Crystal oscillator ndi kiyi mu kapangidwe digito dera, kawirikawiri mu kamangidwe dera, galasi oscillator ntchito monga mtima wa dera digito, ntchito yonse ya dera digito ndi osasiyanitsidwa ndi chizindikiro wotchi, ndi basi krustalo oscillator ndi batani kiyi kuti mwachindunji amazilamulira yachibadwa chiyambi cha dongosolo lonse, tinganene kuti ngati pali digito dera kapangidwe akhoza kuona crystal oscillator.
I. Kodi kristalo oscillator ndi chiyani?
Crystal oscillator nthawi zambiri amatanthauza mitundu iwiri ya quartz crystal oscillator ndi quartz crystal resonator, ndipo imathanso kutchedwa crystal oscillator. Onsewa amapangidwa pogwiritsa ntchito piezoelectric zotsatira za makhiristo a quartz.
Crystal oscillator imagwira ntchito motere: pamene magetsi akugwiritsidwa ntchito pamagetsi awiri a kristalo, kristaloyo idzawonongeka ndi makina, ndipo m'malo mwake, ngati kukakamizidwa kwa makina kumagwiritsidwa ntchito kumapeto kwa kristalo, kristalo idzatulutsa magetsi. Chodabwitsa ichi ndi chosinthika, chifukwa chake kugwiritsa ntchito mawonekedwe a kristalo, ndikuwonjezera kusinthasintha kwa malekezero onse a kristalo, chip chimatulutsa kugwedezeka kwamakina, ndipo nthawi yomweyo kutulutsa minda yamagetsi yosinthira. Komabe, kugwedezeka uku ndi magetsi opangidwa ndi kristalo nthawi zambiri amakhala ochepa, koma malinga ngati ali pafupipafupi, matalikidwewo adzawonjezeka kwambiri, mofanana ndi LC loop resonance yomwe ife okonza madera timawona nthawi zambiri.
II. Gulu la kristalo oscillations (yogwira ntchito komanso yongokhala)
① Passive crystal oscillator
Passive crystal ndi kristalo, nthawi zambiri chipangizo cha 2-pin non-polar (kristalo ina yokhazikika imakhala ndi pini yokhazikika yopanda polarity).
Passive crystal oscillator nthawi zambiri amafunikira kudalira wotchi yomwe imapangidwa ndi capacitor yonyamula katundu kuti ipangitse chizindikiro cha oscillating (sine wave sign).
② Oscillator yogwira ntchito
An yogwira kristalo oscillator ndi oscillator, kawirikawiri ndi 4 mapini. Active crystal oscillator safuna oscillator wamkati wa CPU kuti apange chizindikiro cha square wave. Mphamvu ya kristalo yogwira imapanga chizindikiro cha wotchi.
Chizindikiro cha oscillator yogwira kristalo ndi chokhazikika, khalidwe ndilabwino, ndipo njira yolumikizira ndiyosavuta, cholakwika cholondola ndi chocheperako kuposa cha oscillator wa crystal oscillator, ndipo mtengo wake ndi wokwera mtengo kuposa oscillator wa kristalo.
III. Magawo oyambira a crystal oscillator
Magawo oyambira a crystal oscillator ndi awa: kutentha kwa ntchito, mtengo wolondola, kuthekera kofananira, mawonekedwe a phukusi, pafupipafupi pakatikati ndi zina zotero.
Mafupipafupi amtundu wa crystal oscillator: Kusankhidwa kwa ma frequency a crystal wamba kumatengera zomwe zimafunikira pafupipafupi, monga MCU nthawi zambiri imakhala yosiyana, ambiri mwa iwo amachokera ku 4M mpaka makumi angapo a M.
Kulondola kwa Crystal vibration: kulondola kwa kugwedezeka kwa kristalo nthawi zambiri kumakhala ± 5PPM, ± 10PPM, ± 20PPM, ± 50PPM, etc., tchipisi ta wotchi yolondola kwambiri nthawi zambiri zimakhala mkati mwa ± 5PPM, ndipo kugwiritsa ntchito nthawi zambiri kumasankha ± 20PPM.
Mphamvu yofananira ya kristalo oscillator: kawirikawiri posintha mtengo wa mphamvu yofananira, mafupipafupi apakati a crystal oscillator akhoza kusinthidwa, ndipo pakalipano, njirayi imagwiritsidwa ntchito pokonza oscillator wapamwamba kwambiri.
M'magawo ozungulira, mzere wa mawotchi othamanga kwambiri umakhala wofunika kwambiri. Mzere wa wotchi ndi chizindikiro chodziwika bwino, ndipo kuwonjezereka kwafupipafupi, kufupikitsa mzerewu kumafunika kuonetsetsa kuti kusokonezeka kwa chizindikirocho ndi kochepa.
Tsopano m'madera ambiri, kristalo wotchi pafupipafupi dongosolo ndi mkulu kwambiri, kotero mphamvu kusokoneza harmonics ndi amphamvu, harmonics adzakhala anachokera ku athandizira ndi linanena bungwe mizere iwiri, komanso kuchokera mlengalenga cheza, amenenso kumabweretsa ngati PCB masanjidwe a kristalo oscillator si wololera, izo mosavuta kuchititsa amphamvu osokera poizoniyu vuto, ndipo kamodzi opangidwa ndi njira zina n'zovuta kuthetsa, n'zovuta kuthetsa. Choncho, ndikofunika kwambiri kuti kristalo oscillator ndi CLK chizindikiro mzere masanjidwe pamene bolodi PCB aikidwa.