I-Crystal oscillator iyisihluthulelo ekwakhiweni kwesekethe yedijithali, imvamisa ekwakhiweni kwesekethe, i-crystal oscillator isetshenziswa njengenhliziyo yesekethe yedijithali, wonke umsebenzi wesekethe yedijithali awunakuhlukaniswa nesignali yewashi, futhi nje i-crystal oscillator iyinkinobho yokhiye. elawula ngokuqondile isiqalo esivamile salo lonke uhlelo, kungashiwo ukuthi uma kukhona umklamo wesifunda sedijithali ungabona i-crystal oscillator.
I. Yini i-crystal oscillator?
I-Crystal oscillator ngokuvamile ibhekisela ezinhlotsheni ezimbili ze-quartz crystal oscillator ne-quartz crystal resonator, futhi ingabizwa ngokuqondile ngokuthi i-crystal oscillator. Zombili zenziwe kusetshenziswa umphumela we-piezoelectric wamakristalu e-quartz.
I-crystal oscillator isebenza kanje: lapho insimu kagesi isetshenziswa kuma-electrode amabili e-crystal, i-crystal izoba nokuguqulwa komshini, futhi ngokuphambene nalokho, uma ukucindezela komshini kusetshenziswa emikhawulweni emibili ye-crystal, i-crystal izokhiqiza. inkambu kagesi. Lesi simo siyahlehla, ngakho-ke kusetshenziswa lesi sici sekristalu, kwengeza ama-voltages ashintshanayo kuzo zombili iziphetho zekristalu, i-chip izokhiqiza ukudlidliza komshini, futhi ngesikhathi esifanayo ikhiqize amasimu kagesi ashintshanayo. Kodwa-ke, lokhu kudlidliza kanye nenkambu kagesi ekhiqizwa i-crystal ngokuvamile incane, kodwa uma nje imvamisa ethile, i-amplitude izokwenyuka kakhulu, efana ne-LC loop resonance thina abaklami besifunda esivame ukuyibona.
II. Ukuhlukaniswa kwama-crystal oscillations (okusebenzayo nokungenzi lutho)
① I-passive crystal oscillator
I-Passive crystal iyikristalu, ngokuvamile i-2-pin non-polar device (enye ikristalu ye-passive inophini eligxilile elingenayo i-polarity).
I-passive crystal oscillator ngokuvamile idinga ukuncika kumjikelezo wewashi owenziwe i-capacitor yokulayisha ukuze ukhiqize isignali e-oscillating (isiginali ye-sine wave).
② I-crystal oscillator esebenzayo
I-crystal oscillator esebenzayo iyi-oscillator, ngokuvamile enamaphini angu-4. I-crystal oscillator esebenzayo ayidingi i-oscillator yangaphakathi ye-CPU ukukhiqiza isignali ye-square-wave. Ukunikezwa kwamandla ekristalu esebenzayo kukhiqiza isignali yewashi.
Isignali ye-crystal oscillator esebenzayo izinzile, ikhwalithi ingcono, futhi imodi yokuxhuma ilula, iphutha lokunemba lincane kune-passive crystal oscillator, futhi intengo ibiza kakhulu kune-passive crystal oscillator.
III. Imingcele eyisisekelo ye-crystal oscillator
Imingcele eyisisekelo ye-crystal oscillator evamile yilezi: izinga lokushisa lokusebenza, inani lokunemba, amandla afanayo, ifomu lephakheji, imvamisa eyinhloko njalonjalo.
Imvamisa ewumnyombo ye-crystal oscillator: Ukukhethwa kwefrikhwensi yekristalu ejwayelekile kuncike ezidingweni zezingxenye zemvamisa, njenge-MCU ngokuvamile iyibanga, iningi lazo elisuka ku-4M kuye kwezingu-M.
Ukunemba kokudlidliza kwekristalu: ukunemba kokudlidliza kwekristalu ngokuvamile kungu-±5PPM, ±10PPM, ±20PPM, ±50PPM, njll., amashiphu wewashi anembe kakhulu ngokuvamile angaphakathi kuka-±5PPM, futhi ukusetshenziswa okuvamile kuzokhetha cishe ±20PPM.
I-capacitance ehambisanayo ye-crystal oscillator: ngokuvamile ngokulungisa inani le-capacitance efanayo, imvamisa eyinhloko ye-crystal oscillator ingashintshwa, futhi okwamanje, le ndlela isetshenziselwa ukulungisa i-crystal oscillator enembile kakhulu.
Kuhlelo lokujikeleza, ulayini wesignali yewashi lejubane eliphezulu unokubaluleka okuphezulu kakhulu. Ulayini wewashi uyisignali ebucayi, futhi ukuphakama kwemvamisa, umugqa omfushane uyadingeka ukuze kuqinisekiswe ukuthi ukuhlanekezela kwesignali kuncane.
Manje emijikelezweni eminingi, imvamisa yewashi ye-crystal yesistimu iphezulu kakhulu, ngakho-ke amandla okuphazamisa ama-harmonics nawo anamandla, ama-harmonics azotholakala ekufakeni nasekukhipheni imigqa emibili, kodwa futhi emisebeni yesikhala, ebuye iholele uma ukuhlelwa kwe-PCB ye-crystal oscillator kungenangqondo, kuzobangela kalula inkinga eqinile yemisebe elahlekile, futhi uma sekukhiqiziwe, kunzima ukuxazulula ngezinye izindlela. Ngakho-ke, kubaluleke kakhulu ku-crystal oscillator kanye nesakhiwo somugqa wesignali ye-CLK lapho ibhodi le-PCB libekwe.