Crystal oscillator is the key in digital circuit design, usually in circuit design, crystal oscillator are used as the heart of the digital circuit, all the work of the digital circuit is inseparable from the clock signal, and just the crystal oscillator is the key button that directly controls the normal start of the entire system, it can be said that if there is a digital circuit design can see the crystal oscillator.
I. Quid est crystal oscillator?
Crystal oscillator fere refers ad duas species of Quartz crystal oscillator et quartz crystal resonator, et potest etiam directe dicitur crystal oscillator. Tum fiunt per Piezoelectric effectum de quartz crystalla.
Crystal Oscillator operatur sic: cum electrica agro applicantur ad duo electrodes cristallum, crystallum subire mechanica deformatio et contra, si mechanica applicatur ad duo fines cristallum, quod est applicari ad electrica in agro. Hoc phaenomenon est reversible, ut per hanc proprium crystallum, addendo alterna voltages ad utraque fines cristallum et chip producere mechanica vibrationem, et simul producere alterna electrica agros. Sed hoc vibrationis et electrica agro generatae per crystal est plerumque parva, sed ut dum est ad quaedam frequency, amplitudo erit significantly auctus, similis ad LC loop resonare, ut nos saepius vident.
II. Classification of Crystal Oscillations (Active et Passive)
① passivum crystallum oscillator
Passivum Crystalli est crystal, fere a II-pin non-Suspendisse machinam (quidam passive crystallum habet certum pin cum non verticitatem).
Passivum Crystal oscillator plerumque indiget ad confidunt in horologium circuitu formatae per onus Capacitor ad generare oscillans signum (sine unda signa).
② activae crystal oscillator
Active Crystal oscillator est oscillator, plerumque cum IV paxillos. Active Crystal oscillator non eget CPU scriptor internus oscillator ad producendum quadratum undam signum. Active Crystalli potestate copia generat horologium signum.
Et signum activae crystal oscillator est firmum, quod qualis est melius, et nexum modus est relative simplex, in praecisione errore minor quam passiva crystallum oscillatoris.
III. Basic parametri de crystallum oscillator
In basic parametri generali crystallum oscillator sunt: operating temperatus, praecisione valorem, matching capacitance, sarcina forma, core frequency et sic in.
Core frequency de crystallum oscillator: et elegit de generali crystallum frequency pendeat ex requisitis frequency components, sicut MCU est fere a range, pleraque ex quibus 4m ad dozens M.
Crystalli vibration accuracy: accurate de crystallum vibrationis est fere ± 5ppm, ± 10ppm, ± 20PPM, ± 50PPM, etc., High-Clock Clock Clock, qui sunt plerumque in ± 5PPPM, et in usu erit eligere circa ± 20PPM et generalis usu erit eligere circa ± 20PPM, et communem usum eligere de ± 20PPM et generalis usu et eligere ± 5PPPM et generali usu erit eligere circa ± 20PPM et generali usu erit eligere circa ± 20PPM, et communem usum elige de ± 20PPM, et generalis usum eligere de ± 20PPM, et generalis usu erit eligere circa ± 20PPM et generalis usu et eligere de ± 20PPM, et communem usum eligere de ± 20PPM, et communem usum eligere de ± 20PPM, et communem usum eligere de ± 20PPM, et communem usum eligere de ± 20PPM, et generalis usu et eligere de ± 20PPM.
Et matching capacitance de crystallum oscillator: solet per adjusting ad valorem de matching capacitance, in core frequency de crystal oscillator potest mutari, et in praesenti, hoc modus est ad adjust in altum, et in praesenti, hoc modus est ad adjust in altum, et in praesentem, hoc modus est ad adjust in altum, et in praesenti, hoc modus est ad adjust in altus-praecisione crystal oscillator.
In circuitu ratio, princeps celeritate horologium signum linea habet summum prioritatem. Clock linee est sensitiva signum et altior frequentia brevior linea requiritur ut ad distortis signum est minima.
Now in many circuits, the crystal clock frequency of the system is very high, so the energy of interfering with harmonics is also strong, harmonics will be derived from the input and output two lines, but also from the space radiation, which also leads to if the PCB layout of the crystal oscillator is not reasonable, it will easily cause a strong stray radiation problem, and once produced, it is difficult to solve by other methods. Igitur est valde maximus pro crystallum oscillator et clk signum linea layout cum PCB tabula est posita.