1. Imithetho ejwayelekile
1.1 Izindawo zezintambo zedijithali, ze-analog, ne-DAA zihlukaniswe ngaphambili ku-PCB.
1.2 Izingxenye zedijithali ne-analogi kanye nezintambo ezihambisanayo kufanele zihlukaniswe ngangokunokwenzeka futhi zibekwe ezindaweni zazo zezintambo.
1.3 Ukulandelela isignali yedijithali enesivinini esikhulu kufanele kube kufushane ngangokunokwenzeka.
1.4 Gcina imikhondo yesignali ye-analog ebucayi imfushane ngangokunokwenzeka.
1.5 Ukusatshalaliswa okunengqondo kwamandla nomhlabathi.
1.6 I-DGND, i-AGND, kanye nenkundla kuyahlukaniswa.
1.7 Sebenzisa izintambo ezibanzi ukuze unikeze amandla nokulandela izimpawu ezibalulekile.
1.8 Isekhethi yedijithali ibekwe eduze kwesixhumi esibonakalayo sebhasi/i-serial ye-DTE, bese isekethe ye-DAA ibekwe eduze kwesixhumi esibonakalayo solayini wocingo.
2. Ukubekwa kwengxenye
2.1 Kumdwebo weskimu sesekethe yesistimu:
a) Hlukanisa amasekhethi edijithali, e-analog, e-DAA kanye namasekhethi ahlobene nawo;
b) Hlukanisa izingxenye zedijithali, ze-analog, ezixubile zedijithali/ze-analogi kusekethe ngayinye;
c) Naka ukuma kokuphakelwa kukagesi nezikhonkwane zesignali ze-chip ngayinye ye-IC.
2.2 Hlukanisa ngaphambilini indawo yezintambo zamasekhethi edijithali, e-analog, ne-DAA ku-PCB (isilinganiso esijwayelekile 2/1/1), futhi ugcine izingxenye zedijithali neze-analog kanye nezintambo zazo ezihambisanayo zikude ngangokunokwenzeka futhi zikhawulele kokulandelayo kwazo. izindawo zezintambo.
Qaphela: Uma isifunda se-DAA sithatha ingxenye enkulu, kuzoba khona imikhondo yesignali yokulawula/yesimo eyengeziwe edlula endaweni yayo yezintambo, engalungiswa ngokuvumelana nemithetho yendawo, njengesikhala sengxenye, ukucindezela kwamandla kagesi aphezulu, umkhawulo wamanje, njll.
2.3 Ngemva kokuqedwa kwesigaba sokuqala, qala ukubeka izingxenye ezivela ku-Connector and Jack:
a) Indawo ye-plug-in igcinwe eduze kweSixhumi noJack;
b) Shiya isikhala samandla kanye nezintambo zomhlabathi ezizungeze izingxenye;
c) Beka eceleni indawo ye-plug-in ehambisanayo ezungeze Isokhethi.
2.4 Izingxenye ezixubile ezisendaweni yokuqala (njengamadivayisi eModemu, i-A/D, ama-conversion chips e-D/A, njll.):
a) Nquma indlela yokubeka izingxenye, bese uzama ukwenza isiginali yedijithali namaphinikhodi we-analogi abhekane nezindawo zazo zezintambo;
b) Beka izingxenye ekuhlanganeni kwezindawo zesignali yedijithali ne-analogi.
2.5 Beka zonke izisetshenziswa ze-analog:
a) Beka izingxenye zesekethe ye-analog, okuhlanganisa namasekhethi e-DAA;
b) Imishini ye-analogi ibekwe eduze komunye nomunye futhi ibekwe eceleni kwe-PCB ehlanganisa i-TXA1, TXA2, RIN, VC, ne-VREF yokulandela izimpawu zesignali;
c) Gwema ukubeka izingxenye ezinomsindo omkhulu eduze kwe-TXA1, TXA2, RIN, VC, kanye nezimpawu zesignali ze-VREF;
d) Kumamojula we-serial we-DTE, i-DTE EIA/TIA-232-E
Umamukeli/umshayeli wamasignali ochungechunge lokuxhumana kufanele abe seduze ngangokunokwenzeka kusixhumi futhi abe kude nomzila wesignali yewashi yefrikhwensi ephezulu ukuze anciphise/agweme ukungezwa kwemishini yokucindezela umsindo kulayini ngamunye, njengamakhoyili okuklinywa nama-capacitor.
