Advances in semiconductor technology are powering the innovation behind vehicle electrification and autonomous driving. According to market research firm IHS Markit, the semiconductor content per car will double from $312 in 2013 to $652 in 2025, growing approximately 8% per year. Electronics for hybrid/electric vehicles and ADAS are the fastest growing automotive market segments, at 29% and 13% CAGR, respectively.
Drawbacks of Scaling Quartz
While the pace of innovation in the automotive market has accelerated in recent years, one area that’s lagged behind is the timing technology used to provide reference clocking in ADAS, autonomous vehicles, and infotainment applications. Historically, automotive system developers have relied on quartz crystals and crystal oscillators to provide reference timing in these applications. As the reference timing complexity of these systems increases, the easiest solution is to simply add more quartz-based components to each new design.
This approach has multiple drawbacks and limitations. In addition to the cost and complexity of adding more components to a design, quartz is inherently sensitive to shock and vibrational effects that can impact the long-term reliability of the system.
Automotive applications also typically require extended temperature operation, often −40 to +105°C. Operation at high temperature for long periods of time can negatively impact long-term aging and the product lifecycle for quartz-based components. Collectively, these limitations with quartz make it difficult for automotive hardware developers to design scalable solutions that can grow with overall system complexity.
In the past, it has been prohibitively difficult to replace multiple discrete frequency references. Traditional clock integrated-circuit (IC) solutions were unable to generate multiple unique frequencies from a single device due to frequency synthesis restrictions or degraded clock-jitter performance when generating non-integer-related frequencies. In addition, replacing multiple discrete quartz references with a single clock IC increases printed-circuit-board (PCB) signal-routing complexity and requires distribution of clock signals over long traces.
New Timing Advances for Automotive
New reference clocking solutions are now available to address these system-level challenges. These solutions have significantly lower jitter with greater frequency flexibility, enabling multiple non-integer-related frequencies to be generated by a single IC. They also support integrated signal-integrity tuning capabilities to simplify PCB clock routing and distribution.
Similar timing solutions have been used in networking, communications, wireless infrastructure, and industrial applications for many years. To take advantage of these advances in timing technology, automotive hardware designers should consider jitter performance, frequency flexibility, and signal integrity when selecting highly integrated reference clocking solutions for new designs.