izindaba

Isifinyezo

Ama-inductors ayizingxenye ezibaluleke kakhulu ekushintsheni iziguquli, njengokugcina amandla nezihlungi zamandla. Kunezinhlobo eziningi zama-inductors, njengezinhlelo zokusebenza ezihlukene (kusuka emazingeni aphansi ukuya emazingeni aphezulu), noma izinto ezibalulekile ezithinta izici ze-inductor, njalonjalo. Ama-inductors asetshenziswa ekuguquleni iziguquli yizingxenye kazibuthe ezinemvamisa ephezulu. Kodwa-ke, ngenxa yezici ezihlukahlukene ezifana nezinto ezisetshenziswayo, izimo zokusebenza (ezifana ne-voltage ne-current), kanye nezinga lokushisa le-ambient, izici nemibono ethulwayo kwehluke kakhulu. Ngakho-ke, ekwakhiweni kwesifunda, ngaphezu kwepharamitha eyisisekelo yenani le-inductance, ubudlelwano phakathi kwe-impedance ye-inductor kanye nokumelana ne-AC kanye nemvamisa, ukulahlekelwa okuyinhloko kanye nezici zamanje zokugcwala, njll. kusafanele kucatshangelwe. Le ndatshana izokwethula izinto ezibalulekile ezimbalwa ezibalulekile ze-inductor nezici zazo, futhi iqondise onjiniyela bamandla ukuthi bakhethe ama-inductors ajwayelekile atholakala ngokwentengiso.

Isandulelo

I-Inductor iyingxenye yokungeniswa kuka-electromagnetic, eyakhiwe ngokusonta inombolo ethile yamakhoyili (ikhoyili) kubhobhini noma umongo ngocingo oluvalekile. Le khoyili ibizwa ngokuthi i-inductance coil noma i-Inductor. Ngokomgomo wokungeniswa kukazibuthe, lapho ikhoyili nenkundla kazibuthe inyakaza ngokuhlobene, noma ikhoyili ikhiqiza inkambu kazibuthe eshintshanayo ngokusebenzisa isimanje esishintshayo, kuzokwenziwa i-voltage eyengelwe ukumelana noshintsho lwensimu kazibuthe yasekuqaleni, futhi lesi sici sokuvimbela ushintsho lwamanje sibizwa ngokuthi i-inductance.

Ifomula yenani le-inductance linjengefomula (1), elilingana nokufinyeleleka kazibuthe, isikwele sokujika esijikajikayo esingu-N, kanye nendawo elingana nesifunda sikazibuthe esiphambanayo se-Ae, futhi ilinganisa ngokuphambene nesilinganiso sobude besekethe kazibuthe le. . Kunezinhlobo eziningi ze-inductance, ngayinye ilungele izinhlelo zokusebenza ezahlukene; i-inductance ihlobene nokuma, usayizi, indlela yokujika, inombolo yokujika, kanye nohlobo lwezinto ezimaphakathi kazibuthe.

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Ngokuya ngokuma komgogodla wensimbi, i-inductance ihlanganisa i-toroidal, i-E core nesigubhu; ngokwezinto zensimbi core, kukhona ikakhulukazi Ceramic core nezinhlobo ezimbili ezithambile kazibuthe. Ziyi-ferrite ne-metallic powder. Ngokuya ngesakhiwo noma indlela yokupakisha, kunenxeba locingo, i-multi-layer, futhi elibunjiwe, futhi inxeba locingo linesivikelo esingavikelwe kanye nohhafu weglue kazibuthe Ivikelwe (i-semi-shielded) futhi ivikelekile (ivikelekile), njll.

I-inductor isebenza njengesekethe emfushane kumanje oqondile, futhi iveza ukuthintana okuphezulu kokushintshashintsha kwamandla. Ukusetshenziswa okuyisisekelo kumasekhethi kufaka ukuklinya, ukuhlunga, ukulungisa, nokugcina amandla. Ekusetshenzisweni kwesiguquli esishintshayo, i-inductor iyisici esibaluleke kakhulu sokugcina amandla, futhi yakha isihlungi se-low-pass esine-capacitor ephumayo ukuze kuncishiswe i-voltage ephumayo, ngakho futhi idlala indima ebalulekile emsebenzini wokuhlunga.

Lesi sihloko sizokwethula izinto eziyisisekelo ezahlukahlukene zama-inductors nezici zawo, kanye nezinye izici zikagesi zama-inductors, njengereferensi yokuhlola ebalulekile yokukhetha ama-inductors ngesikhathi sokuklanywa kwesifunda. Esibonelweni sohlelo lokusebenza, indlela yokubala inani le-inductance kanye nendlela yokukhetha i-inductor evamile etholakalayo kwezohwebo izokwethulwa ngezibonelo ezingokoqobo.

Uhlobo lwezinto eziyinhloko

Ama-inductors asetshenziswa ekuguquleni iziguquli yizingxenye kazibuthe ezinemvamisa ephezulu. Into esemqoka emaphakathi ithinta kakhulu izici ze-inductor, ezifana ne-impedance kanye nemvamisa, inani le-inductance kanye nemvamisa, noma izici eziyinhloko zokugcwaliswa kwesikhala. Okulandelayo kuzokwethula ukuqhathaniswa kwezinto ezimbalwa ezivamile zensimbi nezici zokugcwala kwazo njengesithenjwa esibalulekile sokukhetha ama-inductors amandla:

1. I-Ceramic core

I-Ceramic core ingenye yezinto ezivamile ze-inductance. Isetshenziswa kakhulu ukuhlinzeka ngesakhiwo esisekelayo esisetshenziswa lapho ukusonga ikhoyili. Ibizwa nangokuthi "i-air core inductor". Ngenxa yokuthi i-iron core esetshenzisiwe iyinto engekho-magnetic ene-coefficient yokushisa ephansi kakhulu, inani le-inductance lizinzile kakhulu ebangeni lokushisa lokusebenza. Kodwa-ke, ngenxa yezinto ezingezona kazibuthe njenge-medium, i-inductance iphansi kakhulu, engafaneleki kakhulu ukusetshenziswa kweziguquli zamandla.

