iindaba

Isishwankathelo

I-inductors zizinto ezibaluleke kakhulu ekutshintsheni abaguquli, njengokugcinwa kwamandla kunye nezihlungi zamandla. Kukho iintlobo ezininzi ze-inductors, ezifana nezicelo ezahlukeneyo (ukusuka kwi-frequency ephantsi ukuya kwi-frequency ephezulu), okanye izinto ezingundoqo ezahlukeneyo ezichaphazela iimpawu ze-inductor, njalo njalo. Ii-inductors ezisetyenziswa ekutshintsheni abaguquli zizinto ezisebenza kakhulu ezinomagnetic. Nangona kunjalo, ngenxa yezinto ezahlukeneyo ezifana nemathiriyeli, iimeko zokusebenza (ezinje ngombane kunye nangoku), kunye nobushushu be-ambient, iimpawu kunye neethiyori ezibonisiweyo zahluke kakhulu. Ngoko ke, kwi-design yesiphaluka, ukongeza kwi-parameter esisiseko yexabiso le-inductance, ubudlelwane phakathi kwe-impedance ye-inductor kunye nokumelana ne-AC kunye nokuphindaphinda, ilahleko engundoqo kunye neempawu zangoku zokuzalisa, njl njl. Eli nqaku lizakwazisa izinto ezininzi ezibalulekileyo ze-inductor kunye neempawu zazo, kwaye likhokela iinjineli zamandla ukuba zikhethe ii-inductors ezisemgangathweni ezikhoyo kurhwebo.

Intshayelelo

Inductor yi-electromagnetic induction component, eyenziwa ngokujija inani elithile leekhoyili (coil) kwi-bobbin okanye i-core kunye ne-insulated wire. Le khoyili ibizwa ngokuba yi-coil inductance okanye i-Inductor. Ngokomgaqo wokungeniswa kombane we-electromagnetic, xa ikhoyili kunye nemagnethi zishukuma xa zithelekiswa enye kwenye, okanye icoil ivelisa intsimi yamagnetic etshintshanayo ngokutshintshana ngoku, kuya kuveliswa amandla ombane okumelana nokutshintsha kwentsimi yamagnetic. kwaye olu phawu lokuthintela utshintsho lwangoku lubizwa ngokuba yi-inductance.

Ifomula yexabiso le-inductance iyifomyula (1), elungelelaniswa nokufikeleleka kwemagnethi, isikwere sokujikojiko esingu-N, kunye nesekethe yemagnethi elinganayo i-cross-sectional area Ae, kwaye ithelekiseka ngokulinganayo kubude besekethe yemagnethi elinganayo . Kukho iintlobo ezininzi ze-inductance, nganye ifanelekile kwizicelo ezahlukeneyo; i-inductance inxulumene nokumila, ubungakanani, indlela yokujija, inani lokujika, kunye nodidi lwesixhobo esiphakathi.

(1)

Ngokuxhomekeke kwimilo yentsimbi yentsimbi, i-inductance ibandakanya i-toroidal, i-E core kunye ne-drum; ngokwezinto ezingundoqo zentsimbi, kukho undoqo we-ceramic kunye neentlobo ezimbini ezithambileyo zemagnethi. Ziyi-ferrite kunye ne-metallic powder. Ngokuxhomekeke kwisakhiwo okanye indlela yokupakisha, kukho inxeba locingo, i-multi-layer, kunye ne-molded, kwaye inxeba locingo lingenalo i-non-shielded kunye nesiqingatha seglue magnetic Shielded (i-semi-shielded) kwaye ikhuselwe (ikhuselwe), njl.

I-inductor isebenza njengesekethe emfutshane kwi-current ngqo, kwaye inikezela nge-impedance ephezulu kwi-alternating current. Usetyenziso olusisiseko kwiisekethe lubandakanya ukukrwitsha, ukuhluza, ukulungisa, kunye nokugcinwa kwamandla. Ekusetyenzisweni kokuguqulwa kokutshintsha, i-inductor yeyona nto ibalulekileyo yokugcina amandla, kwaye yenza isihluzo esisezantsi esine-capacitor ephumayo yokunciphisa ukuphuma kwe-voltage ripple, ngoko ke ikwadlala indima ebalulekileyo kumsebenzi wokucoca.

Eli nqaku liza kuzisa izinto ezahlukeneyo eziphambili ze-inductors kunye neempawu zabo, kunye nezinye iimpawu zombane ze-inductors, njengesalathiso esibalulekileyo sokuvavanya ukukhetha i-inductors ngexesha loyilo lwesekethe. Kumzekelo wesicelo, indlela yokubala ixabiso le-inductance kunye nendlela yokukhetha i-inductor esemgangathweni ekhoyo yorhwebo iya kuqaliswa ngemizekelo ebonakalayo.

Uhlobo lwezinto eziphambili

Ii-inductors ezisetyenziswa ekutshintsheni abaguquli zizinto ezisebenza kakhulu ezinomagnetic. Izinto eziphambili eziseziko zichaphazela kakhulu iimpawu ze-inductor, ezifana ne-impedance kunye ne-frequency, ixabiso le-inductance kunye ne-frequency, okanye iimpawu ezingundoqo zokuzalisa. Oku kulandelayo kuya kwazisa ukuthelekiswa kwezinto ezininzi eziqhelekileyo zentsimbi kunye neempawu zabo zokuzalisa njengereferensi ebalulekileyo yokukhetha ii-inductors zamandla:

1. Isiseko seCeramic

I-Ceramic core yenye yezinto eziqhelekileyo ze-inductance. Isetyenziselwa ikakhulu ukubonelela ngesakhiwo esixhasayo esisetyenzisiweyo xa ujija ikhoyili. Ikwabizwa ngokuba "yi-air core inductor". Ngenxa yokuba i-iron core esetyenzisiweyo yinto engekho-magnetic ene-coefficient yokushisa ephantsi kakhulu, ixabiso le-inductance lizinzile kakhulu kwiqondo lokushisa lokusebenza. Nangona kunjalo, ngenxa yezinto ezingenamagnetic njengento ephakathi, i-inductance iphantsi kakhulu, engafanelekanga kakhulu ekusebenziseni abaguquli bamandla.

