zomwe zimayendetsedwa impedance mu pcb

Mapulani osindikizira (PCBs) ndi msana wa zipangizo zamakono zamakono. Kuyambira mafoni a m'manja kupita ku zipangizo zamankhwala, matabwa a PCB amatenga gawo lofunika kwambiri pogwirizanitsa ndi kupereka magwiridwe antchito kuzinthu zosiyanasiyana zamagetsi. Kuti awonetsetse kuti akugwira bwino ntchito, opanga PCB ayenera kuganizira zinthu zingapo, kuphatikiza kuwongolera koyendetsedwa. Mu positi iyi yabulogu, tiwunikanso lingaliro la kuletsa kuwongolera m'ma board a PCB ndikumvetsetsa kufunikira kwake kuti tikwaniritse mapangidwe abwino komanso odalirika.

Kodi kulamuliridwa kwa impedance mu PCB ndi chiyani?

Kusokoneza kungatanthauzidwe ngati kukana komwe kumakumana ndi ma alternating current (AC) akuyenda mozungulira. Impedansi yoyendetsedwa imatanthawuza mtengo wolepheretsa mwadala panjira inayake kapena chingwe chotumizira pa bolodi la PCB.

Kuwongolera kwa Impedance ndikofunikira mukakonza ma siginecha apamwamba kwambiri a digito chifukwa kumathandizira kusunga kukhulupirika kwa ma siginecha, kuchepetsa mawonetsedwe azizindikiro, ndikuchepetsa kusokoneza kwamagetsi (EMI). Pamene impedance sichiwongoleredwa, imatha kuwononga mawonekedwe amtundu wa siginecha, kupangitsa kusokonekera, zovuta zanthawi, komanso kuwonongeka kwa magwiridwe antchito.

Zinthu zomwe zimakhudzidwa ndi impedance yoyendetsedwa:

Kuti mukwaniritse zoletsa zoyendetsedwa ndi PCB board, pali zinthu zingapo zomwe ziyenera kuganiziridwa. Zinthu izi zikuphatikizapo:

1. Tsatirani geometry: M'lifupi, makulidwe ndi masinthidwe a mizere ndi mizere yopatsira pa PCB zimakhudza kwambiri kuchuluka kwa mphamvu. Miyeso iyenera kuwerengedwa molondola pogwiritsa ntchito chowerengera cha impedance kapena kuperekedwa ndi wopanga PCB.

2. Zida za dielectric: Zida za dielectric zomwe zimagwiritsidwa ntchito mu PCB zimakhudzanso kusokoneza komwe kumayendetsedwa. Zida zosiyanasiyana zimakhala ndi ma dielectric constants, zomwe zimakhudza momwe ma sign amafalikirira mwachangu.

3. Kutalikirana kwa zizindikiro zoyandikana: Kuyandikira kwa kutumizirana ndi kulandira zizindikiro kudzachititsa kuti mgwirizano ukhale wogwirizana komanso kugwirizanitsa, potero kusintha mtengo wa impedance. Kusunga mtunda wotetezeka pakati pa mayendedwe kumathandizira kuti musamayende bwino.

4. Masanjidwe a zigawo: Makonzedwe ndi katsatidwe ka zigawo za PCB zimagwira ntchito yofunikira pakuwongolera kwa impedance. Kusasinthika kwa ma layer stacking ndikofunikira kuti mupewe kusagwirizana kwa impedance.

Kufunika kwa kuwongolera kowongolera mu kapangidwe ka PCB:

1. Kukhulupirika kwa chizindikiro: Kusokoneza koyendetsedwa kumatsimikizira kuti zizindikiro za digito zimafalitsidwa bwino mu PCB popanda kusokoneza. Kusunga zowongolera kumachepetsa zowunikira, kutayika kwa ma signature, ndi crosstalk, potero kumathandizira kukhulupirika kwazizindikiro.

2. Chepetsani kusokoneza kwa electromagnetic (EMI): Pamene zipangizo zamagetsi zikupitiriza kuwonjezeka movutikira komanso ma frequency azizindikiro amakhala apamwamba, EMI yakhala nkhani yofunika kwambiri. Kuwongolera koyendetsedwa kumathandizira kuchepetsa EMI pochepetsa zowunikira komanso kuwonetsetsa kukhazikika koyenera komanso kutetezedwa.

3. Kuchita kosasintha: Ma PCB omwe ali ndi mphamvu zowongolera amapereka mawonekedwe amagetsi osasinthasintha ngakhale pakusintha kwachilengedwe monga kutentha ndi chinyezi. Kusasinthika uku kumasulira ku magwiridwe antchito odalirika komanso moyo wautali wa zida zanu zamagetsi.

4. Kugwirizana: Kuwongolera koyendetsedwa kumatsimikiziranso kugwirizana ndi zigawo zina ndi machitidwe. Ma board a PCB okhala ndi zofananira zofananira amatha kulumikizana mosavuta ndikulumikizana ndi zida zina, kulola kuphatikiza kopanda msoko.

Kuwongolera koyendetsedwa ndi gawo lofunikira pamapangidwe a PCB, makamaka pama frequency apamwamba komanso zovuta. Mwa kusunga mayendedwe osasinthika, opanga amatha kukulitsa kukhulupirika kwa ma sign, kuchepetsa EMI, ndikuwonetsetsa kuti zikugwirizana. Kumvetsetsa zinthu zomwe zimakhudza kuwongolera koyendetsedwa, monga trace geometry, zida za dielectric, ndi masanjidwe osanjikiza, ndikofunikira kuti tikwaniritse mapangidwe abwino komanso odalirika a PCB. Poika patsogolo kuwongolera kwa impedance, okonza amatha kutsegula zida zonse zamagetsi pomwe akupereka magwiridwe antchito apamwamba komanso moyo wautali.