Reliable circuit protection solutions for three advanced communication technologies
Several years ago, automobiles consisted of several independent electronic systems. Even the vehicle manufacturing process involved assembly lines that required the operation and management of multiple independent systems. Thanks to the growth and expansion of the Internet of Things (IoT), the connectivity that used to only be available in the home or office is now available in modern automobiles. With this dramatic shift in automotive electronics and assembly, the vehicle itself has now become the center of communication.
To promote connectivity and facilitate broadband-like automobile communications, new protocols are being developed and implemented. These communication protocols play a key role in increasing the safety and functionality of these innovative vehicles. However, they also create new technical challenges for the design engineers who develop these modules.
The core challenge facing automotive design engineers is related to size and density. As automotive circuitry and its functionality become more advanced, the technologies from which the chipsets are built decrease in size but increase in density. As a result, the chipsets are more susceptible to electrostatic discharge (ESD). To ensure that these tiny, compact modules deliver reliable, long-term performance in harsh automotive environments, design engineers must fully understand the unique circuit protection requirements of the chipsets and take action accordingly.
A guide to automotive communication technology protection, this article highlights the characteristics and benefits of three new communication protocols: Analog high definition (AHD), BroadR-Reach® and V2X. Then, it will examine the unique ESD protection requirements for each protocol and identify the latest circuit protection solutions designed to ensure the long-term connectivity and reliability of automotive electronics.
Three Protocols that Demand Protection
Automotive design engineers and manufacturers should utilize new communication protocols to support IoT growth and meet consumer demand for increased convenience, safety and mobile communications. The following protocols are at various stages of development and implementation:
1. AHD Provides Fast, Flexible Video Transmission
AHD 1.0 Tx/Rx is being developed to handle analog signals from multiple types of high-definition cameras located around the vehicle for surveillance and safety. It transmits 720p at 25fps/30fps with minimal data loss, while supporting COMET and CVBS signals simultaneously.
While the cameras use analog signals, they must be able to transmit high-definition video throughout the vehicle’s network. AHD is designed to transmit a variety of high-definition video signals that could otherwise be handled by a complex HDMI connection. By supporting multiple video transport protocols, AHD proves to be very versatile and flexible, allowing for backward compatibility of legacy modules that will not phase out immediately. The AHD line can carry the new high-speed data as well as lower speed protocols on the same wire—using the same chipset.
2. Broad R-Reach Decreases Cabling, Replaces Slow Buses
Broad R-Reach technology is still in the early stages of implementation. This technology will allow multiple in-vehicle systems, such as infotainment and automated driver assistance, to simultaneously access high-bandwidth data throughput over a single, unshielded twisted pair cable.
One possible application of Broad R-Reach technology involves streamlining communication on the controller area network (CAN) bus network. The CAN bus is used to communicate with many important systems in the vehicle, including the engine control module (ECM), power train control module (PCM), anti-lock braking system, instrument cluster, air bags and cruise control. While the CAN bus standard is reliable and fault tolerant, it is relatively slow. Since modern vehicles are now expected to collect information from hundreds of sensors throughout the vehicle, this may create a severe bandwidth issue—especially when digital video signals are added to the system.
As an Ethernet-based protocol, Broad R-Reach enables 100 Mbps communication while only using two communication lines instead of four. It can be used as a high-speed link that can move various types of data around the vehicle. Or it can be used to aggregate a large number of slow lines (e.g., CAN bus), thus eliminating the need to run those lines around the vehicle. Therefore, one Broad R-Reach bus can take the place of many slow communication buses—reducing the physical amount of cable that is installed in the vehicle. The reduction in cable will lead to cost savings, a reduction in overall vehicle weight and simplified cable routing.
3. V2X Delivers Safety and Efficiency on the Road
Providing enhanced safety and efficiency for automobile drivers, the V2X protocol enables the vehicle to communicate with roadway infrastructure and other vehicles. While this protocol concept has been tested, the standards and hardware/software coordination are still under development.
Vehicle-to-vehicle (V2V) communications allow the vehicle to perform dynamic calculations based on the velocity and location of other vehicles. When the calculation indicates an imminent collision, the system notifies the driver or autonomous vehicle to take evasive action. This technology prevents the vehicle from hitting other vehicles or pedestrians. In 2017, the National Highway Traffic Safety Administration (NHTSA) and Department of Transportation (DOT)reported that V2V communications could address up to 69 percent of multi-vehicle crashes.
Vehicle-to-infrastructure (V2I) communications enable the traffic system to collect important information such as the vehicle’s rate of speed and direction of travel. During rush hour, the traffic system can use this data to control the timing of traffic lights—enabling efficient, synchronized traffic movement that dramatically improves the commuting experience for drivers.
In addition, V2X could allow companies to deliver location-based advertising and promotion to their driving audience. For instance, when a driver is approaching a particular city or neighborhood, he or she could receive information about items in that city based on a preset profile or preferences. The driver could be notified about a sale at a retail store along his or her route or even a restaurant serving his or her favorite food. While driving business to the companies advertising their products and services, this customized marketing also benefits the driver by providing relevant and convenient opportunities to take advantage of products and services at nearby points of interest.
The Power of Circuit Protection for Communication Protocols
As IoT devices and new communication protocols continue to increase, special demands are imposed on design engineers who build automotive applications and modules. Early in the design process is the best time for engineers to consider ESD protection solutions that address the heightened sensitivity of today’s automotive chipsets. To create robust, reliable designs, engineers should review and understand the system-level ESD testing required for these modules. Table 1 shows ESD protection solutions that will help design engineers develop automotive modules that meet the safety and test standards of the latest communication protocols.
Conclusion
IoT is truly revolutionizing automobile communication. However, with communication advancement comes great responsibility on the part of design engineers to protect highly sensitive chipsets. As new protocols are being developed to promote safety and facilitate automobile-based communication, exceptional ESD protection is needed for automotive modules that will utilize these new protocols.For example, Broad R-Reach and AHD are being developed to increase the speed and efficiency of high-speed data transmission—including high-definition video signals. In addition, V2X is designed to help vehicles to communicate with the road and each other to prevent collisions and optimize traffic flow.ESD protection devices featuring low capacitance, low clamping and a compact footprint will help make modern automobile operation using these advanced protocols safe, efficient and reliable.
Author
James Colby is a manager of semiconductor business development at Littelfuse, Inc. His responsibilities include identifying and developing strategic growth markets as well as introducing new products into those markets. He received his BSEE from Southern Illinois University (Carbondale) and his MBA from Keller Graduate School of Management (Schaumburg). He has been with Littelfuse for over 15 years and has worked in the electronics industry for more than 23 years.
