Analog isolation system with digital communication across a capacitive barrier

A method for conveying an analog signal from a transmitting circuit to a receiving circuit while electrically isolating the transmitting circuit from the receiving circuit, comprising:

• converting the analog signal to a first digital signal;
• transferring the first digital signal to an isolation barrier having at least one capacitive element, the transferring being in a first direction;
• receiving a second digital signal in a second direction from the isolation barrier, the transferring of the first digital signal and the receiving of the second digital signal being configured to occur across the same capacitive element;
• and
• converting the transferred second digital signal to an analog output signal.

A method for conveying a signal across an isolation barrier, comprising:

• providing a receiving circuit operable to communicate with a capacitive isolation barrier and a signal source, the receiving circuit configured to be electrically isolated from a transmitting circuit;
• utilizing information transmitted across the capacitive isolation barrier to provide a receiving circuit clock within the receiving circuit, the information transmitted across the capacitive isolation barrier including clock information;
• and
• extracting power from the information transmitted across the capacitive barrier to provide a power supply for at least a portion of a phone line side circuitry.

An isolation system, comprising:

• isolated side circuitry operable to communicate digitally with a powered side circuitry, said digital communication comprising a digital data transmitted from a bidirectional first input/output node, the first input/output node being within the isolated side circuitry, the first input/output node capable of communicating with a capacitive isolation barrier;
• a clock signal within the isolated side circuitry, the clock signal capable of being generated from information transmitted across the capacitive isolation barrier;
• at least one power supply within the isolated side circuitry, the power supply capable of being generated from information transmitted across the capacitive isolation barrier;
• and
• at least one control signal within the isolated side circuitry, the control signal being capable of being transmitted across the capacitive isolation barrier.

Isolated circuitry for communicating telephone line analog signal information across an isolation barrier in digital format, the isolated circuitry including phone line side circuitry, the isolated circuitry comprising:

• an analog-to-digital converter having a digital output, the analog to digital converter having an input connected to an analog signal containing the telephone line analog signal information to be communicated across the isolation barrier, the isolation barrier comprised of one more capacitive isolation elements;
• control information, the control information being combined with a digital output signal of the analog-to-digital converter to form a combined signal, the combined signal capable of being provided to the isolation barrier;
• a digital-to-analog converter having an input capable of being coupled to the isolation barrier, the digital-to-analog converter providing an analog output signal to be transmitted to the telephone line;
• and
• a power supply circuit located within the phone line side circuitry, the power supply circuit generating a DC power supply from a digital signal received across at least one of the capacitive isolation elements.

An isolated circuit for communicating analog telephone line signal information across an isolation barrier in digital format, the isolated circuit including phone line side circuitry, comprising:

• an analog-to-digital converter having a digital output signal, the analog to digital converter having an input connected to an analog signal containing the analog telephone line signal information to be communicated across the isolation barrier, the isolation barrier comprised of one or more capacitive isolation elements, at least one of the capacitive isolation elements transmitting data in both a forward direction and a reverse direction, the analog-to-digital converter digital output capable of being coupled to the isolation barrier;
• a digital-to-analog converter having an input coupled to the phone line side of the isolation barrier, the digital-to-analog converter providing an analog output signal;
• and
• power circuitry located within the phone line side circuitry, the power circuitry configured to be coupled to the isolation barrier and providing a power supply for at least a portion of the phone line side circuitry by utilizing information transmitted across the isolation barrier.

A method for conveying telephone line signals between a phone line side circuit and a powered side circuit while electrically isolating the phone line side circuit from the powered side circuit, comprising:

• providing a first digital signal in the phone line side circuit;
• transferring in a first direction the first digital signal to a capacitive isolation barrier having at least one capacitive element, the capacitive isolation barrier providing telephone line isolation;
• receiving a second digital signal in a second direction from the isolation barrier, the transferring of the first digital signal and the receiving the second digital signal being through the same capacitive element;
• and
• utilizing at least one signal transmitted received from the capacitive isolation barrier to provide a power supply for at least a portion of the phone line side circuitry.

