Huwandu hwevagadziri vedhijitari uye yedhijitari yedhijitari dhizaini nyanzvi mumunda weinjiniya iri kuramba ichiwedzera, iyo inoratidza maitiro ekusimudzira indasitiri.Kunyangwe kusimbiswa kwedhizaini dhizaini yakaunza budiriro huru muzvigadzirwa zvemagetsi, ichiripo, uye pachagara paine mamwe madhizaini edunhu anobatana neanalogi kana nharaunda chaidzo.Wiring nzira muanalogi uye dhijitari minda ine zvimwe zvakafanana, asi kana iwe uchida kuwana mhedzisiro iri nani, nekuda kwemaitiro avo akasiyana e wiring, nyore redunhu wiring dhizaini haisisiri iyo yakanyanya mhinduro.
Ichi chinyorwa chinokurukura nezvezvakanyanya kufanana uye mutsauko pakati peanalogi nedhijitari wiring maererano nebypass capacitors, magetsi emagetsi, dhizaini yepasi, kukanganisa kwemagetsi, uye kukanganiswa kwemagetsi (EMI) kunokonzerwa nePCB wiring.
Huwandu hwevagadziri vedhijitari uye yedhijitari yedhijitari dhizaini nyanzvi mumunda weinjiniya iri kuramba ichiwedzera, iyo inoratidza maitiro ekusimudzira indasitiri.Kunyangwe kusimbiswa kwedhizaini dhizaini yakaunza budiriro huru muzvigadzirwa zvemagetsi, ichiripo, uye pachagara paine mamwe madhizaini edunhu anobatana neanalogi kana nharaunda chaidzo.Wiring nzira muanalogi uye dhijitari minda ine zvimwe zvakafanana, asi kana iwe uchida kuwana mhedzisiro iri nani, nekuda kwemaitiro avo akasiyana e wiring, nyore redunhu wiring dhizaini haisisiri iyo yakanyanya mhinduro.
Ichi chinyorwa chinokurukura nezvezvakanyanya kufanana uye mutsauko pakati peanalogi nedhijitari wiring maererano nebypass capacitors, magetsi emagetsi, dhizaini yepasi, kukanganisa kwemagetsi, uye kukanganiswa kwemagetsi (EMI) kunokonzerwa nePCB wiring.
Kuwedzera bypass kana decoupling capacitors pane redunhu bhodhi uye nzvimbo yeaya macapacitor pabhodhi inonzwisisika yedhijitari uye analogi dhizaini.Asi zvinofadza, zvikonzero zvakasiyana.
Mune analog wiring dhizaini, bypass capacitor inowanzo shandiswa kunzvenga masaini akakwira-frequency pane magetsi.Kana bypass capacitor ikasawedzerwa, aya ma-high-frequency masiginecha anogona kupinda anonzwisisika analog machipi kuburikidza nemagetsi ekupa mapini.Kazhinji kutaura, kuwanda kweaya masaini akakwira-frequency anodarika kugona kweanalogi zvishandiso kudzvanya masaini epamusoro-frequency.Kana iyo bypass capacitor isingashandiswe munharaunda yeanalog, ruzha runogona kuunzwa munzira yechiratidzo, uye mune zvakakomba zviitiko, zvinogona kutokonzera kudengenyeka.
Mune analog uye dijitari PCB dhizaini, bypass kana decoupling capacitors (0.1uF) inofanira kuiswa padyo nemudziyo sezvinobvira.Iyo magetsi ekupa decoupling capacitor (10uF) inofanirwa kuiswa pamusuwo wemagetsi mutsara wedunhu redunhu.Muzviitiko zvese, mapini eiyi capacitors anofanira kunge ari mapfupi.
Pabhodhi redunhu muMufananidzo 2, nzira dzakasiyana-siyana dzinoshandiswa kufambisa simba uye waya dzepasi.Nekuda kwekubatana kusiri iko uku, zvikamu zvemagetsi uye masekete pabhodhi redunhu zvinonyanya kuve pasi pekukanganiswa kwemagetsi.
