Ku-PCB Design, ukuhambisana kwe-electromagnetic (EMC) kanye nokuphazanyiswa kwe-elektromagnetic okuhlobene nalokhu kuhlale kunezinto ezimbili ezinkulu ezidale ukuthi onjiniyela bezinkinga, ikakhulukazi ekwakhiweni kwengxenye yanamuhla ekwakhiweni kwezomboni, kanti amaphakethe engxenye adinga ukuncipha, futhi ama-oems adinga isimo sejubane eliphakeme.

1. I-Crostalk kanye ne-wiring ngamaphuzu asemqoka

I-wiring ibaluleke kakhulu ukuqinisekisa ukuhamba okujwayelekile kwamanje. Uma okwamanje kuvela e-Oscillator noma kwenye idivaysi efanayo, kubaluleke kakhulu ukugcina okuhlukile kwendiza komhlaba, noma ukungavumeli ukugijima kwamanje kuhambisane nolunye umkhondo. Amasiginali amabili ahamba ngesivinini esikhulu azokhiqiza i-EMC ne-EMI, ikakhulukazi i-crosstalk. Indlela yokumelana kumele ibe emfushane kakhulu, futhi indlela yokubuya yamanje kufanele ibe mfushane ngangokunokwenzeka. Ubude bendlela yokubuyisa indlela kufanele bufane nobude bokuthumela umkhondo.

Kwi-EMI, eyodwa ibizwa ngokuthi "ukwephulwa kwe-wiring" kanti enye "i-wiring ehlukunyeziwe". Ukuhlanganiswa kwe-induclance kanye ne-camacitance kuzothinta umkhondo "isisulu" ngenxa yokuba khona kwamasimu kagesi, ngaleyo ndlela kukhiqize ama-currents adluliselwe phambili nawokubuyela emuva ku- "isisulu sokulandela". Kulokhu, ama-pumples azokwenziwa endaweni ezinzile lapho ubude besikhathi sokuhambisa kanye nobude besiginali bacishe balingana.

Emvelweni ene-wiring enempilo futhi ezinzile, amasondo afakiwe kufanele akhansele omunye komunye ukuze asuse i-crosstalk. Kodwa-ke, sisezweni elingaphelele, futhi izinto ezinjalo ngeke zenzeke. Ngakho-ke, inhloso yethu ukugcina i-crosstalt yabo bonke abalandelwayo. Uma ububanzi obuphakathi kwemigqa ehambisanayo buphindwe kabili ububanzi bemigqa, umphumela we-crosstalk ungancishiswa. Isibonelo, uma ububanzi be-TRACE bungamakhilomitha ama-5, ibanga elincane phakathi kweminonjana emibili egijimayo kufanele ibe ngama-10 amalokhi noma ngaphezulu.

Njengoba izinto ezintsha kanye nezinto ezintsha ziyaqhubeka ukuvela, abaklami be-PCB kumele baqhubeke nokubhekana nokuhambisana kwe-electromagnetic nezinkinga zokuphazamisa.

2.

Ama-capacitors aqothulayo anganciphisa imiphumela emibi ye-crosstalk. Kufanele zitholakale phakathi kwe-PIN yokuhlinzeka ngamandla kanye ne-PIN yenhlabathi yedivayisi ukuqinisekisa ukungcola okuphansi kwe-AC futhi kunciphise umsindo kanye ne-crosstalk. Ukufinyelela ukungcola okuphansi ngaphezulu kobubanzi obuvame kakhulu, kufanele kusetshenziswe ama-capacitors amaningi wokukhohlisa.

Umgomo obalulekile wokubeka ama-capacitors wokuwa okhohlisayo ukuthi i-capacitor enenani elincane kakhulu le-capacitance kufanele lisondele ngangokunokwenzeka kudivayisi ukunciphisa umphumela wokuqalisa ngokulandela umkhondo. Le capacitor ethile isondele ngangokunokwenzeka kwi-PIN yamandla noma umkhondo wamandla wedivayisi, bese uxhuma i-pad ye-capacitor ngqo kwindiza ye-via noma yomhlabathi. Uma umkhondo isikhathi eside, sebenzisa ama-vishi amaningi ukunciphisa umhlabathi wokuphazamiseka.

3. Ground PCB

Indlela ebalulekile yokunciphisa i-EMI ukuklama indiza ye-PCB Ground. Isinyathelo sokuqala ukwenza indawo ebeka phansi ibe nkulu ngangokunokwenzeka endaweni ephelele ye-PCB Circuit Board, enganciphisa ukuphuma, crosstalk nomsindo. Kufanele kuthathwe ukunakekelwa okukhethekile lapho kuxhuma ingxenye ngayinye endaweni ebonakalayo noma endizeni emhlabathini. Uma lokhu kungenziwa, umphumela wokungathathi hlangothi kwendiza yendawo ethembekile ngeke isetshenziswe ngokuphelele.

