1. Umkhuba ojwayelekile
Ekwakhiweni kwe-PCB, ukuze kwenziwe idizayini yebhodi lesekhethi ephezulu ibe nengqondo, ukusebenza okungcono kokumelana nokuphazamiseka, kufanele kucatshangelwe kulezi zici ezilandelayo:
(1) Ukukhethwa okunengqondo kwezendlalelo Lapho uhambisa amabhodi esekethe aphezulu-imvamisa ekwakhiweni kwe-PCB, indiza yangaphakathi phakathi nendawo isetshenziswa njengongqimba lwamandla nomhlabathi, ongadlala indima yokuvikela, unciphise ngempumelelo inductance ye-parasitic, ufinyeze ubude imigqa yesignali, futhi unciphise ukuphazamiseka phakathi kwamasignali.
(2) Imodi yomzila Imodi yomzila kufanele ihambisane nokujika kwe-engeli engu-45° noma ukujika kwe-arc, okunganciphisa ukuphuma kwesignali yemvamisa ephezulu kanye nokuhlanganisana.
(3) Ubude bekhebula Uma ubude bekhebula bufushane, bungcono. Lapho ibanga elihambisanayo limfushane phakathi kwezintambo ezimbili, liba ngcono.
(4) Inani lokudlula izimbobo Ukuba mbalwa kwesibalo sokudlula emigodini, kuba ngcono.
(5) Isiqondiso sezintambo ze-interlayer Isiqondiso sezintambo ezingaphakathi kufanele sime mpo, okungukuthi, isendlalelo esiphezulu sivundlile, isendlalelo esingezansi sime mpo, ukuze kuncishiswe ukuphazamiseka phakathi kwamasignali.
(6) I-Copper enamathelayo yanda i-grounding yethusi enamathela inganciphisa ukuphazamiseka phakathi kwamasignali.
(7) Ukufakwa kokucutshungulwa komugqa wesignali obalulekile, kungathuthukisa kakhulu ikhono lokulwa nokuphazamiseka kwesignali, yebo, kungase futhi kube ukufakwa kokucubungula komthombo wokuphazanyiswa, ukuze kungakwazi ukuphazamisa ezinye izimpawu.
(8)Izintambo zesignali aziwahambisi amasignali kumaluphu. Amasignali omzila kumodi ye-Daisy chain.
2. Izintambo ezihamba phambili
Ukubaluleka komugqa wesignali engukhiye: isignali encane ye-analog, isignali enesivinini esikhulu, isignali yewashi nesignali yokuvumelanisa nezinye izintambo ezibalulekile zamasignali
Umgomo wokuqala wokuminyana: Qala izintambo kusukela ekuxhumekeni okuyinkimbinkimbi kakhulu ebhodini. Qala ukufaka izintambo kusukela endaweni enezintambo eziminyene kakhulu ebhodini
Amaphuzu okufanele uwaqaphele:
I. Zama ukunikeza isendlalelo sezintambo esikhethekile samasignali abalulekile njengamasiginali wewashi, amasignali amaza aphezulu namasignali azwelayo, futhi uqinisekise ubuncane bendawo eyiluphu. Uma kunesidingo, kufanele kwamukelwe izintambo ezibalulekile ezenziwa ngesandla, ukuvikela nokwandisa isikhala sokuphepha. Qinisekisa ikhwalithi yesiginali.
b. Imvelo ye-EMC phakathi kongqimba lwamandla nomhlabathi ayilungile, ngakho amasiginali azwelayo ekuphazamisekeni kufanele agwenywe.
c. Inethiwekhi enezidingo zokulawula i-impedance kufanele ifakwe izintambo ngokusemandleni akho ngokuvumelana nobude bomugqa kanye nezidingo zobubanzi bomugqa.
