Zingwe za SAS zothamanga kwambiri: Zolumikizira ndi Kukhathamiritsa kwa Signal

Zingwe za SAS zothamanga kwambiri: Zolumikizira ndi Kukhathamiritsa kwa Signal

Zizindikiro za Signal Integrity

Zina mwazinthu zazikulu za kukhulupirika kwazizindikiro zimaphatikizapo kutayika kwa kuyika, kuyandikira kumapeto ndi kumapeto kwakutali, kutayika kubwerera, kupotoza kwa skew mkati mwa awiriawiri osiyana, ndi matalikidwe kuchokera kumachitidwe osiyanitsira kupita kumachitidwe wamba. Ngakhale kuti zinthuzi zimagwirizana ndipo zimakhudzirana wina ndi mzake, titha kuganizira chinthu chimodzi ndi nthawi kuti tiphunzire momwe zimakhudzira.
Kutayika Kwawo
Kutayika kwa kulowetsa ndiko kuchepetsedwa kwa matalikidwe a siginecha kuchokera kumapeto otumizira mpaka kumapeto kwa chingwe, ndipo kumagwirizana mwachindunji ndi pafupipafupi. Kutayika koyikirako kumadaliranso mayendedwe a waya, monga momwe tawonetsera pa graph yochepetsera pansipa. Pazigawo zazifupi zamkati zomwe zimagwiritsa ntchito zingwe za 30 kapena 28-AWG, zingwe zapamwamba kwambiri ziyenera kukhala ndi kutsika kochepera 2 dB/m pa 1.5 GHz. Kwa 6 Gb/s SAS yakunja yogwiritsa ntchito zingwe za 10m, tikulimbikitsidwa kugwiritsa ntchito zingwe zokhala ndi waya wapakati wa 24, zomwe zimakhala ndi 13 dB yokha pa 3 GHz. Ngati mukufuna kukwaniritsa malire a siginecha pamitengo yapamwamba yosamutsa deta, tchulani zingwe zocheperako pama frequency apamwamba a zingwe zazitali, monga SFF-8482 yokhala ndi chingwe cha POWER kapena SlimSAS SFF-8654 8i.

Crosstalk
Crosstalk imatanthawuza kuchuluka kwa mphamvu zomwe zimaperekedwa kuchokera ku siginecha imodzi kapena gulu losiyana kupita ku siginecha ina kapena awiri osiyana. Kwa zingwe za SAS, ngati crosstalk ya pafupi-kumapeto (NEXT) siing'ono mokwanira, imayambitsa mavuto ambiri a ulalo. Kuyeza kwa NEXT kumangochitika kumapeto kwa chingwe, ndipo ndi kukula kwa mphamvu yomwe imasamutsidwa kuchokera pagulu la siginecha yotulutsa kupita kumalo olandila. Kuyeza kwa crosstalk yakutali (FEXT) kumachitika polowetsa chizindikiro mumagulu opatsirana kumapeto kwa chingwe ndikuwona kuchuluka kwa mphamvu zomwe zimasungidwabe pa chizindikiro chotumizira kumapeto kwina kwa chingwe. ZOTSATIRA m'zigawo za chingwe ndi zolumikizira nthawi zambiri zimayamba chifukwa cha kusasiyanitsidwa bwino kwa ma siginecha osiyanitsira, mwina chifukwa cha sockets ndi mapulagi, kuyika pansi kosakwanira, kapena kusagwira bwino kwa malo otsekera chingwe. Okonza makina amayenera kuwonetsetsa kuti ophatikiza zingwe athana ndi zinthu zitatuzi, monga zigawo ngati MINI SAS HD SFF-8644 kapena OCuLink SFF-8611 4i.

24, 26 ndi 28 ndi ma curve wamba a 100Ω otayika.