2. I-Ferrite

I-ferrite core esetshenziswa ngokujwayelekile kuma-inductors amafrikhwensi aphezulu iyinhlanganisela ye-ferrite equkethe i-nickel zinc (NiZn) noma i-manganese zinc (MnZn), okuyinto ethambile kazibuthe ye-ferromagnetic enokucindezela okuphansi. Umfanekiso 1 ubonisa ijika le-hysteresis (BH loop) le-general magnetic core. Amandla okuphoqelela i-HC wento kazibuthe abizwa nangokuthi amandla aphoqayo, okusho ukuthi lapho izinto zikazibuthe zifakwe uzibuthe ukuze zifinyelele ekugcwaleni kazibuthe, ukudonsa kwazo (magnetization) kwehliselwa kuqanda Amandla kazibuthe adingekayo ngaleso sikhathi. Ukuphoqwa okuphansi kusho ukumelana okuphansi kokukhishwa kazibuthe futhi kusho ukulahlekelwa kwe-hysteresis ephansi.

I-Manganese-zinc kanye ne-nickel-zinc ferrites inokufinyeleleka okuphezulu okulinganiselwe (μr), mayelana ne-1500-15000 kanye ne-100-1000, ngokulandelana. Ukungena kwawo kukazibuthe okuphezulu kwenza umongo wensimbi uphakame ngevolumu ethile. I-inductance. Kodwa-ke, okubi ukuthi ukugcwala kwayo okubekezelelekayo kuphansi, futhi uma umgogodla wensimbi usugcwele, amandla kazibuthe azokwehla kakhulu. Bheka Umfanekiso 4 ukuze uthole inkambiso enciphayo yokungena kazibuthe kwe-ferrite nama-powder iron cores lapho insimbi igcwele. Ukuqhathanisa. Uma isetshenziswa kuma-inductors amandla, igebe lomoya lizoshiywa kumjikelezo omkhulu kazibuthe, onganciphisa ukungeneka, ugweme ukugcwala futhi ugcine amandla amaningi; lapho igebe lomoya lifakiwe, ukulingana okulinganayo kwesihlobo kungaba mayelana ne-20- Phakathi kuka-200. Njengoba ukumelana okuphezulu kwempahla ngokwayo kunganciphisa ukulahlekelwa okubangelwa i-eddy current, ukulahlekelwa kuphansi kuma-frequencies aphezulu, futhi kufaneleka kakhulu ama-high-frequency transformers, ama-inductors okuhlunga e-EMI kanye nama-inductors okugcina amandla weziguquli zamandla. Mayelana nemvamisa yokusebenza, i-nickel-zinc ferrite ifanele ukusetshenziswa (>1 MHz), kuyilapho i-manganese-zinc ferrite ifanele amabhendi aphansi (<2 MHz).

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Umfanekiso 1. Ijika le-hysteresis of the core magnetic (BR: remanence; BSAT: saturation magnetic flux density)

3. I-Powder iron core

Ama-Powder iron cores nawo ayizinto ezithambile-magnetic ferromagnetic. Zenziwe nge-iron powder alloys yezinto ezihlukene noma i-iron powder kuphela. Ifomula iqukethe izinto ezingezona kazibuthe ezinosayizi wezinhlayiyana ezihlukene, ngakho-ke ijika lokugcwala lithambile. I-powder iron core ngokuvamile i-toroidal. Umfanekiso wesi-2 ubonisa umongo wensimbi oyimpushana kanye nombono wawo wesigaba esiphambene.

Izinsimbi ezivamile eziyimpuphu zihlanganisa i-iron-nickel-molybdenum alloy (MPP), i-sendust (Sendust), i-iron-nickel alloy (high flux) kanye ne-iron powder core (i-iron powder). Ngenxa yezingxenye ezahlukene, izici zayo kanye namanani ahlukene, okuthinta ukukhethwa kwama-inductors. Okulandelayo kuzokwethula izinhlobo eziwumongo ezishiwo ngenhla futhi kuqhathanise izici zazo:

A. I-Iron-nickel-molybdenum alloy (MPP)

Ingxubevange ye-Fe-Ni-Mo ifushanisiwe njenge-MPP, okuyisifinyezo se-molypermalloy powder. Ukungena okuhlobene kucishe kube ngu-14-500, kanti ukuminyana kukakazibuthe okugcwala kucishe kube ngu-7500 Gauss (Gauss), okungaphezulu kokugcwala kukazibuthe okuguquguqukayo kwe-ferrite (cishe 4000-5000 Gauss). Abaningi baphume. I-MPP inokulahleka kwensimbi okuncane kakhulu futhi inozinzo lokushisa olungcono kakhulu phakathi kwama-powder iron cores. Lapho i-DC yangaphandle ifinyelela ku-ISAT yamanje yokugcwaliswa kwesimo, inani le-inductance liyancipha kancane ngaphandle kokumiswa kungazelelwe. I-MPP inokusebenza okungcono kodwa izindleko eziphezulu, futhi imvamisa isetshenziswa njenge-inductor yamandla kanye nokuhlunga kwe-EMI kweziguquli zamandla.

