Isakhiwo sokuphakelwa kwamandla esiyisisekelo seukushaja okusheshayoI-QC isebenzisa i-flyback + uhlangothi lwesibili (olwesibili) lokuvumelanisa lokulungisa i-SSR. Kuziguquli ze-flyback, ngokwendlela yesampula yempendulo, zingahlukaniswa zibe: umthethonqubo wohlangothi oluyinhloko (oluyinhloko) kanye nomthetho wohlangothi lwesibili (olwesibili); ngokuya ngendawo yesilawuli se-PWM. Ingahlukaniswa: Ukulawula ohlangothini oluyinhloko (okuyinhloko) kanye nokulawula ohlangothini lwesibili (okwesibili). Kubonakala sengathi akuhlangene ne-MOSFET. Ngakho,Olukeykufanele abuze: Ifihlwe kuphi i-MOSFET? Yadlala yiphi indima?
1. Ukulungiswa kohlangothi oluyinhloko (okuyinhloko) nokulungiswa kohlangothi lwesibili (okwesibili).
Ukuzinza kwamandla kagesi okukhiphayo kudinga isixhumanisi sempendulo ukuze sithumele ulwazi lwayo olushintshayo kusilawuli esikhulu se-PWM ukuze silungise izinguquko ku-voltage yokufaka nomthwalo ophumayo. Ngokwezindlela ezihlukene zesampula yempendulo, ingahlukaniswa ngohlangothi oluyinhloko (oluyinhloko) ukulungiswa nokulungiswa kohlangothi lwesibili (olwesibili), njengoba kuboniswe kuMfanekiso 1 no-2.
Isignali yempendulo yomthetho wohlangothi oluyinhloko (oluyinhloko) ayithathwa ngokuqondile ku-voltage ephumayo, kodwa isuka kumawindi ayisilekeleli noma amajika ayisisekelo agcina ubudlelwano obuthile obulinganiselwe ne-voltage ephumayo. Izici zayo yilezi:
① Indlela yempendulo engaqondile, izinga eliphansi lokulawula umthwalo kanye nokunemba okubi;
②. Izindleko ezilula neziphansi;
③. Asikho isidingo se-isolation optocoupler.
Isignali yempendulo yokulawula uhlangothi lwesibili (olwesibili) ithathwa ngokuqondile ku-voltage ephumayo kusetshenziswa i-optocoupler ne-TL431. Izici zayo yilezi:
① Indlela yempendulo eqondile, izinga elihle lokulawula umthwalo, izinga lokulawula umugqa, nokunemba okuphezulu;
②. Isifunda sokulungisa siyinkimbinkimbi futhi siyabiza;
③. Kuyadingeka ukuhlukanisa i-optocoupler, enezinkinga zokuguga ngokuhamba kwesikhathi.
2. Ukulungiswa kwe-diode ohlangothini lwesibili (olwesibili) kanyeI-MOSFETukulungiswa kokuvumelanisa kwe-SSR
Uhlangothi lwesibili (olwesibili) lwesiguquli se-flyback ngokuvamile lusebenzisa ukulungiswa kwe-diode ngenxa yomphumela omkhulu wamanje wokushaja okusheshayo. Ikakhulukazi ukushaja okuqondile noma ukushaja kwe-flash, ukuphuma kwamanje kuphezulu njengo-5A. Ukuze kuthuthukiswe ukusebenza kahle, i-MOSFET isetshenziswa esikhundleni se-diode njengesilungisi, esibizwa ngokuthi ukulungiswa kwe-SSR yesibili (yesibili) yokuvumelanisa, njengoba kuboniswe kuMfanekiso 3 no-4.
Izici zokulungiswa kohlangothi lwesibili (olwesibili) lwe-diode:
①. Kulula, asikho isilawuli sedrayivu esengeziwe esidingekayo, futhi izindleko ziphansi;
② Uma okukhiphayo kukhulu, ukusebenza kahle kuphansi;
③. Ukuthembeka okuphezulu.
Izici zohlangothi lwesibili (olwesibili) lokulungiswa kokuvumelanisa kwe-MOSFET:
①. Inkimbinkimbi, edinga isilawuli sedrayivu esengeziwe kanye nezindleko eziphakeme;
②. Lapho ukukhishwa kwamanje kukhulu, ukusebenza kahle kuphezulu;
③. Uma kuqhathaniswa nama-diode, ukwethembeka kwawo kuphansi.