2. I-Ferrite

I-ferrite core esetyenziswa ngokubanzi i-inductors ephezulu ye-high frequency yikhompawundi ye-ferrite equlethe i-nickel zinc (NiZn) okanye i-manganese zinc (MnZn), into ethambileyo yemagnetic ferromagnetic kunye nokunyanzeliswa okuphantsi. Umzobo we-1 ubonisa i-hysteresis curve (BH loop) ye-core magnetic core. Amandla okunyanzelisa i-HC ye-magnetic material ikwabizwa ngokuba yi-coercive force, oku kuthetha ukuba xa izinto eziphathekayo zifakwe kwi-magnetic saturation, i-magnetization yayo (i-magnetization) iyancipha ukuya kwi-zero Amandla ombane afunekayo ngexesha. Ukunyanzeliswa okusezantsi kuthetha ukuxhathisa okuphantsi kwi-demagnetization kwaye kuthetha ukulahleka kwe-hysteresis ephantsi.

I-Manganese-zinc kunye ne-nickel-zinc ferrites inomlinganiselo ophezulu we-permeability (μr), malunga ne-1500-15000 kunye ne-100-1000, ngokulandelanayo. Ukufikeleleka kwazo okuphezulu kwemagneti kwenza umbindi wentsimbi uphakame kumthamo othile. I-inductance. Nangona kunjalo, into engalunganga kukuba i-saturation yangoku enyamezelekayo iphantsi, kwaye emva kokuba i-iron core igcwele, ukunyanzeliswa kwamagnetic kuya kuhla ngokukhawuleza. Jonga kuMzobo 4 malunga nendlela ehlayo yokungena kwemagnethi yeferrite kunye nomgubo wentsimbi xa umbindi wentsimbi ugcwele. Ukuthelekisa. Xa isetyenziswe kwi-inductors yamandla, i-gap yomoya iya kushiywa kwi-circuit yamagnetic engundoqo, enokunciphisa ukunyanzeliswa, ukuphepha ukugcwala kunye nokugcina amandla amaninzi; xa i-gap yomoya ifakiwe, i-permeability yesihlobo esilinganayo ingaba malunga ne-20- Phakathi kwe-200. Ekubeni i-resistivity ephezulu yezinto ngokwayo inokunciphisa ilahleko ebangelwa yi-eddy current, ilahleko iphantsi kwi-frequencies ephezulu, kwaye ifanelekile ngakumbi i-high-frequency transformers, i-EMI filter inductors kunye ne-inductors yokugcina amandla yabaguquli bamandla. Ngokubhekiselele kwi-frequency yokusebenza, i-nickel-zinc ferrite ifanelekile ukusetyenziswa (> 1 MHz), ngelixa i-manganese-zinc ferrite ifanelekile kwiibhendi ezisezantsi (<2 MHz).

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Umzobo 1. Ijiko le-hysteresis le-core magnetic (BR: remanence; BSAT: saturation magnetic flux density)

3. Undoqo wentsimbi

Iintsimbi zomgubo zentsimbi zikwazizixhobo ezithambileyo ze-ferromagnetic. Zenziwe nge-iron powder alloys yezinto ezahlukeneyo okanye umgubo wentsimbi kuphela. Ifomula iqulethe imathiriyeli engeyiyo imagneti enobungakanani bamasuntswana ahlukeneyo, ngoko ke igophe lokugcwalisa lithambile. I-powder iron core ininzi i-toroidal. Umzobo we-2 ubonisa i-powder iron core kunye nombono wayo we-cross-sectional.

Iintsimbi zentsimbi eziqhelekileyo zibandakanya i-iron-nickel-molybdenum alloy (MPP), i-sendust (i-Sendust), i-iron-nickel alloy (i-high flux) kunye ne-iron powder core (i-iron powder). Ngenxa yamacandelo ahlukeneyo, iimpawu zayo kunye namaxabiso nazo zihluke, ezichaphazela ukhetho lwe-inductors. Oku kulandelayo kuya kwazisa ezi ntlobo ziphambili zikhankanywe ngasentla kwaye zithelekise iimpawu zazo:

A. Iron-nickel-molybdenum alloy (MPP)

I-alloy ye-Fe-Ni-Mo ifinyeziwe njenge-MPP, isifinyezo se-molypermalloy powder. I-permeability ehambelanayo imalunga ne-14-500, kwaye ubuninzi be-saturation flux flux malunga ne-7500 Gauss (i-Gauss), engaphezulu kwe-saturation magnetic flux density ye-ferrite (malunga ne-4000-5000 Gauss). Abaninzi ngaphandle. I-MPP ineyona lahleko incinci yentsimbi kwaye inozinzo olungcono lobushushu phakathi kwepowder iron cores. Xa i-DC yangaphandle yangoku ifikelela kwi-Saturation yangoku ye-ISAT, ixabiso le-inductance liyancipha ngokucothayo ngaphandle kokuthotywa ngokukhawuleza. I-MPP inentsebenzo engcono kodwa ixabiso eliphezulu, kwaye lidla ngokusetyenziswa njenge-inductor yamandla kunye nokucoca i-EMI kubaguquli bamandla.

