Network devices with multi-level electrical isolation

An Ethernet communication apparatus comprising:

• a physical interface that forms an input of the apparatus for receiving Ethernet signals and an output of the apparatus for outputting Ethernet signals;
• a physical layer circuit in communication with the physical interface to perform physical layer communication processing with respect to the transmitted or received Ethernet signals at the physical interface;
• a network processing circuit in communication with the physical layer circuit to perform network processing operations in connection with the transmitted or received Ethernet signals at the physical interface;
• and
• a multi-level isolation circuit coupled between the network processing circuit and the physical layer circuit to provide desired high voltage electrical isolation therebetween and structured to include separate isolation circuits electrically coupled in series to partition the desired first electrical isolation amongst the separate isolation circuits so that an isolation circuit is structured to provide only a part of the desired high voltage electrical isolation.

An apparatus comprising:

• a first isolation circuit structured to include a first input and a first output and to allow a first passed voltage at the first input to pass through the first isolation circuit to the first output, the first isolation circuit structured to isolate a first isolated voltage at the first input from a second isolated voltage at the first output;
• a downstream network circuit structured to include a second input and a second output, the second input coupled to the first output of the first isolation circuit to receive the first passed voltage and the second isolated voltage, the downstream network circuit structured to process the first passed voltage to produce a second passed voltage and a third isolated voltage at the second output, the downstream network circuit operable to determine the second isolated voltage without regard to the first isolated voltage;
• a second isolation circuit structured to include a third input and a third output, the third input coupled to the second output of the downstream network circuit to receive the third isolated voltage and the second passed voltage, and structured to allow the second passed voltage to pass through the second isolation circuit to the third output, the second isolation circuit structured to isolate the third isolated voltage at the third input from a fourth isolated voltage at the third output;
• and
• an upstream network circuit structured to include a fourth input and a fourth output, the fourth input coupled to the third output of the second isolation circuit to receive the second passed voltage and the fourth isolated voltage, the upstream network circuit structured to process the second passed voltage to produce digital data, wherein the upstream network circuit is operable to determine the fourth isolated voltage without regard to the third isolated voltage, wherein the upstream network circuit is powered by a first power supply isolated from a second power supply powering the downstream network circuit.