01
Isakhiwo samandla sihlobene
Amasekhethi edijithali ngokuvamile adinga imisinga engaqhubeki, ngakho-ke ama-inrush currents akhiqizelwa amadivayisi athile anesivinini esikhulu.
Uma umkhondo wamandla umude kakhulu, ukuba khona kwe-inrush current kuzodala umsindo we-high-frequency, futhi lo msindo we-high-frequency uzongeniswa kwamanye amasignali. Kumasekhethi anesivinini esikhulu, nakanjani kuzoba ne-inductance ye-parasitic, ukumelana ne-parasitic kanye ne-parasitic capacitance, ngakho-ke umsindo we-high-frequency uzogcina uhlanganiswe nezinye izifunda, futhi ukuba khona kwe-parasitic inductance kuzoholela ekhonweni lomkhondo ukumelana. umthamo omkhulu wamanje Ukwehla, okuholela ekwehleni kwe-voltage ngokwengxenye, okungase kukhubaze isekethe.
Ngakho-ke, kubaluleke kakhulu ukwengeza i-bypass capacitor phambi kwedivayisi yedijithali. I-capacitance inkulu, amandla okudlulisela anqunyelwe izinga lokudlulisela, ngakho-ke amandla amakhulu kanye ne-capacitance encane ngokuvamile kuhlanganiswe ukuze kuhlangatshezwane nobubanzi obugcwele befrikhwensi.
Gwema izindawo ezishisayo: i-signal vias izokhiqiza izikhala kungqimba yamandla nesendlalelo esingezansi. Ngakho-ke, ukubekwa okungenangqondo kwe-vias kungenzeka kukhuphule ukuminyana kwamanje ezindaweni ezithile zamandla kagesi noma indiza yaphansi. Lezi zindawo lapho ukuminyana kwamanje kukhuphuka zibizwa ngokuthi izindawo ezishisayo.
Ngakho-ke, kufanele sizame konke okusemandleni ethu ukugwema lesi simo lapho sibeka i-vias, ukuze sivimbele indiza ukuthi ingahlukaniswa, okuzogcina kuholele ezinkingeni ze-EMC.
Ngokuvamile indlela engcono kakhulu yokugwema izindawo ezishisayo ukubeka i-vias ngephethini ye-mesh, ukuze ukuminyana kwamanje kufane, futhi izindiza ngeke zihlukaniswe ngesikhathi esifanayo, indlela yokubuya ngeke ibe yinde kakhulu, futhi izinkinga ze-EMC zizoba. kungenzeki.
02
Indlela yokugoba yokulandelela
Uma ubeka imigqa yesignali yesivinini esikhulu, gwema ukugoba imigqa yesiginali kaningi ngangokunokwenzeka. Uma kufanele ugobe umkhondo, ungawulandeli nge-engeli ebukhali noma engakwesokudla, kodwa kunalokho sebenzisa i-engeli e-obtuse.
Uma sibeka imigqa yesignali yesivinini esikhulu, sivame ukusebenzisa imigqa yenyoka ukuze sifinyelele ubude obulinganayo. Umugqa ofanayo wenyoka empeleni uwuhlobo lokugoba. Ububanzi bomugqa, isikhala, nendlela yokugoba kufanele zonke zikhethwe ngokunengqondo, futhi isikhala kufanele sihlangabezane nomthetho we-4W/1.5W.
03
Ukusondela kwesignali
Uma ibanga eliphakathi kwemigqa yesignali yesivinini esiphezulu liseduze kakhulu, kulula ukukhiqiza i-crosstalk. Ngezinye izikhathi, ngenxa yesakhiwo, usayizi wefreyimu yebhodi nezinye izizathu, ibanga phakathi kwemigqa yethu yesignali yesivinini esiphezulu idlula ibanga lethu elidingekayo elidingekayo, khona-ke singakwazi ukwandisa kuphela ibanga phakathi kwemigqa yesignali yesivinini esikhulu ngangokunokwenzeka eduze kwebhodlela. ibanga.
Eqinisweni, uma isikhala sanele, zama ukwandisa ibanga phakathi kwemigqa yesignali emibili yesivinini esikhulu.
