Ukuhlaziywa kwethusi kwasakazeka ku PCB

Uma kunenhlabathi eminingi ye-PCB, i-SGND, i-AGND, i-GND, njll., Kuyadingeka ukusebenzisa umhlabathi obaluleke kakhulu njengokubhekisa ngokuzimela ukugqoka ithusi ngokuya ngesikhundla sebhodi le-PCB elihlukile, okungukuthi, xhuma umhlaba ndawonye.

Kunezizathu eziningana zokubeka ithusi ngokujwayelekile. 1, EMC. Endaweni enkulu yomhlaba noma yokunikezwa kwamandla ebeka ithusi, izodlala indima yokuvikela, okunye okukhethekile, okufana ne-PGND kudlala indima yokuvikela.

2. Izidingo zenqubo ye-PCB. Ngokuvamile, ukuze kuqinisekiswe umphumela we-electroplating, noma akukho ukuguqulwa kwe-lamination, kwebhodi le-PCB elinentambo engaphansi yocingo yethusi.

3, izidingo zesimemezelo sobuqotho, nika isignali yedijithali ephezulu imvamisa indlela ephelele yokubuyela emuva, futhi unciphise izintambo zenethiwekhi ze-dc. Vele, kukhona ukushabalalisa ukushisa, izidingo zokufakwa ezikhethekile zedivayisi zethusi njalonjalo. Kunezizathu eziningana zokubeka ithusi ngokujwayelekile.

1, EMC. Endaweni enkulu yomhlaba noma yokunikezwa kwamandla ethutha ithusi, izodlala indima yokuvikela, okunye okukhethekile, okufana ne-PGND kudlala indima yokuvikela.

2. Izidingo zenqubo ye-PCB. Ngokuvamile, ukuze kuqinisekiswe umphumela we-electroplating, noma akukho ukuguqulwa kwe-lamination, kwebhodi le-PCB elinentambo engaphansi yocingo yethusi.

3, izidingo zesimemezelo sobuqotho, kwisignali ephezulu yedijithali indlela ephelele yokuphindela emuva, futhi inciphise izintambo zenethiwekhi ze-DC. Vele, kukhona ukushabalalisa ukushisa, izidingo zokufakwa ezikhethekile zedivayisi zethusi njalonjalo.

Isitolo, inzuzo enkulu yethusi ukunciphisa impedance yomhlaba (bekukhona ingxenye enkulu yalokho okuthiwa i-anti-jamming ukunciphisa impedance yomhlaba) yesekethe ledijithali likhona kunani elikhulu le-pulse yamanje, ngaleyo ndlela linciphisa umhlabathi impedance iyadingeka kakhulu kwabanye, kuvame ukukholelwa ukuthi kuso sonke isifunda esakhiwe ngamadivayisi wedijithali kufanele kube yindawo enkulu, yesekethe le-analog, I-loop yomhlaba eyenziwe ngokubeka ithusi izodala ukuphazamiseka kokuhlangana kwe-electromagnetic (ngaphandle kwamasekethe amvamisa aphezulu). Ngakho-ke, akuwona wonke amasekethe adinga ithusi lendawo yonke (i-BTW: ukusebenza kwenethiwekhi yethusi kungcono kunebhulokhi lonke)

Okwesibili, ukubaluleka kwesifunda okubeka ithusi kulele ku: 1, ukubeka ithusi nocingo lomhlabathi kuxhunyaniswe ndawonye, ​​ukuze sikwazi ukunciphisa indawo yesifunda 2, sisakaze indawo enkulu yethusi elilinganayo ukunciphisa ukumelana nomhlabathi, kunciphise ukwehla kwengcindezi kulawa maphuzu amabili, zombili izibalo, noma ukulingisa kufanele kube ukubeka ithusi ukuze kwandiswe ikhono lokulwa nokuphazanyiswa, futhi ngesikhathi semvamisa ephezulu kufanele futhi isabalalise inhlabathi yabo yedijithali ne-analog ukuze ihlukanise ithusi, bese ixhunywe ngephuzu elilodwa, Iphuzu elilodwa lingaxhunyaniswa ngenxeba yocingo elizungeze iringi kazibuthe izikhathi eziningana. Kodwa-ke, uma imvamisa ingekho phezulu kakhulu, noma izimo zokusebenza zensimbi azimbi, zingakhululeka ngokuqhathaniswa. I-crystal oscillator isebenza njenge-transmitter ephezulu kakhulu esifundeni. Ungabeka ithusi nxazonke bese ugaya igobolondo le-crystal, okungcono.

Uyini umehluko phakathi kwebhulokhi lonke lethusi negridi? Ngokucacile ukuhlaziya izinhlobo ezi-3 zemiphumela: 1 ukucindezela oku-2 okuhle komsindo 3 ukuze kuncishiswe ukuphazamiseka kwemvamisa ephezulu (enguqulweni yesifunda yesizathu) ngokuya ngemikhombandlela ye-wiring: amandla ngokwakhiwa ngangokunokwenzeka kungani kufanele ungeze Igridi ah ayikho ngomgomo ayihambisani nayo? Uma ngokombono wemvamisa ephezulu, akulungile entanjeni yemvamisa ephezulu lapho i-taboo enkulu iyintambo ebukhali, kusendlalelo sokuphakelwa kwamandla sinama-degree angaphezu kwama-90 yizinkinga eziningi. Kungani ukukwenza ngaleyo ndlela kuyindaba yezobuciko ngokuphelele: bheka lezo ezishiselwe ngesandla bese ubona ukuthi zipendwe ngaleyo ndlela yini. Uyawubona lo mdwebo futhi ngiyaqiniseka ukuthi bekukhona i-chip kuwo ngoba bekunenqubo ebizwa ngokuthi i-wave soldering ngenkathi uyifaka futhi uzofudumeza ibhodi endaweni yangakini futhi uma uyifaka yonke ethusi ama-coefficients akhethekile okushisa ezinhlangothini zombili bezihlukile futhi ibhodi belizolamula bese kuvele inkinga, Ekhaveni yensimbi (nayo edingekayo ngenqubo), kulula kakhulu ukwenza amaphutha ku-PIN ye-chip, futhi inani lokwenqatshwa lizokhuphuka ngomugqa oqondile. Eqinisweni, le ndlela nayo inokubi: Ngaphansi kwenqubo yethu yamanje yokugqwala: Kulula kakhulu ukuthi ifilimu inamathele kuyo, bese kuthi kuphrojekthi ye-asidi, lelo phuzu kungenzeka lingadli, futhi kunenqwaba yemfucuza, kodwa uma ikhona, yibhodi kuphela eliphukile futhi yi-chip eyehla nayo ibhodi! Ngokwalo mbono, uyabona yini ukuthi kungani yadwetshwa ngaleyo ndlela? Vele, kukhona nokunamathisela kwetafula ngaphandle kwegridi, ngokombono wokuvumelana komkhiqizo, kungahle kube nezimo ezi-2: 1, inqubo yakhe yokugqwala yinhle kakhulu; 2. Esikhundleni se-wave soldering, usebenzisa i-welding esithuthuke kakhulu, kepha kulokhu, ukutshalwa kwemali kulo lonke umugqa womhlangano kuzoba ngaphezulu izikhathi ezi-3-5.