Amakhebuli e-SAS anesivinini esikhulu: Izixhumi kanye Nokuthuthukiswa Kwesiginali

Amakhebuli e-SAS anesivinini esikhulu: Izixhumi kanye Nokuthuthukiswa Kwesiginali

Izicaciso Zobuqotho Besiginali

Eminye yemingcele eyinhloko yobuqotho besignali ihlanganisa ukulahlekelwa kokufaka, i-crosstalk eseduze nasekupheleni, ukulahlekelwa ukubuyisela, ukuhlanekezela kwe-skew ngaphakathi kwamapheya ahlukene, kanye ne-amplitude ukusuka kumodi yokuhlukanisa ukuya kumodi evamile. Nakuba lezi zici zihlobene futhi zithonya enye kwenye, singacabangela isici ngasinye ngesikhathi ukuze sifunde umthelela wayo oyinhloko.
Ukulahlekelwa Kokufaka
Ukulahlekelwa kokufakwayo ukuncishiswa kobubanzi besignali ukusuka ekugcineni kokudlulisela kuya ekugcineni kokwamukela kwentambo, futhi ilingana ngokuqondile nemvamisa. Ukulahlekelwa kokufaka kuphinde kuncike esilinganisweni socingo, njengoba kukhonjisiwe kugrafu yokunciphisa ngezansi. Ezingxenyeni zangaphakathi zebanga elifushane ezisebenzisa amakhebuli angu-30 noma angu-28-AWG, amakhebuli ekhwalithi ephezulu kufanele abe nokuncipha okungaphansi kuka-2 dB/m ku-1.5 GHz. Ku-6 Gb/s SAS yangaphandle kusetshenziswa izintambo ezingu-10m, kuyatuswa ukusebenzisa izintambo ezinesilinganiso socingo esimaphakathi esingu-24, esinokufinyeza okungu-13 dB kuphela ku-3 GHz. Uma ufuna ukuzuza imajini yesignali engeziwe ngamanani aphezulu okudlulisa idatha, cacisa izintambo ezinokuncishiswa okuphansi kumaza aphezulu kumakhebuli amade, njenge-SFF-8482 enentambo YAMANDLA noma i-SlimSAS SFF-8654 8i.

I-Crosstalk
I-Crosstalk ibhekisela enanini lamandla adluliselwa kusuka kusignali eyodwa noma ukupheya okuhlukile kuya kwenye isignali noma ukupheya okuhlukile. Kuzintambo ze-SAS, uma i-close-end crosstalk (NEXT) ingencane ngokwanele, izodala izinkinga eziningi zesixhumanisi. Isilinganiso se-NEXT senziwa kuphela ekugcineni kwekhebula, futhi siwusayizi wamandla adluliswayo asuka epheya yesignali yokuphumayo ukuya kokubhanqwa kokwamukela okokufaka. Isilinganiso se-far-end crosstalk (FEXT) senziwa ngokujova isignali kumapheya okudlulisela komunye umkhawulo wekhebula nokubheka ukuthi mangakanani amandla asagciniwe kusiginali yokudlulisela komunye umkhawulo wekhebula. OKULANDELAYO ezingxenyeni zekhebula nezixhumi kuvame ukubangelwa ukungahlukaniswa kahle kwepheya yokuhlukanisa isignali, okungenzeka ngenxa yamasokhethi namapulaki, ukubeka phansi okungaphelele, noma ukuphatha okungalungile kwendawo yokunqamula ikhebula. Abaklami bohlelo kumele baqinisekise ukuthi abahlanganisi bekhebula bazisingathile lezi zinkinga ezintathu, njengezingxenye ezifana ne-MINI SAS HD SFF-8644 noma i-OCuLink SFF-8611 4i.

24, 26 kanye no-28 amajika ajwayelekile okulahleka kwekhebula engu-100Ω.

