Enqubweni ye-PCB Design, ngaphambi kokujikeleza, ngokuvamile sifaka izinto esifuna ukuziklama, bese sibala i-Impodance esekelwe ekukhulumeni, i-substrate, inombolo yezendlalelo nolunye ulwazi. Ngemuva kokubala, okuqukethwe okulandelayo kungatholakala.
Njengoba kungabonakala kulokho okuvela ngenhla, ukwakhiwa kwenethiwekhi eyodwa ngenhla kulawulwa ngama-50 ohms, abantu abaningi bazobuza ukuthi kungani kudingeka ukulawula ngokuya ngama-25 ohms esikhundleni sama-ohms angama-25 noma ama-ohms angama-80?
Okokuqala, ama-50 ohms akhethwe ngokuzenzakalelayo, futhi wonke umuntu embonini amukela leli nani. Ngokuvamile, kufanele kufakwe indinganiso ethile yinhlangano eyaziwayo, futhi wonke umuntu uklama ngokuya ngezinga.
Ingxenye enkulu yobuchwepheshe be-elekthronikhi ivela empini. Okokuqala, ubuchwepheshe busetshenziswa empini, futhi budluliswa kancane kusuka empini kuya ekusetshenzisweni kwezempi. Ezinsukwini zokuqala ze-microwave application, phakathi nempi yezwe yesibili, ukukhethwa kokuphazamiseka kwakuncike ngokuphelele kwizidingo zokusebenzisa, futhi alikho inani elijwayelekile. Ngokuthuthuka kobuchwepheshe, amazinga okuvimbela adinga ukunikezwa ukuze ashaye ibhalansi phakathi komnotho nokulula.
E-United States, ama-conduits asetshenziswa kakhulu axhumeke ngezinduku ezikhona namapayipi amanzi. Ama-51.5 ohms ajwayelekile kakhulu, kepha ama-adaptha kanye nabaguquli babona futhi basebenzise ama-50-51.5 ohms; Lokhu kuxazululwa ngebutho elihlanganyelwe nezabiy. Inkinga, inhlangano ebizwa ngokuthi nguJan yasungulwa (ngokuhamba kwesikhathi i-Desc), yakhiwa ngokukhethekile yiMil, futhi ekugcineni yakhetha ama-50 ohm ngemuva kokucatshangelwa okuphelele, futhi kwakhiwa amakhekhe ahlukahlukene futhi aguqulwe abe yizintambo ezahlukahlukene. Amazinga.
Ngalesi sikhathi, indinganiso yaseYurophu yayingama-60 omm. Kungekudala ngemuva, ngaphansi kwethonya lezinkampani eziphambili ezinjenge-hewlett-phaphard, ama-europers nawo aphoqelelwa ukuba aguquke, ngakho-ke ama-50 ohms agcina eba ngcono embonini. Sekuphenduke umhlangano, futhi i-PCB exhunywe kwizintambo ezahlukahlukene ekugcineni iyadingeka ukuthi ihambisane ne-50 OHM Implade Standard yokufanisa kwe-Impodance.
Okwesibili, ukwakhiwa kwamazinga ajwayelekile kuzosuselwa ekucabangeni okuphelele kwenqubo yokukhiqiza kanye nokusebenza komklamo kanye nokwenzeka.
Ngokombono wokukhiqizwa kwe-PCB kanye nobuchwepheshe bokucubungula, futhi ucubungule imishini yabakhiqizi be-PCB abakhona, kulula kakhulu ukukhiqiza ama-PCB nge-50 Ohm Ukuvimbela. Ukusuka kwinqubo yokubalwa kokulwa kwe-Implance, kungabonakala ukuthi ukubulawa okuphansi kakhulu kudinga ububanzi obubanzi obubanzi kanye ne-dielectric medic noma i-dielectric ejwayelekile, okunzima kakhulu ukuhlangana nebhodi yamanje ye-high-density emkhathini; Ukulimala okuphezulu kakhulu kudinga umugqa omncane we-firener ebanzi kanye nemidiya emincane noma ama-dielectric amancane awakufanele ekucindezelweni kwe-EMI naseCrosstalk. Ngasikhathi sinye, ukwethenjwa kokucutshungulwa kwamabhodi ahlukahlukene ahlukahlukene kanye nombono wokukhiqizwa kwesisindo kuzoba mpofu kakhulu. Lawula ukungcola kwe-50 Ohm. Ngaphansi kwemvelo yokusebenzisa amabhodi ajwayelekile (FR4, njll.) Namabhodi ajwayelekile ajwayelekile, akhiqize imikhiqizo evamile yokubukhali yebhodi (njenge-1mm, i-1.2mm, njll.). Ububanzi obujwayelekile obubanzi (4 ~ 10mil) bungakhelwa. Ifektri ilungele kakhulu ukucubungula, kanye nezidingo zemishini zokucubungula kwayo aziphezulu kakhulu.
Ngokombono we-PCB Design, ama-50 ohms nawo akhethwe ngemuva kokucatshangelwa okuphelele. Ukusuka ekusebenzeni kwe-PCB Traces, ukungcola okuphansi kuvame ukungcono. Ngomugqa wokuhambisa onomugqa onikezwe ububanzi, okusondelene nebanga eliya endizeni, i-EMI ehambisanayo izoncishiswa, futhi i-crosstalk izoncishiswa. Kodwa-ke, ngokombono wendlela ephelele yesiginali, enye yezinto ezibucayi kakhulu ezidinga ukucatshangelwa, okungukuthi, amandla okushayela we-chip. Ezinsukwini zokuqala, ama-chips amaningi awakwazanga ukushayela imigqa yokuhambisa ngokuvinjwa okungaphansi kwama-50 ohms, kanye nemigqa yokuhambisa enokuphazamiseka okuphezulu bekungaphazamiseki ukwenza. Ngakho-ke i-50 ohm impodance isetshenziswa njengokuyekethisa.
Umthombo: Le ndatshana idluliswa kusuka kwi-Intanethi, futhi ilungelo lobunikazi lingelombhali wokuqala.