The Changing Face Of Electronic Circuits
The digital electronics era introduced a fundamental change in electronic circuit operation most circuits were now being clocked synchronously. The clock oscillator became more important as it provided the reference timing to all these circuits. As the complexity of digital electronics increased, and as the system performance increased, the requirements on the timing specifications of the clock oscillator became more stringent. While many technologies can be used to create a clock, some of which are even completely electronic, a quartz crystal based clock oscillator became the technology of choice as it provided the best stability and Q (Quality Factor. The use of quartz-based clocks proliferated into all electronic devices such as computers, receiver, transmitters, audio frequency equipment and even wristwatches.
Clock oscillators based on quartz oscillator technology are made by using precision manufacturing techniques. The oscillator consists of three components a resonator, an analog excitation circuit and a package. Usually, the companies that offer these devices have significant expertise in the machining, grinding, and polishing of quartz crystal resonators. However, they typically buy the analog circuit from semiconductor providers, and acquire ceramic packages from industry providers.
Recent advances in semiconductor technology have given birth to a new kind of clock oscillator that is based on a MEMS (Micro-electro-mechanical system) resonator instead of quartz. MEMS oscillators are pin-compatible to quartz oscillators, enabling easy replacement in systems without design or layout changes. The MEMS and analog die of this device are constructed completely in silicon, which leads to unique features and benefits that cannot be offered by the quartz industry, such as SoftEdge drive strength control, Spread Spectrum, the ability to program any frequency, operate at voltages as low as 1.8V and smaller packages than the industry. These features are attractive to designers who have unique problems to solve in their systems, which is leading to increased popularity of MEMS oscillators over quartz oscillator.
Also, as MEMS-based clock oscillators migrate up the performance path, they are expected to replace quartz oscillators in systems which have very stringent performance requirements such as telecom, networking, storage and wireless applications. The increased usage of MEMS-based clock oscillators will result in higher performance electronics that is smaller and significantly more reliable.