Kuti tinzwisise mutsara wenyoka, ngatitaure nezvazvo PCB kutanga kutanga. Pfungwa iyi inoita seisingade kuunzwa. Injiniya yehardware haisi kuita wiring basa mazuva ese? Yese inoteedzera paPCB inoburitswa imwe neimwe neinjiniya yehardware. Chii chingataurwa? Muchokwadi, iyi nzira iri nyore ine zvakare yakawanda yeruzivo mapoinzi atinowanzo kufuratira. Semuenzaniso, pfungwa ye microstrip line uye stripline. Zvichitaurwa zviri nyore, iyo microstrip mutsara ndiyo inoteedzera pamusoro pePCB board, uye mutsara ndiyo inoteedzera inomhanya mukati meiyo PCB. Ndeupi musiyano uripo pakati pemitsara miviri iyi?

Iyo inotaridzirwa ndege ye microstrip line ivhu repasi remukati wePCB, uye rumwe rutivi rwekutsvaga runoratidzwa kumhepo, izvo zvinoita kuti dielectric igare yakatenderedza mutsara isingaenderani. Semuenzaniso, dielectric constant yeinowanzo shandiswa FR4 substrate iri Around 4.2, dielectric constant of air is 1. Kune mareferensi ndege kumativi ose ekumusoro uye pasi pemutsara wemutsara, mutsara wose wakaiswa muPCB substrate, uye iyo dielectric inogara yakatenderedza trace yakafanana. Izvi zvinoitawo kuti TEM wave ifambiswe pamutsara wemutsetse, nepo quasi-TEM wave ichifambiswa pamutsetse wemicrostrip. Nei iri quasi-TEM wave? Izvi zvinokonzerwa nekusawirirana kwechikamu pane chinongedzo pakati pemhepo nePCB substrate. Chii chinonzi TEM wave? Kana ukachera zvakadzama pamusoro penyaya iyi, haungakwanisi kuipedza mumwedzi gumi nechidimbu.

Kuita kuti nyaya refu ive pfupi, ingave mutsara wemicrostrip kana mutsara, basa ravo hapana chimwe kunze kwekutakura masaini, angave masaini edhijitari kana masaini eanalogi. Aya masaini anofambiswa ari muchimiro chemagetsi emagetsi kubva kune imwe mugumo kuenda kune imwe mukutevera. Sezvo iri masaisai, panofanira kuva nekumhanya. Ndeipi kumhanya kwechiratidzo paPCB trace? Maererano nekusiyana kwe dielectric nguva dzose, kumhanya kwakasiyanawo. Kumhanya kwekuparadzira kwemagetsi emagetsi mumhepo ndiko kunozivikanwa kumhanya kwechiedza. Iyo yekuparadzira velocity mune mamwe midhiya inofanirwa kuverengerwa neinotevera formula:

V=C/Er0.5

Pakati pazvo, V ndeyekumhanya kwekuparadzira mukati, C ndiko kumhanya kwechiedza, uye Er ndiyo dielectric yepakati. Kuburikidza neiyi fomula, isu tinogona kuverenga zviri nyore kumhanya kweiyo chiratidzo pane PCB trace. Semuyenzaniso, isu tinongotora dielectric garage yeFR4 base material muforoma yekuiverenga, kureva kuti, kumhanya kwekufambisa kwechiratidzo muFR4 base material ihafu yekumhanya kwechiedza. Zvisinei, nokuti hafu yemutsara we microstrip inotevedzwa pamusoro iri mumhepo uye hafu mu substrate, iyo dielectric nguva dzose ichaderedzwa zvishoma, saka kukurumidza kwekufambisa kuchave kwakakurumidza kudarika iyo yemutsara wemutsara. Iyo inowanzoshandiswa empirical data ndeyekuti kunonoka kweiyo microstrip mutsara kunosvika 140ps/inch, uye kunonoka kweiyo stripline ingangoita 166ps/inch.

