SiTime aims to expand its MEMS oscillator business into the $1.5 billion global telecom and networking timing market with the Elite Platform

Driven by the trend of network densification , the number of devices that must be deployed in uncontrolled environments such as basements, roadsides, rooftops and utility poles is rapidly increasing. As a result, the high-precision clock components in these systems must continue to operate under high temperatures, thermal shock, vibration and unpredictable airflow. As a result, service providers are beginning to worry whether quartz technology can meet such challenges.

MEMS clock solutions are expected to replace traditional quartz products

SiTime has launched the MEMS - based Elite Platform to meet the above environmental requirements. The company also wants to rely on the Elite solution to further expand the global communications and network clock market of $ 1.5 billion. SiTime is a MEMS analog semiconductor company and a wholly-owned subsidiary of MegaChips , providing MEMS -based silicon clock solutions that replace traditional quartz products. Currently, the company has a 90% market share in MEMS clock devices.

“New telecommunications infrastructure uses 4G/5G small cells and synchronous Ethernet networks to increase network data capacity; these systems use high-power components that have high and changing thermal loads,” said Joe Madden , founder and principal analyst at Mobile Experts . “When temperatures change rapidly, the dynamic performance of high-precision timing components becomes a critical requirement for these types of devices. MEMS technology, which inherently performs better in dynamic environments, has become an interesting alternative to quartz technology.”

Elite products are suitable for use in network, server, storage and telecommunication (NSST) equipment. Elite products are also very suitable for other high reliability applications such as test instrumentation, smart grid, high precision GNSS/GPS positioning for automotive ADAS , avionics, surveying and precision agriculture. The Elite platform is targeted at NSST applications. All frequency control products, such as resonators (X , XTAL) and oscillators (XO , VCXO , TCXO , OCXO , specialty oscillators ) , that is, the total effective market (TAM) for NSST devices , exceeds $ 1.5 billion.

Temperature compensation and low noise frequency synthesis

Elite Platform includes Super-TCXO (temperature compensated oscillator) and multiple oscillators. These high-precision devices can be used to solve the long-standing clock problems in telecommunications and network equipment. Even under environmental stress, Elite Platform still helps communication equipment achieve the best performance, reliability and service quality.

Super-TCXOs have excellent dynamic performance under real operating conditions . A key issue with quartz TCXOs is that they cannot meet the performance specifications of real systems under common environmental conditions. Elite Super-TCXOs are designed to maintain rated performance specifications such as stability, phase noise, jitter, and Allan deviation in the presence of environmental hazards such as shock, vibration, airflow, and noisy power supplies. The dynamic stability of the Elite Super-TCXO helps provide stable system performance in situations that directly affect the user experience, such as reducing dropped cell phone calls.

Super-TCXOs provide excellent dynamic characteristics by providing stable clocks in environments with airflow, rapid temperature changes, mechanical shock, vibration, EMI and power supply noise. Elite products also offer many features, such as multi-protocol support and simplified system design using digital control via I2C .

Elite Super-TCXOs are designed to withstand environmental stresses such as air flow, thermal shock and vibration. The Elite dynamic performance example below demonstrates the performance difference. ADEV , TDEV and MTIE curves are compared with the industry's best ± 50 ppb quartz TCXO under standard cooling fan airflow conditions for a CPU -based system.

Dynamic frequency stability; temperature rise characteristics up to 10 ℃ /min

Allan Deviation (ADEV) in still air and in air flow

The Elite clock solution is based on the innovative DualMEMS™ architecture and uses TurboCompensation™ technology. The Elite platform combines accurate temperature sensors, a dedicated temperature compensation scheme and a low-noise frequency synthesizer to provide excellent dynamic stability, ultra-low jitter, wide bandwidth range and programmable performance. The architecture has the following three features to provide excellent dynamic performance:

• Rugged, reliable and proven TempFlatMEMS™ eliminates frequency perturbations ( activity dip ) and is 30 times more vibration immune than quartz

• 100% accurate thermally coupled DualMEMS temperature sensing, resulting in 40x faster temperature tracking , ensuring optimal performance under conditions of airflow and rapid temperature changes
  

• Highly integrated mixed-signal circuits with on-chip regulators, time-to-digital converters ( TDCs ), and low-noise phase-locked loops ( PLLs ) provide 5x immunity to power supply noise, 30 uK temperature resolution , 10x better than quartz , and support for all frequencies from 1-700 MHz
  

Elite MEMS Clock Series

The Elite Platform includes four new product families that offer a wide range of frequencies and the following unique features: All Elite solutions offer 0.1 ppb/g vibration immunity with no frequency perturbations or micro-hops.

Stratum3 specification high-precision Super-TCXO , designed for communication and cloud computing network infrastructure equipment:

Frequency stability is ±100ppb over the -40 °C to + 105 °C temperature range, the widest operating temperature range of all TXCOs

Frequency slope of 1 to 5 ppb/ °C at ultra-fast temperature ramp rates of 10 °C per minute , a level of performance rarely seen in clock components

3e -11 Allan Deviation ( ADEV ) at 10 second averaging time, 10 times better than typical quartz TCXOs

0.2ps / mv power supply noise rejection ( PSNR ), no dedicated system LDO required

Optional I2C / SPI frequency tuning function, ^no external DAC required

Super-TCXO is suitable for global navigation satellite system ( GNSS ), industrial and automotive applications

±0.5ppm frequency stability over -40 °C to + 105 °C temperature range

Ultra-low jitter differential oscillator

• 0.23 ps integrated RMS phase jitter ( 12 kHz to 20 MHz )

• 0.1 ps integrated RMS phase jitter at 10G/40G/100G Ethernet mask

• The frequency stability is ±10 ppm in the temperature range of -40 ℃ to +95 ℃ , making the system more stable

High Temperature, High Reliability Differential VCXO

• Even at +95 °C, the phase noise performance remains very good

• Wide pull range from ±25 ppm to ±3600 ppm

• Frequency tuning linearity can reach 0.1% under all conditions, which is 50 times better than quartz

SiTime 's Competitors

Historically, Rakon and Vectron are the two largest suppliers of precision TCXOs for telecom and networking applications . Other suppliers include Epson , TXC , NDK , Kyocera , and Connor Winfield . In addition, the dynamic stability of Elite Super-TCXOs makes them suitable for replacing OCXOs in emerging applications such as IEEE 1588 and 4G/5G small base stations .

Phase Noise and Phase Jitter Comparison of Super-TCXO and Competitor Devices

Elite Super-TCXO phase noise is a key differentiator, especially for systems operating under normal environmental stress conditions. The figure below compares the phase noise of EliteSuper-TCXO and quartz TCXO under vibration conditions. Elite demonstrates 20 times better performance, significantly improving call quality of service (QoS) by reducing the number of dropped calls . In wired applications such as OLT , DSL/G.fast and synchronous Ethernet, the vibration resistance of Elite products can significantly reduce data link losses and ensure high data throughput, even if these devices are installed in high-vibration environments such as roadsides or near high-density cooling fans.

The vibration test is based on the Mil-STD-883F 2026 method, with a frequency range of 15 Hz to 2 Hz and an overall vibration intensity of 7.5 g rms .

Elite - based ultra-low jitter differential oscillators and high-temperature VCXOs are sampling now. Elite - based Super-TCXOs are expected to sample in the first half of 2017 .

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