Lim capacitors, hom hom inductors, thiab cov hlaws sib nqus yog cov duab hauv EMC tsim circuits, thiab tseem yog peb cov cuab yeej muaj zog los tshem tawm cov kev cuam tshuam electromagnetic.
Rau lub luag hauj lwm ntawm peb lub hauv Circuit Court, kuv ntseeg tias muaj ntau tus engineers tsis to taub, tsab xov xwm los ntawm kev tsim cov ncauj lus kom ntxaws tsom xam ntawm lub hauv paus ntsiab lus ntawm kev tshem tawm peb EMC sharpest.
1. Lim capacitor
Txawm hais tias lub resonance ntawm lub capacitor yog undesirable los ntawm lub point ntawm view ntawm filtering tawm high-frequency suab, lub resonance ntawm lub capacitor tsis yog ib txwm muaj teeb meem.
Thaum qhov zaus ntawm lub suab nrov yuav tsum tau lim tau txiav txim siab, lub peev xwm ntawm lub capacitor tuaj yeem hloov kho kom lub resonant point tsuas yog poob ntawm qhov cuam tshuam zaus.
Nyob rau hauv kev tsim engineering, zaus ntawm electromagnetic nrov yuav tsum tau lim yog feem ntau siab li pua pua MHz, los yog txawm ntau tshaj 1GHz. Rau xws li high zaus electromagnetic suab nrov, nws yog ib qhov tsim nyog yuav tau siv ib tug los ntawm-core capacitor kom zoo lim tawm.
Yog vim li cas vim li cas cov capacitors zoo tib yam tsis tuaj yeem lim tawm cov suab nrov nrov yog vim ob qho laj thawj:
(1) Ib qho laj thawj yog vim li cas qhov inductance ntawm capacitor lead ua rau lub capacitor resonance, uas nthuav tawm lub impedance loj rau lub teeb liab ntau zaus, thiab ua rau tsis muaj zog bypass cuam tshuam ntawm high-frequency teeb liab;
(2) Lwm qhov laj thawj yog tias cov kab mob parasitic capacitance ntawm cov xov hlau txuas nrog lub teeb liab siab, txo cov nyhuv lim dej.
Yog vim li cas vim li cas lub capacitor los ntawm cov tub ntxhais tuaj yeem lim tawm cov suab nrov nrov yog tias lub capacitor los ntawm cov tub ntxhais tsis tsuas yog tsis muaj teeb meem uas cov hlau lead inductance ua rau lub capacitor resonance zaus tsawg dhau.
Thiab los ntawm cov tub ntxhais capacitor tuaj yeem ntsia ncaj qha rau ntawm lub vaj huam sib luag hlau, siv lub vaj huam sib luag hlau los ua lub luag haujlwm ntawm kev sib cais siab. Txawm li cas los xij, thaum siv los ntawm cov tub ntxhais capacitor, qhov teeb meem yuav tsum tau them sai sai rau yog qhov teeb meem kev teeb tsa.
Qhov tsis muaj zog loj tshaj plaws ntawm cov tub ntxhais ntawm lub capacitor yog qhov kev ntshai ntawm qhov kub thiab txias, uas ua rau muaj teeb meem loj thaum welding los ntawm-core capacitor mus rau lub vaj huam sib luag hlau.
Muaj ntau lub capacitor puas thaum vuam. Tshwj xeeb tshaj yog thaum muaj coob tus tub ntxhais capacitors yuav tsum tau muab ntsia rau ntawm lub vaj huam sib luag, tsuav yog muaj kev puas tsuaj, nws yog ib qho nyuaj rau kho, vim hais tias thaum lub puas capacitor raug tshem tawm, nws yuav ua rau puas tsuaj rau lwm yam nyob ze capacitor.
2.Common hom inductance
Txij li cov teeb meem EMC lub ntsej muag yog feem ntau muaj kev cuam tshuam, hom hom inductors kuj yog ib qho ntawm peb cov khoom siv muaj zog.
Hom hom inductor yog hom kev cuam tshuam kev cuam tshuam cov cuab yeej siv nrog ferrite raws li cov tub ntxhais, uas muaj ob lub coils ntawm tib qhov loj thiab tib tus naj npawb ntawm cov lem symmetrically raug mob ntawm tib lub nplhaib ferrite sib nqus core los ua plaub lub davhlau ya nyob twg, uas. muaj ib tug loj inductance suppression nyhuv rau hom hom teeb liab, thiab ib tug me me to inductance rau qhov txawv hom teeb liab.