B. Thumela

I-iron-silicon-aluminium alloy iron core yintsimbi yentsimbi eyenziwe ngesinyithi, i-silicon, kunye ne-aluminium, kunye ne-related magnetic permeability malunga ne-26 ukuya kwi-125. Ilahleko yentsimbi iphakathi kwe-iron powder core kunye ne-MPP kunye ne-iron-nickel alloy. . Uxinaniso lwemagnethi lokuguquguquka luphezulu kune-MPP, malunga ne-10500 Gauss. Uzinzo lobushushu kunye neempawu zangoku zokuzalisa zingaphantsi kancinci kwi-MPP kunye ne-iron-nickel alloy, kodwa ingcono kune-iron powder core kunye ne-ferrite core, kwaye iindleko ezihambelanayo ziphantsi kune-MPP kunye ne-iron-nickel alloy. Isetyenziswa kakhulu kuhluzo lwe-EMI, ulungiso lwamandla (i-PFC) kunye nee-inductors zamandla okutshintsha abaguquli bamandla.

C. Iron-nickel alloy (high flux)

I-iron-nickel alloy core yenziwe ngentsimbi kunye ne-nickel. I-permeability magnetic ehambelanayo malunga ne-14-200. Ukulahleka kwentsimbi kunye nokuzinza kweqondo lokushisa phakathi kwe-MPP kunye ne-iron-silicon-aluminium alloy. I-iron-nickel alloy core inowona mandla aphezulu wokugcwala koxinzelelo lwemagnethi, malunga ne-15,000 ye-Gauss, kwaye inokumelana nemisinga ephezulu ye-DC bias, kunye neempawu zayo ze-DC zingcono. Umda wesicelo: Ulungiso lwamandla asebenzayo, inductance yokugcina amandla, i-inductance yokucoca, isiguquli esiphezulu se-flyback converter, njl.

D. Umgubo wentsimbi

I-core powder yentsimbi yenziwe ngamasuntswana e-high-purity iron powder kunye neencinci ezincinci ezifakwe kwi-insulated ukusuka komnye nomnye. Inkqubo yokuvelisa yenza ukuba ibe ne-gap yomoya eyabiweyo. Ukongeza kwimilo yeringi, iimilo ezingundoqo zentsimbi eziqhelekileyo nazo zineentlobo ze-E kunye neentlobo zesitampu. Ubungakanani bemagnethi obungena kumbindi wentsimbi yomgubo umalunga ne-10 ukuya kuma-75, kwaye ukugcwala okuphezulu koxinzelelo lwemagnethi malunga ne-15000 Gauss. Phakathi kweentsimbi zomgubo wentsimbi, isiseko somgubo wentsimbi sineyona lahleko iphezulu yentsimbi kodwa elona xabiso liphantsi.

Umzobo we-3 ubonisa i-BH curves ye-PC47 manganese-zinc ferrite eyenziwe yi-TDK kunye ne-powdered iron cores -52 kunye ne-2 eyenziwa yi-MICROMETALS; Ubungakanani bemagnethi ehambelanayo ye-manganese-zinc ferrite iphezulu kakhulu kuneyo yomgubo wentsimbi kwaye igcwele I-magnetic flux density nayo yahluke kakhulu, i-ferrite imalunga ne-5000 ye-Gauss kunye ne-iron powder core ingaphezulu kwe-10000 Gauss.

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Umzobo 3. Ijika le-BH le-manganese-zinc ferrite kunye nentsimbi yomgubo wentsimbi yezinto ezahlukeneyo.

Isishwankathelo, iimpawu zokuzaliswa kwentsimbi yentsimbi ziyahluka; emva kokuba i-saturation yangoku idlulile, ukunyanzeliswa kwemagnethi ye-ferrite core kuya kuhla ngokukhawuleza, ngelixa i-iron powder core inokuncipha kancinci. Umzobo we-4 ubonisa iimpawu zokuhla kwamandla kazibuthe zondoqo wentsimbi engumgubo kunye nokungena kwemagnethi efanayo kunye ne-ferrite enesithuba somoya phantsi kwamandla ohlukeneyo omhlaba. Oku kuphinda kuchaze i-inductance ye-core ye-ferrite, kuba i-permeability iyancipha ngokukhawuleza xa i-core ihlutha, njengoko ibonakala kwi-equation (1), iphinda ibangele ukuba i-inductance yehle ngokukhawuleza; ngelixa i-powder core kunye ne-gap yosasazo lomoya, i-permeability magnetic Ireyithi iyancipha ngokucothayo xa i-iron core ihlutha, ngoko i-inductance iyancipha ngakumbi, oko kukuthi, ineempawu ezingcono ze-DC. Ekusetyenzisweni kwabaguquli bamandla, olu phawu lubaluleke kakhulu; ukuba uphawu lokucotha olucothayo lwe-inductor alulungile, i-inductor yangoku iphakama kwi-saturation yangoku, kwaye ukuhla ngokukhawuleza kwe-inductance kuya kubangela ukuba uxinzelelo lwangoku lwe-crystal yokutshintsha lukhuphuke ngokukhawuleza, olulula ukubangela umonakalo.

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Umzobo 4. Imagnetic permeability drop features of powder iron core and ferrite iron core ne-air gap phantsi kwamandla ahlukeneyo magnetic field.

Iimpawu zombane ze-Inductor kunye nesakhiwo sephakheji

Xa uyila umguquli wokutshintsha kunye nokukhetha i-inductor, ixabiso le-inductance L, impedance Z, i-AC yokumelana ne-ACR kunye nexabiso le-Q (umgangatho wexabiso), i-IDC yangoku kunye ne-ISAT, kunye nelahleko engundoqo (ilahleko engundoqo) kunye nezinye iimpawu ezibalulekileyo zombane zonke Kufuneka. kuthathelwe ingqalelo. Ukongezelela, isakhiwo sokupakisha se-inductor siya kuchaphazela ubukhulu bokuvuza kwamagnetic, okuchaphazela i-EMI. Oku kulandelayo kuya kuxoxa ngezi mpawu zikhankanywe apha ngasentla ngokwahlukeneyo njengengqwalasela yokukhetha ii-inductors.