2.6 Beka izingxenye zedijithali kanye nama-capacitor e-decoupling:
a) Izingxenye zedijithali zibekwe ndawonye ukuze kuncishiswe ubude bezintambo;
b) Beka i-0.1uF decoupling capacitor phakathi kokuphakelwa kukagesi nomhlabathi we-IC, futhi ugcine izintambo zokuxhuma zimfushane ngangokunokwenzeka ukuze unciphise i-EMI;
c) Kumamojula ebhasi ahambisanayo, izingxenye zisondelene
Isixhumi sibekwe onqenqemeni ukuze sihambisane nezinga lokusebenzisa ibhasi lesicelo, njengokuthi ubude bomugqa webhasi we-ISA bukhawulelwe ku-2.5in;
d) Kumamojula we-serial DTE, isekethe yesixhumi esibonakalayo iseduze nesixhumi;
e) I-crystal oscillator circuit kufanele ibe seduze ngangokunokwenzeka kudivayisi yayo yokushayela.
2.7 Izintambo eziphansi zendawo ngayinye zivame ukuxhunywa endaweni eyodwa noma ngaphezulu ngo-0 Ohm resistors noma ubuhlalu.
3. Umzila wesiginali
3.1 Emzileni wesiginali yemodemu, imigqa yesignali ethambekele ekubeni nomsindo kanye nemigqa yamasignali esengozini yokuphazamiseka kufanele igcinwe kude ngangokunokwenzeka.Uma ingenakugwenywa, sebenzisa ulayini wesignali omaphakathi ukuze uhlukanise.
3.2 Izintambo zesiginali yedijithali kufanele zibekwe endaweni yokufaka izintambo zesiginali yedijithali ngangokunokwenzeka;
I-wiring yesignali ye-analog kufanele ibekwe endaweni yezintambo zesignali ye-analog ngangokunokwenzeka;
(Imikhondo yokuhlukanisa ingabekwa kusengaphambili ukuze ikhawulelwe ukuze kuvinjelwe imikhondo ekuphumeni komzila endaweni)
Ukulandelelwa kwesignali yedijithali nokulandelelwa kwesignali ye-analog ku-perpendicular ukunciphisa ukuhlanganisana.
3.3 Sebenzisa imikhondo engayodwa (imvamisa iphansi) ukuze uvale ukulandelelwa kwesignali ye-analogi endaweni yomzila wesignali ye-analog.
a) Imikhondo ehlukanisiwe yomhlabathi endaweni ye-analogi ihlelwe nhlangothi zombili zebhodi le-PCB eduze kwendawo yokufaka izintambo zesignali ye-analogi, enobubanzi bomugqa obungu-50-100mil;
b) Imikhondo ehlukanisiwe yomhlabathi endaweni yedijithali izungeza indawo yezintambo zesignali yedijithali nhlangothi zombili zebhodi le-PCB, enobubanzi bomugqa obuyi-50-100mil, futhi ububanzi bohlangothi olulodwa lwebhodi le-PCB kufanele bube ngu-200mil.
3.4 Ububanzi besignali yesibonisi sebhasi elihambisanayo > 10mil (ngokuvamile u-12-15mil), njengokuthi /HCS, /HRD, /HWT, /RESET.
3.5 Ububanzi bomugqa wokulandelela isignali ye-analog ngu>10mil (ngokuvamile u-12-15mil), njenge-MICM, MICV, SPKV, VC, VREF, TXA1, TXA2, RXA, TELIN, TELOUT.
