SiTime, Silicon MEMS Oscillators and Clock Generators

Highest Reliability, Robustness and Resilience

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Silicon MEMS oscillators have superior reliability (operating life), robustness (ability to withstand shock and vibration) and resilience compared to quartz oscillators. SiTime has shipped more than 200 million units with zero MEMS field failures.

MEMS resonators are made of silicon and manufactured in ultra-clean semiconductor foundries using proven design rules to ensure high yield and semiconductor-level quality. The qualification and life-time testing results lead to a mean time between failure (MTBF) of more than 500 million hours (FIT<2). Silicon MEMS devices demonstrate a shock and vibration resistance of 50,000 g and 70 g respectively.

 

Reliable and Robust

A comparison of MEMS oscillator and Quartz oscillator reliability and robustness is shown below.

 
MEMS Oscillators
Quartz Oscillators
Reliability / MTBF
500 million hours
20-30 million hours
Shock Resistance
50,000 g shock
5,000 g shock
Vibration Resistance
70 g vibration
10 g vibration

 

Silicon-level Quality

MEMS-based devices leverage a combination of high quality materials, sophisticated processes and well-established infrastructure. Purified monocrystalline silicon, the base material used for semiconductors and MEMS die, is fundamentally a pure, strong and stable material. MEMS resonators are etched in silicon wafers and encapsulated under a layer of poly-silicon that makes them extremely robust. MEMS resonator wafers are made in CMOS facilities using batch-manufacturing to produce devices with predictability and nanometer precision. Six Sigma philosophy for process design and process control in combination with proven design rules ensures high quality. Learn more about how MEMS are manufactured.

A key disadvantage of crystal oscillators is their susceptibility to vibration and the loss of stability with age. Vibration appears in the jitter performance of quartz devices. Silicon MEMS devices however, are not sensitive to vibration. MEMS devices resonate at a fundamental frequency in a mode that incident vibration does not modulate.

SiTime Product Resilience

SiTime has leveraged the inherent advantages of silicon, and developed the most reliable and robust timing solutions with a proprietary resonator structure and manufacturing process. SiTime MEMS resonators are vacuum-sealed using an advanced EpiSeal™ process that eliminates foreign particles and improves reliability. The very small mass and design of SiTime resonators make them extremely immune to external forces. Using a single-point, center-anchored MEMS resonator that operates like a stiff spring, SiTime devices are designed to eliminate stress error sources. This resonator structure plus the oscillator IC design make the devices extremely immune to electromagnetic or power supply noise.

SiTime oscillators have been tested along with comparable quartz oscillators to measure the effects of mechanical shock and vibration, and electromagnetic noise. Download the the Shock and Vibration Comparison and Electromagnetic Susceptibility Comparison application notes to learn more about testing methodologies and results.

Qualification and Testing

SiTime’s Quality Management System (QMS) is based on the ISO 9001:2013 quality system standard and all SiTime products are designed and brought into production using our robust Six Sigma processes. Learn more about SiTime's certifications and reliability reports.

To ensure the highest quality, SiTime performs Lot Acceptance Testing (LAT) over the temperature range on a sample of parts from each production lot. SiTime’s MEMS oscillators pass all standard CMOS qualifications and additional resonator-specific tests (listed below).

SiTime's commitment to producing products with the highest quality and reliability is backed with a lifetime warranty.

Test Description
EFR Early Life (125ºC 168 hrs dynamic)
HTOL High Temperature Operating Life (125ºC 2000 hrs dynamic)
ESD Electrostatic Discharge (HBM, MM, CDM)
LU Latch Up (85ºC 150 mA)
HAST Biased Temp and Humidity (85 hrs 130ºC 85% RH dynamic)
TC Temp Cycle (MSL1 + 1000 cycles, -65ºC -150ºC)
QA Quartz Style Aging (30 days 85ºC dynamic)
MS Mechanical Shock (50kg shock multi-axis dynamic)
VFV Variable Frequency Vibration (70g dynamic)
VF Vibration Fatigue (20g 30 hrs dynamic)
CA Constant Acceleration (30 kg dynamic)
HTS High Temperature Storage (125ºC 1000 hrs)
PCT Pressure Cooker Test (autoclave 120ºC 100% RH 2atm 96 hrs)
TS Temp Shock (-55ºC -125ºC 100 cycles)
MSL1 Moisture Sensitivity Level 1 (JEDEC)