Lub hauv paus ntsiab lus yog tias thaum hom hom tam sim no ntws, cov hlau nplaum sib nqus hauv lub nplhaib sib nqus sib nqus ua ke, yog li muaj qhov cuam tshuam loj heev, uas cuam tshuam cov hom tam sim no, thiab thaum ob lub coils ntws los ntawm qhov sib txawv tam sim no, cov hlau nplaum sib nqus. nyob rau hauv lub nplhaib sib nqus tshem tawm ib leeg, thiab yuav luag tsis muaj inductance, yog li qhov sib txawv hom tam sim no tuaj yeem dhau yam tsis muaj kev cuam tshuam.
Yog li ntawd, hom hom inductor tuaj yeem cuam tshuam cov hom kev cuam tshuam cov teeb liab hauv cov kab sib npaug, tab sis tsis muaj kev cuam tshuam rau kev sib kis ntawm cov teeb liab sib txawv.
Hom hom inductors yuav tsum ua tau raws li cov cai hauv qab no thaum lawv tsim:
(1) Cov xov hlau raug mob ntawm cov tub ntxhais coil yuav tsum tau insulated los xyuas kom meej tias tsis muaj kev tawg luv luv ntawm kev hloov ntawm lub kauj nyob rau hauv qhov kev txiav txim ntawm instantaneous overvoltage;
(2) Thaum lub kauj ntws los ntawm qhov tam sim no loj tam sim no, cov hlau nplaum yuav tsum tsis txhob saturated;
(3) Cov tub ntxhais hlau nplaum nyob rau hauv lub kauj yuav tsum tau insulated los ntawm lub kauj kom tiv thaiv kev tawg ntawm ob nyob rau hauv qhov kev txiav txim ntawm instantaneous overvoltage;
(4) Lub kauj yuav tsum raug mob hauv ib txheej kom deb li deb tau, txhawm rau txo cov kab mob parasitic capacitance ntawm lub kauj thiab txhim kho lub peev xwm ntawm lub kauj kom xa cov hluav taws xob overvoltage.
Nyob rau hauv ib txwm muaj xwm txheej, thaum them nyiaj rau kev xaiv ntawm cov zaus band yuav tsum tau lim, qhov loj dua hom impedance, qhov zoo dua, yog li peb yuav tsum tau saib cov ntaub ntawv ntaus ntawv thaum xaiv hom hom inductor, feem ntau raws li cov impedance zaus nkhaus.
Tsis tas li ntawd, thaum xaiv, xyuam xim rau qhov cuam tshuam ntawm qhov sib txawv hom impedance ntawm lub teeb liab, feem ntau tsom rau qhov sib txawv hom impedance, tshwj xeeb tshaj yog them rau cov chaw nres nkoj siab.
3.Magnetic hlaws
Nyob rau hauv cov khoom lag luam digital Circuit EMC txheej txheem tsim, peb feem ntau siv cov hlaws sib nqus, cov khoom siv ferrite yog hlau-magnesium alloy lossis hlau-nickel alloy, cov khoom no muaj qhov sib nqus permeability siab, nws tuaj yeem ua tus inductor nruab nrab ntawm cov coil winding nyob rau hauv cov ntaub ntawv siab. zaus thiab siab tsis kam generated capacitance yam tsawg kawg nkaus.
Ferrite cov ntaub ntawv feem ntau yog siv nyob rau hauv high zaus, vim hais tias ntawm tsawg frequencies lawv lub ntsiab inductance yam ntxwv ua rau poob ntawm kab me me heev. Nyob rau hauv high zaus, lawv yog cov feem ntau reactance yam ntxwv piv thiab hloov nrog zaus. Hauv kev siv tswv yim, cov ntaub ntawv ferrite yog siv los ua cov khoom siv hluav taws xob ntau rau cov xov tooj cua zaus circuits.
Qhov tseeb, ferrite zoo dua sib npaug rau qhov sib npaug ntawm qhov tsis kam thiab inductance, qhov tsis kam yog luv luv los ntawm inductor ntawm qhov tsawg zaus, thiab inductor impedance ua siab heev ntawm qhov siab, yog li tam sim no tag nrho dhau los ntawm kev ua haujlwm.
Ferrite yog ib qho khoom siv uas siv hluav taws xob ntau zaus hloov mus rau hauv lub zog hluav taws xob, uas yog txiav txim siab los ntawm nws cov yam ntxwv ntawm hluav taws xob. Ferrite magnetic hlaws muaj qhov zoo ntawm cov khoom siv lim dej zoo dua li cov inductors zoo tib yam.
Ferrite yog resistive ntawm high zaus, sib npaug rau ib qho inductor nrog qhov zoo tshaj plaws, yog li nws muaj peev xwm tswj tau lub siab impedance nyob rau hauv ntau qhov ntau zaus, yog li txhim kho qhov ua tau zoo ntawm kev lim dej ntau zaus.
