Everyone knows doing the principle diagram of the PCB is designed into a real piece of PCB, please don’t look down upon this process, there are a lot of things on the principle of practicable in engineering has difficult to achieve, or something that someone can achieve them,but others can not, so it is not difficult to make a PCB, but make a good PCB board tsis yog ib qho yooj yim tshaj plaws.
Ob tug loj teeb meem nyob rau hauv lub teb ntawm microelectronics yog lub loj lub teeb liab thiab tsis muaj zog teeb liab ua, PCB ntau lawm theem yog tshwj xeeb yog ib qho tseem ceeb nyob rau hauv no hwm, lub ntsiab cai tib yam tsim, tib yam, cov neeg sib txawv ua PCB yuav muaj ntau tau, yog li yuav ua li cas ua ib tug zoo PCB board? Raws li peb yav dhau los, peb xav tham txog peb views on nram qab no sib nrauj:
1. Txhais kom meej koj cov hom phiaj
Tau txais ib tug tsim ua hauj lwm, yuav tsum xub luaj tus tsim cov hom phiaj, yog ib tug Common PCB board , high-zaus PCB , me me teeb liab ua PCB los yog muaj ob leeg siab zaus thiab me me teeb liab ua ntawm lub PCB, yog hais tias nws yog ib tug ntau PCB , raws li ntev raws li tsim nyog layout thiab huv si, neeg kho tshuab loj muaj tseeb, yog hais tias lub load kab thiab kab, yuav muaj leej twg los ntawm ib tug tej yam txhais tau tias, qee kom sib tus load, ntxiv dag zog rau kab ntawm tus tsav, lub ntsiab yog los mus tiv thaiv cov kab lub thiaj. thaum muaj ntau tshaj 40MHz teeb liab kab rau lub rooj tsavxwm, tshwj xeeb xav txog kev teem no yog ua los rau cov teeb liab kab, xws li crosstalk.If zaus yog ntau dua, muaj ntau cov kev txwv ntawm qhov ntev ntawm lub thaiv, raws li lub tsev tsis muaj network kev tshawb xav, lub sis ntawm kev kub ceev circuit Court thiab nws txuas yog lub decisive zoo tshaj, lub kaw lus yuav tsis tau ignored nyob rau hauv design.With cov kev txhim kho ntawm lub qhov rooj kis tau tus mob ceev, ntawm kab tiv thaiv yuav ua rau kom, lub crosstalk ntawm ib sab lub teeb liab kab yuav xwm yeem mus rau kev nce rau hauv, feem ntau high-ceev zog noj thiab tshav kub dissipation ntawm lub Circuit Court yog heev loj, yuav tsum ua rau txaus mloog thaum ua high-ceev PCB.
Thaum board muaj millivolt theem txawm microvolt theem thaum lub zog lub teeb liab, lub teeb liab yuav tsum tau kev pab tshwj xeeb, me me teeb liab yog ib yam nkaus thiab tsis muaj zog, heev lam tau lam ua rau lwm tus muaj zog lub teeb liab cuam, shielding ntsuas yog feem ntau tsim nyog, txwv tsis pub yuav zoo heev txo lub teeb liab-rau-suab nrov ratio.So uas pab tau Pib ntsais koj teeb tuag coob tawm los ntawm cov suab nrov thiab tsis tau zoo muab rho tawm.
Nyob rau lub Rooj Tswjhwm Saib cov kev ntsuas yuav tsum tau muab los xav thaum lub sij hawm tsim theem, lub cev qhov chaw nyob ntawm kev kuaj cov ntsiab lus, kev xeem point ntawm kev rho tawm yam tsis tau ignored, vim hais tias ib co ntawm cov me me teeb liab thiab loj teeb liab yog tsis ncaj qha ntxiv sojntsuam los ntsuas.