Sezvandambotaura, pane chinangwa chimwe chete, ndiko kuti, kufambisa kwemasaini paPCB kwakanonoka! Kureva kuti, chiratidzo hachifambiswe kune imwe pini kuburikidza newaya nekukurumidza mushure mekunge imwe pini yatumirwa. Kunyangwe iyo yekumhanyisa chiratidzo ichimhanya zvakanyanya, chero kureba kwekutsvaga kwakareba zvakakwana, kunoramba kuchikanganisa kufambiswa kwechiratidzo. Semuenzaniso, kune chiratidzo che 1GHz, nguva yacho ndeye 1ns, uye nguva yekukwira kana kudonha mupendero ingangoita chikamu chimwe chete mugumi chenguva, yozove 100ps. Kana kureba kwekutsvaga kwedu kwakapfuura 1 inch (inenge 2.54 cm), ipapo kunonoka kwekutapurirana kuchave kwakawanda kudarika kukwira. Kana iyo yekutsvaga inopfuura masendimita masere (anenge 8 cm), ipapo kunonoka kuchava kutenderera kwakazara!

Zvinoitika kuti PCB ine simba rakakura kudaro, zvakajairika kuti mabhodhi edu ave neanopfuura 1inch traces. Ko kunonoka kunokanganisa kushanda kwebhodhi? Kutarisa kune chaiyo system, kana ingori chiratidzo uye iwe usingade kudzima mamwe masaini, saka kunonoka kunenge kusingaite. Nekudaro, mune yakakwirira-kumhanya system, kunonoka uku kuchaita chaizvo. Semuenzaniso, yedu yakajairwa memory particles yakabatana muchimiro chebhazi, ine data mitsara, kero mitsara, wachi, uye control mitsara. Tarisa uone vhidhiyo yedu interface. Hazvina mhosva kuti machanei mangani HDMI kana DVI, ichange iine data chiteshi uye wachi. Kana mamwe maprotocol ebhazi, ese ari synchronous kuendesa data newachi. Zvadaro, mune chaiyo yekumhanya-mhanya sisitimu, aya masaini masaini uye data masaini anotumirwa synchronously kubva kuhombe chip. Kana PCB yedu yekutsvaga dhizaini yakashata, kureba kwechiratidzo chewachi uye chiratidzo chedata chakasiyana kwazvo. Zviri nyore kukonzera zvisirizvo sampling yedata, uye ipapo iyo system yese haizoshande zvakajairika.

Chii chatinofanira kuita kuti tigadzirise dambudziko iri? Nomuzvarirwo, taizofunga kuti kana mitsetse yenguva pfupi yakarebeswa kuitira kuti kureba kweboka rimwe chete rifanane, zvino kunonoka kuchava kwakafanana? Nzira yekurebesa sei wiring? Tenderera! Bhingo! Hazvisi nyore kuti pakupedzisira udzoke kunyaya. Iri ndiro basa guru remutsara wenyoka mune yepamusoro-speed system. Kupeta, kureba kwakaenzana. Zviri nyore. Mutsara wenyoka unoshandiswa kufambisa hurefu hwakaenzana. Nekukwevera mutsara wenyoka, tinogona kuita kuti boka rimwechete rezviratidzo rive nehurefu hwakafanana, kuitira kuti mushure mokunge chip yekugamuchira inogamuchira chiratidzo, data haizokonzerwi nekunonoka kwakasiyana paPCB trace. Wrong pick. Mutsara wenyoka wakafanana nematanho ari pane mamwe mabhodhi ePCB.

Iwo anoshandiswa kubatanidza masaini, asi akareba uye haana. Saka mutsara wenyoka hauna kudzika uye hauna kunyanya kuoma. Sezvo yakangofanana nedzimwe wiring, dzimwe dzinowanzoshandiswa mitemo ye wiring inoshandiswawo kune mitsara yenyoka. Panguva imwecheteyo, nekuda kwechimiro chakakosha chemitsara yenyoka, iwe unofanirwa kuiteerera kana wiring. Semuenzaniso, edza kuchengetedza mitsara yenyoka yakabatana kune imwe neimwe kure. Mupfupi, ndiko kuti, famba uchitenderedza muhombe sekutaura kunoita chirevo, usaenda wakakora uye mudiki munzvimbo diki.

