Race Through the World of Infotainment
Carmelo De Mola from Microchip Technology introduces a cost-effective, robust, and scalable physical layer designed for high-speed networked infotainment systems, compatible with various network layouts.
High-bandwidth in-vehicle infotainment (IVI) systems, previously exclusive to luxury cars, are now becoming standard in more affordable and mass-market vehicles. Despite the differences in software features that these IVI systems might offer, they all require a solid physical layer that can handle high data rates.
Historically, optical MOST 150 networks served as the go-to technology for high-bandwidth infotainment purposes. They met all the stringent requirements for high bandwidth, scalability, light weight, robustness, electromagnetic compatibility (EMC), and the ability to fit into the limited spaces within vehicles. However, their cost has been a significant drawback for many high-volume car manufacturers.
To meet the market’s demand for a more affordable solution that still meets automotive standards, a new standardized physical layer for IVI networks based on coaxial cables has been developed.
Coaxial cables offer several advantages:
They support high-bandwidth data transfer.
Their shielding provides excellent EMC performance.
They can be assembled automatically.
They meet demanding mechanical specs, including flexibility and high-temperature resistance.
They are cost-effective for automotive use.
They have tightly controlled impedance, which allows full-duplex operations.
They can transmit power and data simultaneously over the same cable.
Coaxial cables have been used in the automotive industry for years, primarily as point-to-point connectors, such as between antennas and radios or GSM modules. This long-term use means the production infrastructure and supply chains are already established.
Coaxial cables meet automotive requirements regarding temperature and mechanical stress. Additionally, the industry uses standardized Fakra connectors, featuring various shapes, colors, and mechanical configurations, which simplify and speed up the assembly process in production lines. These connectors also meet stringent automotive standards and can be produced with a high degree of automation.
The main advantage of coaxial cables lies in their design. The electric field of the signal in the core conductor is contained within the metallic shield, preventing external radiation and protecting the core from external electric fields. This results in robust EMC performance, making the placement of coaxial cables in vehicles more flexible and cost-effective.
Unlike traditional optical MOST systems, coaxial cables offer controlled impedance, enabling dual simplex and bidirectional full-duplex communication. This allows for more complex network topologies, providing greater flexibility in designing IVI systems.