Ngokuhlanganisa ikhebula lekhwalithi ephezulu, i-NEXT elinganiswa ngokuvumelana “ne-SFF-8410 – Ukucaciswa Kwe-HSS Copper Testing kanye Nezimfuneko Zokusebenza” kufanele kube ngaphansi kuka-3%. Ngokuqondene nepharamitha ye-S, i-NEXT kufanele ibe nkulu kuno-28 dB.
Buyisela ukulahlekelwa
Ukulahlekelwa kokubuyisela kulinganisa ubukhulu bamandla avela kusistimu noma ikhebuli lapho isignali ijovwa. Lawa mandla abonisiwe abangela ukuncipha kwe-amplitude yesiginali ekugcineni kokwamukela kwekhebula futhi kungaholela ezinkingeni zesignali yobuqotho ekugcineni kokudlulisela, okungase kubangele izinkinga zokuphazanyiswa kozibuthe kagesi kusistimu nabaklami bohlelo.
Lokhu kulahlekelwa okubuyayo kubangelwe ukungafani kwe-impedance ezingxenyeni zekhebula. Kuphela ngokuphatha le nkinga ngokucophelela lapho i-impedance ingashintshi lapho isignali idlula kumasokhethi, ama-plugs, namatheminali ekhebula, ukuze kuncishiswe ukuhluka kwe-impedance. Izinga lamanje le-SAS-4 libuyekeza inani le-impedance ukusuka ku-±10Ω ku-SAS-2 ukuya ku-±3Ω. Izintambo zekhwalithi ephezulu kufanele zigcine imfuneko ngaphakathi kokubekezelelwa kwegama elithi 85 noma 100 ± 3Ω, njenge-SFF-8639 ene-SATA 15P noma i-MCIO 74 Pin Cable.

Skew ukuhlanekezela
Ezintamboni ze-SAS, kunezinhlobo ezimbili zokuhlanekezela kwe-skew: phakathi kwamapheya ahlukene nangaphakathi kwamapheya ahlukene (ithiyori yobuqotho besiginali - isignali ehlukile). Ngokombono, uma amasignali amaningi efakwa ngesikhathi esisodwa ekugcineni kwekhebula, kufanele afinyelele kwesinye isiphetho ngesikhathi esisodwa. Uma lezi zimpawu zingafiki ngesikhathi esisodwa, lesi simo sibizwa ngokuthi i-cable skew distortion, noma ukuhlanekezela kwe- delay-skew. Ngamapheya ahlukene, ukuhlanekezela kwe-skew ngaphakathi kokubhanqwa kokwahlukana ukubambezeleka phakathi kwamakhondatha amabili okupheya okuhlukile, kuyilapho ukuhlanekezela kwe-skew phakathi kwamapheya ahlukene kuwukubambezeleka phakathi kwamasethi amabili amapheya ahlukene. Ukuhlanekezela okukhudlwana kwe-skew ngaphakathi kwepheya ehlukile kungonakalisa ibhalansi ehlukile yesiginali edlulisiwe, kunciphise i-amplitude yesiginali, kukhuphule i-jitter yesikhathi, futhi kubangele izinkinga zokuphazanyiswa nguzibuthe. Kuzintambo zekhwalithi ephezulu, ukuhlanekezela kwe-skew ngaphakathi kwepheya ehlukile kufanele kube ngaphansi kuka-10 ps, ​​njenge-SFF-8654 8i kuya ku-SFF-8643 noma ikhebula Lokufaka eliphikisana nokungalungile.
Ukuphazanyiswa kwe-electromagnetic
Ziningi izimbangela zezinkinga zokugxambukela kozibuthe ezintanjeni: ukungavikeleki kahle noma ukungavikeleki, indlela yokumisa engalungile, amasiginali omehluko angalingani, futhi ngaphezu kwalokho, ukungafani kokuphazamiseka nakho kuyimbangela. Ezintamboni zangaphandle, ukuvikela nokubeka phansi kungenzeka kube yizici ezimbili ezibaluleke kakhulu okufanele zixazululwe, njenge-SFF-8087 enemeshi ebomvu noma intambo yaphansi ye-Cooper mesh.
Imvamisa, isivikelo sokuphazamisa sangaphandle noma sikazibuthe kufanele sibe isivikelo esikabili se-foil yensimbi kanye nongqimba olulukiwe, olumbozwe ngokuphelele okungenani ngama-85%. Ngesikhathi esifanayo, lesi sivikelo kufanele sixhunywe ejazini langaphandle lesixhumi, ngokuxhumeka okuphelele kwe-360 °. Ukuvikela amapheya angawodwana ahlukanisiwe kufanele ahlukaniswe nesivikelo sangaphandle, futhi imigqa yawo yokuhlunga kufanele iphele esignali yesistimu noma emhlabathini we-DC ukuze kuqinisekiswe ukulawulwa okuhlangene kokuphazamiseka kwesixhumi nezingxenye zekhebula, njenge-SFF-8654 8i I-Full Wrap anti-slash noma intambo yokuxhuma i-Scoop-proof.