SLVSD02D March 2015 – June 2019 TPS65982
The receiver block of the TPS65982 receives a signal that falls within the allowed Rx masks defined in the USB PD specification. The receive thresholds and hysteresis come from this mask. The values for VRXTR and VRXTF are listed in USB-PD Baseband Signal Requirements and Characteristics.
Figure 17 shows an example of a multi-drop USB-PD connection. This connection has the typical UFP (device) to DFP (host) connection, but also includes cable USB-PD TX/Rx blocks. Only one system can be transmitting at a time. All other systems are Hi-Z (ZBMCRX). The USB-PD Specification also specifies the capacitance that can exist on the wire as well as a typical DC bias setting circuit for attach detection.