B. Thuma

I-iron-silicon-aluminium alloy iron core iwumgogodla we-iron alloy owenziwe ngensimbi, i-silicon, ne-aluminium, nokufinyeleleka okuhlobene kazibuthe okungaba ngu-26 kuya ku-125. Ukulahlekelwa kwensimbi kuphakathi kwe-iron powder core ne-MPP kanye ne-iron-nickel alloy. . I-saturation magnetic flux density iphakeme kune-MPP, cishe i-10500 Gauss. Ukuzinza kwezinga lokushisa kanye nezici zamanje zokugcwaliswa kwesimo zingaphansi kancane kune-MPP ne-iron-nickel alloy, kodwa zingcono kune-iron powder core kanye ne-ferrite core, futhi izindleko ezilinganiselwe ishibhile kune-MPP ne-iron-nickel alloy. Isetshenziswa kakhulu ekuhlungeni kwe-EMI, kumasekhethi e-power factor correction (PFC) kanye nama-inductors wamandla okushintsha iziguquli zamandla.

C. Ingxube ye-iron-nickel (i-flux ephezulu)

I-iron-nickel alloy core yenziwe ngensimbi ne-nickel. I-permeability kazibuthe ehlobene imayelana ne-14-200. Ukulahleka kwensimbi nokuzinza kwezinga lokushisa kuphakathi kwe-MPP ne-iron-silicon-aluminium alloy. I-iron-nickel alloy core ine-saturation ephakeme kakhulu ye-magnetic flux density, engaba ngu-15,000 Gauss, futhi ingamelana namagagasi aphezulu okuchema kwe-DC, nezici zayo zokuchema kwe-DC nazo zingcono. Ububanzi bohlelo lokusebenza: Ukulungiswa kwesici samandla asebenzayo, inductance yokugcina amandla, inductance yesihlungi, isiguquli semvamisa ephezulu yesiguquli se-flyback, njll.

D. Impushana yensimbi

I-iron powder core yenziwe ngezinhlayiya ze-iron ezihlanzekile ze-powder ezinezinhlayiya ezincane kakhulu eziboshwe komunye nomunye. Inqubo yokukhiqiza yenza kube negebe lomoya elisabalalisiwe. Ngaphezu komumo wendandatho, umumo ovamile we-iron powder core nawo unezinhlobo ze-E kanye nezinhlobo zokunyathela. Ukungena okuhlobene kazibuthe kwe-iron powder core cishe ku-10 kuya ku-75, futhi ukugcwala okuphezulu komagnetic flux density cishe ku-15000 Gauss. Phakathi kwama-powder iron cores, i-iron powder core inokulahlekelwa kwensimbi okuphezulu kakhulu kodwa izindleko eziphansi kakhulu.

Umfanekiso wesi-3 ubonisa amajika e-BH e-PC47 manganese-zinc ferrite ekhiqizwa yi-TDK kanye nezinsimbi eziyimpuphu zensimbi -52 kanye -2 ezakhiwe yi-MICROMETALS; i-permeability magnetic ehlobene ye-manganese-zinc ferrite iphakeme kakhulu kunaleyo yensimbi eyimpuphu futhi igcwele I-magnetic flux density nayo ihluke kakhulu, i-ferrite imayelana ne-5000 Gauss kanye ne-iron powder core ingaphezu kuka-10000 Gauss.

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Umfanekiso 3. Ijika le-BH le-manganese-zinc ferrite kanye nezinsimbi eziyimpuphu yensimbi yezinto ezahlukene

Kafushane, izici zokugcwala kwe-iron core zihlukile; uma i-saturation current isidluliwe, amandla kazibuthe we-ferrite core azokwehla kakhulu, kuyilapho i-iron powder core ingancipha kancane. Umfanekiso wesi-4 ubonisa izici zokuwa zokungena kazibuthe zomgogodla wensimbi oyimpushana onokungena okufanayo kazibuthe kanye ne-ferrite enegebe lomoya ngaphansi kwamandla ahlukahlukene kazibuthe. Lokhu kuphinde kuchaze ukungeniswa komgogodla we-ferrite, ngoba ukuvuthwa kwehla kakhulu lapho umgogodla ugcwele, njengoba kungabonakala ku-equation (1), futhi kubangela ukuthi i-inductance yehle kakhulu; kuyilapho i-powder core enegebe lomoya esabalalisiwe, amandla kazibuthe Izinga liyancipha kancane uma insimbi igcwele, ngakho-ke i-inductance iyancipha kancane kancane, okungukuthi, inezici ezingcono ze-DC. Ekusetshenzisweni kweziguquli zamandla, lesi sici sibaluleke kakhulu; uma isici sokugcwala kancane kwe-inductor singalungile, i-inductor yamanje ikhuphukela ku-saturation yamanje, futhi ukwehla okungazelelwe kwe-inductance kuzobangela ukucindezeleka kwamanje kwe-crystal yokushintsha kukhuphuke kakhulu, okulula ukubangela umonakalo.

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Umfanekiso 4. Izici zokudonsa zikamagnetic zokwehla kwe-powder iron core kanye ne-ferrite iron core enegebe lomoya ngaphansi kwamandla ahlukene kazibuthe.

Izici zikagesi ze-Inductor kanye nesakhiwo sephakheji

Lapho uklama isiguquli esishintshayo nokukhetha i-inductor, inani le-inductance L, impedance Z, i-AC resistance ACR kanye nevelu ye-Q (isici sekhwalithi), i-IDC yamanje elinganiselwe ne-ISAT, kanye nokulahlekelwa okuyinhloko (ukulahlekelwa okuyisisekelo) nezinye izici ezibalulekile zikagesi konke Kumelwe. kucatshangelwe. Ngaphezu kwalokho, isakhiwo sokupakisha se-inductor sizothinta ubukhulu bokuvuza kazibuthe, okubuye kuthinte i-EMI. Okulandelayo kuzoxoxa ngezici ezibalulwe ngenhla ngokuhlukana njengokucatshangelwa kokukhetha ama-inductors.

