Kurongeka ndeimwe yehunyanzvi hwekuita basa Pcb dhizaini mainjiniya. Hunhu hwewiring hunokanganisa mashandiro ehurongwa hwese, hwakawanda hwekumhanyisa dhizaini dhizaini inofanirwa kuzadzikiswa nekusimbiswa neMarongero, saka zvinogona kuoneka kuti wiring yakakosha mukumhanyisa-kumhanyisa pcb dhizaini. Izvi zvinotevera zvichange zviri mukutarisa kweiyo chaiyo wiring inogona kusangana nemamwe mamiriro ezvinhu, kuongororwa kweyekufunga kwayo, uye nekupa imwe yakagadziriswa nzira yekufambisa. Kunyanya kubva kurudyi Angle mutsetse, musiyano mutsetse, nyoka mutsara uye zvichingodaro pazvinhu zvitatu zvekujekesa.

1. Rectangular enda mutsara

Wiring-kurudyi wiring inowanzo fanirwa kudzivirira mamiriro ari muPCB wiring, uye yave kuda kuve imwe yematanho ekuyera mhando yeiyo wiring, saka ingani mhedzisiro iyo kurudyi-kona wiring ichave nekutumira chiratidzo? Mukutaura, kurudyi-kona wiring kuchachinja hwaro hwemitsara yetambo yekufambisa, zvichikonzera impedance discontinuity. Muchokwadi, kwete chete kurudyi Angle mutsetse, ton Angle, yakaoma Angle mutsetse inogona kukonzera impedance shanduko.

Iko kukanganisa kwekurudyi-kona kurongeka pane chiratidzo kunonyanya kuratidzwa mumatatu zvinhu: chekutanga, iyo kona inogona kunge yakaenzana neiyo capacitive mutoro patambo yekufambisa, ichidzora nguva yekukwira; Chechipiri, impedance discontinuity inokonzeresa chiratidzo chiratidzo. Yetatu, EMI inogadzirwa nekona Angle tip.

Iyo parasitic capacitance inokonzerwa nekona kona yeiyo tambo yekufambisa inogona kuverengerwa neinotevera empirical fomula:

C = 61W (Er) 1/2 / Z0

Mune fomula iri pamusoro, C inoreva iyo yakaenzana capacitance pakona (pF), W inoreva hupamhi hwemutsara (inch), ε R inoreva kudhiraivhidhi yemagetsi yepakati, uye Z0 ndiyo inokanganisa kutapurirana. mutsara. Semuenzaniso, kune 4Mils 50 ohm yekufambisa mutsara (εr 4.3), iyo capacitance yeiyo kurudyi Angle ingangoita 0.0101pF, uye iyo yekukwira nguva kusiana kunogona kufungidzirwa:

T10-90% = 2.2 * C * z0 / 2 = 2.2 * 0.0101 * 50/2 = 0.556ps

Zvinogona kuonekwa kubva pakuverenga kuti iyo capacitance mhedzisiro inounzwa nekona-kona wiring idiki zvakanyanya.

Sezvo mutsetse upamhi hwekona-kona tambo inowedzera, iyo impedance panguva ino ichadzikira, saka pachave nechimwe chiratidzo chekuratidzira chiitiko. Isu tinokwanisa kuverenga iyo yakaenzana impedance mushure mekuwedzera kwemutsara yakaenzana zvinoenderana neiyo impedance yekuverenga fomula inotaurwa muchikamu chemitsara yekutapurirana, uyezve kuverenga iyo coefficient yekuratidzira zvinoenderana nefomula fomula: = Zvakare, sezvazvinogona kuonekwa kubva pamufananidzo uri pazasi, iyo yekuparadzira tambo impedance inochinja kusvika padiki mukati mehurefu hweW / 2 mutsetse, uye wozodzorera kune yakajairwa impedance mushure meW / 2 nguva. Iyo nguva yeiyo yose impedance shanduko ipfupi, kazhinji mukati me10ps. Shanduko yakadaro nekukurumidza uye diki ingangoita isingakoshese kufambiswa kwechiratidzo kwese.

