The Clock Oscillator: The Shift from Quartz to MEMS
The technological era has given birth to numerous electronic gadgets. One of the most popular electronic devices ever
invented is the clock. Eventually technology enabled the use of electo-mechanical resonators to generate a reliable,
accurate frequency for all clocks. This became known as the modern reference clock. With its stable, repeatable
waveform, the reference clock is the heartbeat of an electronic product. In essence, a clock is the most important
component for operation of an electronic device as it controls timing. Depending on the application requirements,
various timing components such as resonators, oscillators and clock generators can be used as reference sources.
However, most electronic systems such as hard drives, cameras, video cards and computer systems use several clock
oscillators to provide accurate timing necessary for the proper operation of the system.
Based on quartz oscillator technology, these clock oscillators were made by using precision manufacturing techniques.
Consisting of three components; a resonator, an analog excitation circuit plus a standard logic output driver, and a
package, the oscillator's main performance parameters include - frequency range and resolution, stability and tolerance,
jitter, power consumption, operating supply voltage, and temperature range. However, the advent of technological
innovation has paved way for the wide spread adoption of the Micro-Electro-Mechanical Systems (MEMS) resonator
instead of quartz in the electronics industry. This has given rise to the design and development of a programmable clock
oscillator, which can customize the oscillator frequency and has been adopted in devices such as Smart Phones, Tablets,
Digital Cameras and gaming systems.
The past few years have seen the quartz crystal oscillators being replaced by the MEMS Oscillators in various electronic
applications. With a number of benefits such as better features, higher performance, faster availability, higher
robustness, lower cost and increased reliability, the MEMS Oscillators score higher than its counterpart in the adoption
processes. These features have given these oscillators a place in Telecom infrastructure routers and optical networking
systems, which uses the TCXOs (Temperature Compensated Oscillators) for their high performance applications. Further,
VCXOs or Voltage Controlled Oscillators provide a level of pullability and fine-tuning that is required for synchronization
of clock signals, in wireless applications, cell phones and base-stations. These are also used in Storage Area Networks
and RAID systems based on SATA, SAS and Fibre Channel protocols.
The MEMS based clock oscillators can be programmed for any frequency levels with performance optimization and
flexibility. SiTIme's MEMS oscillators achieved unparalleled stability and low jitter performance. XOs achieve +/-10 PPM
stability over the -40C to +85C temperature range, and their TCXOs achieve 0.500 PPM stability over the same operating
temperature range. Both devices also feature ultra-low jitter as low as 0.5psRMS. Further, these can be programmed for
any supply voltage as low as 1.8V. Most importantly programmable MEMS oscillators simplify the supply chain with
shorter lead times and fewer dedicated parts at discrete frequencies. The superior frequency stability as low as 10 PPM
(XO) improves system timing margin and reliability and leads to longer life of the electronic systems.
Learn more about :- Clock Generator & Differential Oscillator