1. Inani le-inductance (L)

Inani le-inductance le-inductor liyipharamitha eyisisekelo ebaluleke kakhulu ekwakhiweni kwesekethe, kodwa kufanele ihlolwe ukuthi ingabe inani le-inductance lizinzile emvamisa yokusebenza. Inani legama le-inductance ngokuvamile likalwa ku-100 kHz noma 1 MHz ngaphandle kokuchema kwangaphandle kwe-DC. Futhi ukuqinisekisa ukuthi kungenzeka ukukhiqizwa okuzenzakalelayo okukhulu, ukubekezelelana kwe-inductor kuvame ukuba ± 20% (M) kanye ± 30% (N). Umfanekiso 5 igrafu yesici se-inductance-frequency ye-Taiyo Yuden inductor NR4018T220M elinganiswa imitha ye-LCR ka-Wayne Kerr. Njengoba kuboniswe emfanekisweni, ijika yenani le-inductance liyisicaba ngaphambi kuka-5 MHz, futhi inani le-inductance lingacishe libhekwe njengengashintshi. Ku-band frequency ephezulu ngenxa ye-resonance eyenziwe yi-parasitic capacitance kanye ne-inductance, inani le-inductance lizokhula. Le frequency ye-resonance ibizwa ngokuthi i-self-resonant frequency (SRF), ngokuvamile edinga ukuba phezulu kakhulu kunefrikhwensi yokusebenza.

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Umfanekiso 5, Taiyo Yuden NR4018T220M umdwebo wokulinganisa isici se-inductance-frequency

2. Impedan (Z)

Njengoba kuboniswe kuMfanekiso 6, umdwebo we-impedance ungabuye ubonakale ekusebenzeni kwe-inductance kumafrikhwensi ahlukene. I-impedance ye-inductor icishe ilingane nemvamisa (Z=2πfL), ngakho-ke ukuphakama kwemvamisa, ukusabela kuzoba kukhulu kakhulu kunokumelana ne-AC, ngakho-ke i-impedance iziphatha njenge-inductance emsulwa (isigaba singu-90˚). Emazingeni aphezulu, ngenxa yomphumela we-parasitic capacitance, i-self-resonant frequency point of the impedance ingabonakala. Ngemuva kwaleli phuzu, i-impedance iyehla futhi iba namandla, futhi isigaba sishintsha kancane kancane sibe -90 ˚.

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3. Inani le-Q kanye nokumelana kwe-AC (ACR)

Inani elingu-Q encazelweni ye-inductance isilinganiso sokusabela ekuphikisaneni, okungukuthi, isilinganiso sengxenye ecatshangwayo nengxenye yangempela ye-impedance, njengakufomula (2).

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Lapho i-XL iwukusabela kwe-inductor, futhi i-RL iwukumelana ne-AC kwe-inductor.

Ebangeni eliphansi le-frequency, ukumelana kwe-AC kukhulu kunokusabela okubangelwa i-inductance, ngakho-ke inani layo le-Q liphansi kakhulu; njengoba i-frequency ikhula, ukusabela (cishe 2πfL) kuba kukhulu futhi kukhudlwana, ngisho noma ukumelana ngenxa yomphumela wesikhumba (umphumela wesikhumba) kanye nomphumela wokusondela (ukusondela) Umphumela uba mkhulu futhi ube mkhulu, futhi inani le-Q lisakhula ngokuvama. ; uma usondela ku-SRF, ukusabela kwe-inductive kancane kancane kususwe ukusabela kwe-capacitive, futhi inani le-Q kancane kancane liba lincane; uma i-SRF iba nguziro, ngenxa yokuthi ukusabela kwe-inductive kanye nokusabela kwe-capacitive kufana ngokuphelele ne-Diapar. Umfanekiso 7 ubonisa ubudlelwano phakathi kwevelu ye-Q kanye nemvamisa ye-NR4018T220M, futhi ubudlelwano busesimweni sensimbi ehlanekezelwe.

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Umfanekiso 7. Ubudlelwano phakathi kwevelu ye-Q kanye nemvamisa ye-Taiyo Yuden inductor NR4018T220M

Kubhendi yemvamisa yohlelo lokusebenza ye-inductance, ukuphakama kwevelu ye-Q, kuba ngcono; kusho ukuthi ukusabela kwayo kukhulu kakhulu kunokumelana ne-AC. Ngokuvamile, inani elihle kakhulu le-Q lingaphezulu kwama-40, okusho ukuthi ikhwalithi ye-inductor yinhle. Nokho, ngokuvamile njengoba ukuchema kwe-DC kukhuphuka, inani le-inductance lizokwehla futhi inani le-Q nalo lizokwehla. Uma kusetshenziswa intambo enoqweqwe oluyisicaba noma intambo enameled enezintambo eziningi, umphumela wesikhumba, okungukuthi, ukumelana ne-AC, ungancishiswa, futhi inani le-Q le-inductor lingakhuphuka.

I-DC ukumelana ne-DCR ngokuvamile ibhekwa njengokumelana kwe-DC kocingo lwethusi, futhi ukumelana kungabalwa ngokuya ngobubanzi nobude bentambo. Kodwa-ke, iningi lama-inductors amanje aphansi e-SMD azosebenzisa i-ultrasonic welding ukwenza ishidi le-copper le-SMD endaweni ejikajikayo. Kodwa-ke, ngenxa yokuthi intambo yethusi ayinde ngobude futhi nenani lokumelana aliphezulu, ukumelana nokushisela kuvame ukubala ingxenye enkulu yokumelana ne-DC kukonke. Ukuthatha i-TDK's wire-nxeba SMD inductor CLF6045NIT-1R5N njengesibonelo, ukulinganiswa kwe-DC ukumelana ngu-14.6mΩ, futhi ukumelana kwe-DC kubalwe ngokusekelwe kububanzi bentambo nobude ngu-12.1mΩ. Imiphumela ikhombisa ukuthi lokhu kumelana ne-welding kubala cishe u-17% wokumelana nakho konke kwe-DC.