Ezisetshenziswa ezingokoqobo, i-MOSFET ye-SSR yokulungiswa kokuvumelanisa ivamise ukuhanjiswa ukusuka ekugcineni okuphezulu iye ekugcineni okuphansi ukuze kube lula ukushayela, njengoba kuboniswe kuMfanekiso 5.
Izici ze-MOSFET ephezulu yokulungiswa kokuvumelanisa kwe-SSR:
①. Idinga i-bootstrap drive noma idrayivu entantayo, ebiza kakhulu;
②. I-EMI enhle.
Izici zokulungiswa okuvumelanayo kwe-SSR MOSFET ezibekwe ekugcineni okuphansi:
① Ukushayela okuqondile, ukushayela okulula nezindleko eziphansi;
②. I-EMI embi.
3. Ukulawula ohlangothini oluyinhloko (okuyinhloko) nokulawula uhlangothi lwesibili (okwesibili).
Isilawuli esikhulu se-PWM sibekwe ohlangothini oluyinhloko (oluyinhloko). Lesi sakhiwo sibizwa ngokuthi yi-primary side (primary) control. Ukuze kuthuthukiswe ukunemba kwe-voltage ephumayo, izinga lokulawulwa komthwalo, nezinga lokulawulwa komugqa, ukulawulwa kohlangothi oluyinhloko (okuyinhloko) kudinga i-optocoupler yangaphandle kanye ne-TL431 ukwenza isixhumanisi sempendulo. I-bandwidth yesistimu incane futhi isivinini sokuphendula sihamba kancane.
Uma isilawuli esiyinhloko se-PWM sibekwe ohlangothini lwesibili (olwesibili), i-optocoupler ne-TL431 ingasuswa, futhi i-voltage ephumayo ingalawulwa ngokuqondile futhi ilungiswe ngokuphendula okusheshayo. Lesi sakhiwo sibizwa ngokuthi isilawuli sesibili (sesibili).
Izici zokulawula ohlangothini oluyinhloko (okuyinhloko):
①. I-Optocoupler ne-TL431 iyadingeka, futhi isivinini sokuphendula sihamba kancane;
②. Isivinini sokuvikela okukhiphayo sihamba kancane.
③. Kumodi eqhubekayo yokulungiswa kokuvumelanisa i-CCM, uhlangothi lwesibili (olwesibili) ludinga isignali yokuvumelanisa.
Izici zokulawula okwesibili (kwesibili):
①. Okukhiphayo kutholwa ngokuqondile, akukho optocoupler kanye ne-TL431 edingekayo, isivinini sokuphendula siyashesha, futhi isivinini sokuvikela okukhiphayo siyashesha;
②. Uhlangothi lwesibili (olwesibili) lokulungiswa kokuvumelanisa kwe-MOSFET luqhutshwa ngokuqondile ngaphandle kwesidingo samasignali okuvumelanisa; amathuluzi engeziwe anjengama-pulse transformer, ama-coupling kazibuthe noma ama-capacitive couplers ayadingeka ukuze kudluliselwe izimpawu zokushayela ze-MOSFET yohlangothi oluyinhloko (oluyinhloko) lwe-voltage ephezulu.
③. Uhlangothi oluyinhloko (oluyinhloko) ludinga isifunda sokuqala, noma uhlangothi lwesibili (olwesibili) lunomthombo wamandla asizayo ukuze luqale.
4. Imodi ye-CCM eqhubekayo noma imodi ye-DCM engaqhubeki
Isiguquli se-flyback singasebenza kumodi ye-CCM eqhubekayo noma imodi ye-DCM engaqhubeki. Uma i-current ku-winding yesibili (yesibili) ifinyelela ku-0 ekupheleni komjikelezo wokushintsha, ibizwa ngemodi ye-DCM engapheli. Uma ijika lesibili (lesibili) elijikajikayo lingeyena u-0 ekupheleni komjikelezo wokushintsha, libizwa ngokuthi imodi ye-CCM eqhubekayo, njengoba kuboniswe kuMfanekiso 8 no-9.
Kungabonakala ku-Figure 8 noFigure 9 ukuthi izimo zokusebenza ze-SSR yokulungiswa okuvumelanayo zihlukile ezindleleni ezihlukene zokusebenza zesiguquli se-flyback, okusho futhi ukuthi izindlela zokulawula ze-SSR yokulungiswa kokuvumelanisa zizophinde zihluke.
