Tus lej ntawm cov neeg tsim qauv digital thiab cov digital Circuit Board cov qauv tsim hauv cov tuam txhab Engineering nyob rau hauv cov chaw txua txiag ntoo yog tas li nce, uas qhia txog kev txhim kho ntawm kev lag luam. Txawm hais tias tseem ceeb txog kev tsim qauv digital tau coj txog cov khoom siv hluav taws xob, nws tseem muaj qee qhov kev sib txuas lus uas cuam tshuam nrog ib puag ncig lossis ib puag ncig. Cov tswv yim hluav taws xob hauv cov kab hlau thiab cov duab digital muaj qee cov txiaj ntsig zoo, tab sis thaum koj xav tau cov tswv yim sib txawv, cov ntaub ntawv xov hluav taws xob sib txawv ntxiv lawm.

Kab lus no sib tham txog qhov zoo sib xws thiab qhov sib txawv ntawm cov khoom siv hluav taws xob, hluav taws xob, hluav taws xob tsis raug, thiab hluav taws xob hluav taws xob (EMI) los ntawm PCB hlau.

Tus lej ntawm cov neeg tsim qauv digital thiab cov digital Circuit Board cov qauv tsim hauv cov tuam txhab Engineering nyob rau hauv cov chaw txua txiag ntoo yog tas li nce, uas qhia txog kev txhim kho ntawm kev lag luam. Txawm hais tias tseem ceeb txog kev tsim qauv digital tau coj txog cov khoom siv hluav taws xob, nws tseem muaj qee qhov kev sib txuas lus uas cuam tshuam nrog ib puag ncig lossis ib puag ncig. Cov tswv yim hluav taws xob hauv cov kab hlau thiab cov duab digital muaj qee cov txiaj ntsig zoo, tab sis thaum koj xav tau cov tswv yim sib txawv, cov ntaub ntawv xov hluav taws xob sib txawv ntxiv lawm.

Kab lus no sib tham txog qhov zoo sib xws thiab qhov sib txawv ntawm cov khoom siv hluav taws xob, hluav taws xob, hluav taws xob tsis raug, thiab hluav taws xob hluav taws xob (EMI) los ntawm PCB hlau.

Ntxiv kev hla dhau los yog decoupling capacitors rau ntawm cov Circuit Court Board thiab qhov chaw ntawm cov capacitors ntawm lub rooj tsavxwm yog ib qho kev txiav txim siab zoo rau Digital thiab analog tsim. Tab sis nthuav, cov laj thawj txawv.

Hauv kev tsim hluav taws xob sib zog tsim, cov tshuab hluav taws xob capacitors feem ntau yog siv los hla cov teeb meem tseem ceeb ntawm lub zog. Yog hais tias bypass capacitors tsis ntxiv, cov ntsiab lus siab no yuav nkag mus rau cov chips sib tw ntawm lub zog hluav taws xob pins. Feem ntau hais lus, qhov zaus ntawm cov ntsiab lus siab tshaj plaws tau tshaj qhov muaj peev xwm ntawm cov khoom siv analog kom pom cov khoom siv hluav taws xob siab. Yog hais tias lub cranpass capator yog tsis siv nyob rau hauv analog Circuit Court, suab nrov yuav qhia nyob rau hauv txoj kev teeb liab txoj kev, thiab nyob rau hauv cov xwm txheej loj dua, nws txawm yuav ua kev co.

Hauv analog thiab digital pcb tsim, bypass lossis decoupling capacitors (0.1uf) yuav tsum muab tso rau hauv lub cuab yeej li sai tau. Lub zog muab cov tshuaj tiv thaiv capacting capacitor (10UF) yuav tsum muab tso rau ntawm cov kab hluav taws xob nkag ntawm Circuit Court board. Hauv txhua kis, cov pins ntawm cov capacitors yuav tsum luv.

Ntawm Circuit Court Board hauv daim duab 2, cov kev sib txawv hauv txoj kev siv coj los ua lub zog thiab cov xov hlau. Vim tias qhov kev koom tes tsis raug, cov hluav taws xob hluav taws xob thiab cov voj voog ntawm cov Circuit Court Board muaj ntau yuav muaj kev cuam tshuam hluav taws xob.