Ukumelana ne-AC I-ACR inomphumela wesikhumba kanye nomphumela wokusondele, okuzokwenza ukuthi i-ACR ikhule ngokuvama; ekusetshenzisweni kwe-inductance evamile, ngenxa yokuthi ingxenye ye-AC iphansi kakhulu kunengxenye ye-DC, ithonya elibangelwa i-ACR alibonakali; kodwa ekulayisheni okulula, Ngenxa yokuthi ingxenye ye-DC incishisiwe, ukulahlekelwa okubangelwa i-ACR akunakuzitshwa. Umphumela wesikhumba usho ukuthi ngaphansi kwezimo ze-AC, ukusatshalaliswa kwamanje ngaphakathi kwekhondakta akulingani futhi kugxilwe phezu kocingo, okuholela ekuncipheni kwendawo elinganayo ye-wire cross-sectional area, okubuye kukhulise ukumelana okulingana kocingo imvamisa. Ukwengeza, ekujikeni kocingo, izintambo eziseduze zizobangela ukungezwa nokususwa kwezinkundla kazibuthe ngenxa yamanje, ukuze i-current igxile endaweni eseduze nocingo (noma indawo ekude kakhulu, kuye ngokuthi isiqondiso samanje sibheke kuphi. ), futhi okubangela ukunqanyulwa kwentambo okufanayo. Isenzakalo sokuthi indawo iyancipha futhi ukumelana okufanayo kuyanda yilokho okubizwa ngokuthi umphumela wokusondelana; ekusetshenzisweni kwe-inductance kwe-multilayer winding, umphumela wokusondela ubonakala nakakhulu.

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Umfanekiso 8 ubonisa ubudlelwano phakathi kokumelana kwe-AC kanye nemvamisa ye-wire-nxeba SMD inductor NR4018T220M. Ngemvamisa ye-1kHz, ukumelana cishe ku-360mΩ; ku-100kHz, ukumelana kuphakama ku-775mΩ; ku-10MHz, inani lokumelana lisondele ku-160Ω. Uma ulinganisela ukulahleka kwethusi, isibalo kufanele sicabangele i-ACR edalwe yisikhumba nemiphumela yokusondelana, futhi siyiguqule ibe ifomula (3).

4. Saturation current (ISAT)

I-Saturation yamanje ye-ISAT ngokuvamile iwukuchema kwamanje okumakwayo lapho inani le-inductance lehliswa njengo-10%, 30%, noma 40%. Ku-air-gap ferrite, ngenxa yokuthi isici sayo samanje sokugcwala sishesha kakhulu, awukho umehluko omkhulu phakathi kuka-10% no-40%. Bheka Umfanekiso 4. Kodwa-ke, uma i-iron powder core (njenge-inductor enesitembu), ijika le-saturation lithambile, njengoba kuboniswe ku-Figure 9, i-bias current ku-10% noma i-40% ye-inductance attenuation ikhulu kakhulu. ehlukile, ngakho-ke inani lamanje lokugcwala lizoxoxwa ngokuhlukana ezinhlotsheni ezimbili zensimbi ngendlela elandelayo .

Nge-ferrite ye-air-gap, kunengqondo ukusebenzisa i-ISAT njengomkhawulo ophezulu we-inductor yamanje ephezulu yezinhlelo zokusebenza zesekethe. Kodwa-ke, uma kungumgogodla we-iron powder, ngenxa yesici sokugcwala kancane, ngeke kube khona inkinga ngisho noma ubuningi bamanje besifunda sohlelo lokusebenza budlula i-ISAT. Ngakho-ke, lesi sici se-iron core sifaneleka kakhulu ekushintsheni izinhlelo zokusebenza zokuguqula. Ngaphansi komthwalo osindayo, nakuba inani le-inductance ye-inductor liphansi, njengoba kuboniswe ku-Figure 9, i-ripple factor yamanje iphezulu, kodwa ukubekezelelana kwamanje kwe-capacitor kuphezulu, ngakho-ke ngeke kube yinkinga. Ngaphansi komthwalo okhanyayo, inani le-inductance ye-inductor likhulu, okusiza ukunciphisa ukugeleza kwamanje kwe-inductor, ngaleyo ndlela kunciphise ukulahlekelwa kwensimbi. Umfanekiso 9 uqhathanisa ijika lamanje lokugcwaliswa kwesilonda se-TDK's ferrite SLF7055T1R5N kanye ne-stamp iron powder core inductor SPM6530T1R5M ngaphansi kwevelu efanayo ye-inductance.

