A gaskiya ma, buga kewaye hukumar (PCB) an yi su ne da kayan lantarkin lantarki, watau hana su yakamata ya kasance akai. Don haka me yasa PCB ke gabatar da rashin daidaituwa cikin sigina? Amsar ita ce shimfidar PCB “ba ta layi-layi” dangane da inda halin yanzu ke gudana.

Ko amplifier yana karɓar halin yanzu daga wata tushe ko wani ya dogara da saurin siginar siginar akan nauyin. Gudun yanzu yana gudana daga wutar lantarki, ta hanyar wucewa capacitor, ta cikin amplifier zuwa cikin kaya. Na yanzu yana tafiya daga tashar ƙasa mai ɗaukar nauyi (ko garkuwar haɗin haɗin fitarwa na PCB) zuwa jirgin ƙasa, ta hanyar keɓaɓɓen capacitor, da komawa ga asalin da ya kawo na yanzu.

Manufar ƙaramar hanyar yanzu ta hanyar hanawa ba daidai ba ce. Adadin halin yanzu a cikin dukkan hanyoyin hanawa daban -daban daidai gwargwado. A cikin jirgin sama na ƙasa, galibi ana samun hanyar wucewa fiye da ɗaya ta hanyar da babban rarar ƙasa ke gudana: hanya ɗaya tana da alaƙa kai tsaye da mai wucewa ta capacitor; Excayan kuma yana ba da ƙarfin shigarwar shigarwar har sai an kai ƙarfin wucewa. Hoto 1 yana kwatanta waɗannan hanyoyi guda biyu. Ruwan baya na baya shine ainihin abin da ke haifar da matsalar.

Yadda ake rage murdiyar jituwa a ƙirar PCB

Lokacin da aka sanya masu wucewa masu wucewa a wurare daban -daban akan PCB, yanayin ƙasa yana gudana ta hanyoyi daban -daban zuwa abubuwan haɓakawa daban -daban, wanda shine ma’anar “rashin daidaituwa na sarari”. Idan wani muhimmin sashi na ɓangaren iyakacin ƙasa na halin yanzu yana gudana ta cikin ƙasa na kewayon shigarwar, kawai ɓangaren ɓangaren siginar siginar yana damuwa. Idan sauran polarity na ƙasa na yanzu ba a dame shi ba, ƙarfin siginar siginar shigarwa yana canzawa a cikin layi mara layi. Lokacin da aka canza ɓangaren polarity ɗaya amma ɗayan ba haka bane, murdiya yana faruwa kuma yana bayyana azaman hargitsi na biyu na siginar fitarwa. Hoto na 2 yana nuna wannan tasirin murdiya a cikin ƙari.

Yadda ake rage murdiyar jituwa a ƙirar PCB

Lokacin da ɓangaren polar guda ɗaya kawai na damuwar sine, sakamakon jujjuyawar ba shine raunin sine ba. Daidaita madaidaicin amplifier tare da nauyin 100-and da haɗa haɗin halin yanzu ta hanyar tsayayyar 1-into a cikin wutar lantarki a ƙasa akan siginar siginar guda ɗaya, yana haifar da adadi na 3.Canjin Fourier yana nuna cewa murdiyar murdiyar kusan dukkanin jituwa ta biyu a -68 DBC. A manyan mitoci, ana iya samar da wannan matakin haɗin gwiwa akan PCB cikin sauƙi, wanda zai iya lalata kyawawan halayen ɓarna na amplifier ba tare da yin amfani da yawancin abubuwan da ba su dace da PCB ba. Lokacin da aka gurbata fitowar amplifier guda ɗaya saboda hanyar ƙasa ta yanzu, ana iya daidaita kwararar ƙasa ta hanyar sake tsara madaidaicin madaidaiciyar hanya da kiyaye nesa daga na’urar shigarwa, kamar yadda aka nuna a Figure 4.

Yadda ake rage murdiyar jituwa a ƙirar PCB

Multiamplifier guntu

Matsalar kwakwalwan kwamfuta da yawa (biyu, uku, ko huɗu amplifiers) yana haɗe da rashin iya kiyaye haɗin ƙasa na mai wucewa mai nisa nesa da duk shigarwar. Wannan gaskiya ne musamman ga amplifiers huɗu. Chip-amplifier kwakwalwan kwamfuta suna da tashoshin shigarwa a kowane gefe, don haka babu wani wuri don kewaya hanyoyin da ke rage tashin hankali ga tashar shigarwa.

Yadda ake rage murdiyar jituwa a ƙirar PCB

Hoto 5 yana nuna hanya mai sauƙi zuwa shimfidar amplifier huɗu. Yawancin na’urori suna haɗa kai tsaye zuwa fil amplifier quad. Ƙarfin wutar lantarki guda ɗaya na iya damun shigar da wutar lantarki na ƙasa da na ƙasa na sauran tashar wutar lantarki, yana haifar da murdiya. Misali, za a iya sanya (+Vs) wucewa capacitor akan tashar 1 na amplifier quad kai tsaye kusa da shigar sa; Za’a iya sanya madaidaicin ƙarfin (-Vs) a ɗayan ɓangaren kunshin. Yanayin ƙasa (+Vs) na iya tayar da tashar 1, yayin da (-vs) na yanzu ba zai iya ba.