Nyob rau hauv tas li ntawd, muaj lwm yam tseem ceeb, xws li cov txheej ntawm cov laug cam, lub hnab zoo ntawm lub Cheebtsam thiab tus neeg kho tshuab zog ntawm cov boards.Before ua PCB boards, koj yuav tsum tau muaj ib tug tsim lub hom phiaj nyob rau hauv lub siab.
2. Nkag siab txog cov uas yuav tsum tau ntawm cov nuj nqi ntawm lub Cheebtsam siv nyob rau hauv lub layout
Raws li peb paub, muaj tej yam tshwj xeeb Cheebtsam nyob rau hauv lub layout tau tshwj xeeb uas yuav tsum tau, xws li LOTI thiab APH siv analog teeb liab amplifier, analog teeb liab amplifier rau lub hwj chim uas yuav tsum tau rau tus, me me ripple.The simulation ntawm me me teeb liab qhov chaw yuav tsum tau khaws cia tseg los ntawm hwj chim devices.On lub OTI board, cov me me teeb liab amplification ib feem yog tseem tshwj xeeb uas tsim nrog ib tug shielding daim npog qhov ncauj rau tiv thaiv lub stray electromagnetic interference.GLINK chips siv nyob rau hauv lub NTOI board yog cov ECL txheej txheem, lub hwj chim noj loj kub taub hau, rau qhov teeb meem ntawm tshav kub dissipation yuav tsum tau ua thaum lub layout yuav tsum tshwj xeeb xav, yog tias lub ntuj txias, yuav muab tso rau lub GLINK nti nyob rau hauv cov huab cua khiav yog tus, thiab tawm ntawm lub tshav kub tsis yog ib tug loj feem mus rau lwm cov chips.If muaj yog ib tug horn los yog lwm yam muaj hwj huam ntaus ntawv rau lub rooj tsavxwm, tej zaum nws yuav zoo kuj ua tau teeb meem loj paug lub hwj chim nws yuav tsum tau them txaus mloog.
3. Xav txog kev tivthaiv layout
Lub layout ntawm lub Cheebtsam thawj ib yam yuav tau xav txog yog qhov kev kawm, zoo txog rau kev twb kev txuas ntawm cheebtsam ua ke kom deb li deb li sai tau, tshwj xeeb tshaj yog rau ib co kev kub ceev kab, qhov layout yog ua kom nws raws li luv luv li sai tau cais hwj chim lub teeb liab thiab me me teeb liab device.In lub premise ntawm lub rooj sib tham qhov kev kawm ntawm cov circuit Court, nws yog tseem tsim nyog los xav txog lub arrangement ntawm lub cheebtsam hauv kev txiav txim, zoo nkauj, yooj yim rau kev ntsuam xyuas, tus neeg kho tshuab loj ntawm lub rooj tsavxwm, qhov chaw ntawm lub ntsawb, etc.
Cov kis tau tus mob ncua sij hawm ntawm grounding thiab interconnection nyob rau hauv lub high-ceev system yog kuj tus thawj tau yuav pom tau tias thaum tsim lub system.Signal nyob rau kis tau tus mob lub sij hawm muaj ib tug zoo cawv rau tag nrho cov system ceev, tshwj xeeb tshaj yog rau cov high-ceev ECL circuits, txawm hais tias muaj kev kub ceev kev circuit Court thaiv nws tus kheej, tab sis raws li ib tug tshwm sim ntawm nyob rau hauv pem teb nrog ntau interconnect (txhua txhua 30 cm ntev, hais txog qhov kev ncua ntawm lub 2 NS) coj lub nce ntawm qhov kev ncua sij hawm, yuav ua rau lub system ceev yog zoo heev txo. Zoo li ib tug ua haujlwm register, synchronous counter no synchronization ua hauj lwm qhov chaw nyob rau hauv tib daim card, qhov zoo tshaj plaws vim hais tias ntawm qhov sib txawv kis tau tus mob ncua lub sij hawm rau ntawm lub moos teeb liab rau lub Rooj Tswjhwm Saib yog tsis sib npaug zos, yuav ua rau ib tug ua haujlwm register khoom uas tsis, yog hais tias tsis nyob rau hauv ib tug phaj, qhov twg synchronization yog tus yuam sij, los ntawm pej xeem moos qhov twg los kev cob cog rua rau lub moos kab yuav tsum sib npaug zos rau qhov ntev ntawm lub Rooj Tswjhwm Saib.
