Zingwe za SAS zothamanga kwambiri: Zolumikizira ndi Kukonza Zizindikiro

Zingwe za SAS zothamanga kwambiri: Zolumikizira ndi Kukonza Zizindikiro

Mafotokozedwe a Umphumphu wa Chizindikiro

Zina mwa zinthu zazikulu zomwe zimapangitsa kuti chizindikiro chikhale cholondola ndi monga kutayika kwa mawu, kulankhulana kwapafupi ndi kutali, kutayika kobwerera, kusokonekera kwa mawu mkati mwa ma differential pairs, ndi kutalika kwa mawu kuchokera ku differential mode kupita ku common mode. Ngakhale kuti zinthuzi zimagwirizana ndipo zimakhudzana, tikhoza kuganizira chinthu chilichonse chimodzi ndi chimodzi kuti tiphunzire za mphamvu yake yaikulu.
Kutayika kwa Kuyika
Kutayika kwa chizindikiro ndi kuchepa kwa kukula kwa chizindikiro kuchokera kumapeto otumizira mpaka kumapeto olandirira chingwe, ndipo kumagwirizana mwachindunji ndi kuchuluka kwa ma frequency. Kutayika kwa chizindikiro kumadaliranso ndi gauge ya waya, monga momwe zasonyezedwera mu graph yochepetsera pansipa. Pazida zamkati zazifupi zomwe zimagwiritsa ntchito zingwe za 30 kapena 28-AWG, zingwe zapamwamba ziyenera kukhala ndi kuchepa kwa 2 dB/m pa 1.5 GHz. Pa 6 Gb/s SAS yakunja yomwe imagwiritsa ntchito zingwe za 10m, ndikulimbikitsidwa kugwiritsa ntchito zingwe zokhala ndi gauge ya waya yapakati ya 24, zomwe zimakhala ndi kuchepa kwa 13 dB yokha pa 3 GHz. Ngati mukufuna kukwaniritsa malire ambiri a chizindikiro pamitengo yokwera yosamutsa deta, tchulani zingwe zokhala ndi kuchepa kochepa pama frequency apamwamba pa zingwe zazitali, monga SFF-8482 yokhala ndi chingwe cha POWER kapena SlimSAS SFF-8654 8i.

Crosstalk
Crosstalk imatanthauza kuchuluka kwa mphamvu zomwe zimatumizidwa kuchokera ku chizindikiro chimodzi kapena chosiyana kupita ku chizindikiro china kapena chosiyana. Pa zingwe za SAS, ngati crosstalk yapafupi (NEXT) si yaying'ono mokwanira, imayambitsa mavuto ambiri olumikizirana. Kuyeza kwa NEXT kumachitika kumapeto kwa chingwe, ndipo ndi kukula kwa mphamvu yomwe imasamutsidwa kuchokera ku cholumikizira chotulutsa kupita ku cholumikizira cholandila. Kuyeza kwa crosstalk yakutali (FEXT) kumachitika polowetsa chizindikiro mu cholumikizira kumapeto kwa chingwe ndikuwona kuchuluka kwa mphamvu komwe kumasungidwa pa chizindikiro cholumikizira kumapeto kwina kwa chingwe. NEXT mu zigawo za chingwe ndi zolumikizira nthawi zambiri zimachitika chifukwa cha kusakhazikika bwino kwa chizindikiro chosiyana, mwina chifukwa cha sockets ndi ma plugs, kusakhazikika bwino, kapena kusagwira bwino malo omalizira chingwe. Opanga makina ayenera kuwonetsetsa kuti osonkhanitsa chingwe athetsa mavuto atatuwa, monga m'zigawo monga MINI SAS HD SFF-8644 kapena OCuLink SFF-8611 4i.

24, 26 ndi 28 ndi ma curve odziwika bwino a 100Ω cable loss.

