Ukhetho lwebhodi yePCB kufuneka lubethe ulungelelwano phakathi kweemfuno zoyilo loyilo kunye nemveliso yobuninzi kunye neendleko. Iimfuno zoyilo ziquka iindawo zombane kunye nezomatshini. Le ngxaki imathiriyeli idla ngokubaluleke ngakumbi xa uyila iibhodi zePCB ezinesantya esiphezulu (i-frequency enkulu kuneGHz).
Ngokomzekelo, izinto ezisetyenziswa ngokuqhelekileyo ze-FR-4 ngoku zinelahleko ye-dielectric kwi-frequency ye-GHz eziliqela, enempembelelo enkulu ekunciphiseni umqondiso, kwaye isenokungafaneleki. Ngokubhekiselele kumbane, qaphela ukuba ingaba i-dielectric constant kunye nelahleko ye-dielectric ifanelekile kwi-frequency eyilelwe.2. Ukuphepha njani ukuphazamiseka okuphezulu?
Umbono osisiseko wokunqanda ukuphazamiseka okuhamba rhoqo kukunciphisa ukuphazamiseka kwendawo ye-electromagnetic yeempawu ezijikelezayo, ebizwa ngokuba yi-crosstalk (Crosstalk). Unokwandisa umgama phakathi kwesignali yesantya esiphezulu kunye nesignali ye-analog, okanye ungeze umlindi womhlaba / umkhondo we-shunt ecaleni kwesignali ye-analog. Kwakhona qaphela ukuphazamiseka kwengxolo ukusuka kumhlaba wedijithali ukuya kumhlaba we-analog.3. Indlela yokusombulula ingxaki yengqibelelo yomqondiso kuyilo lwesantya esiphezulu?
Ukunyaniseka komqondiso kuyingxaki yokulinganisa i-impedance. Izinto ezichaphazela ukuhambelana kwe-impedance zibandakanya ukwakheka kunye nokuphazamiseka kwemveliso yomthombo wesignali, i-impedance yeempawu zomkhondo, iimpawu zokuphela komthwalo, kunye ne-topology yomkhondo. Isisombululo kukuxhomekeka kwi-topology yokupheliswa kunye nokulungiswa kwee-wiring.
4. Yenziwa njani indlela yokudityaniswa kwee-wiring?
Kukho amanqaku amabini okufuneka ubeke ingqalelo kwi-layout ye-different pair. Enye kukuba ubude beentambo ezimbini kufuneka zibe zide kangangoko kunokwenzeka, kwaye enye kukuba umgama phakathi kweengcingo ezimbini (lo mgama unqunywe yi-impedance yokwahlukana) kufuneka ugcinwe rhoqo, oko kukuthi, ukugcina i-parallel. Kukho iindlela ezimbini ezihambelanayo, enye yeyokuba imigca emibini ihamba kwicala elinye-ngecala, kwaye enye yeyokuba imigca emibini isebenza kumaleko amabini ameleneyo (ngaphezulu-ngaphantsi). Ngokuqhelekileyo, i-side-by-side (icala necala, i-side-by-side) iphunyezwa ngeendlela ezininzi.
5. Indlela yokuqonda iingcingo zokwahluka komgca wesiginali yewotshi enetheminali enye kuphela ephumayo?
Ukusebenzisa i-wiring eyahlukileyo, kunengqiqo ukuba umthombo wesignali kunye nommkeli nazo zizibonakaliso ezahlukileyo. Ke ngoko, akunakwenzeka ukusebenzisa i-wiring yokwahlula isignali yewotshi ene-terminal enye kuphela yokuphuma.
6. Ngaba isichasi esimatanisayo sinokongezwa phakathi kwezibini zemigca yokwahlukana ekupheleni kokufumana?
Ukuchasana okuhambelanayo phakathi kweebini zomgca ohlukeneyo ekupheleni kokufumana ngokuqhelekileyo kufakwe, kwaye ixabiso layo kufuneka lilingane nexabiso le-impedance yokwahlukana. Ngale ndlela umgangatho wesignali uya kuba ngcono.
7. Kutheni i-wiring ye-different pair kufuneka isondele kwaye ihambelane?
I-wiring ye-different pair kufuneka isondele ngokufanelekileyo kwaye ihambelane. Okubizwa ngokuba kufutshane okufanelekileyo kungenxa yokuba umgama uya kuchaphazela ixabiso le-impedance yokwahlukana, okuyiparameter ebalulekileyo yokuyila izibini ezihlukeneyo. Isidingo sokuhambelana kwakhona kukugcina ukuhambelana kwe-impedance yokwahlukana. Ukuba imigca emibini ikude ngokukhawuleza kwaye isondele, i-impedance eyahlukileyo iya kuba ingahambelani, eya kuchaphazela ingqibelelo yesignali kunye nokulibaziseka kwexesha.