2 days ago
The Evolution Of Timekeeping: From Sundials To MEMS
Markus Lutz is CTO and Founder of SiTime Corporation. He is a MEMS expert, a prolific entrepreneur and inventor who holds over 100 patents.
If there is one thing that modern society has in common with its ancient ancestors, it is the desire to measure time. Whether it's finding common ground between daylight saving time and standard time or tracking the sun's movement, humans have always looked for ways to develop timekeeping methods and track seasons, whether for agricultural reasons or religious celebrations.
Scientists refer to this need to measure time as time consciousness, and humans have been chasing this need to track the hours and seasons for more than 5,000 years. One of the earliest signs of timekeeping was discovered in 2013 when researchers found an ancient sundial in Egypt's Valley of the Kings.
Over the millennia, the ability to measure time has become increasingly precise, driven by technological and societal advancements that have shaped the rise of civilizations around the world. If sundials revolutionized time measurement in the 1400s BC, quartz brought timekeeping into the 20th century and silicon brought it into the 21st century.
The Role Of Precision Time Measurement
Modern time measurement is dependent on oscillators, which work as the heartbeat of the clock.
The earliest clocks to use mechanical oscillators were pendulum clocks, based on observations recorded by Galileo. The first successful pendulum clock was built in 1657 and improved precision from minutes to mere seconds per day. For the first time, mechanical clocks became more reliable than the astronomical observations that had been used for centuries and generally lost 15 seconds per day.
In the 1880s, brothers Pierre and Jacques Curie discovered that quartz crystals can generate a consistent electrical signal when subjected to mechanical stress. It took until 1927 to see the invention of the quartz crystal oscillator and the ability to apply an electric charge to induce precise vibrations at a stable frequency. Quartz crystal resonators harnessed this effect, and the new quartz clock provided a level of consistency far superior to mechanical timekeepers.
By the 1970s, quartz technology dominated electronic timekeeping, powering wristwatches, household clocks, computers and telecommunications systems—where precise synchronization was crucial.
In the never-ending search for the most accurate and precise time measurement system, researchers began to explore silicon microelectromechanical systems (MEMS) as a replacement for quartz, given how susceptible it can be to environmental stressors, including temperature, vibration and shock.
By the early 21st century, silicon MEMS oscillators began being commercialized, building a new foundation of precision timing solutions offered by companies like Microchip, Texas Instruments, Analog Devices and SiTime, where I am the founder and CTO.
Advantages Of Silicon MEMS Technology
MEMS starts with the word micro, and this offers an advantage over crystal oscillators. In this case, a silicon MEMS can create oscillators the size of small semiconductor chips. The small size means the ability to be used in more applications, creating more timekeeping devices. Silicon is also more customizable and scalable than crystal and is manufactured to meet very specific demands.
Silicon MEMS is also more environmentally resistant. As mentioned, quartz oscillators are susceptible to extreme temperature changes and other factors. More locations are now vulnerable to these extreme shifts—40- or 50-degree swings in temperature in a matter of hours are not uncommon. An increasing number of devices that rely on time measurement also rely on infrastructure like cell towers that are impacted by extreme weather.
However, it isn't just the outside environment. Because of the energy consumption required by servers, data centers generate a lot of heat that impacts the performance quality of oscillators. The same scenario applies to industrial plants with high-tech machinery that produce excessive heat. At the other extreme, the aerospace and defense industries need to battle temperatures that plunge hundreds of degrees below zero while ensuring that the time measurement systems in airplanes, satellites and rockets remain accurate.
Transitioning To New Applications And Innovations
AI and edge computing are the buzz in technology right now because they are changing the way we do everything. Both AI and edge computing require precision timing technologies, and silicon-based MEMS clocks and oscillators can play a pivotal role in the synchronization of systems.
Quartz-based device oscillators have played an important role in timekeeping for nearly 100 years, but quartz's limitations and inability to remain accurate outside of stable environmental conditions make it a less desirable choice for a variety of electronic systems.
It comes down to this one bit of research: Crystal oscillators have a mean time between failure of approximately 30 million hours, while silicon MEMS is reliable for over 500 million hours. This suggests MEMS-based timing solutions can offer longer operational lifespans in some use cases like AI, edge computing and autonomous systems.
Advances in technology to support AI and edge computing will likely drive a shift away from quartz timing and begin the era of silicon MEMS and precision timing.
Key Considerations When Selecting Precision Timing Devices
While silicon MEMS timing solutions bring notable benefits in areas like reliability, size and environmental robustness, quartz technology continues to play an important role in specific use cases.
For example, quartz oscillators may offer lower phase noise at certain frequencies and remain a practical choice for maintaining compatibility with legacy systems. Additionally, their established presence in global supply chains can make them a cost-efficient option for high-volume, less performance-intensive applications.
As timing technologies evolve, selecting the right solution depends on the unique demands of each design.
Choosing the right precision timing components is critical to system performance and reliability. Key factors to evaluate include frequency stability, phase noise, jitter, power consumption, size, temperature tolerance, cost, underlying technology and supplier support.
A highly stable frequency ensures consistent accuracy across varying conditions, while low phase noise and jitter are essential for reliable performance and precise data synchronization. Low power consumption is vital for energy efficiency, especially in portable or thermally constrained designs, and compact form factors are preferred for space-limited applications.
Finally, selecting a trusted supplier with strong technical support and long-term availability ensures continuity throughout the product lifecycle.
By carefully weighing these parameters, designers can choose timing solutions that deliver long-term accuracy, synchronization and operational reliability.
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