9

Umfanekiso 9. Ijika lamanje lokugcwaliswa kwesilonda se-ferrite yesilonda kanye nomgogodla wempushana yensimbi enesitembu ngaphansi kwevelu efanayo ye-inductance

5. Ikalwe okwamanje (IDC)

Inani le-IDC liwukuchema kwe-DC lapho izinga lokushisa le-inductor likhuphukela ku-Tr˚C. Imininingwane futhi ikhombisa inani layo lokumelana ne-DC RDC ku-20˚C. Ngokwe-coefficient yezinga lokushisa locingo lwethusi cishe ngu-3,930 ppm, lapho izinga lokushisa le-Tr likhuphuka, inani layo lokumelana lingu-RDC_Tr = RDC (1+0.00393Tr), futhi ukusetshenziswa kwayo kwamandla yi-PCU = I2DCxRDC. Lokhu kulahlekelwa kwethusi kukhishwa ebusweni be-inductor, futhi ukumelana nokushisa kwe-ΘTH kwe-inductor kungabalwa:

(2)

Ithebula 2 libhekisela eshidini ledatha lochungechunge lwe-TDK VLS6045EX (6.0×6.0×4.5mm), futhi libala ukumelana nokushisa ngokunyuka kwezinga lokushisa elingu-40˚C. Ngokusobala, kuma-inductors ochungechunge nobukhulu obufanayo, ukumelana nokushisa okubalwe kucishe kufane ngenxa yendawo efanayo yokushisa ukushisa kwendawo; ngamanye amazwi, i-IDC yamanje elinganiselwe yama-inductors ahlukene ingalinganiselwa. Uchungechunge oluhlukile (amaphakheji) ama-inductors anokumelana okuhlukile kokushisa. Ithebula lesi-3 liqhathanisa ukumelana nokushisa kwama-inductors ochungechunge lwe-TDK VLS6045EX (i-semi-shielded) kanye nochungechunge lwe-SPM6530 (elibunjiwe). Uma kukhulu ukumelana nokushisa, izinga lokushisa eliphakeme likhuphuka lapho i-inductance igeleza ngomthwalo wamanje; kungenjalo, ephansi.

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Ithebula 2. Ukumelana nokushisa kwama-inductors ochungechunge lwe-VLS6045EX ekukhuphukeni kwezinga lokushisa okungu-40˚C

Kungabonakala kuThebula 3 ukuthi ngisho noma ubukhulu be-inductors bufana, ukumelana nokushisa kwama-inductors anesitembu kuphansi, okungukuthi, ukuchithwa kokushisa kungcono.

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Ithebula 3. Ukuqhathaniswa kokumelana nokushisa kwama-inductors ephakheji ahlukene.

6. Ukulahlekelwa okuyinhloko

Ukulahleka kwe-core, okubizwa ngokuthi ukulahlekelwa kwensimbi, kubangelwa ukulahlekelwa kwamanje kwe-eddy kanye nokulahlekelwa kwe-hysteresis. Ubukhulu bokulahlekelwa kwamanje kwe-eddy ikakhulukazi kuncike ekutheni izinto eziyinhloko kulula yini "ukuqhuba"; uma i-conductivity iphezulu, okungukuthi, i-resistivity iphansi, ukulahlekelwa kwamanje kwe-eddy kuphezulu, futhi uma ukumelana kwe-ferrite kuphezulu, ukulahlekelwa kwamanje kwe-eddy kuncane kakhulu. Ukulahlekelwa kwamanje kwe-Eddy nakho kuhlobene nokuvama. Lapho i-frequency iphezulu, kukhulu ukulahlekelwa kwamanje kwe-eddy. Ngakho-ke, izinto eziyinhloko zizonquma imvamisa yokusebenza efanele yengqikithi. Ngokuvamile, imvamisa yokusebenza ye-iron powder core ingafinyelela ku-1MHz, futhi imvamisa yokusebenza ye-ferrite ingafinyelela ku-10MHz. Uma i-frequency yokusebenza idlula le mvamisa, ukulahlekelwa kwamanje kwe-eddy kuzokhula ngokushesha futhi izinga lokushisa le-iron core nalo lizokhula. Kodwa-ke, ngokuthuthukiswa okusheshayo kwezinto eziyinhloko zensimbi, ama-iron cores ane-frequency yokusebenza ephakeme kufanele abe eduze nekhona.

Okunye ukulahlekelwa kwensimbi ukulahlekelwa kwe-hysteresis, okuhambisana nendawo evalelwe ijika le-hysteresis, elihlobene ne-swing amplitude yengxenye ye-AC yamanje; ukushwibeka okukhulu kwe-AC, kulapho ukulahleka kwe-hysteresis kukhulu.

Kumjikelezo olinganayo we-inductor, i-resistor exhunywe ngokuhambisana ne-inductor ivame ukusetshenziselwa ukuveza ukulahlekelwa kwensimbi. Uma i-frequency ilingana ne-SRF, ukusabela kwe-inductive kanye ne-capacitive reactance kuyakhanselwa, futhi ukusabela okulinganayo kunguziro. Ngalesi sikhathi, i-impedance ye-inductor ilingana nokumelana nokulahlekelwa kwe-iron ochungechungeni nokumelana nokugoqa, futhi ukumelana nokulahlekelwa kwensimbi kukhulu kakhulu kunokumelana nokuqina, ngakho I-impedance ku-SRF cishe ilingana nokumelana nokulahlekelwa kwensimbi. Uma sithatha i-inductor ene-voltage ephansi njengesibonelo, ukumelana kwayo nokulahlekelwa kwensimbi cishe ku-20kΩ. Uma i-voltage yenani elisebenzayo kuzo zombili iziphetho ze-inductor ilinganiselwa ku-5V, ukulahlekelwa kwayo kwensimbi cishe ku-1.25mW, okubonisa futhi ukuthi ubukhulu bokumelana nokulahlekelwa kwensimbi, kungcono.

