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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Crystals undergo slow gradual change of frequency with time, known as aging. Patent 5,Issue date: Far fewer activity dips. In other projects Wikimedia Commons.
Operates at the same frequencies as the AT cut. The high frequency cuts are mounted by their edges, usually on springs; the stiffness of the spring has to be optimal, as if it is too stiff, mechanical shocks could be transferred to the crystal and cause it to break, and too little stiffness may allow the crystal to collide with the inside of the package when subjected to a mechanical shock, and break.
On electrical schematic diagrams, crystals are designated with the class letter Y Y1, Y2, etc. A consequence of these activity dips is that the oscillator may lock dstasheet a spurious frequency at specific temperatures.
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 lower or higher than pre-irradiation, swept crystals anneal virtually back to original frequency.
From Wikipedia, the free encyclopedia. This cut therefore combines the power saving feature of allowing relatively low oven temperature with reasonable stability at higher ambient temperatures. Very low radiation doses below rad have disproportionately higher effect, but this nonlinearity saturates at higher doses. InJuergen Staudte invented a photolithographic process for manufacturing quartz crystal oscillators while working at North American Aviation now Rockwell that allowed them to be made small enough for portable products like watches.
A typical Q value for a quartz oscillator ranges from 10 4 to 10 6compared to perhaps 10 2 for an LC oscillator. In a crystal oscillator, the crystal mostly vibrates in one axis, therefore only one phase is dominant. Lithium, sodium, and hydrogen swept crystals are used for, e. Aging decreases logarithmically with time, the largest changes occurring shortly after manufacture. Long Low power temperature-controlled frequency-stabilized oscillator U. For processing involving etching, e.
Molecules of contamination either from the residual atmosphere, outgassed from the crystal, electrodes or packaging materials, or introduced during sealing the housing can be adsorbed on the crystal surface, changing its mass; this effect is exploited in quartz crystal microbalances.
Comprehensive Dictionary of Electrical Engineering. Crystals are also used in other types of electronic circuits, such as crystal filters. Eventually, only the resonant frequency is active. An oscillator crystal has two electrically conductive plates, with a slice or tuning fork of quartz crystal sandwiched between them.
Quartz crystals are also found inside test and measurement equipment, such as counters, signal generatorsand oscilloscopes. The rate of expansion and contraction of the quartz is the resonant frequency, and is determined by the cut and size of the crystal.
The kdss orientation of the acceleration vector to the crystal dramatically influences the crystal’s vibration sensitivity. Potentiometer digital Variable capacitor Varicap. Vig High sensitivity temperature sensor and sensor array U. The trapped holes can be measured by electron spin resonance.
An inappropriate value of the tank capacitor caused the crystal in a control board to be overdriven, jumping to an overtone, and causing the train to speed up instead of slowing down.
KDS Datasheet, PDF – Alldatasheet
To reach higher frequencies, a crystal can be made to vibrate at one of its overtone modes, which occur near multiples of the fundamental resonant frequency. The frequency stability is determined by the crystal’s Q.
Less sensitive to mechanical stresses. The helixes are aligned along the z-axis and merged, sharing atoms. These designs, particularly the OCXO, often produce devices with excellent short-term stability.
Placing a capacitor in series with the crystal and a several-megaohm resistor in parallel can minimize such voltages. Other dynamic stress inducing factors are shocks, vibrations, and acoustic noise. One of the most important traits of quartz crystal oscillators is that they can exhibit very low phase noise.
Germanium impurities tend to trap electrons created during irradiation; the alkali metal cations then migrate towards the negatively charged center and form a stabilizing complex.
Crystals can be manufactured for oscillation over a wide range of frequencies, from datasheeh few kilohertz up to several hundred megahertz. High-intensity radiation can stop the oscillator datasheeh inducing photoconductivity in the crystal and transistors; with a swept crystal and properly designed circuit the oscillations can restart within 15 microseconds after the radiation burst. Spurious frequencies are also generated by subjecting the crystal to vibration.
Temperature-sensitive, can be used as eatasheet sensor.