Muchikamu chimwe chete cheMufananidzo 3, simba uye tambo dzepasi kune zvikamu pabhodhi redunhu zviri pedyo kune mumwe.Chiyero chekufananidza chetambo yemagetsi uye mutsara wepasi mubhodhi redunhu iri rakakodzera sezvinoratidzwa mumufananidzo 2. Mikana yezvikamu zvemagetsi uye masekete mubhodhi redunhu rinoiswa pasi pekukanganiswa kwemagetsi (EMI) inoderedzwa ne679 / 12.8 nguva kana dzinenge 54 nguva.
Kune madivayiri edhijitari akadai sevatongi uye processors, decoupling capacitors inodiwa zvakare, asi nezvikonzero zvakasiyana.Rimwe basa reaya capacitor kuita se "miniature" yekuchaja bhangi.
Mumaseketi edhijitari, huwandu hukuru hwemazuva ano hunowanzodikanwa kuita gedhi state switching.Sezvo kushandura mhepo dzenguva pfupi dzichigadzirwa pane chip panguva yekuchinja uye kuyerera kuburikidza nebhodhi redunhu, zvinobatsira kuve nekuwedzera "spare" macheji.Kana pasina kubhadharisa kwakakwana paunenge uchiita shanduko, magetsi emagetsi anochinja zvakanyanya.Kunyanya kuchinja magetsi kunokonzeresa kuti dhijitari yedhijitari ipinde munzvimbo isina chokwadi, uye inogona kuita kuti muchina wehurumende uri mudhijitari ushande zvisizvo.
Iyo inoshandura ikozvino inoyerera kuburikidza nedunhu bhodhi trace ichaita kuti voltage ichinje, uye redunhu bhodhi trace ine parasitic inductance.Iyi inotevera formula inogona kushandiswa kuverenga shanduko yemagetsi: V = LdI/dt.Pakati pavo: V = voltage shanduko, L = circuit board trace inductance, dI = ikozvino kuchinja kuburikidza nekutsvaga, dt = ikozvino kuchinja nguva.
Nokudaro, nokuda kwezvikonzero zvakawanda, zviri nani kushandisa bypass (kana decoupling) capacitors pamagetsi emagetsi kana pamapini emagetsi emagetsi anoshanda.
Tambo yemagetsi netambo yepasi zvinofanira kufambiswa pamwe chete
Nzvimbo yetambo yemagetsi uye waya yepasi yakanyatsoenderana kudzikisa mukana wekukanganiswa kwemagetsi.Kana tambo yemagetsi uye tambo yepasi zvisina kunyatsoenderana, system loop ichagadzirwa uye ruzha rungangogadzirwa.
Muenzaniso wePCB dhizaini apo tambo yemagetsi uye tambo yepasi zvisina kunyatsoenderana inoratidzwa muMufananidzo 2. Paiyi bhodhi redunhu, iyo yakagadzirirwa loop nzvimbo ndeye 697cm².Uchishandisa iyo nzira inoratidzwa muMufananidzo 3, mukana weiyo ruzha rwemhepo pairi kana kubva pabhodhi redunhu inducing voltage muchiuno inogona kuderedzwa zvakanyanya.
Musiyano uripo pakati peanalog uye digital wiring mazano
▍ Ndege yepasi idambudziko
Ruzivo rwekutanga rwedunhu bhodhi wiring rinoshanda kune ese analog uye dijitari maseketi.Mutemo wekutanga wegunwe kushandisa ndege yepasi isina kukanganiswa.Iyi pfungwa yakajairika inoderedza iyo dI/dt (shanduko yemazuva ano nenguva) mhedzisiro mumaseketi edhijitari, inoshandura kugona kwepasi uye kukonzera ruzha kupinda maseketi eanalogi.
