CAN tsheb npav technology tau dhau los ua qhov dav. Txawm li cas los xij, vim muaj kev cuam tshuam loj ntawm electromagnetic cuam tshuam hauv thaj chaw xws li cov cuab yeej siv thiab kev lag luam automation, kom ntseeg tau tias kev sib txuas lus hauv tsheb npav CAN ib txwm tseem ceeb tshwj xeeb. Kab lus no yuav txheeb xyuas qhov ua rau muaj kev cuam tshuam ntawm electromagnetic cuam tshuam hauv cov tsheb npav uas siv siab -CAN FD transceivers, nrog rau cov kev daws teeb meem tshwj xeeb rau kev txhim kho.
Electromagnetic Compatibility Analysis hauv CAN FD Networks
Hauv kev tsim cov khoom siv hluav taws xob, kev ua haujlwm ntawm electromagnetic compatibility (EMC) muaj kev cuam tshuam loj rau lub cev thiab tseem ceeb heev rau nws txoj haujlwm zoo thiab ruaj khov. Kev txwv tsis pub siv hluav taws xob sib raug zoo ntawm cov khoom siv hluav taws xob tau raug siv thoob ntiaj teb, thiab EMC kev ua tau zoo tau dhau los ua qhov taw qhia tseem ceeb ntawm cov khoom zoo.
Electromagnetic compatibility feem ntau suav nrog ob yam: ib qho yog qhov cuam tshuam tsis zoo ntawm electromagnetic cuam tshuam los ntawm cov khoom nws tus kheej, hu ua electromagnetic cuam tshuam emission (EMI); lwm yam yog cov khoom rhiab heev rau sab nraud electromagnetic signals, hu ua electromagnetic susceptibility (EMS). Qhov chaw cuam tshuam, kev sib txuas, thiab cov khoom siv rhiab yog peb lub ntsiab lus tseem ceeb ntawm electromagnetic compatibility, thiab tsis muaj ib qho yuav raug tshem tawm.
Electromagnetic cuam tshuam cov teeb liab tuaj yeem ua ke los ntawm ob txoj hauv kev: ua thiab tawg. Raws li kev sib txuas ntawm kev sib txuas, kev cuam tshuam tau muab faib ua hom kev cuam tshuam thiab sib txawv- hom cuam tshuam. Feem ntau- hom kev cuam tshuam tshwm sim ntawm txhua kab teeb liab (xws li cov kab teeb liab, kab cov ntaub ntawv, thiab cov kab hluav taws xob) thiab hauv av, thaum qhov sib txawv- hom cuam tshuam tshwm sim ntawm cov kab teeb liab.
Kev ntsuas los txhim kho electromagnetic compatibility (EMC) poob rau hauv peb pawg: txhim kho EMC kev ua tau zoo ntawm cov khoom siv hluav taws xob nws tus kheej, siv cov cuab yeej tiv thaiv kom tsis txhob muaj hluav taws xob sib txuas, thiab siv kev sib cais los tiv thaiv kev sib txuas.
1. EMC Tsim
Kev tsim ntawm tus tswv thiab qhev Circuit Court boards yog qhov tseem ceeb rau lub kaw lus EMC, thiab lub rooj tsav xwm Circuit Court muaj peev xwm tawm thiab tau txais hluav taws xob hluav taws xob feem ntau zoo ib yam. Yog li ntawd, kev txhim kho lub rooj tsav xwm hluav taws xob tiv thaiv kev cuam tshuam kuj tseem cuam tshuam nws cov emissions electromagnetic. Cov yam tseem ceeb hauv PCB EMC tsim muaj xws li hauv qab no:
Cheebtsam xaiv thiab layout
Xaiv cov khoom uas muaj EMC kev ua tau zoo thiab ua qhov tseem ceeb ntawm qhov chaw -mount ntim thaum twg los tau. Npaj cov khoom sib xyaw kom zoo, muab cov khoom sib txuas ua ke kom zoo li ua tau kom txo tau cov txhuas qhov ntev ntawm qhov chaw. Tshwj xeeb, cov siv lead ua oscillators ua haujlwm raws li lub moos rau microcontrollers thiab CAN controllers yuav tsum tau muab tso rau raws li specifications; txwv tsis pub, lawv yuav ua tsis tau oscillate.