Nyob rau hauv ib lub vaj huam sib luag ntawm daim duab 3, lub zog thiab hauv av xaim rau cov cheeb tsam ntawm Circuit Court Board yog ze rau ib leeg. Qhov piv sib piv ntawm cov kab hluav taws xob thiab cov hauv av hauv Circuit Court thiab circuit) yog qhov tsim nyog raws li cov hluav taws xob hluav taws xob raug txo qis los ntawm 679 / 12.8 zaug lossis txog 54 zaug.
　　
Rau cov khoom siv digital xws li cov tswj thiab cov processors, decoupling capacitors tseem yuav tsum tau, tab sis rau ntau yam. Ib qho haujlwm ntawm cov capacitors yog los ua tus "me me" nqi txhab nyiaj.

Hauv cov khoom siv digital, cov nyiaj ntau ntawm cov tam sim no feem ntau yuav tsum tau ua GATE State hloov. Txij li thaum hloov pauv cov dej ntws tawm yog tsim tawm ntawm lub nti thaum hloov thiab ntws los ntawm Circuit Court Board, nws yog qhov zoo kom muaj ntxiv "cov nqi ntxiv. Yog tias tsis muaj nqi txaus thaum ua qhov hloov tawm, lub zog hluav taws xob voltage yuav hloov siab heev. Ntau dhau voltage hloov yuav ua rau lub teeb liab digital kom nkag rau hauv lub xeev tsis muaj tseeb, thiab tuaj yeem ua rau lub xeev cov cuab yeej ua haujlwm tsis raug.

Tus hloov hloov tam sim no ntws los ntawm Circuit Court Board kab mob yuav ua rau tus voltage hloov, thiab Circuit Court pawg thawj coj muaj parasitic inductance. Cov mis hauv qab no tuaj yeem siv los suav qhov hloov hluav taws xob hloov: V = LDI / DT. Ntawm lawv: V = voltage hloov, l = Circuit Court Board
　　
Yog li ntawd, rau ntau yam laj thawj, nws yog qhov zoo dua rau kev thov bypass (lossis decoupling) capacitors ntawm lub zog hluav taws xob lossis ntawm lub zog hluav taws xob pins ntawm cov khoom siv hluav taws xob.

Lub zog cord thiab av xaim yuav tsum tau nyob ua ke

Txoj hauj lwm ntawm lub hwj chim qaum thiab av xaim tau raug zoo rau txo cov peev xwm ntawm hluav taws xob cuam tshuam. Yog tias cov kab hluav taws xob thiab kab hauv av tsis raug cai, lub voj kaw lus kaw lus yuav tsim qauv thiab lub suab nrov yuav tsim tawm.

Ib qho piv txwv ntawm tus qauv PCB uas cov kab hluav taws xob thiab cov kab hauv av tsis yog qhia hauv daim duab 2. Ntawm thaj chaw voj voos, lub nroog Loop yog 697cm². Siv cov txheej txheem qhia hauv daim duab 3, qhov ua tau ntawm cov suab nrov radiated ntawm lossis tawm ntawm Circuit Court board inducking voltage nyob rau hauv lub voj tuaj yeem txo qis heev.

Qhov sib txawv ntawm analog thiab digital wireing tswv yim

▍Qhov av hlau yog ib qho teeb meem

Cov kev paub yooj yim ntawm Circuit Court board wireing yog siv rau ob qho tib si analog thiab cov kab sib chaws digital. Ib txoj cai tseem ceeb ntawm tus ntiv tes xoo yog siv lub dav hlau tsis muaj kev cuam tshuam hauv av. Qhov kev txiav txim siab zoo no txo ​​qhov di / dt (hloov pauv tam sim no nrog lub sijhawm tam sim no) qhov kev hloov pauv hauv av muaj peev xwm thiab ua rau muaj suab nrov rau kev nkag mus rau kev sib tw analog.