3, izintambo zewashi
Ulayini wewashi ungenye yezinto ezinkulu ezithinta i-EMC. Yenza izimbobo ezimbalwa emugqeni wewashi, gwema ukuhamba neminye imigqa yesignali ngangokunokwenzeka, futhi uqhelelane nemigqa yamasignali evamile ukuze ugweme ukuphazamiseka kwemigqa yamasignali. Ngesikhathi esifanayo, ukunikezwa kwamandla ebhodini kufanele kugwenywe ukuvimbela ukuphazamiseka phakathi kokunikezwa kwamandla kanye newashi.
Uma kukhona iwashi lewashi elikhethekile ebhodini, alikwazi ukuhamba ngaphansi komugqa, kufanele libekwe ngaphansi kwethusi, uma kunesidingo, lingaba elikhethekile emhlabeni walo. Kwabaningi be-crystal oscillator yereferensi ye-chip, lezi oscillator zekristalu akufanele zibe ngaphansi komugqa, ukubeka ukuhlukaniswa kwethusi.
4. Umugqa kuma-engeli angakwesokudla
Ikhebula ye-engeli engakwesokudla ngokuvamile iyadingeka ukuze kugwenywe isimo kuzintambo ze-PCB, futhi sekucishe kube ngeyodwa yezindinganiso zokukala ikhwalithi yezintambo, ngakho-ke ungakanani umthelela wokuba nentambo ye-engeli engakwesokudla ekudluliselweni kwesignali? Empeleni, umzila we-engeli yesokudla uzobangela ukuthi ububanzi bomugqa wokudlulisela kushintshe, okuholela ekunqanyulweni kokuvinjelwa. Eqinisweni, akuwona nje umzila olungile we-Engeli, i-Ton Angle, i-acute Angle routing ingase ibangele izinguquko zokuthikamezeka.
Umthelela womzila we-engeli yesokudla kusiginali ubonakala kakhulu ezicini ezintathu:
Okokuqala, ikona lingalingana nomthwalo we-capacitive kulayini wokudlulisa, unciphisa isikhathi sokukhuphuka;
Okwesibili, ukungaqhubeki kwe-impedance kuzodala ukubonakaliswa kwesignali;
Okwesithathu, i-EMI ikhiqizwa ithiphu ye-Engeli elungile.
5. I-Angle Ebukhali
(1) Ngomsinga wamafrikhwensi aphezulu, lapho iphoyinti elijikayo locingo liveza i-engeli engakwesokudla noma i-engeli ebukhali, eduze nekhona, ukuminyana kazibuthe kanye nokuqina kwenkundla kagesi kuphakeme ngokuqhathaniswa, kuzokhipha imisebe enamandla kagesi kagesi, kanye ne-inductance. lapha kuzoba kukhulu uma kuqhathaniswa, i-inductive izoba nkulu kune-engeli eyi-obtuse noma i-engeli eyindilinga.
(2) Ngocingo lwebhasi lwesekethe yedijithali, ikhoneni lezintambo liyi-obtuse noma liyindilinga, indawo yezintambo incane ngokuqhathaniswa. Ngaphansi kwesimo esifanayo sokuhlukanisa umugqa, ingqikithi yesikhala somugqa ithatha ububanzi obuphindwe izikhathi ezingu-0.3 obungaphansi kokujika kwe-Engeli engakwesokudla.
6. Umzila ohlukile
Cf. I-wiring ehlukile kanye nokulinganisa kwe-impedance
I-Differential Signal isetshenziswa kabanzi nangokwengeziwe ekwakhiweni kwamasekhethi anesivinini esikhulu, ngoba amasiginali abaluleke kakhulu kumasekethe ahlala esebenzisa isakhiwo sokuhlukanisa. Incazelo: NgesiNgisi esilula, kusho ukuthi umshayeli uthumela amasignali amabili alinganayo, aguqulayo, bese umamukeli anquma ukuthi isimo esiphusile singu-“0” noma “1” ngokuqhathanisa umehluko phakathi kwama-voltage amabili. Ipheya ephethe isignali ehlukile ibizwa ngokuthi umzila ohlukile.
