Yog tias nyob rau lub hnub nyoog txawj ntse no, hauv daim teb no, koj xav kom muaj txuj ci hauv FPGA, tom qab ntawd lub ntiaj teb yuav tso koj tseg, Lub Sijhawm yuav tso koj tseg.

Kev txiav txim siab rau kev ua haujlwm siab PCB design related to serdes applications are as follows:

(1) Microstrip thiab Txoj hlua txuas.

Microstrip kab tau txuas xov hla txheej txheej txheej txheej ntawm lub dav hlau siv (GND lossis Vcc) sib cais los ntawm cov xov hluav taws xob kom txo qis qeeb; Cov xov hluav taws xob tau hla mus rau txheej txheej txheej sab hauv nruab nrab ntawm ob lub dav hlau siv (GND lossis Vcc) kom muaj peev xwm ua tau zoo dua qub, tswj tau yooj yim dua thiab tiv thaiv teeb liab, raws li qhia hauv daim duab.

Microstrip kab thiab kab txaij yog qhov zoo tshaj rau kev thaiv

(2) high-speed sib txawv teeb liab teeb liab.

Cov txheej txheem siv hluav taws xob ntau rau kev sib txawv ntawm cov teeb liab sib txawv muaj xws li Ntug Coupled microstrip (txheej saum toj kawg nkaus), Ntug Coupled ribbon kab (teeb tsa teeb liab txheej, tsim nyog rau kev kub ceev SERDES sib txawv teeb liab khub) thiab Broadside Coupled microstrip, raws li qhia hauv daim duab.

High speed differential signal pair wiring

(3) bypass capacitance (BypassCapacitor).

Bypass capacitor is a small capacitor with very low series impedance, which is mainly used to filter high frequency interference in high speed conversion signals. Muaj peb hom kev hla dhau cov khoom siv feem ntau siv hauv FPGA system: kev siv hluav taws xob nrawm (100MHz ~ 1GHz) feem ntau siv bypass capacitors ntau ntawm 0.01nF txog 10nF, feem ntau faib hauv 1cm los ntawm Vcc; Cov kab ke nruab nrab-nrawm (ntau dua kaum MHZ 100MHz), qhov kev hla dhau qhov sib txawv ntau yog 47nF txog 100nF tantalum capacitor, feem ntau tsis pub dhau 3cm ntawm Vcc; Cov txheej txheem qis-tsawg (tsawg dua 10 MHZ), feem ntau siv hla dhau lub tshuab hluav taws xob ntau yog 470nF txog 3300nF lub tshuab hluav taws xob, txheej txheem ntawm PCB yog dawb xwb.

(4) Capacitance pom kev thaiv zoo.

Capacitor wiring can follow the following design guidelines, as shown.

Capacitive optimal thaiv

Capacitive pin pads are connected using large size through holes (Via) to reduce coupling reactance.

Use a short, wide wire to connect the pad of the capacitor pin to the hole, or directly connect the pad of the capacitor pin to the hole.

LESR capacitors (Low Effective Series Resistance) were used.

Txhua tus GND tus pin lossis lub qhov yuav tsum tau txuas nrog lub dav hlau hauv av.

(5) Cov ntsiab lus tseem ceeb ntawm kev siv lub xov tooj cua nrawm nrawm.

Tsis txhob zigzag winding thiab teev cov moos kom ncaj li sai tau.

Sim ua txoj hauv kev ib txheej txheej teeb liab.

Tsis txhob siv dhau-qhov ntau li ntau tau, raws li dhau los ntawm qhov yuav qhia txog qhov muaj zog xav thiab cuam tshuam tsis sib xws.

Siv cov xov hluav taws xob microstrip nyob rau txheej sab saum toj kom ntau li ntau tau kom tsis txhob siv lub qhov thiab txo lub teeb liab qeeb.

Muab lub dav hlau hauv av ze rau ntawm txheej txheej teeb liab kom deb li sai tau kom txo tau suab nrov thiab hla kev. Yog tias txheej txheej txheej sab hauv tau siv, txheej txheej ntawm lub moos tuaj yeem sib xyaw ntawm ob lub dav hlau hauv av kom txo suab nrov thiab cuam tshuam. Ua kom qeeb teeb liab ncua.

Lub moos teeb liab yuav tsum ua kom raug qhov cuam tshuam.

(6) Cov teeb meem xav tau kev saib xyuas tshwj xeeb hauv kev sib txuas thiab txuas hluav taws xob.

Note the impedance matching of the differential signal.

Nco tseg qhov dav ntawm kab teeb liab sib txawv kom nws tuaj yeem tiv taus 20% ntawm lub teeb liab nce lossis lub sijhawm poob.

Nrog cov khoom sib txuas tsim nyog, qhov ntsuas zaus ntawm cov khoom sib txuas yuav tsum ua tau raws qhov siab tshaj plaws ntawm kev tsim qauv.

Kev sib txuas ntawm ob leeg yuav tsum tau siv kom deb li deb tau kom tsis txhob muaj ob tog sib txuas ua ke, 3S txoj cai faib ua feem yuav tsum siv kom tsis txhob muaj kev sib txuas dhau los lossis hla kab lus.

(7) Cov lus ceeb toom ntawm kev lim suab nrov rau cov tshuab ua haujlwm siab.

Txo qis cuam tshuam cuam tshuam (qis dua 1KHz) tshwm sim los ntawm lub zog hluav taws xob lub suab nrov, thiab ntxiv kev tiv thaiv lossis lim lub Circuit Court ntawm txhua lub zog siv nkag mus rau qhov kawg.

Ntxiv 100F electrolytic capacitor lim ntawm txhua qhov chaw uas lub hwj huam nkag mus rau PCB.

Txhawm rau txo cov suab nrov ntau, tso ntau qhov txiav tawm lub zog ntawm txhua Vcc thiab GND li sai tau.

Teem tawm Vcc thiab GND lub dav hlau ua ke, cais lawv nrog dielectrics (xws li FR-4PCB), thiab tso tawm hla dhau lub tshuab hluav taws xob hauv lwm txheej.

(8) Kev kub ceev qhov av Bounce

Sim ntxiv decoupling capacitor rau txhua Vcc/GND teeb liab khub.

Tsis pub lwm tus sab nraud ntxiv rau qhov tso tawm qhov kawg ntawm kev hloov pauv nrawm nrawm xws li cov txee kom txo qhov xav tau ntawm kev tsav tsheb muaj peev xwm.

Lub Quav Tsawg (qis-nce-nqes hav) hom tau teeb tsa rau cov paib qhia tawm uas tsis xav tau nrawm nrawm.

Tswj load reactance.

Txo lub moos tig lub teeb liab, lossis faib nws kom zoo ib yam li nyob ib puag ncig ntawm lub nti.

Lub teeb liab uas ntxeev ntau yog ze rau GND tus pin ntawm lub nti li sai tau.

Kev tsim qauv ntawm lub sijhawm ua haujlwm synchronous yuav tsum zam qhov hloov pauv sai ntawm cov zis.

Kev hloov pauv lub hwj chim thiab hauv av tuaj yeem ua lub luag haujlwm hauv kev ua haujlwm tag nrho.