4. Xav txog xov
Nrog rau cov qauv siv los ntawm OTNI thiab cov hnub qub kho qhov muag fiber network, ntau tshaj 100MHz ntawm cov kev kub ceev teeb liab kab yuav tsum tau yuav tsum tau tsim nyob rau hauv lub neej yav tom ntej. Ib txhia tswv yim ntawm kev kub ceev kab yuav tsum tau qhia ntawm no.
Kis kab
Tej "ntev" taw pathway rau ib tug luam Circuit Court boardyuav suav hais tias ib tug kis tau tus mob line.If cov kis ncua sij hawm ntawm cov kab yog ntau luv dua lub teeb liab sawv lub sij hawm, rau thiaj yuav rau tswv thaum lub sij hawm lub teeb liab sawv yuav submerged.No ntev tshwm sim overshoot, recoil thiab ringing, rau thaum lub caij, feem ntau ntawm cov mos circuit Court, vim hais tias ntawm lub siab ntxiv lub sij hawm ntawm kab kis tau tus mob ncua sij hawm yog loj npaum li cas, yog li nws yuav ua tau nyob rau hauv meters ntev thiab tsis muaj teeb liab distortion.And kom sai logic circuits, tshwj xeeb tshaj yog ultra-high ceev ECL.
Nyob rau hauv cov ntaub ntawv ntawm kev circuits, qhov ntev ntawm lub ib co kua nplaum yuav tsum tau ho zog nyob rau hauv thiaj li yuav muaj lub meej mom ntawm lub teeb liab vim sai ntug speeds.
Muaj ob txoj kev uas yuav ua rau lub high-ceev Circuit Court nyob rau hauv ib tug kuj ntev kab ua hauj lwm tsis loj distortion, yog siv rau cov ceev ceev poob nyob rau hauv ntug TTL schottky diode clamping txoj kev, ua lam ua tau khi nyob rau hauv ib tug diode yog qis dua hauv av tej zaum siab nco nyob rau theem ntawm kev txo lub recoil nyob rau tom qab ntawm lub amplitude, cov qeeb qeeb microscopic ntug ntawm lub overshoot yog tso cai, tab sis nws yog ib theem "H" nyob rau hauv ib lub xeev ntawm siab kuj tso zis impedance ntawm lub circuit Court (50 ~ 80 Ω) attenuation .Nyob rau hauv tas li ntawd, vim mus rau theem ntawm "H" xeev tiv thaiv, loj recoil teeb meem yog tsis heev zoo heev, ntaus ntawv ntawm HCT series, yog siv schottky diode clamping thiab series kuj sab txuas rau txoj kev, tus paub zoo yuav tau cuab kev ntau.
Thaum muaj ib tug kiv cua tawm raws lub teeb liab kab, qhov TTL shaping txoj kev piav saum toj no yog tsis nyob rau hauv ntau dua me ntsis nqi thiab sai ntug speed.Because muaj thaws rov los tsis nyob rau hauv kab, lawv yuav yuav tsum tsim nyob rau hauv lub siab npaum li cas, yog li rau muaj mob loj distortion ntawm lub teeb liab thiab zuj zus lawm anti-cuam ability.Therefore, nyob rau hauv thiaj li yuav daws tau qhov teeb meem thiaj yuav, lwm txoj kev yog feem ntau yog siv nyob rau hauv lub ECL system: txoj kab impedance txuam method.In no txoj kev rau thiaj yog tshuaj thiab kev ncaj ncees ntawm lub teeb liab yog guaranteed.