What Is Aging?
A military-grade navigation system may be operational but what if it is slowly losing the ability to track mission-critical data with pinpoint accuracy? The consequences are not always immediately obvious, but even small timing deviations can compromise vital functions when dependable performance is needed most. This gradual loss of precision is known as aging. Aging specifications are one of the most important characteristics engineers use to evaluate oscillators. Aging is the deterministic change in an oscillator’s output frequency over time, typically expressed in parts per million or billion (ppm or ppb) across years. Understanding it helps engineers estimate how consistently and how long an electronic system can meet requirements.
While aging occurs at the component level, its effects can extend to the system level. Because all electronic systems depend on synchronization and timing precision, and some rely on holdover—where operations continue even after the loss of a reference clock—aging can affect behavior and reliability. As the frequency reference degrades and changes accumulate, systems may require more frequent calibration, experience reduced holdover performance or become increasingly difficult to maintain at their desired level of accuracy, potentially leading to errors and other system malfunctions.
Why Aging Matters
Aging is more than a datasheet specification, it is a characteristic of performance. Keeping an oscillator’s output closer to its nominal value over an extended duration improves frequency stability, supports reliable synchronization and helps devices remain within their acceptable parameters for longer.
Many applications rely on extreme timing precision for long periods with little or no intervention. In the 5G radio access network, for instance, aging affects holdover oscillators in distributed units (DUs) that perform real-time processing of radio signals. These oscillators help sustain synchronization when external timing references are disrupted, allowing services to remain available during an outage.
Systems that rely on holdover during Global Navigation Satellite System (GNSS) outages or network reference loss can uphold tighter alignment when the underlying oscillator ages more slowly. Lower aging can also minimize recalibration cycles and prolong service intervals.
For test and measurement equipment, long-term frequency variation can influence calibration intervals and measurement confidence. Another example is remote seismic sensing applications, particularly when they are positioned in locations that are difficult or costly to access. In these environments, lower aging can reduce maintenance requirements, extend deployment duration and preserve performance between service visits.
The SiTime Advantage
While aging may be unavoidable, advanced Precision Timing solutions can significantly minimize its impact. Frequency changes stem from two primary sources: physical aging of the timing element itself and post-reflow mechanical relaxation within the device package. SiTime addresses both drivers through a combination of MEMS innovation and specialized packaging expertise.
The resonator choice is key. A resonator establishes the frequency at which the oscillator operates. SiTime’s MEMS resonators do not age. Manufactured using the proprietary Episeal® process, the silicon resonator is sealed in an ultra-clean vacuum, eliminating the material degradation and contamination that causes frequency instability. Second, to manage post-reflow mechanical strain—which relaxes over time and induces frequency shifts—SiTime relies on a dedicated team focused solely on how physical stress interacts with timing behavior. By designing products to mitigate these effects, SiTime achieves industry-leading aging performance.
For demanding applications, this core architecture is paired with advanced capabilities to further limit frequency variation. Integrated temperature sensing and adaptive compensation in SiTime’s Super-TCXOs (e.g., SiT5156, SiT5356, SiT5358) suppress aging-related effects. Additionally, solutions like the Epoch PlatformTM OCXOs (e.g., SiT5811) support system-level calibration and precise holdover during reference loss, improving long-term stability throughout the life of the device.
Want To Learn More?
Take the next step to expand your understanding of aging and how it’s managed in modern systems:
1. Explore Our Timing Solutions: Oscillator, Clock and Resonator Products
2. Understand the Technology: Silicon MEMS Timing
3. Advance Your Expertise: Aging in OCXO and TCXO