, the demultiplexer having a digitized data signal output and a control signal output; and a digital to analog converter having an input connected to the digitized data signal output and an analog output terminal.

Claim 13

The system of claim 6, wherein the isolation barrier is a capacitive isolation barrier.

Claim 14

The system of claim 6, wherein the multiplexed digital signal is conveyed across the isolation barrier as a differential digital signal.

Claim 15

The isolation system of claim 6, wherein the analog to digital converter and the digital to analog converter are delta sigma converters.

Claim 16

An isolation system for communicating analog signal information across an isolation barrier in digital format, comprising: an analog-to-digital converter with an input connected to an analog signal containing information to be communicated across the isolation barrier; an isolation barrier having an input coupled to a digital output of the analog-to-digital converter; a digital-to-analog converter having an input coupled to an output of the isolation barrier, the digital-to-analog converter providing an analog output signal; and a digital control signal coupled to the input of the isolation barrier; wherein the analog-to-digital converter and the digital-to-analog converter are synchronized to a common clock signal.

Claim 17

An isolation system for communicating analog signal information across an isolation barrier in digital format, comprising: an analog-to-digital converter with an input connected to an analog signal containing information to be communicated across the isolation barrier; an isolation barrier having an input coupled to a digital output of the analog-to-digital converter; a digital-to-analog converter having an input coupled to an output of the isolation barrier, the digital-to-analog converter providing an analog output signal; and a digital control signal coupled to the input of the isolation barrier; wherein the analog-to-digital converter and the digital-to-analog converter are synchronized to a common clock signal.

Claim 18

The isolation system of claim 10, further comprising a multiplexer having a first input connected to the digital output of the analog-to-digital converter, a second input connected to receive the digital control signal, and an output coupled to the isolation barrier.