Iyo wiring matekiniki edhijitari uye analog maseketi akafanana, kunze kwechimwe chete.Kumaseketi eanarogi, pane imwe pfungwa yekucherechedza, ndiko kuti, chengetedza mitsetse yechiratidzo chedhijitari uye zvishwe mundege yepasi kure kure nemasekete eanalogi sezvinobvira.Izvi zvinogona kuwanikwa kuburikidza nekubatanidza iyo analogi yepasi ndege kune iyo system system yekubatanidza zvakasiyana, kana kuisa anaroji redunhu kumucheto kure kwebhodhi redunhu, inova kuguma kwemutsara.Izvi zvinoitirwa kuchengetedza kupindira kwekunze munzira yechiratidzo kusvika kushoma.
Hapana chikonzero chekuita izvi kune dhijitari maseketi, ayo anogona kushivirira ruzha rwakanyanya pasi pasi pasina matambudziko.
Mufananidzo 4 (kuruboshwe) unoparadzanisa dhijitari yekuchinja chiito kubva kudunhu reanalogi uye inoparadzanisa dhijitari uye analog zvikamu zvedunhu.(Kurudyi) Iyo yakakwira frequency uye yakaderera frequency inofanirwa kuparadzaniswa zvakanyanya sezvinobvira, uye iyo yakakwirira frequency zvikamu zvinofanirwa kunge zviri padyo nedhiketi bhodhi zvibatanidza.
Mufananidzo 5 Gadzirisa mbiri dzepedyo paPCB, zviri nyore kugadzira parasitic capacitance.Nekuda kwekuvapo kwerudzi urwu rwe capacitance, kukurumidza kuchinja kwemagetsi pane imwe trace inogona kuburitsa chiratidzo chazvino pane imwe trace.
Mufananidzo 6 Kana iwe ukasatarisisa pakuiswa kwezvironda, zvinoteedzana muPCB zvinogona kuburitsa mutsara inductance uye mutual inductance.Iyi parasitic inductance inokuvadza zvakanyanya pakushanda kwemaseketi kusanganisira dhijitari switching circuits.
▍Chikamu nzvimbo
Sezvambotaurwa pamusoro apa, mune imwe neimwe PCB dhizaini, iyo ruzha chikamu chedunhu uye "yakanyarara" chikamu (isina-ruzha chikamu) chinofanira kuparadzaniswa.Kazhinji kutaura, maseketi edhijitari "akapfuma" muruzha uye haanzwe ruzha (nekuti maseketi edhijitari ane yakakura kushivirira ruzha);pane zvinopesana, iyo voltage ruzha kushivirira kweanalogi masekete idiki zvakanyanya.
Pakati peaya maviri, analogi masekete ndiwo anonyanya kunzwisiswa nekuchinja ruzha.Mune wiring yeakasanganiswa-signal system, aya matunhu maviri anofanira kupatsanurwa, sezvakaratidzwa mumufananidzo 4.
▍Parasitic zvikamu zvinogadzirwa nePCB dhizaini
Zvinhu zviviri zvakakosha zveparasitic izvo zvinogona kukonzera matambudziko zvinoumbwa zviri nyore muPCB dhizaini: parasitic capacitance uye parasitic inductance.
Paunenge uchigadzira bhodhi redunhu, kuisa mitsetse miviri padyo nemumwe kunoburitsa parasitic capacitance.Iwe unogona kuita izvi: Pazvikamu zviviri zvakasiyana, isa imwe trace pamusoro peimwe;kana pachikamu chimwe chete, isa chironda chimwe padivi pechimwe chinotevera, sezvaratidzwa mumufananidzo 5.
Mune maviri aya magadzirirwo ekutsvaga, shanduko mumagetsi nekufamba kwenguva (dV/dt) pane imwe trace inogona kukonzera ikozvino pane imwe trace.Kana iyo imwe trace yakakwira impedance, ikozvino inogadzirwa nemunda wemagetsi inoshandurwa kuita voltage.