Izvi zvese zvinobatsira kuderedza kukanganiswa kwechiratidzo. Mutsara wenyoka uchave nepesvedzero yakaipa pachiratidzo nekuda kwekuwedzera kwekuwedzera kwemutsara kureba, chero bedzi ichigona kuzadzisa zvinodiwa zvenguva muhurongwa, usashandise. Mamwe mainjiniya anoshandisa DDR kana masaini ekumhanya-mhanya kuti boka rese rienzane kureba. Mitsara yenyoka inobhururuka nepamusoro pebhodhi. Zvinoita sekuti iyi iri nani wiring. Kutaura zvazviri, uhwu husimbe uye husina hanya. Nzvimbo dzakawanda dzisingadi kukuvara dzakakuvadzwa, izvo zvinoparadza nzvimbo yebhodhi, uye zvakare zvinoderedza chiratidzo chechiratidzo. Isu tinofanirwa kuverenga kunonoka redundancy zvinoenderana nechaiyo chiratidzo chekumhanyisa zvinodiwa, kuitira kuti titarise iyo wiring mitemo yebhodhi.

Pamusoro pebasa rehurefu hwakaenzana, mamwe mabasa akati wandei emutsetse wenyoka anowanzo kutaurwa muzvinyorwa paInternet, saka ini ndichataurawo muchidimbu nezvazvo pano.

1. Rimwe remazwi andinowanzo kuona ibasa rekufananidza. Mashoko aya anoshamisa zvikuru. Iyo impedance yePCB trace ine hukama nehupamhi hwemutsara, iyo dielectric inogara, uye chinhambwe chendege yereferensi. Rini rine hukama nemutsara wenyoka? Ndeipi iyo chimiro chekutsvaga chinokanganisa impedance? Handizivi kuti mashoko aya anobva kupi.

2. zvinonziwo ibasa rekusefa. Iri basa haringanzi haripo, asi hapafanirwe kuve nekusefa mumaseketi edhijitari kana isu hatifanire kushandisa basa iri mumaseketi edhijitari. Muredhiyo frequency circuit, iyo nyoka trace inogona kuumba LC dunhu. Kana iine yekusefa pane imwe frequency chiratidzo, ichiri yapfuura.

3. Kugamuchira antenna. Izvi zvinogona kuva. Tinogona kuona kuita uku pane dzimwe nharembozha kana maredhiyo. Mamwe antenna anogadzirwa nePCB traces.

4. Inductance. Izvi zvinogona kuva. Zvese zvinoteedzera paPCB pakutanga zvine parasitic inductance. Izvo zvinogoneka kugadzira mamwe maPCB inductors.

5. Fuse. Mhedzisiro iyi inondishamisa. Waya ipfupi uye nhete yenyoka inoshanda sei sefiyuzi? Kusvirwa kana ikozvino yakakwira? Bhodhi harina kuputswa, mutengo weiyi fuse wakanyanya kukwira, handizive kuti ichashandiswa rudzii.

Kuburikidza nesumo iri pamusoro, tinogona kujekesa kuti muanalog kana redhiyo frequency maseketi, mitsara yenyoka ine mamwe mabasa akakosha, ayo anotemerwa nehunhu hwemitsetse mitsetse. Mudhizaini yedunhu dhizaini, mutsara wenyoka unoshandiswa kwehurefu hwakaenzana kuwana nguva yekufananidza. Pamusoro pezvo, mutsara wenyoka uchakanganisa kunaka kwechiratidzo, saka zvinodiwa zvehurongwa zvinofanirwa kujekeswa muhurongwa, iyo system redundancy inofanirwa kuverengerwa zvinoenderana nezvinodiwa chaizvo, uye mutsara wenyoka unofanirwa kushandiswa nekuchenjerera.