This reference design shows the implementation of an Ethernet interface consisting of a single-pair Ethernet (SPE) PHY with the option for powering a link partner through the same cable. This is part of Power over Data Lines (PoDL). Although PoDL is standardized in IEEE802.3bu for 100/1000Base-T1, this reference design is not compliant to IEEE802.3bu to address the automotive requirements. In the automotive sector, the car OEM defines which ECUs and sensor modules are used in the system and therefore a detection and classification is not required. This assumption is based on the fact that the network does not change over the lifetime of the vehicle. The boards are designed to fulfill the automotive requirements for a cost- and weight-efficient implementation.

With transmitting the power over the same cable as the data, the use of the classic fuse is no longer applicable, which is why the integration of a high-side switch (HSS) is strongly recommended to protect the link partner from any damage. The 12V supply for power coupling to the data line is generated on the Jacinto™ 7 EVM by a LM5175 buck-boost converter. This device already supports protection features including cycle-by-cycle current limiting, output overvoltage protection (OVP), and thermal shutdown. This reference design includes the TPS4H160-Q1 (High-Side Switch) which includes adjustable current limit, short-to-GND protection, thermal shutdown, and an inductive load negative voltage clamp.