Vehicle computers not only have to offer plenty of computing power, but also have to be able to communicate with high bandwidth and low latency. Ideally, this is done via broadband fibre optic cables. The electronics company Renesas meets this requirement by integrating an optical interface into its communication gateway control unit VC4. This interface is controlled by a chip from the Spanish gigabit fibre optics expert KDPOF.
The VC4’s data communication runs via the KD1053 PHY IC and the integrated KD9351 FOT (fibre optic transceiver) from KDPOF. “The VC4 is the first time we have integrated an optical Ethernet interface into our automotive evaluation boards,” explains Tobias Belitz, Principal Engineer at Renesas. “KDPOF provided us with its 1000BASE RH transceiver KD1053 and KD9351 FOT according to IEEE 802.3bv, which also cover the wide temperature range we are targeting.”
The four megatrends of autonomous driving, connected vehicles, electromobility and shared mobility mean that E/E architecture is evolving from domain-based to zonal architecture to meet the increasing complexity and computing power requirements of the next generation of vehicles. With the VC4 communication gateway ECU, Renesas offers its automotive customers a universal development platform based on the R-Car-S4 system-on-module.
In this environment, optical connectivity scores with low weight, low cost and electromagnetic compatibility due to inherent galvanic isolation. Especially in environments with high levels of electromagnetic interference, optical fibre is considered unbeatable, as it cannot be knocked out of sync even by strong interference voltages. “We are proud that Renesas has selected our compact automotive Ethernet chipset for its pioneering VC4 vehicle computer,” explains Carlos Pardo, CEO and co-founder of KDPOF. “With the integrated KD9351 FOT combined with the KD1053 PHY IC, we deliver a complete automotive 1000BASE-RHC physical layer.” Applications include secure Ethernet backbones, smart antenna modules and sensor connections for driver assistance systems (ADAS) and audio/video.
By integrating the transmit and receive optoelectronics – such as a transimpedance amplifier, photodiode, LED driver and LED – into a single device, the KD9351 is a 1 Gbit/s optical transceiver (optional 100 Mbit/s version) with reduced board space requirements. Other benefits include a shorter supply chain and elimination of test duplication with final testing at Tier1. In addition, assembly is simplified and the connector offers a “snap-in” connection without soldering. The KD9351 uses a low-cost MEMs encapsulation and allows SMD reflow assembly with 8 x 7 mm LGA components. It is fully shielded against electromagnetic radiation. The temperature range of -40 °C to +105 °C meets the harsh environmental requirements in the automotive sector.
KDPOF plans to showcase these and other highlights of its in-vehicle optical networking technology at the Automotive Ethernet Congress in Munich, Germany, 1-2 June 2022. On 2 June at 10:00 a.m., Carlos Pardo will also give a presentation on “Automotive Optical Ethernet Reaching for 50 Gb/s”.