Category Archives: Crystals & Oscillators

MEMS Replacing Quartz?

The automotive market is transforming very fast. We have next-generation technologies already—semi-autonomous cars, ADAS or advanced driver assistance systems, and an array of electric vehicle options—smart mirrors, backup cameras, voice recognition, smartphone integration, telematics, keyless entry, and start. Some of the latest models feature lane-keep assist technology, automated parallel parking, and many other self-driving capabilities as these vehicles move steadily toward fully autonomous driving.

All the above has required a redefinition of the automotive design, including infotainment, convenience, and safety features, as the users of smart and connected cars expect. With automotive being the fastest-growing market segment in the semiconductor field, the key drivers for this growth come from electronic components for ADAS and other EV applications. Consider that an average car has about 1,500 semiconductors to control everything from the drivetrain to the safety systems.

However, apart from sensing, processing, and communication chips, there is another critical technology contributing to the reliable, safe operation of autonomous systems, and that is precision timing.

Most car owners understand automotive timing as the timing that belts, camshafts, or ignition systems keep for the engine to run efficiently and smoothly. For automotive systems developers, however, timing means devices providing the clock for buffers, oscillators, and resonators. In the vehicle, each timing device has a different but essential clocking function that ensures stable, accurate, and reliable frequency control for digital components. This precision timing is especially important for modern complex automotive systems like the ADAS that generate, process, and transmit huge volumes of data.

As a result, modern cars may use up to 70 timing devices to keep the automotive system operating smoothly. As vehicles get smarter with each new model, the number of timing devices is also growing. The automotive design has a wide array of digital systems that require precise, reliable timing references from clock generators and oscillators. They provide the essential timing functions for networks, infotainment, and other subsystems within the vehicle and electronic control system units like ADAS.

With the accelerating pace of automotive innovation, one critical component has remained constant for the past 70 years—the quartz-base timing devices, or the quartz crystal oscillator. But in the automotive environment, quartz crystals face fundamental limitations like fragility due to their susceptibility to environmental and mechanical stresses. Quartz timing devices are now becoming a bottleneck for safety and reliability because of their inherent drawbacks.

MEMS timing components, on the other hand, can easily meet the rigors of AEC-Q100 automotive qualification requirements. MEMS is a well-established technology, widely useful in many fields, including automotive systems. Here, they serve as gyroscopes, accelerometers, and a wide variety of sensor types.

The industry qualification of AEC-Q100 for MEMS devices offers the assurance that these timing components will provide the robustness, reliability, ad performance as the automotive electronic systems demand.

Stringent testing has proven the greater reliability of the silicon-based MEMS technology overclocking applications of quartz crystals. Being much smaller than quartz crystals, MEMS resonators are ideal for space-sensitive automotive applications like radar/LIDAR, smart mirrors, and camera module sensors. Their low mass and smaller size make MEMS timing devices far more resilient to mechanical shock and vibration.