3.6 Konke okunye ukulandelelwa kwesignali kufanele kube banzi ngangokunokwenzeka, ububanzi bomugqa kufanele bube >5mil (10mil ngokuvamile), futhi ukulandelelwa phakathi kwezingxenye kufanele kube kufushane ngangokunokwenzeka (ukucatshangelwa kusengaphambili kufanele kucatshangelwe lapho kufakwa imishini).
3.7 Ububanzi bomugqa we-bypass capacitor ku-IC ehambisanayo kufanele bube >25mil, futhi ukusetshenziswa kwe-vias kufanele kugwenywe ngangokunokwenzeka.3.8 Imigqa yamasignali edlula ezindaweni ezihlukene (njengezimpawu zokulawula isivinini esiphansi/isimo) kufanele dlula izintambo zomhlabathi ezingazodwa endaweni eyodwa (ekhethwayo) noma amaphuzu amabili.Uma ukulandelelwa kuhlangothini olulodwa kuphela, ukulandelelwa komhlaba okuhlukanisiwe kungaya kolunye uhlangothi lwe-PCB ukweqa ukulandelelwa kwesignali nokuyigcina iqhubekayo.
3.9 Gwema ukusebenzisa amakhona angu-90-degree kumzila wesignali wemvamisa ephezulu, futhi usebenzise ama-arcs abushelelezi noma amakhona angu-45-degree.
3.10 Umzila wesignali wefrikhwensi ephezulu kufanele unciphise ukusetshenziswa koxhumano.
3.11 Gcina yonke imikhondo yesignali ikude nesekhethi ye-crystal oscillator.
3.12 Ngomzila wesignali yemvamisa ephezulu, umzila owodwa oqhubekayo kufanele usetshenziselwe ukugwema isimo lapho izingxenye ezimbalwa zomzila zisuka endaweni eyodwa.
3.13 Kusekhethi ye-DAA, shiya isikhala okungenani esingu-60mil eduze nokubhobozwa (zonke izendlalelo).
4. Ukunikezwa kwamandla
4.1 Nquma ubudlelwano bokuxhunywa kwamandla.
4.2 Endaweni yokufakwa kwezintambo zesignali yedijithali, sebenzisa i-electrolytic capacitor engu-10uF noma i-tantalum capacitor ngokuhambisana ne-0.1uF Ceramic capacitor bese uyixhuma phakathi kwamandla kagesi nomhlabathi.Beka eyodwa ekugcineni kwe-inlet yamandla nasekupheleni kwebhodi le-PCB ukuze uvimbele ama-spikes amandla okubangelwa ukuphazamiseka komsindo.
4.3 Kumabhodi anezinhlangothi ezimbili, kusendlalelo efanayo nesekhethi edla amandla, zungeza isekethe ngokulandela amandla onobubanzi bomugqa obungu-200mil nhlangothi zombili.(Olunye uhlangothi kufanele lucutshungulwe ngendlela efanayo naleyo yedijithali)
4.4 Ngokuvamile, imikhondo yamandla ibekwa kuqala, bese kuthi imikhondo yesignali ibekwe.
5. umhlabathi
5.1 Ebhodini elinezinhlangothi ezimbili, izindawo ezingasetshenzisiwe ezizungeze nangaphansi kwezingxenye zedijithali neze-analogi (ngaphandle kwe-DAA) zigcwaliswa ngezindawo zedijithali noma ze-analog, futhi izindawo ezifanayo zesendlalelo ngasinye zixhunywe ndawonye, futhi izindawo ezifanayo zezendlalelo ezahlukene zixhunywe ndawonye. ixhunywe ngama- vias amaningi : Iphinikhodi ye-Modem DGND ixhunywe endaweni ephansi yedijithali, futhi iphinikhodi ye-AGND ixhunywe endaweni ephansi ye-analog;indawo ephansi yedijithali kanye nendawo ye-analog yomhlabathi ihlukaniswe igebe eliqondile.
