Enqubweni yokuklama kwe-PCB, ukuhlukaniswa kwendiza yamandla noma ukuhlukaniswa kwendiza ephansi kuzoholela endizeni engaphelele. Ngale ndlela, lapho isignali ihanjiswa, indiza yayo eyinkomba izosuka kwelinye indiza yamandla iye kwenye indiza yamandla. Lesi simo sibizwa ngokuthi ukuhlukaniswa kwe-signal span.
Umdwebo wohlelo lwezenzakalo ezihlukanisayo
Ukuhlukaniswa kwezingxenye eziphambanayo, ngoba isignali yesivinini esiphansi ingase ingabi nabudlelwane, kodwa ohlelweni lwesignali yedijithali yesivinini esikhulu, isignali yesivinini esikhulu ithatha indiza eyinkomba njengendlela yokubuya, okungukuthi, indlela yokubuya. Uma indiza yereferensi ingaphelele, imiphumela emibi elandelayo izokwenzeka: ukuhlukaniswa kwezigaba kungase kungafaneleki kumasignali anesivinini esiphansi, kodwa ezinhlelweni zesignali yedijithali yesivinini esikhulu, amasignali anesivinini esikhulu athatha indiza yereferensi njengendlela yokubuya, leyo yiyona ndlela yokubuya. Uma indiza eyinkomba ingaphelele, imiphumela emibi elandelayo izokwenzeka:
l Ukunqamuka kokuphazamiseka okuholela ekusebenzeni kwezintambo;
l Kulula ukudala i-crosstalk phakathi kwezimpawu;
l Idala ukucabanga phakathi kwamasignali;
l I-waveform okukhiphayo kulula ukuyishintsha ngokwandisa indawo eyiluphu yamanje kanye ne-inductance yeluphu.
l Ukuphazamiseka kwemisebe emkhathini kuyanda futhi insimu kazibuthe emkhathini ithinteka kalula.
l Ukwandisa amathuba okuhlangana kazibuthe namanye amasekethe ebhodini;
l Ukwehla kwamandla kagesi aphezulu ku-loop inductor kwakha umthombo wemisebe wemodi evamile, okhiqizwa ngekhebuli yangaphandle.
Ngakho-ke, izintambo ze-PCB kufanele zibe seduze nendiza ngangokunokwenzeka, futhi zigweme ukuhlukana phakathi. Uma kudingekile ukuwela ukuhlukana noma kungenakuba eduze kwendiza yamandla aphansi, lezi zimo zivunyelwe kuphela emugqeni wesignali wesivinini esiphansi.
Kucutshungulwa kuwo wonke ama-partitions ekwakhiweni
Uma ukuhlukaniswa kungenakugwema ekwakhiweni kwe-PCB, ungabhekana kanjani nakho? Kulesi simo, ukuhlukaniswa kufanele kulungiswe ukuze kunikezwe indlela emfushane yokubuyisela isignali. Izindlela zokucubungula ezijwayelekile zihlanganisa ukungeza i-capacitor yokulungisa nokuwela ibhuloho lentambo.
l I-Stichitor Capacitor
I-0402 noma 0603 i-ceramic capacitor enamandla angu-0.01uF noma 0.1uF ivamise ukubekwa endaweni yesiphambano sesignali. Uma isikhala sivuma, amanye ama-capacitor anjalo angengezwa.
Ngesikhathi esifanayo, zama ukuqinisekisa ukuthi intambo yesignali ingaphakathi kwebanga lokuthunga elingu-200mil, futhi ibanga elincane, lingcono; Amanethiwekhi emikhawulweni yomibili ye-capacitor ngokulandelanayo ahambisana namanethiwekhi endiza eyireferensi lapho amasignali adlula khona. Bona amanethiwekhi axhunywe kuzo zombili iziphetho ze-capacitor esithombeni esingezansi. Amanethiwekhi amabili ahlukene agqanyiswe ngemibala emibili yilawa:
lIbhuloho phezu kocingo
Kuvamile "ukucubungula phansi" isignali ekuhlukaniseni ungqimba lwesignali, futhi kungase kube ezinye imigqa yesignali yenethiwekhi, umugqa "ophansi" ujiye ngangokunokwenzeka.
Amakhono ezintambo zesignali enesivinini esiphezulu
a)uxhumano lwe-multilayer
Isifunda somzila wesignali yesivinini esiphezulu sivame ukuba nokuhlanganiswa okuphezulu, ukuminyana kwezintambo eziphezulu, ukusebenzisa ibhodi le-multilayer akudingekile kuphela ku-wiring, kodwa futhi kuyindlela ephumelelayo yokunciphisa ukuphazamiseka.