Vanhu vazhinji vane kunzwisiswa kwakadaro kwenzira yekurudyi-yekona, vachifunga kuti muromo wacho uri nyore kuburitsa kana kugamuchira mafungu emagetsi uye kugadzira EMI, inova imwe yezvikonzero nei vanhu vazhinji vachifunga nzira yekukona-nzira isingagone. Nekudaro, yakawanda inoshanda mhedzisiro mhedzisiro inoratidza kuti kurudyi-kona mutsara haigadzire EMI yakawanda kupfuura yakatwasuka mutsara. Zvichida ikozvino chiridzwa mashandiro uye chiyero cheyedzo chinodzivisa kurongeka kweye bvunzo, asi zvirinani zvinoratidza kuti mwaranzi yekona-kona mutsara wakaderera pane iko kuyera kukanganisa kwechiridzwa icho zvacho. Kazhinji, kurudyi-kona kurongeka hakuna kutyisa sezvingaite sekunge. Zvirinani mukushandisa pazasi peGHz, chero mhedzisiro senge capacitance, ratidziro, EMI, nezvimwe hazvifanirwe kuratidzwa mukuedzwa kweTDR. Iyo mainjiniya ekugadzira epamusoro-kumhanyisa pcb anofanirwa kutarisa pakurongeka, simba / pasi dhizaini, dhizaini dhizaini, perforation, nezvimwe. Kunyangwe hazvo, mhedzisiro yemakona emakona ekuenda mutsara isiri yakakomba, asi hazvireve kuti isu tinogona kufamba kurudyi Angle mutsetse, kutarisa kune yakadzama ndiyo yakakosha mhando kune ese akanaka mainjiniya, uye, nekukurumidza kukurumidza kwemadhijitari edhijitari. , MaPBB mainjiniya ekugadzirisa frequency chiratidzo zvakare ichaenderera nekuvandudza, kune anopfuura gumi GHZ RF dhizaini munda, Aya madiki angles ekurudyi anogona kuve tarisiro yeakakwira-mhanyisa matambudziko.

2. Musiyano we

DifferenTIal Signal inoshandiswa zvakanyanya mukumhanyisa-kumhanya wedunhu dhizaini. Chiratidzo chakakosha kwazvo mudunhu ndiDigerenTIal Signal dhizaini. Nzira yekuona sei kuita kwayo kwakanaka muPCB dhizaini? Tichifunga iyi mibvunzo miviri, tinoenderera kuchikamu chinotevera chehurukuro yedu.

Chii chinonzi musiyano chiratidzo? MuChirungu chakajeka, mutyairi anotumira maviri akaenzana uye inverting masaini, uye iye anogamuchira anofananidza musiyano uripo pakati pemaviri voltages kuti aone kana zvine musoro nyika iri “0” kana “1”. Iwo waya maviri akatakura akasiyana masignasi anonzi masiyano waya.

Inofananidzwa neyakajairika imwechete-inopera siginara, chiratidzo chekusiyanisa chine zvakwakanakira zvakanyanya muzvinhu zvitatu zvinotevera:

A. Simba rekurwisa kupindira, nekuti kubatana pakati pemitsara miviri yakanaka kwazvo, kana paine kupindirana kweruzha, anenge akabatana netambo mbiri panguva imwe chete, uye iye anogamuchira anongoita hanya nezve mutsauko uripo pakati pezviratidzo zviviri, saka ruzha rwekunze-modhi ruzha runogona kudzimwa zvachose.

B. Inogona kudzvinyirira EMI. Saizvozvowo, nekuti maviri maseru ari eopokana polarity, iyo electromagnetic munda inopenyerwa navo inogona kukanzirana. Iyo yepedyo yekubatanidza ndeye, iyo shoma magetsi magetsi inosunungurwa kune yekunze nyika.

C. Kuisa nguva kwakaringana. Sezvo shanduko yekuchinja kwemasaini akasiyana iri pamharadzano yemasaini maviri, kusiyana nezviratidzo zvakajairika zvinongotariswa nematanho epasi uye akaderera, hainyanyo kukanganiswa nemaitiro uye tembiricha, iyo inogona kudzikamisa nguva yekukanganisa uye inokodzera yemasekete ane akaderera amplitude zviratidzo. LVDS (yakaderera voltage mutsaukoTIalsignaling) inoreva kune iyi diki amplitude kusiyanisa chiratidzo tekinoroji.