Tsim kom muaj av zoo kom txo tau av impedance
Lub peev xwm hauv av ua haujlwm raws li kev siv peev xwm rau txhua qhov teeb meem. Qhov zoo tshaj plaws, tag nrho cov ntsiab lus hauv av ntawm PCB yuav tsum nyob ntawm tib lub peev xwm; Txawm li cas los xij, vim av impedance, muaj peev xwm sib txawv ntawm cov ntsiab lus hauv av. Yog li ntawd, av impedance yuav tsum tau txo kom ntau li ntau tau. Txoj kev ua tau zoo tshaj plaws yog siv lub rooj tsav xwm multilayer nrog lub dav hlau hauv av nyob hauv nruab nrab.
Stabilizing Cov Khoom Siv Hluav Taws Xob
Unideal tej yam kev mob, xws li ib ntus cuam tshuam thaum lub sij hawm logic rooj vag tso zis lub xeev hloov thiab lub xub ntiag ntawm lub hwj chim kab impedance, inevitably qhia suab nrov rau hauv lub hwj chim mov kab. Cov suab nrov no tsis tsuas yog ua rau kev ua haujlwm tsis zoo hauv Circuit Court tab sis kuj tsim hluav taws xob hluav taws xob tseem ceeb. Ntxiv nrog rau kev siv lub zog hluav taws xob mesh los txo qhov inductance thiab impedance ntawm cov kab hluav taws xob, cov khoom ntim cia kuj tuaj yeem ua haujlwm.
2. Electromagnetic Radiation thiab Electromagnetic Shielding
Electromagnetic shielding yog ib txoj hauv kev tseem ceeb los daws cov teeb meem electromagnetic compatibility. Nws tsis cuam tshuam nrog kev ua haujlwm ib txwm muaj ntawm circuits thiab tsis tas yuav hloov pauv hauv Circuit Court. Kev ua tau zoo ntawm daim thaiv npog yog ntsuas los ntawm nws qhov kev tiv thaiv kev ua haujlwm, uas muaj ob yam: kev xav tsis zoo thiab kev nqus nqus. Kev tuav cov hluav taws xob txuas ntxiv ntawm cov ntaub thaiv npog yog qhov tseem ceeb rau nws txoj kev ua tau zoo. CAN tsheb npav cables muaj kev cuam tshuam rau ob qho tib si radiating thiab txais kev cuam tshuam.
Lub voj cheeb tsam ntawm ob lub xov hlau nyob rau hauv ib qho twisted -pair cable yog me me, thiab cov tam sim no induced nyob rau hauv ob qho tib si loops nyob rau hauv opposite lus qhia, yog li tshem tawm ib leeg. Qhov nruj dua qhov sib tw hauv qhov sib tw -pair cable, qhov ua tau zoo tshaj qhov no. Txhawm rau txo qis kev sib tham ntawm ob lub tsheb npav CAN hauv lub network, txhua khub ntawm twisted -pair cables yuav tsum tau tiv thaiv nyias, thiab txhua yam tsis siv neeg txuas hauv cable yuav tsum txuas nrog lub teeb liab hauv av.
Ua kom cov twisting ceev; hauv av daim ntaub thaiv
3. Ua kev cuam tshuam thiab teeb liab cais
Thaum lub sijhawm ua haujlwm ib txwm muaj, cov khoom siv uas ua rau muaj kev cuam tshuam tseem ceeb suav nrog kev hloov cov khoom siv hluav taws xob, servo drives, thiab I / O tswj cov cuab yeej. Txawm li cas los xij, hom kev cuam tshuam loj tshaj plaws yog kev cuam tshuam ib ntus, uas yog lub sijhawm luv luv, siab amplitude, thiab qis zog.