Hauv qhov tsawg zaus band, impedance yog tsim los ntawm inductance. Ntawm qhov tsawg zaus, R yog me me, thiab qhov sib nqus permeability ntawm cov tub ntxhais yog siab, yog li qhov inductance loj. L ua lub luag haujlwm tseem ceeb, thiab kev cuam tshuam ntawm electromagnetic cuam tshuam los ntawm kev xav. Thiab lub sijhawm no, qhov poob ntawm cov tub ntxhais sib nqus yog me me, tag nrho cov cuab yeej poob qis, siab Q yam ntxwv ntawm inductor, qhov inductor no yooj yim ua rau resonance, yog li nyob rau hauv qis zaus band, tej zaum yuav muaj kev cuam tshuam zoo dua. Tom qab siv cov ferrite sib nqus hlaws.
Nyob rau hauv lub high zaus band, lub impedance yog tsim los ntawm cov khoom tiv thaiv. Raws li qhov zaus nce, qhov permeability ntawm cov tub ntxhais sib nqus tau txo qis, ua rau txo qis ntawm inductance ntawm inductor thiab txo qis ntawm inductive reactance tivthaiv.
Txawm li cas los xij, nyob rau lub sijhawm no, qhov poob ntawm cov tub ntxhais sib nqus nce, cov khoom tiv thaiv kev tiv thaiv nce, ua rau muaj kev nce ntxiv hauv tag nrho impedance, thiab thaum lub teeb liab siab dhau los ntawm ferrite, electromagnetic cuam tshuam yog absorbed thiab hloov mus rau hauv daim ntawv. ntawm tshav kub dissipation.
Ferrite suppression Cheebtsam yog dav siv nyob rau hauv cov ntawv luam Circuit Court boards, fais fab kab thiab cov ntaub ntawv kab. Piv txwv li, ib qho ferrite suppression element yog ntxiv rau qhov kawg ntawm lub hwj chim qaum ntawm cov ntawv luam tawm los lim tawm cov kev cuam tshuam ntau zaus.
Ferrite magnetic nplhaib los yog sib nqus hlaws tshwj xeeb yog siv los txhawm rau muaj kev cuam tshuam ntau zaus thiab kev cuam tshuam siab tshaj plaws ntawm cov teeb liab kab thiab cov kab hluav taws xob, thiab nws kuj muaj peev xwm nqus tau electrostatic paug pulse cuam tshuam. Kev siv cov chip magnetic hlaws lossis nti inductors feem ntau yog nyob ntawm daim ntawv thov.
Chip inductors yog siv nyob rau hauv resonant circuits. Thaum tsis tsim nyog EMI suab nrov yuav tsum tau muab tshem tawm, kev siv cov nti sib nqus hlaws yog qhov kev xaiv zoo tshaj.
Daim ntawv thov ntawm chip magnetic hlaws thiab nti inductors
Chip inductors:Xov tooj cua zaus (RF) thiab kev sib txuas lus wireless, cov khoom siv thev naus laus zis, radar detectors, automotive electronics, cellular phones, pagers, audio equipment, personal digital assistant (PDAs), wireless remote control systems, and low-voltage power supply modules.
Chip magnetic hlaws:Clock-generating circuits, filtering ntawm analog thiab digital circuits, I/O input/output internal connectors (xws li serial ports, parallel ports, keyboards, nas, long-distance telecommunications, local area networks), RF circuits thiab logic devices susceptible to cuam tshuam, filtering ntawm high-frequency ua cuam tshuam nyob rau hauv lub hwj chim mov circuits, computers, printers, video recorders (VCRS), EMI suab suppression nyob rau hauv TV systems thiab xov tooj ntawm tes.
Chav tsev ntawm cov hlaws sib nqus yog ohms, vim hais tias chav tsev ntawm cov hlaws sib nqus yog nominal raws li qhov impedance nws tsim ntawm qee zaus, thiab chav tsev ntawm impedance kuj yog ohms.
Cov hlaws sib nqus DATASHEET feem ntau yuav muab cov zaus thiab impedance yam ntxwv ntawm qhov nkhaus, feem ntau 100MHz raws li tus qauv, piv txwv li, thaum lub zaus ntawm 100MHz thaum impedance ntawm cov hlaws sib nqus sib npaug rau 1000 ohms.
Rau qhov zaus peb xav lim, peb yuav tsum xaiv qhov loj dua qhov impedance ntawm cov hlau nplaum, qhov zoo dua, feem ntau xaiv 600 ohm impedance lossis ntau dua.
Tsis tas li ntawd, thaum xaiv cov hlaws sib nqus, nws yuav tsum tau them sai sai rau qhov flux ntawm cov hlaws sib nqus, uas feem ntau yuav tsum tau derated los ntawm 80%, thiab qhov cuam tshuam ntawm DC impedance ntawm voltage poob yuav tsum tau txiav txim siab thaum siv hauv cov hluav taws xob circuits.
Post lub sij hawm: Lub Xya hli ntuj-24-2023