Fast voltage transients inowanzoitika padivi redhijitari reiyo analog chiratidzo dhizaini.Kana iwo maronda ane kukurumidza voltage transients ari padyo neakakwira-impedance analog traces, kukanganisa uku kuchakanganisa zvakanyanya kurongeka kweanalog wedunhu.Munharaunda iyi, masekete eanaroji ane zvipingamupinyi zviviri: kushivirira kwavo ruzha kwakaderera zvakanyanya kupfuura kwedhijitari matunhu;uye yakakwirira impedance traces inowanzoitika.
Kushandisa imwe yenzira mbiri dzinotevera kunogona kuderedza chiitiko ichi.Iyo inonyanya kushandiswa nzira ndeyekushandura saizi pakati pematanho zvichienderana neiyo capacitance equation.Hukuru hunobudirira zvikuru hwekushandura ndiyo chinhambwe chiri pakati pematanho maviri.Zvinofanira kucherechedzwa kuti shanduko d iri mudhinomineta ye capacitance equation.Sezvo d ichiwedzera, iyo capacitive reactance inoderera.Imwe shanduko inogona kushandurwa kureba kwemavara maviri.Muchiitiko ichi, kureba L kunoderera, uye capacitive reactance pakati pematanho maviri achadererawo.
Imwe nzira ndeyekuisa tambo yepasi pakati pezvitsva zviviri izvi.Iyo yepasi waya yakaderera impedance, uye kuwedzera imwe tsvakiridzo senge iyi kunoderedza kupindira kwemagetsi munda, sezvakaratidzwa mumufananidzo 5.
Nheyo yeparasitic inductance mubhodhi redunhu yakafanana neyeparasitic capacitance.Zvinorevawo kuisa mitsara miviri.Pazvikamu zviviri zvakasiyana, isa imwe trace pamusoro peimwe trace;kana pachikamu chimwe chete, isa chironda chimwe padivi pechimwe, sezvinoratidzwa mumufananidzo 6.
Mune idzi mbiri dzekugadzirisa wiring, shanduko yemazuva ano (dI / dt) yekutsvaga nenguva, nekuda kwekuita kwekutsvaga kwekutsvaga uku, kuchaita voltage pane imwechete;uye nekuda kwekuvapo kwekuwirirana inductance, ichaita A proportional current inogadzirwa pane imwe trace.Kana magetsi achinja pane yekutanga trace yakakura zvakakwana, kupindira kunogona kuderedza kushivirira kwevoltage yedhijitari yedunhu uye kukonzera kukanganisa.Chiitiko ichi hachingoitike mumaseketi edhijitari, asi chiitiko ichi chinowanzoitika mumaseketi edhijitari nekuda kweiyo hombe yekuchinjisa mafungu mumaseketi edhijitari.
Kuti ubvise ruzha runogona kuitika kubva kumagetsi emagetsi ekukanganisa masosi, zviri nani kupatsanura "yakanyarara" mitsetse yeanalogi kubva kune ine ruzha I / O ports.Kuedza kuwana yakaderera-impedance simba uye pasi network, iyo inductance yedhijitari yedunhu waya kunofanirwa kuderedzwa, uye capacitive coupling yemasekete analogi inofanira kuderedzwa.
03
Mhedziso
Mushure mekunge dhijitari neanalogi siyana dzatemerwa, kutarisisa kwakakosha kune yakabudirira PCB.Wiring zano rinowanzounzwa kune wese munhu sekutonga kwechigunwe, nekuti zvakaoma kuyedza kubudirira kwekupedzisira kwechigadzirwa munzvimbo yerabhoritari.Naizvozvo, zvisinei nekufanana kwemaitiro ewaya edhijitari neanalogi maseketi, misiyano yemaitiro avo ekuisa waya inofanira kucherechedzwa uye kutorwa zvakanyanya.