Uma isikhathi esifile singanakwa, lapho usebenza kumodi ye-CCM eqhubekayo, i-SSR yokulungiswa okuvumelanayo inezifunda ezimbili:
①. Uhlangothi oluyinhloko (oluyinhloko) lwe-MOSFET yamandla aphezulu luyavulwa, futhi uhlangothi lwesibili (olwesibili) lokulungiswa kokuvumelanisa kwe-MOSFET luvaliwe;
②. Uhlangothi oluyinhloko (oluyinhloko) lwe-MOSFET yamandla aphezulu luvaliwe, futhi uhlangothi lwesibili (olwesibili) lokulungiswa kokuvumelanisa kwe-MOSFET luyavulwa.
Ngokufanayo, uma isikhathi esifile singanakwa, i-SSR yokulungiswa kokuvumelanisa inezifunda ezintathu lapho isebenza kumodi ye-DCM engaqhubeki:
①. Uhlangothi oluyinhloko (oluyinhloko) lwe-MOSFET yamandla aphezulu luyavulwa, futhi uhlangothi lwesibili (olwesibili) lokulungiswa kokuvumelanisa kwe-MOSFET luvaliwe;
②. Uhlangothi oluyinhloko (oluyinhloko) lwe-MOSFET yamandla aphezulu luvaliwe, futhi uhlangothi lwesibili (olwesibili) lokulungiswa kokuvumelanisa kwe-MOSFET luyavulwa;
③. Uhlangothi oluyinhloko (oluyinhloko) lwe-high-voltage ye-MOSFET luvaliwe, futhi uhlangothi lwesibili (olwesibili) lokulungiswa kokuvumelanisa kwe-MOSFET luvaliwe.
5. Uhlangothi lwesibili (olwesibili) lokulungiswa kokuvumelanisa kwe-SSR kumodi ye-CCM eqhubekayo
Uma isiguquli se-flyback esishaja ngokushesha sisebenza kumodi ye-CCM eqhubekayo, indlela yokulawula yohlangothi oluyinhloko (eyinhloko), uhlangothi lwesibili (olwesibili) ukulungisa okuhambisanayo kwe-MOSFET kudinga isignali yokuvumelanisa kusukela ohlangothini oluyinhloko (oluyinhloko) ukuze ulawule ukuvala shaqa.
Izindlela ezimbili ezilandelayo zivame ukusetshenziselwa ukuthola isignali yedrayivu evumelanisiwe yohlangothi lwesibili (olwesibili):
(1) Sebenzisa ngokuqondile ukujikajika kwesibili (kwesibili), njengoba kuboniswe kuMfanekiso 10;
(2) Sebenzisa izingxenye ezengeziwe zokuzihlukanisa njengeziguquli ze-pulse ukuze udlulisele isignali ye-synchronous drive kusukela ohlangothini oluyinhloko (oluyinhloko) ukuya ohlangothini lwesibili (olwesibili), njengoba kuboniswe kuMfanekiso 12.
Ngokuqondile usebenzisa i-winding yesibili (yesibili) ukuze uthole isignali ye-synchronous drive, ukunemba kwesiginali ye-synchronous drive kunzima kakhulu ukuyilawula, futhi kunzima ukuzuza ukusebenza kahle nokuthembeka okulungiselelwe. Ezinye izinkampani zize zisebenzisa izilawuli zedijithali ukuze zithuthukise ukunemba kokulawula, njengoba kuboniswe kuMfanekiso 11 Bonisa.
Ukusebenzisa i-pulse transformer ukuthola izimpawu zokushayela ezivumelanisiwe kunokunemba okuphezulu, kodwa izindleko ziphezulu uma kuqhathaniswa.
Indlela yokulawula ohlangothini lwesibili (olwesibili) ngokuvamile isebenzisa i-pulse transformer noma indlela yokuhlanganisa kazibuthe ukuze idlulisele isignali ye-synchronous drive isuka ohlangothini lwesibili (olwesibili) iye ohlangothini oluyinhloko (oluyinhloko), njengoba kuboniswe kuMfanekiso 7.v
6. Uhlangothi lwesibili (olwesibili) lokulungiswa kokuvumelanisa kwe-SSR kumodi ye-DCM engaqhubeki
Uma isiguquli se-flyback esishaja ngokushesha sisebenza kumodi ye-DCM engaqhubeki. Kungakhathalekile ukuthi iyiphi indlela yokulawula ohlangothini oluyinhloko (oluyinhloko) noma indlela yokulawula yohlangothi lwesibili (olwesibili), ukwehla kwamandla kagesi ka-D no-S we-MOSFET yokulungiswa okuhambisanayo kungatholwa futhi kulawulwe ngokuqondile.