1. Ixabiso le-inductance (L)

Ixabiso le-inductance ye-inductor yeyona parameter ibaluleke kakhulu kwi-design yesiphaluka, kodwa kufuneka ihlolwe ukuba ixabiso le-inductance lizinzile kwi-frequency yokusebenza. Ixabiso legama le-inductance lidla ngokulinganiswa kwi-100 kHz okanye i-1 MHz ngaphandle kwe-DC yangaphandle. Kwaye ukuqinisekisa ukuba kunokwenzeka ukuveliswa kwe-automated mass, ukunyamezela kwe-inductor ngokuqhelekileyo ku-± 20% (M) kunye ne-± 30% (N). Umzobo we-5 yigrafu ye-inductance-frequency character of Taiyo Yuden inductor NR4018T220M elinganiswe ne-Wayne Kerr's LCR meter. Njengoko kubonisiwe kumzobo, ijika lexabiso le-inductance lithe tyaba phambi kwe-5 MHz, kwaye ixabiso le-inductance liphantse lithathwe njengento eqhubekayo. Kwibhanti ye-frequency ephezulu ngenxa ye-resonance eyenziwa yi-parasitic capacitance kunye ne-inductance, ixabiso le-inductance liya kwanda. Le resonance frequency ibizwa ngokuba yi-self-resonant frequency (SRF), edla ngokufuna ukuba phezulu kakhulu kunokusebenza.

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Umzobo 5, Taiyo Yuden NR4018T220M inductance-frequency character measurement diagram

2. Ukuphazamiseka (Z)

Njengoko kuboniswe kwi-Figure 6, umzobo we-impedance unokubonwa kwakhona ekusebenzeni kwe-inductance kwiifrikhwensi ezahlukeneyo. I-impedance ye-inductor imalunga nomlinganiselo we-frequency (Z=2πfL), ngoko ke ukuphakama kwe-frequency, ukusabela kuya kuba kukhulu kakhulu kunokumelana ne-AC, ngoko ke i-impedance iziphatha njenge-inductance ecocekileyo (isigaba yi-90˚). Kwii-frequencies eziphezulu, ngenxa ye-parasitic capacitance effect, i-self-resonant frequency point ye-impedance ingabonwa. Emva kweli nqanaba, i-impedance iyehla kwaye ibe namandla, kwaye isigaba sitshintsha ngokuthe ngcembe ukuya -90 ˚.

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3. Ixabiso le-Q kunye nokuchasana kwe-AC (ACR)

Ixabiso le-Q kwinkcazo ye-inductance ngumlinganiselo wokusabela ekuchaseni, oko kukuthi, umlinganiselo wecandelo elicingelwayo ukuya kwindawo yangempela ye-impedance, njengefomula (2).

(2)

Apho i-XL i-reactance ye-inductor, kunye ne-RL yi-AC yokumelana ne-inductor.

Kwinqanaba eliphantsi le-frequency, ukuchasana kwe-AC kukhulu kunokusabela okubangelwa yi-inductance, ngoko ke ixabiso layo le-Q liphantsi kakhulu; njengoko i-frequency inyuka, i-reactance (malunga ne-2πfL) iba nkulu kwaye ikhudlwana, nangona ukuchasana ngenxa yempembelelo yesikhumba (impembelelo yesikhumba) kunye nokusondela (ukusondela) umphumo uya kuba mkhulu kwaye ukhulu, kwaye ixabiso le-Q lisanyuka ngokuphindaphindiweyo. ; xa usondela kwi-SRF, i-inductive reactance iyancipha ngokuthe ngcembe yi-capacitive reactance, kunye nexabiso le-Q ngokuthe ngcembe liba lincinci; xa i-SRF iba ngu-zero, kuba i-inductive reactance kunye ne-capacitive reactance ziyafana ngokupheleleyo Ukunyamalala. Umzobo we-7 ubonisa ubudlelwane phakathi kwexabiso le-Q kunye nokuphindaphinda kwe-NR4018T220M, kwaye ubudlelwane bukwimo yentsimbi eguquliweyo.

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Umzobo 7. Ubudlelwane phakathi kwexabiso le-Q kunye nokuphindaphinda kwe-Taiyo Yuden inductor NR4018T220M

Kwibhendi ye-frequency yesicelo ye-inductance, iphezulu ixabiso le-Q, ngcono; kuthetha ukuba ukusabela kwayo kukhulu kakhulu kunokumelana ne-AC. Ngokuqhelekileyo, ixabiso elihle le-Q lingaphezulu kwe-40, oku kuthetha ukuba umgangatho we-inductor ulungile. Nangona kunjalo, ngokubanzi njengoko i-DC inyuka, ixabiso le-inductance liya kuncipha kwaye ixabiso le-Q liya kuncipha. Ukuba i-flat enameled wire okanye i-multi-strand enameled wire isetyenzisiweyo, umphumo wesikhumba, oko kukuthi, ukuxhathisa kwe-AC, unokuncitshiswa, kwaye ixabiso le-Q le-inductor linganyuswa.

Uxhathiso lwe-DC DCR luthathwa ngokubanzi njengoxhathiso lwe-DC locingo lobhedu, kwaye ukuxhathisa kunokubalwa ngokobubanzi bocingo kunye nobude. Nangona kunjalo, uninzi lwee-inductors eziphantsi ze-SMD zangoku ziya kusebenzisa i-ultrasonic welding ukwenza iphepha lobhedu le-SMD kwi-terminal ejikelezayo. Nangona kunjalo, ngenxa yokuba ucingo lobhedu alulude ubude kwaye ixabiso lokumelana alikho phezulu, ukuxhathisa i-welding kudla ngokubala umlinganiselo omkhulu wokuchasana kwe-DC jikelele. Ukuthatha i-TDK yocingo-inxeba SMD inductor CLF6045NIT-1R5N njengomzekelo, umlinganiselo DC ukumelana 14.6mΩ, kunye noxhathiso DC kubalwa ngokusekelwe wire ububanzi kunye nobude 12.1mΩ. Iziphumo zibonisa ukuba oku kuxhathisa i-welding malunga ne-17% ye-DC yokuxhathisa.

