JAJSJV4 November 2020 THVD8010
PRODUCTION DATA
In order to combine data and power over a single pair of wires, capacitors and inductors are used in a bias-tee configuration. High-frequency differential data is AC-coupled onto the bus lines via series capacitances while power is DC-coupled via series inductances. The values of these components will depend on the carrier frequency, number of nodes on the bus, and the power delivery requirements (i.e., voltage and total current sourced or consumed by a given node).
In Figure 9-1, there is an optional rectifier network pictured on the bus lines. This network of diodes can ensure that the node is receives power correctly from the bus wires, even if the lines get swapped.
A termination resistance, RT, is not required for device functionality but can be useful in improving signal integrity in some applications by reducing reflections that can occur at cable ends.