Pamisonkhano yama chingwe apamwamba kwambiri, NEXT yoyezedwa molingana ndi "SFF-8410 - Mafotokozedwe a HSS Copper Testing and Performance Requirements" iyenera kukhala yotsika kuposa 3%. Ponena za S-parameter, NEXT iyenera kukhala yayikulu kuposa 28 dB.
Bwererani kutaya
Kutaya kobweza kumayesa kukula kwa mphamvu zomwe zimawonekera kuchokera kudongosolo kapena chingwe pamene siginecha ibayidwa. Mphamvu zowonetserazi zimapangitsa kuchepa kwa matalikidwe a siginecha kumapeto kwa chingwe ndipo zimatha kubweretsa zovuta zaumphumphu pamapeto otumizira, zomwe zimatha kuyambitsa zovuta zosokoneza ma elekitiroma pamakina ndi opanga makina.
Kutayika kobwereraku kumachitika chifukwa cha kusagwirizana kwa zigawo za chingwe. Pokhapokha pothana ndi vutoli mosamala kwambiri pomwe cholepheretsa sichingasinthe chizindikirocho chikadutsa muzitsulo, mapulagi, ndi ma terminals a chingwe, kuti muchepetse kusiyanasiyana kwa impedance. Muyezo waposachedwa wa SAS-4 umasintha mtengo wa impedance kuchokera ku ± 10Ω mu SAS-2 mpaka ± 3Ω. Zingwe zapamwamba kwambiri ziyenera kusunga zofunikira mkati mwa kulolerana kwa dzina la 85 kapena 100 ± 3Ω, monga SFF-8639 yokhala ndi SATA 15P kapena MCIO 74 Pin Cable.

Kupotoza kwa skew
Mu zingwe za SAS, pali mitundu iwiri ya kupotoza kwa skew: pakati pa awiriawiri osiyana ndi mkati mwa awiriawiri osiyana (chidziwitso cha umphumphu - chizindikiro chosiyana). Mwachidziwitso, ngati ma siginecha angapo akulowetsedwa nthawi imodzi kumapeto kwa chingwe, ayenera kufika kumalekezero ena nthawi imodzi. Ngati zizindikirozi sizifika nthawi imodzi, chodabwitsachi chimatchedwa cable skew kupotoza, kapena kuchedwa-skew kupotoza. Kwa awiriawiri osiyana, kupotoza kwa skew mkati mwa awiriwa osiyanitsa ndiko kuchedwa pakati pa oyendetsa awiri a awiriawiri osiyanitsa, pamene kupotoza kwa skew pakati pa awiriawiri osiyana ndiko kuchedwa pakati pa magulu awiri a awiriawiri osiyana. Kusokonekera kwakukulu kwa skew mkati mwa masiyanidwe awiriwa kumatha kusokoneza kusiyanasiyana kwa siginecha yopatsirana, kuchepetsa matalikidwe a siginecha, kuonjezera jitter ya nthawi, ndikuyambitsa zovuta zosokoneza ma electromagnetic. Kwa zingwe zapamwamba kwambiri, kupotoza kwa skew mkati mwa awiriwa osiyanitsa kuyenera kukhala osachepera 10 ps, ​​monga SFF-8654 8i kupita ku SFF-8643 kapena chingwe cha Anti-misalignment Insertion.
Kusokoneza kwa electromagnetic
Pali zinthu zambiri zomwe zimayambitsa zovuta zosokoneza ma electromagnetic mu zingwe: kusatetezedwa bwino kapena kusatchinga, njira yolakwika yokhazikitsira pansi, ma siginecha osagwirizana, ndi kupitilira apo, kusagwirizana ndi chifukwa. Pazingwe zakunja, kutchingira ndi kuyika pansi ndi zinthu ziwiri zofunika kwambiri zomwe zikuyenera kuthetsedwa, monga SFF-8087 yokhala ndi mauna ofiira kapena chingwe cha Cooper mesh grounding.
Nthawi zambiri, chotchinga chakunja kapena chamagetsi chamagetsi chimayenera kukhala chotchinga chapawiri chazojambula zachitsulo ndi chosanjikiza choluka, chokhala ndi chophimba chonse cha 85%. Panthawi imodzimodziyo, chitetezo ichi chiyenera kugwirizanitsidwa ndi jekete lakunja la cholumikizira, ndi 360 ° kugwirizana kwathunthu. Kutetezedwa kwa awiriawiri osiyana siyana kuyenera kupatulidwa ku chitetezo chakunja, ndipo mizere yawo yosefera iyenera kuyimitsidwa pa siginecha ya dongosolo kapena DC pansi kuti zitsimikizire kuwongolera kogwirizana kwa cholumikizira ndi zida za chingwe, monga SFF-8654 8i Full Wrap anti-slash kapena Scoop-proof cholumikizira chingwe.