Dab tsi yog impedance tswj hauv pcb

PCB Impedance Board yog dab tsi? Yuav ua li cas xam PCB impedance? Dab tsi yog Impedance Control thiab Impedance Matching?

Ua ntej, lub ntsiab lus ntawm PCB impedance board

Cov phaj impedance feem ntau kuj hu ua impedance strips. Cov qauv laminated zoo tuaj yeem tswj hwm tus yam ntxwv impedance ntawm PCB, thiab nws cov kab tuaj yeem tsim tau yooj yim tswj tau thiab kwv yees cov kab sib kis tau hu ua impedance phaj.

Qhov thib ob, cov yam ntxwv impedance ntawm PCB

(1) Raws li txoj kev xav ntawm cov teeb liab kis tau tus mob, lub teeb liab yog lub luag haujlwm ntawm lub sijhawm thiab qhov sib txawv ntawm qhov sib txawv, yog li txhua feem ntawm lub teeb liab yuav hloov pauv ntawm kev sib txuas. Yog li, AC impedance ntawm kev sib txuas yog txiav txim siab, uas yog, qhov sib piv ntawm qhov hloov pauv ntawm qhov hluav taws xob thiab qhov hloov pauv tam sim no yog cov yam ntxwv impedance ntawm cov kab sib txuas: cov yam ntxwv impedance ntawm cov kab sib txuas tsuas yog cuam tshuam nrog cov yam ntxwv ntawm cov teeb liab kev sib txuas. nws tus kheej.

(2) Nyob rau hauv qhov tseeb Circuit Court, tus nqi kuj ntawm cov xaim nws tus kheej yog tsawg tshaj li qhov faib impedance ntawm lub system, tshwj xeeb tshaj yog nyob rau hauv high-frequency circuits, tus yam ntxwv impedance feem ntau yog nyob ntawm qhov faib impedance los ntawm chav tsev faib capacitance thiab chav tsev faib. inductance ntawm kev sib txuas. Tus yam ntxwv impedance ntawm ib qho zoo tagnrho cov kab kis tau tus mob tsuas yog nyob ntawm lub unit faib capacitance thiab unit faib inductance ntawm kev sib txuas.

3. Yuav ua li cas xam PCB impedance

(1) Qhov kev sib raug zoo ntawm qhov nce ntawm lub sijhawm ntawm lub teeb liab thiab lub sijhawm xav tau rau lub teeb liab xa mus rau qhov kawg tau txais kev txiav txim siab seb lub teeb liab txuas puas raug suav tias yog kab sib kis. Cov kev sib raug zoo tshwj xeeb tuaj yeem piav qhia los ntawm cov qauv hauv qab no: Yog tias qhov ntev ntawm cov xaim sib txuas ntawm PCB ntau dua li l / b, qhov kev sib txuas ntawm cov xov tooj ntawm cov teeb liab tuaj yeem suav tau tias yog kab sib kis.

(2) According to the calculation formula of the signal equivalent impedance, the impedance of the transmission line can be expressed by the following formula: In the case of high frequency (tens of megahertz to hundreds of megahertz), wL>>R (ntawm chav kawm, nyob rau hauv qhov ntau ntawm cov teeb liab zaus ntau dua 109Hz), cov nyhuv ntawm daim tawv nqaij yog txiav txim siab, thiab qhov kev sib raug zoo no yuav tsum tau ua tib zoo kawm). Tom qab ntawd rau qee txoj kab sib kis, nws cov yam ntxwv impedance yog qhov tsis tu ncua.

(3) Qhov tshwm sim ntawm qhov cuam tshuam ntawm lub teeb liab yog tshwm sim los ntawm qhov tsis sib xws ntawm cov yam ntxwv impedance ntawm kev tsav tsheb kawg ntawm lub teeb liab thiab cov kab sib kis thiab qhov impedance ntawm qhov kawg tau txais. Rau CMOS Circuit Court, qhov tso zis impedance ntawm kev tsav tsheb kawg ntawm lub teeb liab yog me me, kaum ntawm ohms. Lub input impedance ntawm qhov kawg tau txais yog qhov loj.