Yadda ake rage murdiyar jituwa a ƙirar PCB

Don gujewa wannan matsalar, bari yanayin ƙasa ya rikitar da shigarwar, amma bari halin yanzu na PCB ya gudana cikin salo na layi -layi. Don cimma wannan, za a iya shirya madaidaicin capacitor akan PCB ta yadda igiyar ƙasa (+Vs) da ( – Vs) ke gudana ta wannan hanya. Idan siginar shigarwa daidai yake da damuwa ta yanayin mai kyau da mara kyau, murdiya ba zai faru ba. Sabili da haka, daidaita madaidaitan abubuwan haɓakawa biyu kusa da juna don su raba maƙasudin ƙasa. Saboda ɓangarorin polar biyu na halin yanzu suna fitowa daga wuri guda (garkuwar haɗin haɗin fitarwa ko ƙasa mai ɗaukar nauyi) kuma duka biyun suna komawa zuwa wuri ɗaya (haɗin ƙasa na gama -gari na kewaya capacitor), tabbatacce/mummunan halin yanzu yana gudana ta hanya ɗaya. Idan juriya na shigar da tashar ta damu da (+Vs) na yanzu, ( – Vs) halin yanzu yana da tasiri iri ɗaya akan sa. Saboda rikice -rikicen da suka haifar iri ɗaya ne ba tare da la’akari da polarity ba, babu murdiya, amma ƙaramin canji a ribar tashar zai faru, kamar yadda aka nuna a Figure 6.

Yadda ake rage murdiyar jituwa a ƙirar PCB

Don tabbatar da ƙimar da ke sama, an yi amfani da shimfidu daban-daban na PCB: shimfida mai sauƙi (Hoto 5) da shimfidar ƙasa-ƙasa (Hoto 6). An nuna murdiya da FHP3450 mai ƙaramin aiki mai amfani da huɗu ke amfani da semiconductor na fairchild a cikin tebur 1. An nuna madaidaicin bandwidth na FHP3450 shine 210MHz, gangaren shine 1100V/mu, shigarwar halin yanzu shine 100nA, kuma halin yanzu na aiki a kowace tashar shine 3.6 mA. Kamar yadda ake iya gani daga Teburin 1, mafi gurbata tashar, mafi kyawun haɓakawa, ta yadda tashoshi huɗu sun kusan daidaita daidai.

Yadda ake rage murdiyar jituwa a ƙirar PCB

Ba tare da ingantaccen amplifier quad akan PCB ba, auna tasirin tashar amplifier guda ɗaya na iya zama da wahala. A bayyane yake, tashar amplifier da aka bayar tana damun ba kawai shigar da kansa ba, har ma da shigar da wasu tashoshi ma. Haɗin ƙasa yana gudana ta duk hanyoyin shigar tashoshi daban -daban kuma yana haifar da sakamako daban -daban, amma kowane tasiri yana tasiri akan shi, wanda ake iya aunawa.

Teburin 2 yana nuna jituwa da aka auna akan sauran tashoshin da ba a lalata ba lokacin da tashar guda ɗaya kawai ke tuƙi. Tashar da ba a daidaita ba tana nuna ƙaramin sigina (crosstalk) a madaidaicin mitar, amma kuma tana haifar da murdiya kai tsaye ta yanayin ƙasa ta gabatar idan babu wata alama mai mahimmanci. Siffar karkacewar ƙasa a cikin Hoto na 6 yana nuna cewa halayen jituwa na biyu da jimlar hargitsi (THD) an inganta su sosai saboda kusancin kawar da tasirin ƙasa na yanzu.

Yadda ake rage murdiyar jituwa a ƙirar PCB

Takaitaccen labarin

A taƙaice, a kan PCB, halin da ake ciki na baya yana gudana ta hanyoyi daban -daban masu kewaya (don wadatar wutar lantarki daban -daban) da kuma wutan lantarkin da kanta, wanda ya yi daidai da yadda ake gudanar da shi. Babban siginar mitar da ke gudana tana komawa zuwa ƙaramin abin ƙera capacitor. Ƙananan mitoci, kamar na siginar sauti, na iya kwarara da farko ta hanyar manyan abubuwan wucewa. Ko da ƙarancin mitar mitar na iya “watsi da” cikakken ikon wucewa da gudana kai tsaye zuwa jagorar wutar. Aikace -aikacen takamaiman zai tantance wace hanya ce mafi mahimmanci. Abin farin ciki, yana da sauƙi don kare duk hanyar ƙasa ta yanzu ta amfani da maƙasudin ƙasa ɗaya da maɓallin kewaya ƙasa a gefen fitarwa.

Dokar zinare don shimfidar HF PCB shine kiyaye HF kewaye capacitor kusa da fakitin wutar lantarki mai yuwuwa, amma kwatancen Hoto na 5 da Hoto na 6 yana nuna cewa canza wannan dokar don inganta halayen murdiya ba ta da yawa. Ingantattun halaye na murdiya sun zo ne ta hanyar ƙara kusan inci 0.15 na keɓaɓɓen hanyar wucewa ta ƙarfin lantarki, amma wannan yana da ɗan tasiri kan aikin mayar da martani na AC na FHP3450. Tsarin PCB yana da mahimmanci don haɓaka aikin ingantaccen amplifier, kuma batutuwan da aka tattauna anan ba’a iyakance su ga amplifiers hf ba. Ƙananan siginar mitar kamar sauti yana da buƙatun murdiya da yawa. Tasirin ƙasa na yanzu ya yi ƙanƙanta a ƙananan mitoci, amma har yanzu yana iya zama muhimmiyar matsala idan an inganta jigon murdiya da ake buƙata daidai.