Kune mainjiniya ePBB, chinonyanya kukosha inyaya yekuita chokwadi chekuti izvi zvakanaka zvekusiyanisa nzira dzinogona kushandiswa zvizere munzira chaiko. Zvichida sekureba sekunge kuri kusangana neRarongedzo vanhu vanonzwisisa izvo zvakajairika zvinodikanwa zvekusiyanisa nzira, iyo “yakaenzana kureba, yakaenzana daro”. Isometric ndeyekuona kuti iwo maviri masiyano masaini anogara achiramba akatarisana polarity, inoderedza yakajairwa mode chinhu; Isometric ndeye kunyanya kuona imwecheteyo kusiyanisa impedance, kudzikisa kuratidza. “Sezvo padhuze nepazvinogona” dzimwe nguva chimwe chezvinhu zvinodiwa kusiyanisa nzira. Asi hapana kana imwe yemitemo iyi inoitirwa kuti ishandiswe nenzira, uye mainjiniya mazhinji anoita kunge asinganzwisise hunhu hwekuratidzira kwekumhanya-mhanyisa. Izvi zvinotevera zvinotarisa pane zvakajairika zvikanganiso muPCB kusiyanisa chiratidzo dhizaini.

Kufungidzira zvisizvo 1: Zviratidzo zvakasiyana hazvidi ndege yepasi senzira yekudzokera shure, kana kufunga kuti mitsara yekusiyanisa inopa nzira yekudzokera kune imwe neimwe. Chikonzero chekusanzwisisa uku chakakanganiswa neicho chepamusoro chiitiko, kana mashandiro ekumhanyisa-kumhanyisa chiratidzo kutapurirana hakuna kudzika zvakakwana. Sezvinoonekwa kubva kune chimiro chemugumo wekugamuchira muFIG. 1-8-15, emitter mafungu e transistors Q3 uye Q4 akaenzana uye akatarisana, uye yavo yazvino pamharadzano kunyatso kubviswa (I1 = 0). Naizvozvo, musiyano wedunhu hauna hanya neakafanana epasi majekiseni uye mamwe maratidziro eruzha anogona kunge aripo mumagetsi uye ndege yepasi. Kukamurwa kusarudzika kwekudzoserwa kwendege yepasi hazvireve kuti musiyano wedunhu hautore ndege yekuratidzira senzira yekudzoka kwemasaini. Muchokwadi, mune chiratidzo backflow ongororo, iyo nzira yekusiyanisa nzira yekufambisa yakafanana neiyo yakajairwa imwechete-yekupedzisira nzira, kureva, yakakwira

Iyo frequency chiratidzo inogara ichiyerera ichidzoka pamwe nedunhu neiyo diki inductance. Musiyano mukuru uripo pakuti mutsetse wemutsara haungobatanidzi pasi chete, asi zvakare une kubatana pakati peumwe neumwe. Iyo yakasimba coupling inova iyo huru yekudzoka nzira.

Mune pcb wedunhu dhizaini, iko kubatanidza pakati pekusiyanisa wiring kunowanzo kuve kudiki, kazhinji kuverenga chete kwe10 ~ 20% yeiyo yekubatanidza degree, uye yakawanda yekubatanidza ndeye pasi, saka iyo huru yekudzoka nzira yekusiyanisa wiring ichiripo muvhu ndege. Panyaya yekurega kuenda mundege yemuno, kubatana pakati penzira dzakasiyana kunopa nzira yekudzokera kumashure mudunhu isina ndege yekutaurisa, sezvakaratidzwa muFIG. 1-8-17. Kunyangwe hazvo kukanganiswa kwekuregeredzwa kwereferensi yendege pamusiyano wiring isiri yakakomba seyeyeyechete-magumo wiring, icharamba ichideredza mhando yemasaini chiratidzo uye kuwedzera EMI, iyo inofanirwa kudzivirirwa kusvika pazvinogona. Vamwe vagadziri vanodavira kuti ndege yereferenzi yemutsara wekusiyanisa hutachiona inogona kubviswa kudzvinyirira chikamu cheyakajairwa modhi chiratidzo mukutenderera kwekusiyanisa, asi dzidziso iyi nzira haina kudikanwa. Ungadzora sei impedance? Pasina kupa pasi impedance chiuno kune yakajairika-modhi chiratidzo, EMI radiation inosungirwa kukonzerwa, iyo inokuvadza kupfuura kunaka.

