Lapho siklama i-PCB, imvamisa sithembela kulwazi namakhono esivame ukuwathola ku-Intanethi. Idizayini ngayinye ye-PCB ingenziwa ngohlelo oluthile. Ngokuvamile, imithetho yayo yokwakhiwa isebenza kuphela kuhlelo lokusebenza oluqondiwe. Isibonelo, imithetho ye-ADC PCB ayisebenzi kuma-RF PCBs futhi okuphambene nalokho. Kodwa-ke, eminye imihlahlandlela ingabhekwa njengokujwayelekile kunoma yikuphi ukwakheka kwe-PCB. Lapha, kulesi sifundo, sizokwethula ezinye izinkinga eziyisisekelo namakhono angathuthukisa kakhulu ukwakheka kwe-PCB.
Ukusatshalaliswa kwamandla kuyisici esiyinhloko kunoma yikuphi ukuklanywa kukagesi. Zonke izinto zakho zincike emandleni okwenza imisebenzi yazo. Ngokuya ngomklamo wakho, ezinye izingxenye zingaba nokuxhuma kwamandla okuhlukile, kanti ezinye izingxenye ebhodini elifanayo zingaba nokuxhuma kwamandla amabi. Isibonelo, uma zonke izinto zinikezwa amandla wiring eyodwa, ingxenye ngayinye izobona impedance ehlukile, okuholele kuzinkomba eziningi zokubeka phansi. Isibonelo, uma unamasekethe amabili e-ADC, eyodwa ekuqaleni enye ekugcineni, futhi womabili ama-ADC afunda i-voltage yangaphandle, isifunda ngasinye se-analog sizofunda isihlobo esingahle sibe yiso.
Singafingqa ukusatshalaliswa kwamandla ngezindlela ezintathu: umthombo owodwa wephuzu, umthombo we-Star nomthombo we-multipoint.
(a) Ukunikezwa kwamandla kwephuzu elilodwa: ukunikezwa kwamandla kanye nocingo lomhlabathi lwento ngayinye kuhlukanisiwe komunye nomunye. Ukuhanjiswa kwamandla kwazo zonke izinto kuhlangana kuphela endaweni eyodwa yesethenjwa. Iphuzu elilodwa libhekwa njengelifanele amandla. Kodwa-ke, lokhu akwenzeki kumaphrojekthi ayinkimbinkimbi noma amakhulu / aphakathi nendawo.
(b) Umthombo wenkanyezi: Umthombo wenkanyezi ungathathwa njengokuthuthukiswa komthombo wamaphoyinti owodwa. Ngenxa yezimpawu zayo ezibalulekile, kwehlukile: ubude bokuhamba phakathi kwezinto buyafana. Ukuxhuma kwenkanyezi kuvame ukusetshenziselwa amabhodi wesiginali esheshayo anamawashi ahlukahlukene. Ku-PCB yesiginali yesivinini esikhulu, isignali imvamisa iqhamuka onqenqemeni bese ifinyelela enkabeni. Zonke izimpawu zingadluliselwa zisuka enkabeni ziye kunoma iyiphi indawo yebhodi lesifunda, futhi ukubambezeleka phakathi kwezindawo kungancishiswa.
(c) Imithombo ye-multipoint: ithathwa njengempofu kunoma yikuphi. Noma kunjalo, kulula ukuyisebenzisa kunoma yisiphi isifunda. Imithombo ye-Multipoint ingaveza umehluko wesethenjwa phakathi kwezingxenye nokuhlangana okuvamile kwe-impedance. Lesi sitayela sokuklama sivumela nokushintsha okuphezulu kwe-IC, iwashi kanye namasekethe e-RF ukwethula umsindo kumasekethe aseduze abelana ngokuxhumana.
Vele, empilweni yethu yansuku zonke, ngeke sihlale sinohlobo olulodwa lokusabalalisa. I-tradeoff esingayenza ukuxuba imithombo yamaphoyinti owodwa nemithombo yamaphoyinti amaningi. Ungafaka amadivayisi azwelayo e-analog kanye nezinhlelo zejubane eliphezulu / ze-RF endaweni eyodwa, nakuzo zonke ezinye izinto ezizwakala kancane endaweni eyodwa.
Wake wacabanga ukuthi kufanele usebenzise izindiza zamandla? Impendulo inguyebo. Ibhodi yamandla ingenye yezindlela zokudlulisa amandla nokunciphisa umsindo wanoma isiphi isifunda. Indiza yamandla inciphisa indlela yokubeka phansi, inciphisa ukwehla kwamandla futhi ithuthukise ukusebenza kokuhambisana kwe-electromagnetic (EMC). Futhi kungenxa yokuthi i-parallel plate decoupling capacitor nayo ikhiqizwa ezindizeni ezihambisa ugesi ezinhlangothini zombili, ukuvimbela ukusakazwa komsindo.