7. Isakhiwo sesihlangu

Isakhiwo sokupakishwa se-ferrite inductors sihlanganisa okungavikelwe, okuvikelwe kancane ngeglue kazibuthe, futhi evikelekile, futhi kunegebe elikhulu lomoya kunoma iyiphi yazo. Ngokusobala, igebe lomoya lizoba nokuvuza kazibuthe, futhi esimweni esibi kakhulu, lizophazamisa amasekhethi amasignali amancane azungezile, noma uma kukhona okubalulekile kazibuthe eduzane, inductance yayo nayo izoshintshwa. Esinye isakhiwo sokupakisha i-inductor ye-iron powder enesitembu. Njengoba lingekho igebe ngaphakathi kwe-inductor kanye nesakhiwo esimazombezombe siqinile, inkinga yokukhishwa kwamagnetic field incane kakhulu. Umfanekiso we-10 uwukusetshenziswa komsebenzi we-FFT we-oscilloscope ye-RTO 1004 ukukala ubukhulu benkundla kazibuthe evuzayo ku-3mm ngaphezulu nasohlangothini lwe-inductor enesitembu. Ithebula lesi-4 libala ukuqhathaniswa kwendawo kazibuthe evuzayo yama-inductors esakhiwo sephakeji. Kungabonakala ukuthi ama-inductors angavikelwe anokuvuza okuyingozi kakhulu kazibuthe; ama-inductors anesitembu anokuvuza kukazibuthe okuncane kakhulu, okubonisa umphumela omuhle kakhulu wokuvikela kazibuthe. . Umehluko kubukhulu benkundla kazibuthe evuzayo yama-inductors alezi zakhiwo ezimbili cishe u-14dB, okuyizikhathi ezicishe zibe ngu-5.

10

Umfanekiso 10. Ubukhulu benkundla kazibuthe evuzayo ilinganiswa ngo-3mm ngaphezulu nasohlangothini lwe-inductor egxiviziwe.

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Ithebula 4. Ukuqhathaniswa kwendawo kazibuthe yokuvuza yama-inductors esakhiwo sephakheji ehlukene

8. ukuhlanganisa

Kwezinye izinhlelo zokusebenza, ngesinye isikhathi kuba namasethi amaningi eziguquli ze-DC ku-PCB, ezivame ukuhlelwa eduze kwelinye, futhi ama-inductors ahambisanayo nawo ahlelwa eduze komunye nomunye. Uma usebenzisa uhlobo olungavikelekile noma oluvikeleke kancane oluneglue kazibuthe Ama-Inductors angase ahlanganiswe namanye ukuze akhe ukuphazamiseka kwe-EMI. Ngakho-ke, lapho ubeka i-inductor, kunconywa ukuthi umake i-polarity ye-inductor kuqala, futhi uxhume indawo yokuqala neyokugoqa yongqimba lwangaphakathi lwe-inductor ku-voltage yokushintsha yesiguquli, njenge-VSW yesiguquli sebhaka, okuyiphuzu elinyakazayo. Itheminali yokuphuma ixhunywe ku-capacitor ephumayo, okuyiphoyinti elimile; Ngakho-ke i-copper wire winding yenza izinga elithile lokuvikela insimu kagesi. Kuhlelo lwezintambo lwe-multiplexer, ukulungisa i-polarity ye-inductance kusiza ukulungisa ubukhulu be-mutual inductance futhi ugweme ezinye izinkinga ze-EMI ezingalindelekile.

Izicelo:

Isahluko esandulele sixoxe ngezinto eziwumgogodla, isakhiwo sephakheji, nezici ezibalulekile zikagesi ze-inductor. Lesi sahluko sizochaza indlela yokukhetha inani elifanele le-inductance le-converter ye-buck kanye nokucatshangelwa kokukhetha i-inductor etholakalayo kwezohwebo.

Njengoba kuboniswe kuzibalo (5), inani le-inductor kanye nemvamisa yokushintsha yesiguquli kuzothinta i-inductor ripple current (ΔiL). I-inductor ripple current izogeleza ku-capacitor ephumayo futhi ithinte i-ripple current ye-output capacitor. Ngakho-ke, kuzothinta ukukhethwa kwe-capacitor okukhiphayo futhi kuthinte nakakhulu usayizi we-ripple we-voltage ephumayo. Ngaphezu kwalokho, inani le-inductance kanye nevelu yamandla okukhiphayo kuzophinde kuthinte ukwakheka kwempendulo yesistimu kanye nokuphendula okuguquguqukayo komthwalo. Ukukhetha inani elikhulu le-inductance kunengcindezi encane yamanje ku-capacitor, futhi kuyazuzisa ukunciphisa ukuphuma kwe-voltage ripple futhi kungagcina amandla engeziwe. Kodwa-ke, inani elikhulu le-inductance libonisa umthamo omkhulu, okungukuthi, izindleko eziphezulu. Ngakho-ke, lapho uklama isiguquli, ukwakheka kwevelu ye-inductance kubaluleke kakhulu.

(5)

Kungabonakala kufomula (5) ukuthi uma igebe phakathi kwe-voltage yokufaka ne-voltage ephumayo inkulu, i-inductor ripple current izoba nkulu, okuyisimo esibi kakhulu somklamo we-inductor. Ngokuhambisana nokunye ukuhlaziya okufakwayo, indawo yokuklama ye-inductance yesiguquli esehlayo kufanele ngokuvamile sikhethwe ngaphansi kwemibandela ye-voltage ephezulu yokufaka nomthwalo ogcwele.

Lapho uklama inani le-inductor, kuyadingeka ukwenza ukuhwebelana phakathi kwe-inductor ripple current kanye nosayizi we-inductor, kanye nento yamanje ye-ripple (i-ripple current factor; γ) ichazwa lapha, njengefomula (6).

(6)

Ukushintsha ifomula (6) kufomula (5), inani le-inductance lingavezwa njengefomula (7).

(7)

Ngokusho kwefomula (7), lapho umehluko phakathi kwe-voltage yokufaka nokuphumayo inkulu, inani lika-γ lingakhethwa libe likhudlwana; ngokuphambene nalokho, uma i-voltage yokufaka ne-output iseduze, idizayini yenani lika-γ kufanele ibe mncane. Ukuze ukhethe phakathi kwe-inductor ripple current kanye nosayizi, ngokuya ngevelu yolwazi lomklamo ovamile, u-γ ngokuvamile ungu-0.2 ukuya ku-0.5. Okulandelayo kuthatha i-RT7276 njengesibonelo ukukhombisa ukubalwa kwe-inductance kanye nokukhethwa kwama-inductors atholakala ngokwentengiso.