(1) Ukuvula i-MOSFET yokulungisa ehambisanayo
Lapho i-voltage ye-VDS yokulungiswa okuvumelanayo kwe-MOSFET ishintsha isuka kokuhle iye kokubi, i-diode ye-parasitic yangaphakathi iyavula, futhi ngemva kokubambezeleka okuthile, ukulungisa okuhambisanayo kwe-MOSFET kuyavula, njengoba kuboniswe kuMfanekiso 13.
(2) Ukuvala ukulungiswa kokuvumelanisa kwe-MOSFET
Ngemva kokuvulwa kokulungiswa kwe-MOSFET, VDS=-Io*Rdson. Lapho i-current winding yesibili (yesibili) yehla ibe ngu-0, okungukuthi, lapho i-voltage yesiginali yokuthola yamanje i-VDS ishintsha isuka ku-negative iye ku-0, ukulungisa okuhambisanayo kwe-MOSFET kuyavalwa, njengoba kuboniswe kuMfanekiso 13.
Kuzinhlelo zokusebenza ezingokoqobo, i-MOSFET yokulungisa ehambisanayo iyavalwa ngaphambi kokuba umsinga wamajika wesibili (okwesibili) ufinyelele ku-0 (VDS=0). Amanani wamanje wereferensi wamandla kagesi asethwe ama-chips ahlukene ahlukile, njenge -20mV, -50mV, -100mV, -200mV, njll.
I-voltage yereferensi yamanje yesistimu igxilile. Uma likhulu inani eliphelele le-voltage yesithenjwa yamanje, liba lincane iphutha lokuphazamisa futhi kuba ngcono nokunemba. Kodwa-ke, lapho umthwalo ophumayo wamanje we-Io wehla, i-MOSFET yokulungiswa kokuvumelanisa izocima ekuphumeni okukhulu kwamanje, futhi i-diode yayo yangaphakathi ye-parasitic izoqhuba isikhathi eside, ngakho ukusebenza kahle kuyehla, njengoba kuboniswe kuMfanekiso 14.
Ngaphezu kwalokho, uma inani eliphelele le-voltage yereferensi yokuthola lincane kakhulu. Amaphutha esistimu nokuphazamiseka kungase kubangele ukuthi i-MOSFET yokulungiswa okuvumelanayo ivalwe ngemva kokuba umsinga wamajika wesibili (okwesibili) udlule u-0, okuholela ekungeneni okubuyela emuva, okuthinta ukusebenza kahle nokuthembeka kwesistimu.
Izimpawu zamanje zokunemba okuphezulu zingathuthukisa ukusebenza kahle nokuthembeka kwesistimu, kodwa izindleko zedivayisi zizokhuphuka. Ukunemba kwesiginali yokuthola yamanje kuhlobene nezinto ezilandelayo:
①. Ukunemba kanye nokukhukhuleka kwezinga lokushisa kwe-voltage yereferensi yokuthola yamanje;
②. I-voltage echemile ne-offset voltage, i-bias current kanye ne-offset current, kanye nokwehla kwezinga lokushisa kwe-amplifier yamanje;
③. Ukunemba nezinga lokushisa lokunyakaziswa kwe-on-voltage Rdson ye-MOSFET yokulungiswa okuvumelanayo.
Ngaphezu kwalokho, ngokombono wesistimu, ingathuthukiswa ngokulawulwa kwedijithali, ukushintsha i-voltage yereferensi yokuthola yamanje, kanye nokushintsha i-voltage yokushayela ye-MOSFET yokulungiswa okuvumelanayo.
Lapho umthwalo ophumayo wamanje we-Io wehla, uma i-voltage yokushayela yamandla e-MOSFET inhla, i-voltage yokuvula i-MOSFET ehambisanayo i-Rdson iyakhula. Njengoba kuboniswe kuMfanekiso 15, kungenzeka ukugwema ukuvala kwangaphambi kwesikhathi kwe-MOSFET yokulungiswa okuvumelanayo, ukunciphisa isikhathi sokuqhuba kwe-parasitic diode, futhi uthuthukise ukusebenza kahle kwesistimu.