Plaub, lub impedance tswj ntawm PCB

(1) Yuav muaj ntau yam teeb liab kis tau tus mob nyob rau hauv lub conductors nyob rau hauv lub Circuit Court board. Yuav kom nce tus nqi sib kis, qhov zaus yuav tsum tau nce ntxiv. Yog hais tias lub Circuit Court nws tus kheej txawv vim yog yam xws li etching, pawg tuab, thiab hlau dav, tus nqi impedance yuav hloov. , distorting nws lub teeb liab. Yog li ntawd, tus nqi impedance ntawm tus neeg xyuas pib ntawm high-speed Circuit Court board yuav tsum tau tswj nyob rau hauv ib tug tej yam ntau yam, uas yog hu ua "impedance tswj".

(2) Lub ntsiab tseem ceeb uas cuam tshuam rau impedance ntawm PCB kab yog qhov dav ntawm cov hlau tooj liab, lub thickness ntawm cov tooj liab hlau, qhov dielectric qhov nruab nrab, lub thickness ntawm nruab nrab, thickness ntawm lub ncoo, txoj kev ntawm kab hauv av, kab ib ncig ntawm kab, thiab lwm yam.. Yog li ntawd, thaum tsim lub PCB, nws yog ib qho tsim nyog los tswj qhov impedance ntawm cov xaim ntawm lub rooj tsavxwm, kom tsis txhob cuam tshuam cov teeb liab thiab lwm yam kev cuam tshuam ntawm electromagnetic cuam tshuam thiab teeb liab teeb meem kev ncaj ncees kom ntau li ntau tau, thiab xyuas kom muaj kev ruaj ntseg ntawm kev siv tiag tiag. PCB pawg thawj coj saib. Txoj kev suav ntawm microstrip kab thiab strip kab impedance ntawm PCB lub rooj tsavxwm tuaj yeem xa mus rau cov qauv empirical sib raug.

5. impedance txuam ntawm PCB

(1) Nyob rau hauv lub rooj tsavxwm Circuit Court, yog tias muaj cov teeb liab kis tau tus mob, nws cia siab tias nws tuaj yeem ua tau yooj yim xa mus rau qhov kawg tau txais nrog qhov tsawg kawg nkaus lub zog poob los ntawm kev xa cov khoom siv hluav taws xob kawg, thiab qhov kawg tau txais yuav nqus tag nrho. tsis muaj kev xav. Yuav kom ua tiav qhov kev sib kis no, qhov impedance hauv kab yuav tsum sib npaug rau qhov impedance hauv qhov kawg xa, uas yog hu ua "impedance matching".

(2) Thaum tsim kev kub ceev PCB circuits, impedance txuam yog ib qho ntawm cov qauv tsim. Tus nqi impedance muaj kev sib raug zoo nrog txoj kev routing. Piv txwv li, seb puas yuav taug kev ntawm txheej txheej los yog txheej sab hauv, qhov kev ncua deb ntawm cov khoom siv hluav taws xob siv hluav taws xob lossis txheej hauv av, qhov dav ntawm kab, cov khoom ntawm PCB, thiab lwm yam yuav cuam tshuam rau tus yam ntxwv impedance tus nqi ntawm cov taug qab.

(3) Uas yog hais, tus nqi impedance tsuas yog txiav txim siab tom qab xaim. Feem ntau, cov software simulation yuav tsis tuaj yeem xav txog qee qhov xwm txheej thaiv nrog kev cuam tshuam tsis tu ncua vim qhov txwv ntawm cov qauv Circuit Court lossis cov lej siv lej siv. Qee qhov kev txiav tawm, xws li cov resistors series, tuaj yeem khaws cia kom txo tau qhov cuam tshuam ntawm qhov tsis sib xws ntawm cov kab impedance.

Tab sis qhov kev daws teeb meem tiag tiag yog sim kom tsis txhob muaj kev cuam tshuam ntawm impedance thaum xaim.

Cov saum toj no yog cov lus piav qhia ntawm cov ntsiab lus ntawm PCB impedance board. Beton muaj kev paub ntau lawm hauv kev ua haujlwm ntawm impedance tswj thiab txhawb impedance tswj, ntau theem impedance, thiab impedance txuam. Rau PCB xav tau, thov hu rau kev muag khoom ntawm linda@pcbsfactory.com.