Kurongeka kweCrystal Oscillators: 1ppm Kanganiso Inorevei?
Mukunyatsoita nguva uye akasiyana emagetsi emagetsi, makristasi oscillator anoshanda seyepakati wachi masosi, uye frequency yavo kugadzikana inotarisisa nguva chaiyo yehurongwa. Zvisinei, mukushanda kwekushanda, crystal oscillators haisi zvikamu zvakanaka; yavo yekubuda frequency inogona kutsauka nekuda kwezvinhu zvakasiyana. Ichi chinyorwa chichaongorora kunzwisisa iyo frequency kukanganisa unit ppm uye kuishandura kuita inonzwisisika zuva nezuva kutsauka.
ppm (zvikamu pamiriyoni) chinhu chakajairwa chekuyera hukama hwe frequency kutsauka. Kukanganisa kwe1ppm kunoratidza kuti kutsauka pakati peiyo frequency chaiyo uye yezita frequency chikamu chimwe pamiriyoni.
Kuverengera kutsauka kwenguva yekuwedzera pamusoro pezuva rimwe kuri nyore:
Yese masekonzi pazuva: maawa makumi maviri nemana × maminitsi makumi matanhatu × makumi matanhatu masekonzi=86,400 masekonzi.
Kuverengera kutsauka: Kukanganisa kwe1ppm kunoreva kuti pamasekonzi 1,000,000 ega ega, pane kutsauka kwesekondi imwe. Naizvozvo, kutsauka pamusoro pe86,400 seconds ndeiyi:
Nguva yekutsauka=(1 / 1,000,000) × 86,400 masekonzi=0.0864 masekonzi
Izvi zvinoreva kuti crystal oscillator ine +1ppm frequency kukanganisa ichawana ingangoita 0.0864 seconds (inenge 86.4 milliseconds) pazuva. Kuverenga uku ndekwepasirese uye kwakazvimiririra kune chaiyo yezita frequency yekristaro (seyakajairika 32.768kHz) nekuti yakavakirwa pamusimboti wekukanganisa. Saizvozvo, a -1ppm kukanganisa kunoreva kurasikirwa 0.0864 masekondi pazuva.
Zvinhu Zvikuru Zvinokanganisa Frequency Kugadzikana uye Countermeasures
Mumashandisirwo anoshanda, kuti uwane chaiyo nguva, zvakakosha kuti unzwisise nekugadzirisa zvakasiyana siyana zvinokanganisa kugadzikana kwekristaro oscillator.
1. Environmental Temperature
Mhedzisiro: Kuchinja kwetembiricha ndicho chinhu chikuru chinokonzera frequency kudonha mumakristasi. Iyo resonant frequency yekristaro inosiyana nekupisa mu cubic curve.
Countermeasure:Kumaapplication ane musiyano mukuru wetembiricha, tembiricha-yakabhadharwa makristaro oscillator (TCXO) inofanira kushandiswa; Nekuda kwepamusoro-zvinodiwa nemazvo, hovhoni{2}}controlled crystal oscillator (OCXO) inodiwa, iyo inoisa kristaro muhovhoni yetembiricha isingaperi kuti ibvise zvakanyanya kupisa.
2. Load Capacitance Matching
Mhedzisiro: Iwo mapini maviri ekristaro oscillator anoda kubatanidzwa kune akakodzera load capacitor (CL) kuti ishande panguva yezita frequency. Zvisizvo capacitance kukosha zvinogona kukonzera zvakananga frequency kutsauka.
Countermeasure:Kunyatso sarudza ekunze anofananidza capacitors zvichibva pane inorema capacitance kukosha inokurudzirwa mukristaro redhetabheti, uye funga nezveparasitic capacitance muPCB marongero.
3. Power Supply Voltage
Mhedzisiro: Kuchinja-chinja kwemagetsi ekushanda kunogona kushandura zvishoma maitiro eiyo oscillator, nekudaro ichikanganisa kubuda kwakawanda.
Countermeasure:Ipa magetsi akachena uye akatsiga emagetsi edunhu reoscillator, kazhinji uchishandisa LDO (yakaderera-dropout regulator) uye kubatanidza kwakakwana.
4. Kukwegura Kunoita
Impact:Nekufamba-kwenguva refu, kristaro nezvikamu zvayo zvinofamba zvishoma nezvishoma, unidirectional frequency drift (kazhinji yakanaka) nekuda kwekurerutsira mukati, kubuda kwezvinhu, nezvimwewo.
Countermeasure:Sarudza zvigadzirwa zvekristaro zvine mwero wakaderera wekuchembera. Kune masisitimu anoda kushanda-kwenguva refu, dhizainira otomatiki otomatiki kana manyorerwo ewachi.
5. Kupindira Kwekunze
Impact: Electromagnetic interference (EMI) pabhodhi redunhu, pamwe nekuzunguzika kwemuchina uye kuvhunduka, zvinogona kukonzera kusagadzikana kwechinguvana-nguva.
Countermeasure: Yakanaka PCB dhizaini (senge kutenderedza kutenderera wachi, kushandiswa kwemagaba ekudzivirira, uye kusarudza makristaro mapakeji ane zvirinani kuzunguza kuramba (senge simbi mapakeji) mhinduro dzinoshanda.
Summary
Muchidimbu, kukanganisa kwe1ppm mune crystal oscillator inoshandura zvakananga kune zuva nezuva kutsauka kweanenge 0.0864 masekondi. Pakusarudza nekugadzira maseketi ewachi, zvinodikanwa kuenzanisa mutengo uye kuita zvinoenderana nezvinodiwa zvechishandiso (sezvakajairwa mutengi zvemagetsi, smartwatches, zviteshi zvekutaurirana, kana masisitimu ekufambisa), sarudza akakodzera oscillator marudzi (semuenzaniso, SPXO, TCXO, OCXO), uye shandisa inowirirana dhizaini dhizaini. Kunzwisisa aya masosi ekukanganisa uye matanho ekupikisa kwakakosha pakuona nguva yakavimbika uye chaiyo mumidziyo yemagetsi.