Cov kev siv hluav taws xob tawm rau cov kab hlau thiab analog circuits yog ib qho zoo ib yam, nrog ib qho tshwj xeeb. Rau kev ntsuas analog, muaj lwm tus taw tes rau cov ntawv cim, uas yog, khaws cov paib digital teeb liab kab thiab loops hauv av dav hlau kom deb li deb ntawm analog voj voog li sai tau. Qhov no tuaj yeem ua tiav los ntawm kev sib txuas hauv av analog av mus rau lub system av sib txuas sib cais, lossis tso cov analog Circuitely, lossis tso cov khoom sib txuas ntawm cov Circuit Court Board, uas yog qhov kawg ntawm txoj kab. Qhov no yog ua kom muaj kev cuam tshuam sab nraud sab nraud ntawm txoj kev teeb liab txoj kev mus rau qhov tsawg kawg nkaus.

Tsis tas yuav ua qhov no rau cov khoom siv digital, uas tuaj yeem ua rau muaj suab nrov ntau ntawm cov av dav hlau tsis muaj teeb meem.

Daim duab 4 (sab laug) cais cov digital hloov kev ua los ntawm analog Circuit Court thiab cais cov digital thiab analog qhov chaw ntawm Circuit Court. (Txoj cai) lub zog loj thiab tsawg zaus yuav tsum tau sib cais kom ntau li ntau tau, thiab cov khoom siab ntau zaus yuav tsum nyob ze rau cov Circuit Court Board txuas.

Daim duab 5 Layout Ob qhov ze ntawm tus PCB, nws yooj yim los tsim parasitic capacitance. Vim tias lub hav zoov ntawm hom kev tsim hluav taws xob no, kev hloov nrawm nrawm ntawm ib qho chaw tuaj yeem tsim cov teeb liab tam sim no.

Daim duab 6 yog tias koj tsis them sai sai rau qhov chaw tso rau ntawm cov kab, cov kab hauv PCB yuav tsim cov kab inductance thiab kev sib koom tes ua ntu zus. Qhov kev ntsuas no yog qhov ua rau muaj kev phom sij rau kev ua haujlwm xws li cov kev hloov digital.

▍Componnon Nyob rau qhov chaw

Raws li tau hais los saum toj no, nyob rau hauv txhua tus qauv PCB, lub suab nrov ntawm Circuit Court thiab "nyob ntsiag to" (tsis yog suab nrov. Feem ntau hais lus, digital circuits yog "nplua nuj" hauv suab nrov thiab tsis muaj suab nrov (vim tias cov suab nrov digital (vim hais tias digital circuits (vim hais tias digital circuart rau cov suab nrov loj); Ntawm qhov tsis sib xws, lub suab nrov voltage ntawm analog circuits yog ntau me dua.

Ntawm ob, analog circuits yog qhov rhiab tshaj plaws hloov suab nrov. Hauv cov xaim-teeb liab, cov kab hluav taws xob no yuav tsum sib cais, raws li muaj nyob hauv daim duab 4.
　　
Cov Cheebtsam uas tsim los ntawm PCB tsim

Ob lo ntsiab lus theem pib uas yuav tsim teeb meem tau yooj yim tsim nyob rau hauv PCB tsim: parasiticic capacitance thiab parasitic inductance.

