What determines the frequency of a crystal oscillator?

“Engineers often solely know {that a} crystal oscillator is a frequency element, and there could also be only a few individuals who have divided basic frequency crystal oscillators and overtone crystal oscillators for crystal oscillators. So what's a basic frequency crystal oscillator, what's an overtone crystal oscillator, and what's the distinction between the 2 used within the circuit.

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Engineers often solely know {that a} crystal oscillator is a frequency element, and there could also be only a few individuals who have divided basic frequency crystal oscillators and overtone crystal oscillators for crystal oscillators. So what's a basic frequency crystal oscillator, what's an overtone crystal oscillator, and what's the distinction between the 2 used within the circuit.

The vibration of the crystal oscillator is sort of a spring; the vibration frequency of the crystal is said to the world, thickness, reducing orientation, and so forth. of the quartz crystal.

The longer it's, the slower it shakes;
The thicker it's, the slower it shakes;
The softer it's, the slower it shakes;

However it’s too brief, too skinny, and too laborious to shake.

Crystal oscillator is mechanical vibration, which has the traits of mechanical vibration: form, geometric dimension, mass, and so forth., which decide the vibration frequency.

Crystal oscillators are usually composed of quartz or ceramic supplies plus an inner chip, and the frequency of the crystal oscillator depends upon the thickness of the chip.

By way of manufacturing course of, the scale of the wafer and the thickness of the wafer are intently associated to the frequency of the crystal oscillator. Typically talking, the upper the frequency of the quartz crystal, the thinner the quartz wafer required. For instance, the thickness of the wafer required for a 40MHz quartz crystal is 41.75 microns, which will be achieved, however for a 100MHz quartz crystal, the required wafer thickness is 16.7 microns. Even when the thickness will be achieved, the loss may be very excessive, and the wafer shall be damaged when it's barely dropped after the completed product. Subsequently, the crystals at excessive frequencies are usually achieved by the expertise of the third overtone, the fifth overtone and the seventh overtone. For instance, a crystal with a basic frequency of 20MHz can get hold of a crystal of 100MHz after the fifth overtone. Typically talking, under 40MHz is mainly a basic frequency crystal oscillator, and above 40MHz, it's an overtone crystal oscillator. Subsequently, it's not troublesome for us to grasp why the frequencies of many energetic crystal oscillators are mainly high-frequency, and the fee is comparatively costly. The price of energetic crystal oscillators isn't solely the skinny inner chip, but additionally an oscillator itself.

So what's using basic frequency crystal oscillator and overtone crystal oscillator in use. There may be positively a distinction between the 2 in use. For instance, the crystal of the elemental frequency can work solely by connecting to the suitable capacitor, whereas the overtone crystal must be used along with the Inductor and the capacitor to vibrate the overtone frequency, in any other case it could solely vibrate the bottom. frequency.

Introduction of overtone crystal oscillator: Quartz crystal oscillator is product of quartz crystal, and the scale and thickness of quartz crystal akin to completely different frequency quartz crystal oscillators are completely different.