Methods and apparatus for resistive voltage sensing in an isolated power distribution unit

An apparatus, comprising:

• a primary side circuit including one or more voltage nodes;
• a secondary side circuit including at least one processing circuit;
• and
• a resistor network having an input for receiving a first sensed voltage from a first of the one or more voltage nodes of the primary side circuit, traversing an isolation boundary between the primary side circuit and the secondary side circuit while adhering to a safety specification which includes a primary-secondary isolation requirement, and having an output for providing a first modified sensed voltage to the processing circuit;
• wherein said resistor network does not span any isolation circuit and further includes:
• a plurality of series-coupled resistors, which are connected at one end to the first voltage node of the primary side circuit, and are connected at an opposite end to a junction node;
• a shunt resistance coupled from the junction node to a reference potential;
• and
• the output providing the first modified sensed voltage to the processing circuit is at least one of taken from, and derived from, a voltage at the junction node;
• wherein the first and second voltage nodes of the primary side circuit produce a differential voltage;
• and
• wherein the plurality of series-coupled resistors includes first and second pluralities of series-coupled resistors, the first plurality of series-coupled resistors being connected at one end to the first voltage node of the primary side circuit and being connected at an opposite end to a first junction node, and the second plurality of series-coupled resistors are connected at one end to the second voltage node of the primary side circuit, and are connected at an opposite end to a second junction node.