Uma kuqhathaniswa nomzila wesignali onesiphelo esisodwa esijwayelekile, isignali ehlukile inezinzuzo ezisobala kakhulu kulezi zici ezintathu ezilandelayo:
a. Ikhono eliqinile lokulwa nokuphazamiseka, ngoba ukuhlangana phakathi kwezintambo ezimbili ezihlukene kuhle kakhulu, lapho kukhona ukuphazamiseka komsindo ovela ngaphandle, cishe kuhlanganiswe nemigqa emibili ngesikhathi esisodwa, futhi umamukeli ukhathalela kuphela umehluko phakathi amasignali amabili, ukuze umsindo wemodi evamile ovela ngaphandle ungakhanselwa ngokuphelele.
b. ingavimbela ngempumelelo i-EMI. Ngokufanayo, ngenxa yokuthi i-polarity yamasignali amabili iphambene, izinkambu kazibuthe ezisakazwa yizo zingakhansela zodwa. Lapho ukuhlangana kuseduze, amandla kazibuthe amancane akhululwa ezweni langaphandle.
c. Ukuma kwesikhathi okunembile. Njengoba izinguquko zokushintsha kwamasignali okuhlukanisa zitholakala lapho kuhlangana khona amasignali amabili, ngokungafani namasignali avamile anesiphelo esisodwa ancike ku-voltage ephezulu nephansi, umthelela wobuchwepheshe nezinga lokushisa mncane, onganciphisa amaphutha ngesikhathi futhi ungaphezulu. ilungele izifunda ezinezimpawu eziphansi ze-amplitude. I-LVDS (i-low voltage differential signaling), edumile njengamanje, ibhekisela kulobu buchwepheshe bokuhlukanisa umehluko we-amplitude encane.
Konjiniyela be-PCB, into ebaluleke kakhulu ukuqinisekisa ukuthi izinzuzo zokuhlukanisa umzila zingasetshenziswa ngokugcwele emzileni wangempela. Mhlawumbe inqobo nje uma ukuxhumana nabantu be-Layout bezoqonda izidingo ezijwayelekile zomzila ohlukile, okungukuthi, "ubude obulinganayo, ibanga elilinganayo".
Ubude obulinganayo ukuqinisekisa ukuthi amasignali amabili ahlukene agcina i-polarity ephambene ngaso sonke isikhathi futhi anciphise ingxenye yemodi evamile. I-Equidistance ngokuyinhloko iwukuqinisekisa ukuthi i-impedance yomehluko iyahambisana futhi inciphisa ukubonakaliswa. "Ngokuseduze ngangokunokwenzeka" ngezinye izikhathi kuyimfuneko yomzila ohlukile.
7. Umugqa wenyoka
Umugqa wenyoka uwuhlobo Lwesakhiwo oluvame ukusetshenziswa ekuhlelweni. Inhloso yayo eyinhloko ukulungisa ukubambezeleka nokuhlangabezana nezidingo zomklamo wesikhathi wesistimu. Into yokuqala abaklami okufanele bayiqaphele ukuthi izintambo ezinjengezinyoka zingalimaza ikhwalithi yesiginali futhi ziguqule ukubambezeleka kokudlulisela, futhi kufanele zigwenywe lapho zifakwa izintambo. Kodwa-ke, ekwakhiweni kwangempela, ukuze kuqinisekiswe isikhathi esanele sokubamba amasignali, noma ukunciphisa isikhathi sokunciphisa phakathi kweqembu elifanayo lamasignali, ngokuvamile kudingekile ukuvunguza ngamabomu.
Amaphuzu okufanele uwaqaphele:
Amapheya emigqa yesignali ehlukile, ngokuvamile imigqa ehambisanayo, kancane ngangokunokwenzeka embobeni, kufanele ibhotshozwe, kufanele ibe imigqa emibili ndawonye, ukuze kuzuzwe ukufanisa okuthintekile.
Iqembu lamabhasi anezibaluli ezifanayo kufanele lihanjiswe eduze ngangokunokwenzeka ukuze kuzuzwe ubude obulinganayo. Imbobo eholela kuphedi yesichibi iqhelelene nephedi ngangokunokwenzeka.
Isikhathi sokuthumela: Jul-05-2023