Cov ntaub ntawv ntawm kev cuam tshuam ib ntus suav nrog: cov pab pawg hluav taws xob ceev ceev tsim tawm thaum lub xeev ntawm lub cev hloov pauv; surges tshwm sim los ntawm xob laim lossis siab - fais fab hloov ntawm cables; thiab electrostatic paug (ESD) induction. Kev cuam tshuam kev cuam tshuam feem ntau tshwm sim - hom, txawm tias qee qhov sib txawv - hom cuam tshuam kuj tshwm sim. EMC kev ntsuas siv nyob rau hauv lub kaw lus los xyuas kom meej qhov kev cia siab ntawm CAN tsheb npav kev sib txuas lus muaj xws li: teeb liab protectors, transient voltage suppressor (TVS) diodes, cais transceivers, thiab optical cais.
Teeb liab tiv thaiv
Sab nraud mob siab rau cov teeb liab tiv thaiv tshem tawm kev cuam tshuam; Piv txwv li, ZF-12Y2 absorbs cuam tshuam, thiab CANFDbridge ua tus cais.
Teeb liab tiv thaiv thiab CANFDBridge Isolation
Transient Voltage Suppressor (TVS)
Transient voltage suppressors tau txuas nrog nyob rau tib lub sijhawm ntawm cov kab teeb liab thiab cov teeb liab hauv av los tiv thaiv cov kab hluav taws xob los ntawm qhov siab -voltage surges los ntawm xob laim lossis hluav taws xob tawm. Thaum qhov hluav taws xob thoob plaws TVS tshaj li ib qho chaw pib, lub cuab yeej ua haujlwm sai, yog li dissipating lub zog surge thiab limiting qhov voltage amplitude rau ib qho tshwj xeeb.
Isolated Transceivers
Kev rho tawm yog ib qho kev daws teeb meem zoo tshaj plaws rau kev hais txog kev cuam tshuam kev cuam tshuam, muab cov hluav taws xob rwb thaiv tsev zoo heev thiab cuam tshuam kev tiv thaiv. Thaum xaiv ib qho kev sib cais transceiver, kev ncua sij hawm yuav tsum yog thawj qhov kev txiav txim siab, vim nws cuam tshuam rau ob qho tib si kis tau tus mob thiab qhov zoo ntawm lub tsheb npav. Nws raug nquahu kom siv cov sib nqus sib nqus CTM5MFD los tsim cov interface transceiver Circuit Court.
Optical Isolation
Optical isolation yog ib qho kev daws teeb meem zoo tshaj plaws los daws cov teeb meem cuam tshuam, vim nws muaj cov hluav taws xob rwb thaiv tsev zoo thiab cuam tshuam kev tiv thaiv. Thaum xaiv optocouplers, ob qhov kev ntsuas yuav tsum raug txiav txim siab: kev nthuav tawm qeeb thiab ntau yam -mode rejection (CMR). Muab hais tias qhov kev nthuav tawm qeeb ua tau raws li cov ntaub ntawv kev sib txuas lus baud tus nqi yuav tsum tau, cov qauv uas muaj ntau ntau- hom kev tsis lees paub yuav tsum raug xaiv thaum twg los tau. Txoj kev ntsuas qhov sib xws -hom rejection muaj peev xwm ntawm optocoupler yog qhov siab tshaj plaws -mode voltage nce (poob) tus nqi (CMH/CML) uas cov zis tuaj yeem tiv taus thaum tseem siab (qis). Tom qab siv qhov kev sib cais kho qhov muag, kev rho tawm hluav taws xob yuav tsum tau ua haujlwm.
Cov ntsiab lus
Cov hluav taws xob los ntawm ntau qhov chaw ntawm kev cuam tshuam yog qhov nyuaj, thiab tshem tawm cov kev cuam tshuam electromagnetic kiag li yog ib txoj haujlwm tsis yooj yim sua. Txawm li cas los xij, raws li cov hauv paus ntsiab lus ntawm electromagnetic compatibility, kev ntsuas tuaj yeem ua kom txo qis kev cuam tshuam ntawm electromagnetic cuam tshuam thiab ua kom nws nyob rau hauv qhov kev txwv tsis pub dhau, yog li ua kom muaj kev ntseeg siab ntawm lub kaw lus lossis khoom siv. Kev txhim kho kev ntsuas tau teev tseg saum toj no tuaj yeem txhim kho qhov kev ua tau zoo ntawm electromagnetic compatibility ntawm CAN FD li.