Nhema dzechipiri: Kuchengetedza nzvimbo dzakaenzana kwakakosha kupfuura kuenzanisa urefu hwemutsara. Mune iyo chaiyo pcb wiring, kazhinji haigone kuzadzisa zvinodiwa nemusiyano dhizaini. Nekuda kwekuparadzirwa kwepini, maburi, uye wiring nzvimbo uye zvimwe zvinhu, zvinofanirwa kuzadzisa chinangwa chehurefu hwakaenzana kuburikidza nekukomberedza kwakakodzera, asi mhedzisiro yacho isingadzivisike chikamu chemusiyano vaviri haugone kufanana, panguva ino, sei kusarudza? Tisati tasvetukira kumhedziso, ngatitarisei pane anotevera simulation mhedzisiro. Zvinogona kuonekwa kubva pamhedzisiro yekuenzanisira iri pamusoro yekuti mafomu ekushambadzira echirongwa 1 uye Scheme 2 angangoenderana, ndiko kuti, simba rekusiyanisa nzvimbo rakashomeka, uye pesvedzero yemutsara kureba mismatch yakanyanya kukura pakuteedzana kwenguva (Scheme 3) . Kubva pakuona kwekuongorora kwedzidziso, kunyangwe nzvimbo isingaenderane inotungamira kune mutsauko impedance shanduko, asi nekuti iko kubatanidza pakati pemusiyano vaviri pachawo hauna kukosha, saka huwandu hweiyo impedance shanduko zvakare diki kwazvo, kazhinji mukati me10%, chete zvakaenzana kuchiratidziro chinokonzerwa negomba, icho chisingazokonzere kukanganisa kukuru kutapurirana kwechiratidzo. Kana kureba kwetambo kukatadza kuenzanisirwa, mukuwedzera pakateedzana kwenguva, zvakajairika mamodhi zvikamu zvinounzwa musiyano chiratidzo, izvo zvinoderedza mhando yemasaini uye zvinowedzera EMI.

Zvinogona kutaurwa kuti wakanyanya kukosha mutemo muPCB kusiyanisa wiring dhizaini ndeyekuenderana nehurefu hwemutsara, uye mimwe mirau inogona kubatika nenzira inoshanduka zvinoenderana nezvinodiwa dhizaini uye mashandiro anoshanda.

Manyepo matatu: funga mutsauko mutsara unofanirwa kuvimba nepedyo chaizvo. Iyo poindi yekuchengeta misiyano mitsara padyo pamwe hapana chimwe kunze kwekuwedzera kubatanidza kwavo, zvese kuvandudza hutachiona hwavo kuruzha uye kutora mukana wekupokana polarity yemagineti kudzima magetsi emagetsi kupindira kubva kunze kwenyika. Kunyangwe iyi nzira ichifarira kwazvo muzviitiko zvakawanda, haina mhedziso. Kana vachigona kudzivirirwa zvizere kubva mukukanganisa kwekunze, saka isu hatidi kuzadzikisa chinangwa chekurwisa-kupindira uye kudzvinyirira EMI kuburikidza nekubatana kwakasimba nemumwe nemumwe zvakare. Nzira yekuona sei kuti kusiyanisa nzira kune yakasarudzika yakanaka uye inodzivirira? Kuwedzera chinhambwe pakati pemitsara nezvimwe zviratidzo ndiyo imwe yenzira dzakanyanya kukosha. Simba remagetsi emagetsi rinoderera nehukama hwenzvimbo yedaro. Kazhinji, kana daro pakati pemitsara iri kanopfuura kanokwana kana paupamhi hwemutsara, kupindira pakati payo kwakanyanya kusimba uye kunogona kufuratirwa. Uye zvakare, kuzviparadzanisa kuburikidza nendege yepasi kunogona zvakare kupa yakanaka yekudzivirira maitiro. Ichi chimiro chinowanzo shandiswa mune yakakwira-frequency (pamusoro pe10G) IC yakarongedzwa pcb magadzirirwo, anozivikanwa seiyo CPW chimiro, kuve nechokwadi chakasimba kusiyanisa impedance control (2Z0), FIG. 1-8-19.