Ukumelana ne-AC i-ACR inefuthe lolusu kunye nefuthe elisondele, eliya kubangela ukuba i-ACR inyuke ngokuphindaphindiweyo; ekusetyenzisweni kwe-inductance ngokubanzi, kuba icandelo le-AC liphantsi kakhulu kunecandelo le-DC, impembelelo ebangelwa yi-ACR ayibonakali; kodwa kumthwalo okhanyayo, Ngenxa yokuba icandelo le-DC liyancitshiswa, ilahleko ebangelwa yi-ACR ayinakuhoywa. Isiphumo solusu sithetha ukuba phantsi kweemeko ze-AC, ulwabiwo lwangoku ngaphakathi kwi-conductor alulingani kwaye lugxininise kumphezulu wocingo, okukhokelela ekunciphiseni kwendawo ye-wire cross-sectional elinganayo, nto leyo eyandisa ukuxhathisa okulinganayo kocingo kunye. rhoqo. Ukongeza, kwi-wire winding, iingcingo ezikufutshane ziya kubangela ukongezwa kunye nokuthatyathwa kwemimandla yamagnetic ngenxa yangoku, ukwenzela ukuba i-current igxininiswe kumphezulu ojongene nocingo (okanye indawo ekude kakhulu, kuxhomekeke kwicala langoku. ), nto leyo ebangela ukuba i-wire interception elinganayo. Isenzeko sokuba indawo iyancipha kwaye ukuchasana okulinganayo kuyanda yinto ebizwa ngokuba yi-proximity effect; kwi-inductance application ye-multilayer winding, i-proximity effect ibonakala ngakumbi.

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Umzobo we-8 ubonisa ubudlelwane phakathi kokuxhatshazwa kwe-AC kunye nokuphindaphinda kwe-wire-nxeba inductor ye-SMD NR4018T220M. Kwi-frequency ye-1kHz, ukuchasana malunga ne-360mΩ; kwi-100kHz, ukuchasana kuphakama kwi-775mΩ; kwi-10MHz, ixabiso lokumelana lisondele kwi-160Ω. Xa kuqikelelwa ukulahleka kobhedu, ukubala kufuneka kuthathelwe ingqalelo i-ACR ebangelwa lusu kunye nemiphumo esondeleyo, kwaye iyiguqule kwifomula (3).

4. Saturation current (ISAT)

I-Saturation yangoku i-ISAT idla ngokuba ngumkhethe okhoyo ophawulwayo xa ixabiso lokuthotyelwa lithotyiwe njenge-10%, 30%, okanye 40%. Kwi-air-gap ferrite, ngenxa yokuba i-saturation yayo yangoku ikhawuleza kakhulu, akukho mahluko ungako phakathi kwe-10% kunye ne-40%. Jonga kuMzobo 4. Nangona kunjalo, ukuba i-iron powder core (njenge-inductor enesitampu), i-curve ye-saturation inobumnene, njengoko kuboniswe kwi-Figure 9, i-bias yangoku kwi-10% okanye i-40% ye-inductance attenuation ininzi. ezahlukeneyo, ngoko ixabiso langoku lokuhluza liya kuxutyushwa ngokwahlukileyo kwiindidi ezimbini zentsimbi ngolu hlobo lulandelayo.

Kwi-air-gap ferrite, kunengqiqo ukusebenzisa i-ISAT njengomda ophezulu we-inductor yangoku ye-inductor yangoku kwizicelo zesekethe. Nangona kunjalo, ukuba i-iron powder core, ngenxa yesimo sokucotha saturation, akuyi kuba nangxaki nokuba ubuninzi bangoku besiphaluka sesicelo budlula i-ISAT. Ke ngoko, olu phawu lwentsimbi lufaneleke kakhulu ekutshintsheni izicelo zokuguqula. Ngaphantsi komthwalo onzima, nangona ixabiso le-inductance ye-inductor liphantsi, njengoko kuboniswe kwi-Figure 9, i-ripple factor yangoku iphezulu, kodwa i-capacitor yangoku yokunyamezela iphezulu, ngoko ayiyi kuba yingxaki. Ngaphantsi komthwalo wokukhanya, ixabiso le-inductance ye-inductor likhulu, elinceda ukunciphisa i-ripple current ye-inductor, ngaloo ndlela inciphisa ilahleko yentsimbi. Umzobo we-9 uthelekisa i-curve yangoku ye-saturation ye-TDK yesilonda se-ferrite SLF7055T1R5N kunye ne-stamped iron powder core inductor SPM6530T1R5M phantsi kwexabiso elifanayo le-inductance.

9

Umzobo 9. I-Saturation ijika yangoku ye-ferrite yesilonda kunye ne-stemped iron powder core phantsi kwexabiso elifanayo le-inductance.