Kungabonwa kuMfanekiso 14 ukuthi lapho umthwalo ophumayo wamanje we-Io wehla, i-voltage yereferensi yokuthola yamanje nayo iyehla. Ngale ndlela, lapho i-Io yamanje ephumayo inkulu, i-voltage yereferensi ephezulu yokutholwa yamanje isetshenziselwa ukuthuthukisa ukunemba kokulawula; uma i-Io yamanje ephumayo iphansi, kusetshenziswa i-voltage yereferensi ephansi yamanje. Ingase futhi ithuthukise isikhathi sokwenziwa kwe-MOSFET yokulungiswa okuvumelanayo futhi ithuthukise ukusebenza kahle kohlelo.
Uma indlela engenhla ingakwazi ukusetshenziselwa ukuthuthukisa, ama-Schottky diode nawo angaxhunywa ngokuhambisana kuzo zombili iziphetho ze-MOSFET yokulungiswa okuvumelanayo. Ngemuva kokuthi i-MOSFET yokulungiswa okuhambisanayo icishwe kusenesikhathi, i-Schottky diode yangaphandle ingaxhunywa ukuze ihambe ngamasondo mahhala.
7. Okwesibili (okwesibili) lawula imodi eyingxube ye-CCM+DCM
Njengamanje, kunezixazululo ezimbili ezivame ukusetshenziswa zokushaja ngokushesha umakhalekhukhwini:
(1) Ukulawula ohlangothini oluyinhloko (okuyinhloko) kanye nemodi yokusebenza ye-DCM. Uhlangothi lwesibili (olwesibili) ukulungiswa kokuvumelanisa I-MOSFET ayidingi isignali yokuvumelanisa.
(2) Ukulawula kwesibili (kwesibili), imodi yokusebenza exubile ye-CCM+DCM (lapho umthamo ophumayo uncipha, usuka ku-CCM uye ku-DCM). Uhlangothi lwesibili (olwesibili) lokulungiswa kokuvumelanisa kwe-MOSFET luqhutshwa ngokuqondile, futhi imigomo yayo yokuvula nokuvala iboniswa kuMfanekiso 16:
Ivula i-MOSFET yokulungiswa okuvumelanayo: Uma i-voltage ye-VDS yokulungiswa okuvumelanayo ishintsha i-MOSFET isuka kokuphozithiyo iye kwenegethivu, i-diode yayo yangaphakathi ye-parasitic iyavuleka. Ngemva kokulibaziseka okuthile, ukulungisa okuvumelanayo kwe-MOSFET kuyavula.
Ivala ukulungiswa kokuvumelanisa kwe-MOSFET:
① Uma i-voltage ephumayo ingaphansi kwevelu emisiwe, isignali yewashi yokuvumelanisa isetshenziswa ukulawula ukucisha kwe-MOSFET nokusebenza ngemodi ye-CCM.
② Uma i-voltage ephumayo inkulu kunevelu ebekiwe, isignali yewashi yokuvumelanisa ivikelekile futhi indlela yokusebenza iyafana nemodi ye-DCM. Isiginali ye-VDS=-Io*Rdson ilawula ukuvalwa kwe-MOSFET yokulungiswa okuvumelanayo.
Manje, wonke umuntu uyazi ukuthi iyiphi indima edlalwa yi-MOSFET kukho konke ukushaja okusheshayo kwe-QC!
Mayelana no-Olukey
Ithimba eliwumgogodla lika-Olukey seligxile ezingxenyeni ezithile iminyaka engu-20 futhi ikomkhulu lakhe lise-Shenzhen. Ibhizinisi eliyinhloko: MOSFET, MCU, IGBT namanye amadivaysi. Imikhiqizo ye-ejenti eyinhloko yi-WINSOK ne-Cmsemicon. Imikhiqizo isetshenziswa kakhulu embonini yezempi, ukulawulwa kwezimboni, amandla amasha, imikhiqizo yezokwelapha, i-5G, i-inthanethi Yezinto, amakhaya ahlakaniphile, kanye nemikhiqizo ehlukahlukene ye-electronics yabathengi. Ngokuthembela kuzinzuzo ze-ejenti evamile yomhlaba wonke, sisekelwe emakethe yaseShayina. Sisebenzisa izinsiza zethu ezibanzi ezinenzuzo ukwethula izingxenye ze-elekthronikhi ezisezingeni eliphezulu ezithuthukile kumakhasimende ethu, sisize abakhiqizi ekukhiqizeni imikhiqizo yekhwalithi ephezulu futhi banikeze ngamasevisi aphelele.
Isikhathi sokuthumela: Dec-14-2023