Nzira dzakasiyana dzinogona kuitwawo mumatanho emasaini akasiyana, asi izvi hazviwanzo kukurudzirwa, nekuti misiyano senge impedance uye kuburikidza nemakomba mumativi akasiyana anogona kuparadzanisa kusiyanisa kwemaitiro ekuparadzira mhedzisiro uye kuunza yakajairika modhiyo ruzha. Pamusoro pezvo, kana zvidimbu zviviri zviri padhuze zvisina kusunganidzwa, kugona kwekusiyanisa nzira kurwisa ruzha kunoderedzwa, asi crosstalk harisi dambudziko kana nzvimbo yakakodzera ichichengetedzwa nemigwagwa yakatenderedza. Kazhinji kazhinji (pazasi peGHz), EMI haizove dambudziko rakakomba. Ongororo dzinoratidza kuti mwaranzi yekudzivirira simba remitsara yekusiyanisa ine chinhambwe che500Mils kupfuura 3 metres yasvika 60dB, izvo zvinokwana kusangana nemagetsi emagetsi eECCROMAGNETIC. Naizvozvo, vagadziri havafanirwe kunetseka zvakanyanya pamusoro pemagetsi kusaenderana kunokonzerwa nekusakwana kwekubatanidza kwetambo dzakasiyana.

3. serpentine

Mutsara wenyoka unowanzo shandiswa mu Layout. Chinangwa chayo chikuru kugadzirisa nguva yekunonoka uye kusangana nezvinodiwa zvehurongwa hwenguva yekugadzira. Vagadziri vanofanirwa kutanga vanzwisisa kuti nyoka yenyoka ichaparadza mhando yemasaini, kuchinja kunonoka kwekufambisa, uye kunofanirwa kudzivirirwa kana wiring. Nekudaro, mukugadzirwa kunoshanda, kuitira kuti uve nechokwadi chakakwana chekubata nguva yemasaini, kana kudzikisira nguva kubva pakati peboka rimwe chete remasaini, kumhanyisa kunofanirwa kuitwa nemaune.

Saka chii chinoitwa nenyoka kuratidza kutapurirana? Chii chandinofanira kutarisisa kana ndichifamba mutsetse? Iwo maviri akakosha parameter akaenzana yekubatanidza kureba (Lp) uye yekubatanidza daro (S), sezvakaratidzwa muFIG. 1-8-21. Zviripachena, kana chiratidzo chichifambiswa mumutsara wenyoka, pachave nekubatana pakati pezvikamu zvemitsara yakafanana muchimiro chemusiyano modhi. Idiki S iri, yakakura Lp iri, uye yakakura dhi yekubatanidza ichave. Izvi zvinogona kukonzera kudzikisira kutapudza kwekutapudza uye kudzikisira kwakakosha kwehunhu hwechiratidzo nekuda kwecrosstalk, sezvakatsanangurwa muchitsauko 3 chekuongororwa kweyakajairika modhi uye musiyano modhiyo crosstalk.

Heano mamwe matipi e Layout mainjiniya kana uchibata nenyokaine:

1. Edza kuwedzera chinhambwe (S) chechikamu cheiyi mutsara, icho chakati kurei kupfuura 3H. H inoreva kureba kubva pamutsara wemutsara kuenda kunhandare yereferenzi. Kazhinji kutaura, iko kutora rakakura curve. Chero bedzi S iri yakakura zvakakwana, iyo yekubatanidza mhedzisiro inogona kunge ingangove yakadzivirirwa zvachose.

2. Kana urefu hwekubatanidza Lp hwaderedzwa, iyo crosstalk inogadzirwa inosvika pakuzadza apo kunonoka kweLp kunosvika kaviri kana kudarika nguva yekusimuka kwechiratidzo.

3. Iko kunonoka kwekutapudza kwechiratidzo kunokonzerwa nenyoka-senge Mutsetse we-tambo-tambo kana Yakabatanidzwa micro-strip iri diki pane yeiyo micro-strip. Pfungwa, tambo yerabhoni haigadzirise chiyero chekutapurirana nekuda kwekusiyanisa nzira crosstalk.

4. Kune yakakwira-kumhanya uye mitsara yemasaini ine zvinyatso kudiwa panguva, edza kusafamba mitsara yenyoka, kunyanya munzvimbo diki.

5. Iyo yenyoka yekufambisa pane chero Angle inogona kugamuchirwa kazhinji. Iyo C chimiro muFIG. 1-8-20 inogona kudzora zvinobudirira kubatanidza pakati peumwe neumwe.

6. Mukumhanyisa-kumhanyisa pcb dhizaini, nyokaine haina kunzi kusefa kana kugona kupokana nekukanganisa, uye inogona chete kudzikisira mhando yechiratidzo, saka inongoshandiswa chete mukuenzanisa nguva uye hapana chimwe chinangwa.

7. Dzimwe nguva kutenderera kwemhepo kunogona kutariswa. Kufananidza kunoratidza kuti maitiro acho ari nani pane zvakajairwa nyoka kumhanyisa.