A yawancin lokuta, PCB wayoyi za su ratsa cikin ramuka, gamsassun tabo na gwaji, gajerun labule, da sauransu, dukkansu suna da ƙarfin parasitic, wanda babu makawa zai shafi siginar. Yakamata a bincika tasirin ƙarfin ƙarfin akan siginar daga ƙarshen watsawa da ƙarshen karɓa, kuma yana da tasiri akan farawa da ƙarshen.

Da farko danna don ganin tasirin mai watsa siginar. Lokacin da siginar siginar da ke tashi cikin sauri ta isa capacitor, ana cajin capacitor da sauri. Yanayin caji yana da alaƙa da yadda ƙarfin siginar siginar ke tashi. Tsarin cajin yanzu shine: I = C*dV/dt. Mafi girman ƙarfin, mafi girman cajin caji, saurin saurin siginar siginar, ƙaramin dt, shima yana haɓaka mafi girma na caji.

Mun san cewa tsinkayar siginar tana da alaƙa da canjin rashin ƙarfi wanda siginar ke ji, don haka don bincike, bari mu kalli canjin rashin ƙarfin da ƙarfin ƙarfin ke haifar. A matakin farko na cajin capacitor, impedance an bayyana shi kamar haka:

Anan, dV a zahiri shine canjin wutan lantarki na siginar mataki, dt shine lokacin haɓaka siginar, kuma ƙirar ƙarancin ƙarfin ƙarfin ya zama:

Daga wannan dabarar, zamu iya samun mahimmin bayani, lokacin da aka yi amfani da siginar mataki zuwa matakin farko a ƙarshen ƙarshen capacitor, ƙwanƙwasa ƙarfin ƙarfin yana da alaƙa da lokacin tashin siginar da ƙarfin sa.

Yawancin lokaci a matakin farko na cajin capacitor, impedance yana da ƙanƙanta sosai, ƙasa da halayen rashin ƙarfi na wayoyi. Mummunan tunani na siginar yana faruwa a cikin capacitor, kuma siginar wutar lantarki mara kyau ta mamaye tare da siginar asali, wanda ke haifar da rashin amintaccen siginar a mai watsawa da rashin monotonic na siginar a mai watsawa.

Don ƙarshen karɓa, bayan siginar ta kai ƙarshen karɓa, kyakkyawan tunani yana faruwa, siginar da aka nuna ta isa matsayin capacitor, irin wannan mummunan tunani yana faruwa, kuma ƙarancin ƙarfin tunani na baya baya zuwa ƙarshen karɓa yana haifar da siginar a karɓa. ƙare don samar da ƙasa.

Domin hayaniyar da ake nunawa ta zama ƙasa da 5% na jujjuyawar wutar lantarki, wanda ake iya jurewa ga siginar, dole ne canjin impedance ya kasance ƙasa da 10%. Don haka menene ƙarancin ƙarfin ƙarfin ƙarfin ƙarfin? Ƙarfin ƙarfin ƙarfi shine daidaitaccen daidaituwa, kuma zamu iya amfani da madaidaicin madaidaiciyar madaidaiciya da madaidaiciyar madaidaicin tsari don ƙayyade kewayon ta. Don wannan rashin daidaituwa, muna son ƙarancin ƙarfin ƙarfin ya zama babba sosai. Da tsammanin cewa ƙarancin ƙarfin ƙarfin ƙarfin shine lokutan K na PCB wayoyin halayen rashin ƙarfi, za a iya samun ƙanƙantar da siginar da ke cikin capacitor bisa ga madaidaicin madaidaicin dabara:

Wato, gwargwadon wannan kyakkyawan lissafin, ƙalubalen capacitor dole ne ya zama aƙalla sau 9 halayyar rashin daidaiton PCB. A zahiri, yayin da ake cajin capacitor, rashin ƙarfin capacitor yana ƙaruwa kuma ba koyaushe yana kasancewa mafi ƙarancin ƙarancin ƙarfi ba. Bugu da ƙari, kowane naúrar na iya samun shigarwar parasitic, wanda ke ƙaruwa rashin ƙarfi. Don haka za a iya sassauta wannan iyakar ninki tara. A cikin tattaunawar da ke tafe, ɗauka cewa iyakar ita ce sau 5.

Tare da mai nuna alamar rashin ƙarfi, za mu iya ƙayyade adadin ƙarfin da za a iya jurewa. Haƙƙin halayyar haɓakar hamsin 50 a kan allon da’irar ta zama ruwan dare gama gari, don haka na yi amfani da 50 ohms don ƙididdige shi.

An kammala cewa:

A wannan yanayin, idan lokacin haɓaka siginar shine 1ns, ƙarfin ƙarfin ƙasa da picogram 4. Hakanan, idan ƙarfin shine picogram 4, lokacin tashin siginar shine 1ns a mafi kyau. Idan lokacin tashin siginar shine 0.5ns, wannan ƙarfin picograms 4 zai haifar da matsaloli.

Lissafi a nan shine kawai don bayyana tasirin ƙarfin ƙarfi, ainihin da’irar tana da rikitarwa, akwai ƙarin abubuwan da ake buƙata, don haka ko lissafin anan daidai ne ba mahimmancin amfani ba. Makullin shine fahimtar yadda ƙarfin aiki ke shafar siginar ta wannan lissafin. Da zarar mun sami fahimtar fahimta na tasirin kowane abin da ke kan allon kewaye, za mu iya ba da jagorar da ta dace don ƙira kuma mu san yadda ake bincika matsaloli lokacin da suka faru. Ƙididdiga daidai na buƙatar kwaikwayon software.

Kammalawa:

1. Ƙarfin ƙarfin aiki yayin zirga -zirgar PCB yana haifar da siginar ƙarshen watsawa don samar da ƙasa, kuma siginar ƙarshen mai karɓa ita ma za ta haifar da raguwa.

2. Haƙurin ƙarfin ƙarfin yana da alaƙa da lokacin haɓaka siginar, da sauri lokacin haɓaka siginar, ƙaramin haƙuri na ƙarfin.