New Endura Super-TCXO rearchitects precision timing for aerospace and defense, delivering 100x higher reliability
Posted By: Odile Ronat

Boosting data networking performance with ruggedized, easy-to-design MEMS timing

Armed forces around the world are facing ever more complex threats and are working vigorously to implement advanced systems that can detect and respond to these threats faster. Data networks are the backbone of these emerging systems. To achieve the highest operational performance in dynamic environments, today’s advanced aerospace and defense communication and networking systems rely on ruggedized precision timing technology to synchronize the flow of data with accuracy and reliability.

Military ground radar system on the left, Manpack military radio in dessert in the middle, Military helicopter flying against sunset on the right

Military services rely on vast amounts of data collected throughout dynamic ground, naval and airborne operations and are implementing massive cloud computing, big data analytics, AI, and machine learning infrastructure to accelerate threat detection and response. In high-speed data transmission, the tolerance for clock drift has grown ever smaller, making clock stability ever more important. Precision timekeeping is essential for synchronizing the transmission and reception of error-free data by minimizing clock signal drift in harsh operational environments subject to extreme temperatures, acceleration, vibration, or shock.

Endura ruggedized MEMS Super-TCXOs are ready to serve

To address these mission-critical requirements, SiTime has added a new member to its field-proven Endura™ MEMS ruggedized Super-TCXO® family—the SiT5543. This temperature-controlled oscillator redefines the TCXO landscape for aerospace and defense with unmatched stability in challenging environments. SiTime’s new SiT5543 Super-TCXO offers an unprecedented ±5 ppb frequency stability over temperature from -40°C to 95°C. In addition, it offers remarkable stability during fast temperature transients with 0.3 ppb/°C frequency slope and under vibration with 0.01 ppb/g acceleration sensitivity. Today, there are no quartz based, commercially available TCXOs with stability better than ±100 ppb. Compared to open-market quartz TCXOs, the SiT5543 delivers an impressive 20x improvement in frequency stability over temperature.

SiT5543 – Frequency stability ±5 ppb up to 95°C
Measured frequency stability of four SiT5543 Super-TCXO DUTs over temperature from -40°C to 95°C is within the ±5 ppb specification and shows excellent device-to-device repeatability.

Before the availability of SiTime Super-TCXOs, designers had to use an oven-controlled quartz oscillator (OCXO) to achieve ±5 ppb frequency stability. Using a quartz OCXO comes with several drawbacks. They are notoriously expensive, bulky, fragile, power hungry and have long lead times. The SiT5543 overcomes these problems and offers designers of ruggedized systems a remarkably better option. It provides 100x higher reliability, 2x lower power consumption, and 40 percent smaller size than quartz OCXOs, making the SiT5543 an ideal replacement for OCXOs in applications such as high-speed data communications, military networks, and avionics.

SiTime Endura™ Super-TCXO: 100x more reliable, 2x lower power, 40% smaller size
In a compact 7 x 5 mm footprint and 2 mm height, the SiT5543 Super-TCXO offers much better reliability, lower power consumption, and smaller size than comparable quartz OCXOs.

The SiT5543 Super-TCXO significantly reduces bit error rate, system size, and power consumption while enhancing reliability and operational performance in harsh operating conditions. The technical specifications of this MEMS-based Super-TCXO enables a new level of secure, timing-dependent encryption technology to protect military radios, GPS receivers, navigation, and guidance systems from jamming events. This Endura Super-TCXO provides the stability over temperature and under vibration required for high-speed networks that form the backbone of today’s aerospace and defense systems. It reduces risk, cycle time, and cost in meeting tough operational requirements due to the superior robustness of MEMS technology over legacy quartz alternatives.

Silicon MEMS timing technology is the powerful enabler

The SiT5543 Endura Super-TCXO is engineered for exceptional dynamic performance. The MEMS resonator — at the heart of the SiT5543 — uses high purity silicon, enabling it to leverage the many benefits of MEMS timing technology to provide the most reliable timing in the presence of environmental stressors such as airflow, temperature perturbation, vibration, shock, and EMI. The design and manufacturing process of the MEMS resonator, which is encapsulated in a low-vacuum, particle-free cavity, enables very low aging and high reliability.

DualMEMS device architecture
The SiT5543 is built on a DualMEMS architecture, consisting of a two MEMS mounted on top of a mixed-signal CMOS IC, to deliver exceptional stability over temperature and during rapid temperature transients.

The SiT5543 uses SiTime’s DualMEMS® technology where two MEMS resonators are collocated on a single die. One of the resonators is optimized for ultra-stable temperature stability while the other is optimized for temperature sensing which is used for temperature compensation. This results in a near linear frequency stability over temperature. The SiT5543 delivers ±0.3 ppb/°C typical frequency slope (dF/dT). This design also reduces random noise and delivers a stability of 1.5e-11 ADEV at 10 second averaging time. The construction of the MEMS resonator and its very low mass make it resistant to shock and vibration, delivering a remarkable 0.01 ppb/g acceleration sensitivity — the best in the industry — and 20,000 g shock survivability.

SiT5543 – Temperature slope dF/dT is less than 0.3 ppb/°C
Measured frequency versus temperature slope (dF/dT) of the SiT5543 Super-TCXO is within the 0.3 ppb/°C (typical) specification.

The SiT5443 Super-TCXO reduces design cost and complexity due to its small 7 mm x 5 mm surface-mount footprint, low 2 mm height, low power requirements, and unique ability to mitigate the effects of harsh operating conditions. Since it is factory-programmable to support output frequencies ranging from 1 to 60 MHz, it eliminates the high cost, risks, and delays of custom oscillators. The SiT5543 is available with I2C digital control for on-the-fly frequency tuning or for in-circuit user-defined compensation. Digital control provides noise-insensitive frequency adjustment with smooth frequency shifts. The low ±150 ppb 20-year aging specified at 85°C can eliminate the need for system level aging compensation.

The SiT5543 MEMS Super-TCXO is manufactured using world-class semiconductor processes with statistical process control and 6-sigma specification limits to ensure they operate reliably out of the box and meet specification both in the lab and in the real world.

Bottom line, the SiT5443 enables faster, low-latency data transmission and reduces bit error rates in dynamic environments. System designers no longer need to use costly, bulky, custom-made OCXOs, which are highly sensitive to acceleration, shock, and vibration.

Endura SiT5543 Super-TCXO highlights

  • 1 to 60 MHz programmable output frequency
  • ±5 ppb stability over -40°C to +95°C temperature range
  • ±0.3 ppb/°C stability over temperature slope
  • 0.01 ppb/g acceleration sensitivity
  • 0.5 ppb/day daily aging
  • ±150 ppb aging over 20 years
  • 2 seconds to final stability over temperature
  • Optional ±3200 ppm digital control with I2C
  • 20,000 g shock survivability
  • 110 mW typ. power consumption at 2.5V supply
  • 2.5 to 3.3V supply voltage
  • 7.0 mm x 5.0 mm ceramic surface-mount package

More information

Product page: Endura Ruggedized SiT5543 Super-TCXO

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Sep 26, 2023

Sep 19, 2023