03
Ukusondela kwesignali
Uma ibanga eliphakathi kwemigqa yesignali yesivinini esiphezulu liseduze kakhulu, kulula ukukhiqiza i-crosstalk. Ngezinye izikhathi, ngenxa yesakhiwo, usayizi wefreyimu yebhodi nezinye izizathu, ibanga phakathi kwemigqa yethu yesignali yesivinini esiphezulu idlula ibanga lethu elidingekayo elidingekayo, khona-ke singakwazi ukwandisa kuphela ibanga phakathi kwemigqa yesignali yesivinini esikhulu ngangokunokwenzeka eduze kwebhodlela. ibanga.
Eqinisweni, uma isikhala sanele, zama ukwandisa ibanga phakathi kwemigqa yesignali emibili yesivinini esikhulu.
05
I-impedance ayiqhubeki
Inani le-impedance le-trace ngokuvamile lincike kububanzi bomugqa kanye nebanga phakathi komkhondo nendiza eyireferensi. Lapho i-trace ibanzi, i-impedance iyancipha. Kwamanye amatheminali okuxhumana namaphedi wedivayisi, umgomo uyasebenza futhi.
Lapho iphedi yetheminali yokuxhumana ixhunywe kulayini wesignali wesivinini esikhulu, uma iphedi inkulu kakhulu ngalesi sikhathi, futhi ulayini wesignali wesivinini esikhulu umncane kakhulu, ukuvinjelwa kwephedi enkulu kuncane, futhi kuncane umkhondo kufanele ube ne-impedance enkulu. Kulesi simo, ukunqanyulwa kwe-impedance kuzokwenzeka, futhi ukubonakaliswa kwesignali kuzokwenzeka uma i-impedance ingaqhubeki.
Ngakho-ke, ukuze kuxazululwe le nkinga, ishidi lethusi elinqatshelwe lifakwa ngaphansi kwephedi elikhulu letheminali yesixhumi esibonakalayo noma idivayisi, futhi indiza yereferensi yephedi ibekwe kwesinye isendlalelo sokwandisa i-impedance ukuze i-impedance iqhubeke.
I-Vias ingomunye umthombo wokunqanyulwa kwe-impedance. Ukuze unciphise lo mphumela, isikhumba sethusi esingadingekile esixhunywe kungqimba lwangaphakathi kanye ne-via kufanele sisuswe.
Eqinisweni, lolu hlobo lokusebenza lungaqedwa ngamathuluzi e-CAD ngesikhathi sokuklama noma thintana nomkhiqizi wokucubungula we-PCB ukuze uqedele ithusi elingadingekile futhi uqinisekise ukuqhubeka kwe-impedance.
I-Vias ingomunye umthombo wokunqanyulwa kwe-impedance. Ukuze unciphise lo mphumela, isikhumba sethusi esingadingekile esixhunywe kungqimba lwangaphakathi kanye ne-via kufanele sisuswe.
Eqinisweni, lolu hlobo lokusebenza lungaqedwa ngamathuluzi e-CAD ngesikhathi sokuklama noma thintana nomkhiqizi wokucubungula we-PCB ukuze uqedele ithusi elingadingekile futhi uqinisekise ukuqhubeka kwe-impedance.
Akuvunyelwe ukuhlela i-vias noma izingxenye kupheya ehlukile. Uma i-vias noma izingxenye zibekwe kupheya ehlukile, izinkinga ze-EMC zizokwenzeka futhi ukunqanyulwa kokuphazamiseka kuzoholela.
Kwesinye isikhathi, imigqa yesignali ehlukile yesivinini esikhulu idinga ukuxhunywa ochungechungeni olunama-coupling capacitor. I-coupling capacitor nayo idinga ukuhlelwa ngokulinganayo, futhi iphakheji ye-coupling capacitor akufanele ibe nkulu kakhulu. Kunconywa ukusebenzisa i-0402, i-0603 nayo iyamukeleka, futhi ama-capacitor angaphezu kuka-0805 noma ama-capacitor ahlangene angcono kakhulu ukuthi angasetshenziswa.
Imvamisa, i-vias izokhiqiza ukungaqhubeki okukhulu kwe-impedance, ngakho-ke kumapheya womugqa wesiginali ohlukile ngesivinini esikhulu, zama ukunciphisa i-vias, futhi uma ufuna ukusebenzisa i-vias, ihlele ngokulinganayo.