5. Ireyithiwe yangoku (IDC)

Ixabiso le-IDC licala le-DC xa ubushushu be-inductor bunyuka ukuya kwi-Tr˚C. Iinkcukacha zikwabonisa ixabiso lokuxhathisa kwe-DC ye-RDC kwi-20˚C. Ngokwe-coefficient yokushisa yocingo lobhedu malunga ne-3,930 ppm, xa ukushisa kweTr kuphakama, ixabiso layo lokumelana ne-RDC_Tr = RDC (1 + 0.00393Tr), kunye nokusetyenziswa kwayo kwamandla yi-PCU = I2DCxRDC. Olu lahleko lobhedu luchithwa kumphezulu we-inductor, kwaye ukumelana ne-thermal ΘTH ye-inductor ingabalwa:

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Itheyibhile ye-2 ibhekisela kwiphepha ledatha ye-TDK VLS6045EX series (6.0 × 6.0 × 4.5mm), kwaye ibala ukuchasana kwe-thermal ekunyukeni kweqondo lokushisa kwe-40˚C. Ngokucacileyo, kwi-inductors yochungechunge olufanayo kunye nobukhulu, ukuchasana kwe-thermal kubalwa kuphantse kufane ngenxa yendawo efanayo yokutshatyalaliswa kobushushu; ngamanye amazwi, i-IDC yangoku elinganisiweyo yee-inductors ezahlukeneyo inokuqikelelwa. Uluhlu oluhlukeneyo (iiphakheji) ze-inductors zineendlela ezahlukeneyo zokuchasana ne-thermal. Itheyibhile ye-3 ithelekisa ukuchasana kwe-thermal ye-inductors ye-TDK VLS6045EX series (i-semi-shielded) kunye ne-SPM6530 series (ebunjiweyo). Inkulu ukuchasana kwe-thermal, ukunyuka kweqondo lokushisa okuphezulu okwenziweyo xa i-inductance ihamba ngomthwalo wangoku; kungenjalo, ephantsi.

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Itheyibhile 2. Ukuxhathisa kwe-Thermal ye-VLS6045EX ii-inductors zochungechunge ekunyukeni kobushushu be-40˚C

Inokubonwa kwiThebhile 3 ukuba nangona ubukhulu be-inductors bufana, ukuchasana kwe-thermal ye-inductors enesitampu kuphantsi, oko kukuthi, ukutshatyalaliswa kobushushu kungcono.

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Itheyibhile 3. Ukuthelekiswa kokumelana nokushisa kwee-inductors zephakheji ezahlukeneyo.

6. Ilahleko engundoqo

Ukulahleka kwe-core, okubizwa ngokuba yilahleko yentsimbi, ibangelwa ikakhulu yilahleko yangoku ye-eddy kunye nokulahleka kwe-hysteresis. Ubungakanani belahleko yangoku ye-eddy ikakhulu kuxhomekeke ekubeni izinto eziphambili zilula "ukuqhuba"; ukuba i-conductivity iphezulu, oko kukuthi, i-resistivity iphantsi, ilahleko yangoku ye-eddy iphezulu, kwaye ukuba i-resistiveivity ye-ferrite iphezulu, ilahleko yangoku ye-eddy iphantsi. Ilahleko yangoku ye-Eddy nayo inxulumene rhoqo. Okukhona iphezulu frequency, kokukhona ilahleko eddy yangoku. Ngoko ke, izinto eziphambili ziza kugqiba i-frequency yokusebenza efanelekileyo ye-core. Ngokuqhelekileyo, ukusebenza rhoqo kwe-iron powder core kunokufikelela kwi-1MHz, kunye nokusebenza rhoqo kwe-ferrite kunokufikelela kwi-10MHz. Ukuba i-frequency yokusebenza idlula le frequency, ilahleko yangoku ye-eddy iya kwanda ngokukhawuleza kwaye iqondo lobushushu lentsimbi liya kwanda. Nangona kunjalo, ngophuhliso olukhawulezayo lwezinto eziphambili zentsimbi, iintsimbi zentsimbi ezinamaza okusebenza aphezulu kufuneka zibe kufutshane nekona.

Enye ilahleko yentsimbi yilahleko ye-hysteresis, ehambelana nommandla ovalelwe yi-hysteresis curve, ehambelana ne-swing amplitude yecandelo le-AC langoku; Ujingi olukhulu lwe-AC, kokukhona ilahleko enkulu ye-hysteresis.

Kwisekethe elinganayo ye-inductor, i-resistor edibeneyo ngokuhambelana ne-inductor isoloko isetyenziselwa ukubonakalisa ilahleko yentsimbi. Xa i-frequency ilingana ne-SRF, i-inductive reactance kunye ne-capacitive reactance iyacima, kunye ne-reactance efanayo nguziro. Ngeli xesha, i-impedance ye-inductor ilingana nokuchasana kwelahleko yentsimbi kwichungechunge kunye nokumelana nokujikeleza, kunye nokumelana nokulahlekelwa kwentsimbi kukhulu kakhulu kunokumelana nokujikeleza, ngoko ke i-impedance kwi-SRF iphantse ilingane nokuxhatshazwa kwentsimbi. Ukuthatha i-inductor ye-low-voltage njengomzekelo, ukuchasana kwelahleko yentsimbi malunga ne-20kΩ. Ukuba i-voltage yexabiso elisebenzayo kwiziphelo zombini ze-inductor iqikelelwa ukuba yi-5V, ilahleko yayo yentsimbi imalunga ne-1.25mW, ebonisa kwakhona ukuba inkulu ukuchasana kwelahleko yentsimbi, kungcono.