Ukukhethwa okunengqondo kwezendlalelo kunganciphisa kakhulu ubukhulu bebhodi lokunyathelisa, kungasebenzisa ngokugcwele ungqimba oluphakathi ukuze kubekwe isihlangu, kungakwazi ukubona kangcono isisekelo esiseduze, kunganciphisa ngokuphumelelayo i-inductance ye-parasitic, kungafinyeza ngokuphumelelayo ubude bokudluliselwa kwesiginali. , kunganciphisa kakhulu ukuphazamiseka phakathi kwamasignali, njll.
b)Uma umthofu ugobile kancane, kuba ngcono
Ukugoba komthofu omncane phakathi kwezikhonkwane zamasekhethi anesivinini esikhulu, kuba ngcono.
Intambo yokuhola yesekethe yomzila wesignali enesivinini esikhulu isebenzisa umugqa oqondile ogcwele futhi idinga ukujika, engasetshenziswa njenge-45° polyline noma i-arc turning. Le mfuneko isetshenziselwa kuphela ukuthuthukisa amandla okubamba we-foil yensimbi kumjikelezo we-low-frequency.
Kumasekhethi anesivinini esikhulu, ukuhlangabezana nale mfuneko kunganciphisa ukudluliswa nokuhlanganisa amasignali anesivinini esikhulu, futhi kunciphise imisebe nokubonakaliswa kwamasignali.
c)Umthofu omfushane, ungcono
Ukuthi umthofi ube mfushane phakathi kwezikhonkwane zedivayisi yomzila wesignali yesivinini esikhulu, kuba ngcono.
Uma ukuhola isikhathi eside, kuyanda inani le-inductance ne-capacitance elisabalalisiwe, elizoba nomthelela omkhulu ekudluleni kwesignali ye-high-frequency yesistimu, kodwa futhi iguqule ukukhubazeka kwesici sesekhethi, okuholela ekuboniseni nasekuzuleni kwesistimu.
d)Ukushintshashintsha okuncane phakathi kwezingqimba zomthofu, kuba ngcono
Ukushintshashintsha okuncane kwe-interlayer phakathi kwezikhonkwane zesekhethi yesivinini esikhulu, kungcono.
Okubizwa ngokuthi "ukushintshaniswa okuncane kwe-interlayer yomkhondo, kungcono" kusho ukuthi izimbobo ezimbalwa ezisetshenziswa ekuxhumekeni kwezingxenye, zingcono. Kukalwe ukuthi imbobo eyodwa ingaletha cishe i-0.5pf ye-capacitance esabalalisiwe, okuholela ekwandeni okukhulu kokulibaziseka kwesifunda, ukunciphisa inani lezimbobo kungathuthukisa kakhulu isivinini.
e)Qaphela ukuphazamiseka kwesiphambano esihambisanayo
Izintambo zesignali enesivinini esikhulu kufanele zinake “ukuphazamiseka okuphambanayo” okwethulwa umugqa wesignali webanga elifushane izintambo ezihambisanayo. Uma ukusabalalisa okufanayo kungenakugwenywa, indawo enkulu "yomhlabathi" ingahlelwa ngakolunye uhlangothi lomugqa wesignali ofanayo ukuze kuncishiswe kakhulu ukuphazamiseka.
f)Gwema amagatsha neziphunzi
Izintambo zesignali enesivinini esiphezulu kufanele zigweme ukuhlanganisa amagatsha noma ukwenza i-Stub.
Izigaxa zinomthelela omuhle ku-impedance futhi zingabangela ukubonakaliswa kwesignali kanye ne-overshoot, ngakho-ke kufanele sigweme iziphunzi namagatsha ekwakhiweni.
I-Daisy chain wiring izonciphisa umthelela kusignali.
g)Imigqa yesignali iya phansi ngaphakathi ngangokunokwenzeka
Ulayini wesignali wefrikhwensi ephezulu ehamba phezulu kulula ukukhiqiza imisebe emikhulu kagesi, futhi kulula nokuphazanyiswa imisebe yangaphandle ye-electromagnetic noma izici.
Ulayini wesignali wefrikhwensi ephezulu uhanjiswa phakathi kokuphakelwa kwamandla kanye nentambo yaphansi, ngokumuncwa kwegagasi kagesi ngokuphakelwa kwamandla kanye nongqimba olungezansi, imisebe ekhiqizwayo izoncipha kakhulu.