07
Ubude obulinganayo
Kwezinye izixhumanisi zesignali ezinesivinini esikhulu, ngokuvamile, njengebhasi, iphutha lesikhathi sokufika nelokulibala phakathi kwemigqa yesignali ngayinye kumele kucatshangelwe. Isibonelo, eqenjini lamabhasi ahambisanayo anesivinini esiphezulu, isikhathi sokufika sayo yonke imigqa yesignali yedatha kufanele siqinisekiswe ngaphakathi kwephutha elithile lesikhathi sokulinda ukuze kuqinisekiswe ukuhambisana kwesikhathi sokusetha kanye nesikhathi sokubamba. Ukuze sihlangabezane nalesi sidingo, kufanele sicabangele ubude obulinganayo.
Ulayini wesignali ohlukanisayo wesivinini esikhulu kufanele uqiniseke ukuthi kunesikhathi esiqinile semigqa emibili yesignali, ngaphandle kwalokho ukuxhumana kungase kuhluleke. Ngakho-ke, ukuze kuhlangatshezwane nale mfuneko, umugqa wenyoka ungasetshenziswa ukuze kuzuzwe ubude obulinganayo, ngaleyo ndlela uhlangabezane nemfuneko yesikhathi.
Umugqa wenyoka kufanele ngokuvamile ubekwe emthonjeni wokulahlekelwa ubude, hhayi ekugcineni okude. Kusemthonjeni kuphela lapho amasiginali asemikhawulweni ephozithivu nenegethivu yomugqa wokuhlukanisa angasakazwa ngokuhambisanayo isikhathi esiningi.
Umugqa wenyoka kufanele ngokuvamile ubekwe emthonjeni wokulahlekelwa ubude, hhayi ekugcineni okude. Kusemthonjeni kuphela lapho amasiginali asemikhawulweni ephozithivu nenegethivu yomugqa wokuhlukanisa angasakazwa ngokuhambisanayo isikhathi esiningi.
Uma kukhona ukulandelelwa okubili okugobile futhi ibanga phakathi kwakho kokubili lingaphansi kuka-15mm, ukulahlekelwa ubude phakathi kokubili kuzonxephezelana ngalesi sikhathi, ngakho asikho isidingo sokwenza ukucubungula ubude obulinganayo ngalesi sikhathi.
Ezingxenyeni ezihlukene zemigqa yesignali ehlukile yesivinini esikhulu, kufanele ibe nobude obulinganayo ngokuzimela. I-Vias, ama-coupling capacitor ochungechunge, namatheminali esixhumi esibonakalayo yonke imigqa yesignali ehlukile enesivinini esiphezulu ehlukaniswe izingxenye ezimbili, ngakho-ke qaphela ngokukhethekile ngalesi sikhathi.
Kumele kube ubude obufanayo ngokwehlukana. Ngoba isoftware eminingi ye-EDA inaka kuphela ukuthi zonke izintambo zilahlekile yini e-DRC.
Ezixhunyweni ezifana namadivayisi wokubonisa we-LVDS, kuzoba namapheya amaningana amapheya ahlukile ngesikhathi esisodwa, futhi izidingo zesikhathi phakathi kwamapheya ahlukile ngokuvamile ziqinile kakhulu, futhi izimfuneko zokulibaziseka kwesikhathi zincane kakhulu. Ngakho-ke, kumapheya esignali ahlukile anjalo, ngokuvamile sidinga ukuthi abe endizeni efanayo. Yenza isinxephezelo. Ngoba isivinini sokudlulisa isignali sezendlalelo ezahlukene sihlukile.
Uma enye isofthiwe ye-EDA ibala ubude bokulandelela, ukulandelelwa okungaphakathi kwephedi nakho kuzobalwa phakathi nobude. Uma isinxephezelo sobude senziwa ngalesi sikhathi, umphumela wangempela uzolahlekelwa ubude. Ngakho-ke qaphela ngokukhethekile ngalesi sikhathi lapho usebenzisa isofthiwe ethile ye-EDA.
Nganoma yisiphi isikhathi, uma ukwazi, kufanele ukhethe umzila olinganayo ukuze ugweme isidingo sokugcina wenze umzila wenyoka ubude obulinganayo.
Uma isikhala sivuma, zama ukwengeza iluphu encane emthonjeni womugqa omfushane wokuhlukanisa ukuze uzuze isinxephezelo, esikhundleni sokusebenzisa ulayini wenyoka ukuze unxephezele.