As electric vehicle battery voltages increase from 400V to 800V and beyond, switching transients from silicon carbide motor controllers induce extreme electromagnetic radiation. Heavy copper shielding adds weight and cost. IEEE 802.3cz (automotive optical multi-gigabit Ethernet) replaces copper with lightweight optical glass and plastic fibers, offering complete galvanic isolation.
In an 800V powertrain, ground potential differences between the front inverter and the rear central compute can exceed tens of volts during hard regenerative braking. Copper cables carry dangerous ground-loop currents that corrupt differential signals. Optical transceivers transmit photons instead of electrons, eliminating electrical coupling entirely.
While telecommunication glass fibers are brittle and require cleanroom splicing tools, automotive plastic optical fiber (POF) features durable polymer cladding that withstands severe chassis vibration, tight bend radiuses under 10mm, and automated push-pull automotive connectors rated for 25Gbps throughput.