A bidirectional isolated circuit for providing an isolated communication channel for communicating telephone line data signals in a forward direction and in a reverse direction across an isolation barrier comprised of at least one capacitive isolation element, the circuit comprising:

• an isolated system on a phone line side of the isolation barrier, the isolated system comprising an output for driving a reverse direction signal across the isolation barrier and an input for receiving a forward direction signal from the isolation barrier;
• and
• a power supply circuit located within the isolated system, the power supply circuit generating a DC power supply from a signal received from the capacitive isolation barrier,
• wherein the forward direction signal and the reverse direction signal are both driven and received through the same node of the isolated system so that forward and reverse signals are configured to be provided through the same capacitive isolation element.

A method for provided a signal for use with a phone line, the signal provided from a transmitting circuit to a receiving circuit while electrically isolating the transmitting circuit from the receiving circuit, the method comprising:

• providing a first digital signal within the transmitting circuit;
• transferring the first digital signal to an isolation barrier having at least one capacitive element, the transferring being in a first direction;
• and
• receiving a second digital signal in a second direction from the isolation barrier, the transferring of the first digital signal and receiving of the second digital signal being across the same capacitive element.

A method for conveying a signal across an isolation barrier, comprising:

• providing transmitting circuit operable to communicate with a capacitive isolation barrier and a signal source, the transmitting circuit being electrically isolated from a receiving circuit;
• providing information from a first node of the transmitting circuit to the capacitive isolation barrier to provide a receiving circuit clock within the receiving circuit, the information provided to the capacitive isolation barrier including clock information;
• and
• wherein the information provided from the first node of the transmitting circuit to the capacitive barrier is also utilized to provide a power supply for at least a portion of the receiving circuit.

A telephone line isolation system, comprising:

• powered side circuitry operable to communicate digitally with isolated side circuitry, said digital communication comprising digital data transmitted from a bidirectional first input/output node, the first input/output node being within the powered side circuitry, the first input/output node configured to communicate with a capacitive isolation barrier;
• a clock signal within the powered side circuitry, the clock signal capable of being transmitted to the capacitive isolation barrier;
• and
• at least one control signal within the powered side circuitry, the control signal being capable of being transmitted to the capacitive isolation barrier,
• wherein the powered side circuitry is configured to provide power to the isolated side circuitry through the capacitive isolation barrier so that a power supply is capable of being generated within the isolated side circuitry.

A method for conveying telephone line signals between a phone line side circuit and a powered side circuit while electrically isolating the phone line side circuit from the powered side circuit, comprising:

• providing a first digital signal in the powered side circuit;
• transferring in a first direction the first digital signal to a capacitive isolation barrier having at least one capacitive element, the capacitive isolation barrier providing telephone line isolation;
• receiving a second digital signal in the powered side circuit in a second direction from the isolation barrier, the transferring of the first digital signal and the receiving of the second digital signal being across the same capacitive element;
• and
• transmitting at least one signal from the powered side circuit to the capacitive isolation barrier to provide power for generating a power supply for at least a portion of the phone line side circuitry.

A bidirectional communication system for conveying telephone line data signals between an isolated circuit and a powered circuit while electrically isolating the powered circuit from the isolated circuit, the system comprising:

• an isolation barrier including at least a first isolation capacitor, the first isolation capacitor capable of providing at least some of the isolation between the powered circuit and the isolated circuit;
• and
• the powered circuit, the powered circuit comprising,
• a powered circuit input, wherein an input signal at the powered circuit input is the data signal to be transmitted across the first isolation capacitor, and
• a powered circuit input/output node coupled to a first side of the isolation capacitor, wherein an output signal at the powered circuit input/output node is a first digital signal to be transmitted across the isolation capacitor in a first direction and wherein an input signal at the powered circuit input/output node is a second digital signal transmitted across the isolation capacitor in a second direction,
• wherein the powered circuit is configured to provide power to the isolation barrier from which a power supply is capable of being generated in the isolated circuit.