7. Ulwakhiwo lwekhaka

Ulwakhiwo lokupakisha lwe-ferrite inductors lubandakanya ukungakhuseleki, okukhuselweyo kunye neglue magnetic, kunye nekhuselo, kwaye kukho umsantsa omkhulu womoya kuzo zombini. Ngokucacileyo, i-gap yomoya iya kuba nokuvuza kwamagnetic, kwaye kwimeko embi kakhulu, iya kuphazamisa imijikelezo yesignali encinci ejikelezileyo, okanye ukuba kukho into esondeleyo yamagnetic, i-inductance yayo iya kutshintshwa. Esinye isakhiwo sokupakisha yi-inductor yentsimbi egxininisiweyo yomgubo. Ekubeni akukho sithuba ngaphakathi kwe-inductor kunye nesakhiwo somoya siqinile, ingxaki yokutshatyalaliswa kwamagnetic field incinci. Umzobo we-10 kukusetyenziswa komsebenzi we-FFT we-oscilloscope ye-RTO 1004 ukulinganisa ubukhulu bomhlaba ovuzayo wamagnetic kwi-3mm ngaphezulu kunye necala le-inductor enesitampu. Itheyibhile yesi-4 idwelisa uthelekiso lokuvuza kwamagnetic kwi-inductors yesakhiwo sephakheji eyahlukeneyo. Inokubonwa ukuba ii-inductors ezingakhuselekanga zinokuvuza okukhulu kakhulu; ii-inductors ezinesitampu zinokuvuza kuncinci kwemagnethi, ebonisa eyona mpembelelo ibalaseleyo yokhuselo. . Umahluko kubukhulu bendawo yamagnetic evuzayo ye-inductors yezi zakhiwo zimbini malunga ne-14dB, ephantse ibe ngamaxesha ama-5.

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Umfanekiso we-10. Ubungakanani bomhlaba ovuzayo wemagnethi ulinganiswe kwi-3mm ngaphezulu kunye nakwicala le-inductor egxininisiweyo.

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Itheyibhile 4. Ukuthelekiswa kommandla wamagnetic ovuzayo we-inductors yesakhiwo sephakheji eyahlukeneyo

8. ukudibanisa

Kwezinye izicelo, ngamanye amaxesha kukho iiseti ezininzi ze-DC converters kwi-PCB, ezidla ngokucwangciswa ecaleni kwenye, kwaye i-inductors yazo ehambelanayo nazo zicwangciswe ecaleni kwenye. Ukuba usebenzisa uhlobo olungakhuselweyo okanye uhlobo olukhuselweyo oluneglu enemagnethi Ii-Inductors zinokudityaniswa enye kwenye ukwenza uphazamiseko lwe-EMI. Ke ngoko, xa ubeka i-inductor, kuyacetyiswa ukuba uphawule i-polarity ye-inductor kuqala, kwaye uqhagamshele indawo yokuqala kunye neyokujika yomaleko wangaphakathi we-inductor ukuya kumbane wokutshintsha umguquli, njengeVSW yoguqulo lwebhanti, eyona ndawo ishukumayo. I-terminal yokuphuma ixhunyiwe kwi-capacitor yokuphuma, eyona ndawo i-static point; i-winging wire winding ke ngoko yenza iqondo elithile lokukhusela indawo yombane. Kwilungiselelo le-wiring ye-multiplexer, ukulungiswa kwe-polarity ye-inductance kunceda ukulungisa ubukhulu be-inductance kunye nokuphepha ezinye iingxaki ze-EMI ezingalindelekanga.

Usetyenziso:

Isahluko sangaphambili sixoxe ngezinto eziphambili, isakhiwo sephakheji, kunye neempawu ezibalulekileyo zombane ze-inductor. Esi sahluko siya kuchaza indlela yokukhetha ixabiso elifanelekileyo le-inductance ye-converter ye-buck kunye neengqwalasela zokukhetha i-inductor ekhoyo yorhwebo.

Njengoko kuboniswe kwi-equation (5), ixabiso le-inductor kunye ne-frequency switching frequency of converter iya kuchaphazela i-inductor ripple current (ΔiL). I-inductor ripple yangoku iya kuhamba nge-capacitor ephumayo kwaye ichaphazele i-ripple current ye-capacitor output. Ke ngoko, iya kuchaphazela ukukhethwa kwe-capacitor ephumayo kwaye ichaphazele ngakumbi ubungakanani be-ripple yombane wokuphuma. Ngaphezu koko, ixabiso le-inductance kunye nexabiso le-output capacitance liya kuchaphazela noyilo lwengxelo yenkqubo kunye nokuphendula okuguquguqukayo komthwalo. Ukukhetha ixabiso elikhulu le-inductance kunoxinzelelo oluncinci lwangoku kwi-capacitor, kwaye kuluncedo ekunciphiseni ukuphuma kwe-voltage ripple kwaye kunokugcina amandla amaninzi. Nangona kunjalo, ixabiso elikhulu le-inductance libonisa umthamo omkhulu, oko kukuthi, ixabiso eliphezulu. Ke ngoko, xa uyila umguquli, uyilo lwexabiso le-inductance libaluleke kakhulu.

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Inokubonwa kwifomula (5) ukuba xa umsantsa phakathi kombane wegalelo kunye nombane wokuphuma umkhulu, i-inductor ripple current iya kuba nkulu, eyona meko imbi kakhulu yoyilo lwe-inductor. Idityaniswe nolunye uhlalutyo lwe-inductive, indawo yoyilo lwe-inductance ye-converter-down-down converter ngokuqhelekileyo kufuneka ikhethwe phantsi kweemeko ze-voltage yegalelo eliphezulu kunye nomthwalo opheleleyo.

Xa uyila ixabiso le-inductance, kuyimfuneko ukwenza urhwebo phakathi kwe-inductor ripple current kunye nobukhulu be-inductor, kunye ne-ripple current factor (i-ripple current factor; γ) ichazwa apha, njengefomula (6).

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Ukutshintsha ifomyula (6) kwifomula (5), ixabiso le-inductance lingabonakaliswa njengefomula (7).

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Ngokutsho kwefomula (7), xa umehluko phakathi kwegalelo kunye ne-voltage ephumayo inkulu, ixabiso le-γ linokukhethwa likhulu; ngokuchaseneyo, ukuba igalelo kunye ne-voltage yemveliso isondele, uyilo lwexabiso le-γ kufuneka libe lincinci. Ukuze ukhethe phakathi kwe-inductor ripple current kunye nobukhulu, ngokwexabiso lamava oyilo lwendabuko, γ idla ngokuba ngu-0.2 ukuya ku-0.5. Oku kulandelayo kuthatha i-RT7276 njengomzekelo ukubonisa ukubalwa kwe-inductance kunye nokukhethwa kwee-inductors ezithengiswayo.