Idizayini ye-PCB eyinkimbinkimbi enobunzima obuningi abazinzile. Ngokufanelekile, i-voltage ngayinye yereferensi inendiza yayo ehambisanayo yomhlaba. Kodwa-ke, uma ungqimba lomhlabathi lukhulu kakhulu, luzokhulisa izindleko zokukhiqiza ze-PCB futhi zenze inani liphezulu kakhulu. Ukuyekethisa ukusebenzisa izindiza zomhlaba ezikhundleni ezihlukene ezintathu kuya kwezihlanu, futhi indiza ngayinye yendawo ingaqukatha izingxenye eziningi zomhlaba. Lokhu akugcini nje ngokulawula izindleko zokukhiqiza zebhodi yesekethe, kepha futhi kunciphisa i-EMI ne-EMC.

Uma ufuna ukunciphisa i-EMC, uhlelo oluphansi lwe-Imperance lubaluleke kakhulu. Kwi-PCB enobungqingili, kungcono ukuba nendiza yendawo ethembekile, kunokuba kube yindiza yomhlabathi evuthayo noma ehlakazekile, ngoba inokuphazamiseka okuphansi, inganikeza indlela yamanje, ingumthombo wesiginali omuhle kakhulu.

Ubude besikhathi isiginali ibuyela emhlabathini nayo ibaluleke kakhulu. Isikhathi esiphakathi kwesiginali nomthombo wesiginali kufanele silinganiswe, ngaphandle kwalokho sizokhiqiza into efana ne-antenna, okwenza amandla aqhamukayo abe yingxenye ye-EMI. Ngokufanayo, iminonjana edlulisela kwangamanje kuye / emthonjeni wesiginali kufanele ibe mfushane ngangokunokwenzeka. Uma ubude bendlela yomthombo nendlela yokubuyisa ayilingani, i-bour bounce izokwenzeka, okuzothuthukisa i-EMI.

4. Gwema i-90 ° °

Ukuze unciphise i-EMI, gwema i-wiring, i-vias nezinye izinto ezakha i-angle engu-90 °, ngoba ama-engeli angakwesokudla azokhipha imisebe. Kulesi ekhoneni, amandla azokwanda, futhi ukungcola okucacile kuzoshintsha, okuholele ekubonisweni bese kuthi i-EMI. Ukugwema ama-angles angama-900 °, iminonjana kufanele idluliselwe emakhoneni okungenani kuma-engeli angama-45 °.

5. Sebenzisa i-vias ngokuqapha

Cishe kuzo zonke izakhiwo ze-PCB, kufanele kusetshenziswe i-VIAS ukuhlinzeka ngokuxhumeka okusebenzayo phakathi kwezendlalelo ezahlukene. Onjiniyela be-PCB Lahleka badinga ukuqaphela ikakhulukazi ngoba i-vias izokhiqiza i-wactance kanye ne-camacitance. Kwezinye izimo, bazokhiqiza izibonakaliso, ngoba ukungcola okusobala kuzoshintsha lapho nge-via yenziwa emkhondweni.

Khumbula futhi ukuthi i-vias izokhulisa ubude be-trace futhi idinga ukufaniswa. Uma kungukulandelela okuhlukile, i-vias kufanele igwenywe ngangokunokwenzeka. Uma kungagwenywa, sebenzisa i-vias kuyo yomibili iminonjana yokunxephezela ukubambezeleka kwisiginali nasendleleni yokubuya.

6. Ikhebula kanye nokuvikelwa ngokomzimba

Izintambo ezithwele amasekethe edijithali kanye nemisinga ye-analog zizokhiqiza amandla okuhambisana nokukha kwamandla kanye nokuqalwa, okwenza izinkinga eziningi ezihlobene ne-EMC. Uma kusetshenziswa ikhebula elisontekile, izinga lokuhlanganisa lizogcinwa liphansi futhi amandla kazibuthe akhiqizwayo azoqedwa. Kumasignali avelele amabanga avemvane, ikhebula elivikelwe kumele lisetshenziswe, futhi ngaphambili nangemuva kwentambo kufanele kufakwe phansi ukuze kuqedwe amandla e-EMI.

Ukuvikelwa ngokomzimba ukusonga yonke noma ingxenye yohlelo ngephakeji yensimbi ukuvikela i-EMI ukuthi ingene kwi-PCB Circtuit. Lolu hlobo lokuvikelwa lufana nesitsha sokuqhutshwa esivaliwe, esinciphisa usayizi we-antenna loop futhi simunca i-EMI.