5.2 Ebhodini elinezingqimba ezine, sebenzisa indawo ephansi yedijithali ne-analogi ukumboza izingxenye zedijithali neze-analogi (ngaphandle kwe-DAA);iphinikhodi ye-Modemu ye-DGND ixhunywe endaweni ephansi yedijithali, futhi iphinikhodi ye-AGND ixhunywe endaweni ephansi ye-analog;indawo ephansi yedijithali kanye nendawo ye-analog yomhlabathi isetshenziswa ihlukaniswe igebe eliqondile.
5.3 Uma isihlungi se-EMI sidingeka ekwakhiweni, isikhala esithile kufanele sigcinwe kusokhethi esibonakalayo.Imishini eminingi ye-EMI (ubuhlalu/ama-capacitor) ingafakwa kule ndawo;exhunywe kuyo.
5.4 Ukunikezwa kwamandla kwemojuli esebenzayo ngayinye kufanele kuhlukaniswe.Amamojula asebenzayo angahlukaniswa abe: isixhumi esibonakalayo sebhasi elihambisanayo, isibonisi, isifunda sedijithali (i-SRAM, i-EPROM, i-Modem) ne-DAA, njll. Amandla/umhlabathi wemojula ngayinye yokusebenza ingaxhunywa kuphela emthonjeni wamandla/umhlaba.
5.5 Kumamojula we-serial DTE, sebenzisa ama-decoupling capacitor ukuze unciphise ukuhlangana kwamandla, futhi wenze okufanayo ngezintambo zocingo.
5.6 Intambo yaphansi ixhunywe ngephuzu elilodwa, uma kungenzeka, sebenzisa i-Bead;uma kudingekile ukucindezela i-EMI, vumela intambo yaphansi ixhunywe kwezinye izindawo.
5.7 Zonke izintambo eziphansi kufanele zibe banzi ngangokunokwenzeka, zibe ngu-25-50mil.
5.8 Ukulandelela kwe-capacitor phakathi kwakho konke ukuphakelwa kukagesi/phansi kwe-IC kufanele kube kufushane ngangokunokwenzeka, futhi akufanele kusetshenziswe izimbobo.
6. I-Crystal oscillator circuit
6.1 Yonke iminonjana exhunywe kumatheminali okufakwayo/okukhiphayo kwe-crystal oscillator (njenge-XTLI, i-XTLO) kufanele ibe mfushane ngangokunokwenzeka ukuze kuncishiswe ithonya lokuphazamiseka komsindo kanye namandla okusabalalisa ku-Crystal.I-trace ye-XTLO kufanele ibe mfushane ngangokunokwenzeka, futhi i-engeli yokugoba akufanele ibe ngaphansi kwama-degree angu-45.(Ngoba i-XTLO ixhunywe kumshayeli onesikhathi sokukhuphuka ngokushesha namanje kakhulu)
6.2 Akukho ungqimba lomhlabathi ebhodini elinamacala amabili, futhi ucingo oluphansi lwe-crystal oscillator capacitor kufanele luxhunywe kudivayisi ngocingo olufushane olubanzi ngangokunokwenzeka.
Iphinikhodi ye-DGND eseduze ne-crystal oscillator, futhi unciphise inani lama-vias.
6.3 Uma kungenzeka, gcoba ikesi lekristalu.
6.4 Xhuma i-resistor engu-100 Ohm phakathi kwephinikhodi ye-XTLO kanye ne-crystal/capacitor node.
6.5 Umhlabathi we-crystal oscillator capacitor uxhumeke ngqo kuphinikhodi ye-GND yeModemu.Ungasebenzisi indawo ephansi noma amathrekhi aphansi ukuxhuma i-capacitor kuphinikhodi ye-GND yeModemu.