Umzekelo wokuyila: Uyilwe kunye ne-RT7276 eqhubekayo eqhubekayo ngexesha (i-Advanced Constant On-Time; i-ACOTTM) i-synchronous rectification step-down converter, i-frequency yayo yokutshintsha yi-700 kHz, i-voltage yegalelo yi-4.5V ukuya kwi-18V, kunye ne-voltage ephumayo yi-1.05V . Umthwalo opheleleyo wangoku yi-3A. Njengoko kukhankanyiwe ngasentla, ixabiso le-inductance kufuneka lenziwe phantsi kweemeko ze-voltage ephezulu ye-18V kunye nomthwalo opheleleyo we-3A, ixabiso le-γ lithathwa njenge-0.35, kwaye ixabiso elingentla lifakwe kwi-equation (7), i-inductance. ixabiso li

Sebenzisa i-inductor enexabiso eliqhelekileyo le-nominal inductance eyi-1.5 µH. Ifomula yokutshintsha (5) ukubala i-inductor ripple current ngolu hlobo lulandelayo.

Ngoko ke, isantya esiphezulu se-inductor

Kwaye ixabiso elisebenzayo le-inductor current (IRMS) yi

Ngenxa yokuba i-inductor ripple component incinci, ixabiso elisebenzayo le-inductor yangoku liyinxalenye yalo ye-DC, kwaye eli xabiso elisebenzayo lisetyenziswa njengesiseko sokukhetha i-IDC yangoku ye-inductor. Ngoyilo lwe-80% yokunciphisa (derating), iimfuno ze-inductance zezi:

L = 1.5 µH (100 kHz), IDC = 3.77 A, ISAT = 4.34 A

Itheyibhile ye-5 idwelisa ii-inductors ezikhoyo zoluhlu oluhlukeneyo lwe-TDK, ezifanayo ngobukhulu kodwa ezahlukeneyo kwisakhiwo sephakheji. Inokubonwa kwitheyibhile ukuba i-saturation yangoku kunye nokulinganiswa kwangoku kwe-inductor enesitampu (SPM6530T-1R5M) inkulu, kwaye ukuchasana kwe-thermal kuncinci kwaye ukutshatyalaliswa kobushushu kulungile. Ukongezelela, ngokwengxoxo kwisahluko sangaphambili, izinto eziphambili ze-inductor ezinesitampu ziyintsimbi ye-powder core, ngoko ifaniswa ne-ferrite core ye-semi-shielded (VLS6045EX-1R5N) kunye ne-inductors ekhuselekileyo (SLF7055T-1R5N) ngeglu yamagnetic. , Ineempawu ezilungileyo zomkhethe we-DC. Umzobo we-11 ubonisa uthelekiso olusebenzayo lwee-inductors ezahlukeneyo ezisetyenzisiweyo kwi-RT7276 eqhubela phambili rhoqo ngexesha lokuguquguquka kwe-synchronous-down-down converter. Iziphumo zibonisa ukuba umahluko osebenzayo phakathi kwezi zintathu awubalulekanga. Ukuba uqwalasela ukutshatyalaliswa kobushushu, iimpawu ze-DC bias kunye nemiba yokuchithwa kwemagnethi, kuyacetyiswa ukuba usebenzise i-SPM6530T-1R5M inductors.

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Itheyibhile 5. Ukuthelekiswa kwee-inductances zechungechunge ezahlukeneyo ze-TDK

11

Umzobo 11. Ukuthelekiswa kobuchule bokuguqula kunye ne-inductors ezahlukeneyo

Ukuba ukhetha ukwakhiwa kwephakheji efanayo kunye nexabiso le-inductance, kodwa i-inductors encinci yesayizi, njenge-SPM4015T-1R5M (4.4 × 4.1 × 1.5mm), nangona ubungakanani bayo buncinci, kodwa i-DC yokumelana ne-RDC (44.5mΩ) kunye nokumelana nokushisa ΘTH ( 51˚C) /W) Enkulu. Kubaguquli beenkcukacha ezifanayo, ixabiso elisebenzayo langoku elinyamezelwa yi-inductor likwafana. Ngokucacileyo, ukuxhathisa kwe-DC kuya kunciphisa ukusebenza kakuhle phantsi komthwalo onzima. Ukongezelela, ukuxhathisa okukhulu kwe-thermal kuthetha ukutshatyalaliswa kobushushu obuhlwempuzekileyo. Ngoko ke, xa ukhetha i-inductor, akuyimfuneko kuphela ukuqwalasela izibonelelo zobungakanani obuncitshisiweyo, kodwa nokuvavanya ukusilela kwayo okuhamba nayo.

Ukuququmbela

I-Inductance yenye yezinto ezisetyenziswa ngokuqhelekileyo ekutshintsheni abaguquli bamandla, ezinokusetyenziselwa ukugcina amandla kunye nokucoca. Nangona kunjalo, kuyilo lwesekethe, akusiyo kuphela ixabiso le-inductance ekufuneka liqwalaselwe, kodwa ezinye iiparameters ezibandakanya ukumelana ne-AC kunye nexabiso le-Q, ukunyamezela kwangoku, ukugcwala kwentsimbi, kunye nesakhiwo sephakheji, njl. kuqwalaselwa xa ukhetha i-inductor. . Ezi parameters zihlala zihambelana nezinto eziphambili, inkqubo yokuvelisa, kunye nobukhulu kunye neendleko. Ke ngoko, eli nqaku lizisa iimpawu zezixhobo ezahlukeneyo zentsimbi kunye nendlela yokukhetha i-inductance efanelekileyo njengesalathiso soyilo lonikezelo lwamandla.