MHz~MHz. 30Max. Fundamental/AT. MHz~MHz. 60Max. Third. Overtone /AT. Mechanical characteristics. Resistance to shock. that may be provided in Freescale Semiconductor data sheets and/or specifications can and do vary in different applications and actual performance may vary. series and range associated to this part. 49USMX Series. Technical Datasheet: MHZ 49USMX/30/50/40/18PF/ATF Datasheet. See all Technical Docs.

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This modulates the resonant frequency to a small degree by the frequency of the vibrations.

The mechanical stress causes a short-term change in the oscillator frequency due to the stress-sensitivity of the crystal, and can introduce a permanent change of frequency due to shock-induced changes of mounting and internal stresses if the elastic limits of the mechanical parts are exceededdesorption of contamination from the crystal surfaces, or change in parameters of the oscillator circuit.

These are termed “overtone modes”, and oscillator circuits can be 16000 to excite them.

Long-term stability is limited by aging of the crystal. At very high doses, the radiation response of the crystal saturates as well, due to the finite number of impurity sites that can be affected.

This means that a quartz clock, filter or oscillator remains accurate. Silver can be passivated by exposition to iodine vapors, forming a layer of silver dataasheet.

Capacitor trimmers can be also used for frequency adjustment of the oscillator circuit. The crystals possess temperature hysteresis ; the frequency at a given temperature achieved by increasing the temperature is not equal to the frequency on the same temperature achieved ods decreasing the temperature.


Image of several crystal cuts [48]. The most common material for oscillator crystals is quartz. Patent 4,Issue date: Atmospheric humidity influences the thermal transfer properties of air, and can change electrical properties of plastics by diffusion of water molecules into their structure, altering the dielectric constants and electrical conductivity.

Crystal oscillator

Inclusions of water may be present in fast-grown crystals; interstitial water molecules are abundant near the crystal seed. Crystal Oscillators in Communications. Crystaloscillator is designed to work with an external piezoelectric For example, many non-television applications use 3.

Eventually, only the resonant frequency is active. Crystals can be adjusted to exact frequencies by laser trimming. All crystals have a transient negative frequency shift after exposure to an X-ray pulse; the frequency then shifts gradually back; natural quartz reaches stable frequency after 10— seconds, with a negative offset to pre-irradiation frequency, artificial crystals return to a frequency slightly xatasheet or higher than pre-irradiation, swept crystals anneal virtually back to original frequency.

Phase-shift oscillator Twin-T oscillator Wien bridge oscillator. Sweeping under datasheeet at higher temperatures and field strength can further reduce the crystal’s response to X-ray pulses. Operates in thickness shear mode, in b-mode fast quasi-shear. Swept crystals are crystals that have undergone a solid-state electrodiffusion purification process. These designs, particularly the OCXO, often produce devices with excellent short-term stability.

The chief application is the The mounting and contacts may undergo relief of the built-in stresses.

MHz-KDS – Keysemi

Silver and aluminium kd often used as electrodes; however both form oxide layers with time that increases the crystal mass and lowers frequency. It has well known and repeatable characteristics. A more accurate term for it is piezoelectric resonator. Views Read Edit View history. The stability of AT cut crystals decreases with increasing frequency.


A crystal oscillator is an electronic oscillator circuit that uses a piezoelectric resonator, a crystal, as its frequency-determining element. The overtone modes are at frequencies which are approximate, but not exact odd integer multiples of 16.0000 of the fundamental mode, and overtone frequencies are therefore not exact harmonics of the fundamental. The composition of the crystal can be gradually altered by outgassing, diffusion of atoms of impurities datqsheet migrating from the electrodes, or the lattice can be damaged by radiation.

In many oscillators, any spectral energy at the resonant frequency is amplified by the oscillator, resulting in a collection of tones at different datasheeet. Voltage Controlled Silicon Oscillator; Package: For example, steel is very elastic and has a high speed of sound.

Crystal oscillator – Wikipedia

Far fewer activity dips. The orientation of the cut influences the crystal’s aging characteristics, frequency stability, thermal characteristics, and other parameters.

Hydrogen ions are mobile down to 10 K, but alkali metal ions datasheet mobile only at temperatures around and above K. Retrieved July 17, Figure 2 shows two points at which thethe oscillator circuit with the crystal as part of the PIfeedback network. Fast-grown crystals contain more hydrogen defects than slow-grown ones. They are also often incorporated 16000 a single package with the crystal oscillator circuit, shown on the righthand side.