Ibhodi yamandla nayo inenzuzo esobala: ngenxa yendawo yayo enkulu, ivumela okwengeziwe manje ukuthi kudlule, ngaleyo ndlela kwandise ibanga lokushisa elisebenzayo le-PCB. Kepha ngicela uqaphele: ungqimba lwamandla lungathuthukisa izinga lokushisa elisebenzayo, kepha izintambo kufanele zicatshangelwe futhi. Imithetho yokulandela umkhondo inikezwa yi-ipc-2221 ne-ipc-9592
Ukuze uthole i-PCB enomthombo we-RF (noma noma yiluphi uhlelo lokusebenza lwesiginali esinejubane), kufanele ube nendiza ephelele yomhlaba ukwenza ngcono ukusebenza kwebhodi lesifunda. Amasiginali kufanele abekwe ezindizeni ezihlukile, futhi cishe akunakwenzeka ukuhlangabezana nezimfuneko zombili ngasikhathi sinye usebenzisa izingqimba ezimbili zamapuleti. Uma ufuna ukuklama i-antenna noma enye ibhodi ye-RF eyinkimbinkimbi, ungasebenzisa izingqimba ezimbili. Lesi sibalo esilandelayo sikhombisa umfanekiso wokuthi i-PCB yakho ingazisebenzisa kanjani kangcono lezi zindiza.
Ekudizayineni kwesiginali exubile, abakhiqizi bavame ukuncoma ukuthi umhlaba we-analog uhlukaniswe nomhlabathi wedijithali. Amasekethe we-analog abucayi athinteka kalula ngokushintshwa kwejubane eliphezulu namasiginali. Uma i-analog ne-digital grounding yehlukile, indiza yokuqinisa izokwehlukaniswa. Noma kunjalo, inezinkinga ezilandelayo. Kufanele sinake indawo ye-crosstalk ne-loop yomhlabathi ohlukanisiwe obangelwe ikakhulu ukuyekiswa kwebhanoyi lomhlaba. Umfanekiso olandelayo ukhombisa isibonelo sezindiza ezimbili ezihlukene zomhlaba. Ngasohlangothini lwesobunxele, i-current Return ayikwazi ukudlula ngqo kumzila wesiginali, ngakho-ke kuzoba nendawo yeluphu esikhundleni sokwakhiwa endaweni eyi-loop efanele.
Ukuhambisana kwe-Electromagnetic nokuphazamiseka kwe-electromagnetic (EMI)
Okwenzelwe imvamisa ephezulu (njengezinhlelo ze-RF), i-EMI ingaba yinkinga enkulu. Indiza yasemhlabeni okukhulunywe ngayo ngaphambili isiza ukunciphisa i-EMI, kepha ngokwe-PCB yakho, indiza engaphansi ingadala ezinye izinkinga. Kumalaminithi anezendlalelo ezine noma ngaphezulu, ibanga lendiza libaluleke kakhulu. Lapho amandla aphakathi kwezindiza emancane, inkambu kagesi izokwanda ebhodini. Ngasikhathi sinye, impedance phakathi kwalezi zindiza ezimbili iyancipha, ivumela amandla okubuya ukuthi agelezele endizeni yesiginali. Lokhu kuzokhiqiza i-EMI yanoma isiphi isignali yemvamisa ephezulu edlula endizeni.
Isixazululo esilula sokugwema i-EMI ukuvimbela amasiginali anejubane elikhulu ukweqa izingqimba eziningi. Faka i-decoupling capacitor; Futhi beka ama-vias azungeze izintambo zesiginali. Lesi sibalo esilandelayo sikhombisa ukwakheka okuhle kwe-PCB okunesiginali yemvamisa ephezulu.
Hlunga umsindo
Ama-Bypass capacitors nobuhlalu be-ferrite ama-capacitors asetshenziselwa ukuhlunga umsindo owenziwe yinoma iyiphi into. Ngokuyinhloko, uma isetshenziswa kunoma yisiphi isicelo esinejubane elikhulu, noma iyiphi iphini ye-I / O ingaba ngumthombo womsindo. Ukuze sikusebenzise kangcono lokhu okuqukethwe, kuzofanele sinake la maphuzu alandelayo:
Njalo beka ubuhlalu be-ferrite futhi udlule ama-capacitors eduze ngangokunokwenzeka emthonjeni womsindo.
Lapho sisebenzisa ukubekwa okuzenzakalelayo nomzila othomathikhi, kufanele sicabangele ibanga esizolihlola.
Gwema i-vias nanoma yimuphi omunye umzila phakathi kwezihlungi nezinto.
Uma kunendiza yaphansi, sebenzisa amaningi ngokusebenzisa izimbobo ukuze uyigxumeke kahle.