07/14/2025 | News release | Distributed by Public on 07/14/2025 18:17
From smartphones and satellites to 5G base stations and industrial systems, Precision Timing devices are the heartbeat of every design-synchronizing subsystems, managing data flow, and ensuring reliable operations. Even minor timing errors can trigger communication failures, data corruption or system crashes.
To maintain accuracy, engineers rely on high-performance solutions like ultra-stable oscillators, phase-locked loops (PLLs) and advanced timing analysis tools. Among the most critical timing components are temperature-compensated oscillators (TCXOs) and oven-controlled oscillators (OCXOs)-both engineered to deliver stable frequency across temperature fluctuations.
This guide helps system engineers evaluate high-level tradeoffs to choose the right oscillator based on frequency stability, power budget, board space and system cost.
Temperature variation is one of the biggest challenges for oscillator stability. Frequency stability (F/T) is typically measured in parts per million (ppm) or parts per billion (ppb), and system designers closely watch the frequency slope over temperature (dF/dT) when choosing a timing component.
Both TCXOs and OCXOs are designed to combat temperature variations:
With each successive generation, TCXOs have grown more stable and OCXOs have become smaller and more efficient, closing the performance gap between them. Many of these advancements stem from silicon MEMS-based Precision Timing, driven by innovations in analog circuitry and packaging. Recent advances have brought MEMS TCXO performance into new territory, achieving frequency stability as tight as ±5 ppb (.005 ppm), expanding their utility into higher precision applications once reserved for OCXOs. In addition, OCXOs are beginning to encroach on the size and power advantages of the TCXO.
In choosing a TCXO or OCXO the materials matter. While quartz is commonly used, it can be problematic in applications that require:
Designers face a critical choice: continue using legacy quartz-based TCXOs and OCXOs or adopt MEMS Precision Timing solutions. MEMS -based oscillators, built with ultra-pure monocrystalline silicon resonators, deliver advantages over quartz in these areas.
Advanced datacenter, networking and communications applications are pushing traditional timing components to their limits. For instance, workload management in AI datacenters is critical to maintaining performance, efficiency and uptime. If tasks are not precisely scheduled and synchronized, it can lead to resource issues, data corruption or workload interruption-especially in large-scale parallel processing environments. Frequency precision ensures that timing signals remain stable and synchronized across systems, enabling smooth coordination of compute-intensive operations. Without accurate timing, even minor discrepancies can cascade into major failures or costly downtime.
In these dynamic settings, quartz-based TCXOs and OCXOs often struggle to maintain frequency precision-particularly in protocols such as IEEE 1588, where even minor timing deviations can degrade synchronization. MEMS OCXOs are the go-to solution for their superior stability but in some cases low-end OCXOs can be replaced with MEMS TCXOs and large, expensive and power hungry, high-performance OCXOs can be replaced with smaller, lower power and more integrated solutions.
Holdover is the ability of a timing system to maintain accurate time or frequency in the absence of its primary reference signal, for instance during GNSS signal loss due to severe weather. TCXO-based systems may drift several microseconds within minutes of losing its reference signal, while some OCXOs can hold to microsecond precision over much longer periods.
SiTime's Epoch™ OCXOs are particularly well-suited for holdover scenarios. What sets Epoch apart is its combination of tight frequency stability, low phase noise and efficient thermal design, all in a compact and power-conscious footprint. This enables longer and more predictable holdover durations compared to traditional OCXOs, which may consume more power or drift more significantly over time. In addition, the SiTime TimeFabric™ Software Suite delivers IEEE-1588-2019-based precision timing synchronization and extended holdover: sub-microsecond synchronization and 24-hour holdover without hardware upgrades, additional power consumption, or increased complexity. System designers can build more resilient timing architectures that reduce reliance on constant GNSS connectivity while still meeting stringent performance and reliability requirements.
Next-generation timing solutions are turning to MEMS technology, built on ultra-pure silicon resonators. These resonators are hermetically sealed in a vacuum through epi-seal process, which protects the components from moisture, contamination and aging-ensuring reliable performance over years of operation.
A key advantage of MEMS-based timing is multi-resonator integration. Unlike quartz, MEMS enables the design of resonators with different temperature coefficients in the same package, allowing engineers to fine-tune performance across wide temperature ranges.
MEMS innovation doesn't stop there. SiTime has developed radically new architectures that depart from traditional quartz-based designs:
Backed by features like dual-resonator temperature detection circuits (TDCs), high-resolution fractional-N PLLs, and fully digital temperature compensation, MEMS-based oscillators from SiTime are delivering timing precision once thought unattainable in harsh environments. These advanced architectures unlock a new class of timing devices that combine the size and power efficiency of TCXOs with the performance typically reserved for OCXOs-delivering reliability in datacenters, networking and communications, 5G, aerospace and defense, automotive, industrial, IoT and much more.
TCXOs are closing the performance gap with OCXOs, just as OCXOs are shrinking in size and power. This convergence is driven by silicon MEMS technology, along with advances in analog design and packaging. As these devices advance, system designers gain new flexibility in choosing high-precision timing solutions, to achieve greater performance and reliability in their next design.
Learn more about SiTime MEMS-based Elite RF Differential Super-TCXOs®, Epoch OCXOs and TimeFabric Software Suite.