Pa ma cable assemblies apamwamba kwambiri, NEXT yoyesedwa motsatira "SFF-8410 - Specification for HSS Copper Testing and Performance Requirements" iyenera kukhala yochepera 3%. Ponena za S-parameter, NEXT iyenera kukhala yoposa 28 dB.
Kutayika kobwerera
Kutayika kobwerera kumayesa kukula kwa mphamvu zomwe zimawonetsedwa kuchokera ku dongosolo kapena chingwe pamene chizindikiro chikulowetsedwa. Mphamvu yowonetsedwayi imayambitsa kuchepa kwa kukula kwa chizindikiro kumapeto kwa chingwe cholandirira ndipo ingayambitse mavuto okhudzana ndi umphumphu wa chizindikiro kumapeto kwa chotumizira, zomwe zingayambitse mavuto osokoneza maginito amagetsi kwa makina ndi opanga makina.
Kutayika kobwerera kumeneku kumachitika chifukwa cha kusagwirizana kwa impedance mu zigawo za chingwe. Pokhapokha ngati vutoli likuchitidwa mosamala kwambiri, impedance singasinthe pamene chizindikiro chikudutsa m'ma socket, ma plugs, ndi ma cable terminals, kuti achepetse kusiyana kwa impedance. Muyezo wa SAS-4 wamakono umasintha mtengo wa impedance kuchokera ku ±10Ω mu SAS-2 kufika ku ±3Ω. Zingwe zapamwamba ziyenera kusunga zofunikira mkati mwa kulekerera kwa nominel 85 kapena 100 ± 3Ω, monga SFF-8639 yokhala ndi SATA 15P kapena MCIO 74 Pin Cable.

Kupotoza kolakwika
Mu zingwe za SAS, pali mitundu iwiri ya kusokonekera kwa skew: pakati pa ma differential pairs ndi mkati mwa ma differential pairs (signal integrity theory - differential signal). Mwachidziwitso, ngati zizindikiro zingapo zilowetsedwa nthawi imodzi kumapeto kwa chingwe, ziyenera kufika kumapeto ena nthawi imodzi. Ngati zizindikirozi sizifika nthawi imodzi, izi zimatchedwa cable skew distortion, kapena delay-skew distortion. Pa ma differential pairs, skew distortion mkati mwa differential pairs ndi kuchedwa pakati pa ma conductor awiri a differential pairs, pomwe skew distortion pakati pa ma differential pairs ndi kuchedwa pakati pa ma seti awiri a differential pairs. Kusokonezeka kwakukulu kwa skew mkati mwa differential pairs kungawononge differential balance ya transmission signal, kuchepetsa amplitude ya signal, kuwonjezera time jitter, ndikuyambitsa mavuto a electromagnetic interference. Pa zingwe zapamwamba kwambiri, kusokonezeka kwa skew mkati mwa differential pairs kuyenera kukhala kochepera 10 ps, ​​monga SFF-8654 8i to SFF-8643 kapena Anti-misalignment Insertion cable.
Kusokoneza kwa maginito
Pali zifukwa zambiri zomwe zimayambitsa mavuto okhudzana ndi kusokonezeka kwa ma elekitiroma m'ma chingwe: kutchinga bwino kapena kusatchinga bwino, njira yolakwika yokhazikitsira pansi, zizindikiro zosiyana siyana, komanso kusagwirizana kwa impedance ndi chifukwa chake. Pa zingwe zakunja, kutchinga ndi kutchinga pansi mwina ndi zinthu ziwiri zofunika kwambiri zomwe ziyenera kuthetsedwa, monga SFF-8087 yokhala ndi maukonde ofiira kapena chingwe chokhazikitsira pansi cha Cooper mesh.
Kawirikawiri, chitetezo chakunja kapena chamagetsi chiyenera kukhala chotchingira chachiwiri cha zojambulazo zachitsulo ndi wosanjikiza wolukidwa, ndi chophimba chonse cha osachepera 85%. Nthawi yomweyo, chitetezochi chiyenera kulumikizidwa ku jekete lakunja la cholumikizira, ndi kulumikizana kwathunthu kwa 360°. Chitetezo cha ma differential payokha chiyenera kuchotsedwa ku chitetezo chakunja, ndipo mizere yawo yosefera iyenera kutha pa chizindikiro cha dongosolo kapena pansi pa DC kuti zitsimikizire kuti cholumikizira ndi zigawo za chingwe ndi zachitsulo zimayang'aniridwa bwino, monga chingwe cha SFF-8654 8i Full Wrap anti-slash kapena Scoop-proof connector.