7. Idizayini yeModemu ezimele isebenzisa isixhumi esibonakalayo se-EIA/TIA-232
7.1 Sebenzisa ikesi lensimbi.Uma igobolondo lepulasitiki lidingeka, ucwecwe lwensimbi kufanele lunanyathiselwe ngaphakathi noma impahla eqhutshwayo kufanele ifuthwe ukuze kuncishiswe i-EMI.
7.2 Beka ama-Chokes ephethini efanayo entanjeni yamandla ngayinye.
7.3 Izingxenye zibekwe ndawonye futhi ziseduze nesixhumi se-EIA/TIA-232 interface.
7.4 Wonke amadivaysi e-EIA/TIA-232 axhumeke ngawodwana emandleni/emhlabathini asuka emthonjeni wamandla.Umthombo wamandla/umhlabathi kufanele kube itheminali yokufaka amandla ebhodini noma itheminali ephumayo ye-chip yesilawuli sikagesi.
7.5 EIA/TIA-232 isignali yekhebula ifika emhlabathini wedijithali.
7.6 Kulezi zimo ezilandelayo, isihlangu sekhebula se-EIA/TIA-232 asidingi ukuxhunywa kugobolondo leModemu;uxhumano olungenalutho;exhunywe emhlabathini wedijithali ngokusebenzisa ubuhlalu;ikhebula le-EIA/TIA-232 lixhunywe ngokuqondile emhlabathini wedijithali lapho indandatho kazibuthe ifakwa eduze kwegobolondo leModemu.
8. Izintambo ze-VC kanye ne-VREF circuit capacitor kufanele zibe mfushane ngangokunokwenzeka futhi zibekwe endaweni engathathi hlangothi.
8.1 Xhuma itheminali ephozithivu ye-10uF VC electrolytic capacitor kanye ne-0.1uF VC capacitor ku-VC pin (PIN24) yeModemu ngocingo oluhlukile.
8.2 Xhuma itheminali enegethivu ye-10uF VC electrolytic capacitor kanye ne-0.1uF VC capacitor kuphinikhodi ye-AGND (PIN34) yeModemu ngoBuhlalu futhi usebenzise intambo ezimele.
8.3 Xhuma itheminali ephozithivu ye-electrolytic capacitor engu-10uF VREF kanye ne-0.1uF VC capacitor kuphinikhodi ye-VREF (PIN25) yeModemu ngocingo oluhlukile.
8.4 Xhuma itheminali enegethivu ye-10uF VREF electrolytic capacitor kanye ne-0.1uF VC capacitor ku-VC pin (PIN24) yeModemu ngomkhondo ozimele;qaphela ukuthi izimele ku-trace engu-8.1.
I-VREF ——+———+
┿ 10u ┿ 0.1u
VC ——+———+
┿ 10u ┿ 0.1u
+——–+—–~~~~~—+ AGND
Ubuhlalu obusetshenzisiwe kufanele buhlangane:
Impedance = 70W ku-100MHz;;
ikalwe okwamanje = 200mA;;
Ukumelana okuphezulu = 0.5W.
9. Ifoni kanye ne-handset interface
9.1 Beka i-Choke kusixhumi esibonakalayo phakathi kweThiphu neRing.
9.2 Indlela yokuhlukanisa intambo yocingo iyafana naleyo yokuphakelwa kukagesi, kusetshenziswa izindlela ezifana nokwengeza inhlanganisela ye-inductance, ukuminyanisa, kanye ne-capacitor.Kodwa-ke, ukuhlukaniswa kocingo locingo kunzima kakhulu futhi kuphawuleka kakhulu kunokwehliswa kwamandla kagesi.Umkhuba ojwayelekile ukugodla izikhundla zalawa madivayisi ukuze zilungiswe ngesikhathi sokusebenza/ukuthola isitifiketi sokuhlolwa kwe-EMI.
Isikhathi sokuthumela: May-11-2023