Isibonelo sedizayini: Idizayinelwe nge-RT7276 esezingeni eliphezulu engaguquki ngesikhathi (Advanced Constant On-Time; ACOTTM) isiguquli sokuya phansi sokulungiswa okuvumelanayo, imvamisa yokushintsha kwayo ingu-700 kHz, i-voltage yokufaka ingu-4.5V ukuya ku-18V, kanti i-voltage ephumayo ingu-1.05V . Umthwalo ogcwele wamanje ngu-3A. Njengoba kushiwo ngenhla, inani le-inductance kufanele lenziwe ngaphansi kwemibandela ye-voltage ephezulu yokufaka engu-18V kanye nomthwalo ogcwele we-3A, inani lika-γ lithathwa njengo-0.35, futhi inani elingenhla lifakwe esikhundleni se-equation (7), i-inductance. inani li

Sebenzisa i-inductor enevelu ye-inductance evamile engu-1.5 µH. Faka esikhundleni sefomula (5) ukuze ubale i-ripple current ngendlela elandelayo.

Ngakho-ke, inani eliphakeme kakhulu le-inductor

Futhi inani elisebenzayo le-inductor current (IRMS) liyi

Ngenxa yokuthi ingxenye ye-inductor ripple incane, inani elisebenzayo le-inductor yamanje ngokuyinhloko liyingxenye yayo ye-DC, futhi leli nani elisebenzayo lisetshenziswa njengesisekelo sokukhetha i-IDC yamanje elinganiselwe nge-inductor. Ngomklamo wokwehlisa (derating) ongu-80%, izidingo ze-inductance yilezi:

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

Ithebula lesi-5 libala ama-inductors atholakalayo ochungechunge oluhlukile lwe-TDK, afanayo ngosayizi kodwa ahlukile ngesakhiwo sephakheji. Kungabonakala etafuleni ukuthi i-saturation yamanje kanye nesilinganiso samanje se-inductor esigxiviziwe (SPM6530T-1R5M) sikhulu, futhi ukumelana nokushisa kuncane futhi ukuchithwa kokushisa kuhle. Ngaphezu kwalokho, ngokusho kwengxoxo esahlukweni esandulele, izinto eziyinhloko ze-inductor ezinesitembu ziyi-iron powder core, ngakho-ke iqhathaniswa ne-ferrite core ye-semi-shielded (VLS6045EX-1R5N) kanye nama-inductors avikelekile (SLF7055T-1R5N). ngeglue kazibuthe. , Inezici ezinhle zokuchema kwe-DC. Umfanekiso we-11 ubonisa ukuqhathaniswa kokusebenza kahle kwama-inductors ahlukene asetshenziswa kusiguquli sokuya phansi se-RT7276 esithuthukisiwe esiqhubekayo sokulungiswa kokuvumelanisa. Imiphumela ibonisa ukuthi umehluko wokusebenza kahle phakathi kokuthathu awubalulekile. Uma ucabangela ukuchithwa kokushisa, izici zokuchema kwe-DC kanye nezinkinga zokuchithwa kwenkundla kazibuthe, kuyanconywa ukuthi usebenzise ama-inductors e-SPM6530T-1R5M.

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Ithebula 5. Ukuqhathaniswa kwama-inductance ochungechunge oluhlukile lwe-TDK

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Umfanekiso 11. Ukuqhathaniswa kokusebenza kahle kokuguqula ngama-inductors ahlukene

Uma ukhetha ukwakheka kwephakheji efanayo kanye nenani le-inductance, kodwa ama-inductors kasayizi amancane, njenge-SPM4015T-1R5M (4.4×4.1×1.5mm), nakuba ubukhulu bayo buncane, kodwa i-DC yokumelana ne-DC (44.5mΩ) nokumelana nokushisa ΘTH ( 51˚C) /W) Okukhudlwana. Kuziguquli zokucaciswa okufanayo, inani elisebenzayo lamanje elibekezelelwa i-inductor nalo liyafana. Ngokusobala, ukumelana ne-DC kuzonciphisa ukusebenza kahle ngaphansi komthwalo osindayo. Ngaphezu kwalokho, ukumelana nokushisa okukhulu kusho ukuchithwa kokushisa okubi. Ngakho-ke, lapho ukhetha i-inductor, akudingekile kuphela ukucabangela izinzuzo zobukhulu obuncishisiwe, kodwa futhi nokuhlola ukushiyeka kwayo okuhambisanayo.

Ekuphetheni

I-Inductance ingenye yezingxenye ezivame ukusetshenziswa ezingasetshenziswa ekushintsheni iziguquli zamandla, ezingasetshenziselwa ukugcina amandla nokuhlunga. Kodwa-ke, ekwakhiweni kwesekethe, akulona nje inani le-inductance elidinga ukunakwa, kodwa amanye amapharamitha afaka ukumelana ne-AC kanye nevelu ye-Q, ukubekezelelana kwamanje, ukugcwala kwe-iron core, kanye nesakhiwo sephakheji, njll., yonke imingcele okufanele kucatshangelwe lapho ukhetha i-inductor. . Lawa mapharamitha ngokuvamile ahlobene nezinto eziyinhloko, inqubo yokukhiqiza, nosayizi nezindleko. Ngakho-ke, lesi sihloko sethula izici zezinto eziyinhloko zensimbi kanye nendlela yokukhetha i-inductance efanele njengereferensi yokuklama kokunikezwa kwamandla.