Thaum tsim qauv Circuit Court, tso ob txoj kab ke sib ze yuav ua rau cov parseitic capacitance. Koj tuaj yeem ua qhov no: ntawm ob txheej sib txawv, muab ib qho chaw nyob rau sab saum toj ntawm lwm cov kab; Los yog ntawm tib txheej txheej, tso ib txoj kab ib sab ntawm lwm cov kab tawm, raws li qhia hauv Daim Duab 5.
　　
Hauv ob lub tsheb laij teb no, hloov hauv cov hluav taws xob feem ntau (DV / DT) ntawm ib qho kev ua haujlwm yuav ua rau lwm txoj kab. Yog tias lwm txoj kab yog qhov yuam kev siab, cov teeb tsa tam sim no los ntawm hluav taws xob teb yuav hloov mus rau hauv cov hluav taws xob.
　　
Ceev ceev cov kev hloov hluav taws xob feem ntau tshwm sim ntawm cov qauv kev tsim qauv analog. Yog hais tias cov kab sib tw nrog cov khoom siv nrawm nrawm yog ze rau qhov kev ua yuam kev ntawm lub siab, qhov yuam kev no yuav cuam tshuam qhov tseeb ntawm cov analog Circuit Court. Nyob rau hauv qhov chaw ib puag ncig no, analog circuits muaj ob qhov tsis zoo: lawv lub suab nrov ua tau qis dua li ntawm cov khoom lag luam digital; Thiab siab impedance cov kab muaj ntau dua.
　　
Siv ib qho ntawm ob cov tswv yim hauv qab no tuaj yeem txo qhov tshwm sim no. Cov txheej txheem siv feem ntau yog hloov qhov loj ntawm cov kab raws li kev muaj kuab sib npaug. Qhov loj tshaj plaws kom hloov yog qhov kev ncua deb ntawm ob txoj kab. Nws yuav tsum raug sau tseg tias cov sib txawv D yog nyob rau hauv tus neeg tsis muaj peev xwm ntawm lub peev xwm sib npaug. Raws li D nce ntxiv, qhov muaj peev xwm yuav txo qis. Lwm qhov sib txawv uas tuaj yeem hloov tau yog qhov ntev ntawm ob kab. Hauv qhov no, qhov ntev l txo, thiab cov peev xwm ntsuas ntawm ob txoj kab yuav poob qis.
　　
Lwm cov txheej txheem yog kom nteg hauv av xaim ntawm ob kab ntawv no. Cov kav hlau hauv av yog qhov tsis tshua muaj kev cuam tshuam, thiab ntxiv lwm qhov cim zoo li qhov no yuav ua rau cov hluav taws xob hluav taws xob ntau li, raws li muaj nyob hauv daim duab 5.
　　
Lub hauv paus ntsiab lus ntawm cov cab ntawm kev txhawb nqa hauv Cirasitic hauv Circuit Cournal Board tau zoo ib yam li ntawd ntawm cov cab muaj peev xwm. Nws tseem yuav nteg ob kab. Ntawm ob txheej sib txawv, muab ib txoj lw nyob rau sab saum toj ntawm lwm txoj kab; Los yog ntawm tib txheej txheej, tso ib txoj kab ib sab ntawm lwm qhov, raws li qhia hauv daim duab 6.

Hauv ob txoj kev sib tw no, cov kev hloov pauv tam sim no (DT) ntawm lub sijhawm, vim yog qhov tsis sib xws ntawm cov kab no, yuav tsim hluav taws xob ntawm tib txoj kab; Thiab vim muaj lub neej ntawm kev sib nrig sib pab, nws yuav ua ntu zus tam sim no yog tsim tawm ntawm lwm txoj kab. Yog tias qhov hloov hluav taws xob ntawm thawj qhov yog qhov loj txaus, cuam tshuam yuav ua rau muaj kev tiv thaiv kev tiv thaiv digital thiab ua rau yuam kev. Qhov tshwm sim no tsis yog tshwm sim hauv cov voj voog digital, tab sis qhov xwm txheej no muaj ntau dua hauv cov khoom siv digital vim tias qhov loj inantaneous hloov mus rau hauv cov kab ncig digital.
　　
Txhawm rau tshem tawm cov suab nrov muaj suab nrov los ntawm kev cuam tshuam hluav taws xob, nws yog qhov zoo dua los cais "cov kab uas tsis muaj suab nrov ntawm no / o. Txhawm rau kom ua tiav lub zog uas tsis muaj zog thiab hauv av ntawm cov kav hlau hluav taws xob digital yuav tsum tau txo qis, thiab lub capacitive txuas ntawm analog circuits yuav tsum muaj tsawg.
　　
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Tom qab cov digital thiab analog muaj kev txiav txim siab, kev ua tib zoo txoj kev yog qhov tseem ceeb rau kev vam meej pcb. Kev siv hluav taws xob feem ntau tau qhia rau txhua tus neeg raws li txoj cai ntawm tus ntiv tes xoo, vim tias nws nyuaj rau kev ua tiav kev vam meej kawg ntawm cov khoom lag luam hauv chav kuaj. Yog li ntawd, cov tswv yim zoo sib xws hauv cov tswv yim hluav taws xob ntawm cov kab hlau thiab analog voj voog, qhov sib txawv ntawm lawv cov tswv yim hluav taws xob yuav tsum tau lees paub thiab tau mob siab.