U-Olukey: Masithethe ngendima ye-MOSFET kuyilo olusisiseko lokutshaja ngokukhawuleza

Isiseko sonikezelo lwamandla ombaneukutshaja ngokukhawulezaI-QC isebenzisa i-flyback + icala lesibini (lesibini) ukulungiswa kwe-synchronous SSR. Kubaguquli be-flyback, ngokwendlela yesampula yempendulo, inokwahlulwa ibe: ummiselo wecala eliphambili (eliphambili) kunye necala lesibini (lesibini) umgaqo; ngokwendawo yomlawuli we-PWM. Inokwahlulwa ibe: kwicala eliphambili (eliphambili) ulawulo kunye necala lesibini (lesibini) ulawulo. Kubonakala ngathi ayinanto yakwenza neMOSFET. Ngoko,OlukeyKufuneka ibuze: Ifihlwe phi iMOSFET? Idlale yiphi indima?

1. Icala eliphambili (eliphambili) ukulungiswa kunye necala lesibini (isibini) ukulungiswa

Ukuzinza kwe-voltage yokuphuma kufuna ikhonkco lempendulo ukuthumela ulwazi lwayo olutshintshileyo kumlawuli oyintloko we-PWM ukulungisa utshintsho kwi-voltage yegalelo kunye nomthwalo wokuphuma. Ngokweendlela ezahlukeneyo zesampulu zeempendulo, inokuhlulwa kwinqanaba eliphambili (eliphambili) ukulungiswa kunye nokulungiswa kwesibini (kwesibini), njengoko kuboniswe kwiMifanekiso 1 kunye ne-2.

Icala lesibini (lesibini) ukulungiswa kwediode

I-SSR yolungiso oluhambelanayo MOSFET ibekwe ezantsi

Umqondiso wengxelo yecala eliphambili (eliphambili) lommiselo awuthathwa ngokuthe ngqo kumbane ophumayo, kodwa usuka kwi-winding encedisayo okanye i-primary primary winding egcina unxulumano oluthile lolungelelwaniso lombane oluphumayo. Iimpawu zayo zezi:

① Indlela yengxelo engathanga ngqo, izinga lolawulo lomthwalo elilambathayo kunye nokungachaneki kakuhle;

②. Ixabiso elilula kwaye eliphantsi;

③. Akukho mfuneko yokuba yedwa optocoupler.

Umqondiso wempendulo kwicala lesibini (okwesibini) umgaqo uthathwa ngokuthe ngqo kwi-voltage yemveliso usebenzisa i-optocoupler kunye ne-TL431. Iimpawu zayo zezi:

① Indlela yengxelo ethe ngqo, isantya esilungileyo solawulo lomthwalo, ireyithi yolawulo lomda, kunye nokuchaneka okuphezulu;

②. Isekethe yohlengahlengiso inzima kwaye iyabiza;

③. Kuyimfuneko ukuhlukanisa i-optocoupler, eneengxaki zokuguga ngexesha.

2. Icala lesibini (lesibini) ukulungiswa kwediode kunyeI-MOSFETulungiso olungqamaniso lweSSR

Icala lesibini (eliyesibini) le-flyback converter ngokuqhelekileyo isebenzisa ukulungiswa kwe-diode ngenxa yemveliso enkulu yangoku yokutshaja ngokukhawuleza. Ngokukodwa ukutshaja ngokuthe ngqo okanye ukutshaja kwe-flash, imveliso yangoku iphezulu njenge-5A. Ukuze kuphuculwe ukusebenza kakuhle, i-MOSFET isetyenziswa endaweni ye-diode njenge-rectifier, ebizwa ngokuba yi-SSR yesibini (yesibini) yokulungiswa kwe-synchronous, njengoko kubonisiwe kwiMifanekiso 3 kunye ne-4.

Icala lesibini (okwesibini) MOSFET ulungiso olungqamaniso

Iimpawu zecala lesibini (lesibini) ukulungiswa kwediode:

①. Elula, akukho mlawuli owongezelelweyo ofunekayo, kwaye ixabiso liphantsi;

② Xa imveliso yangoku inkulu, ukusebenza kakuhle kuphantsi;

③. Ukuthembeka okuphezulu.

Iimpawu zecala lesibini (lesibini) MOSFET uhlengahlengiso oluhambelanayo:

①. I-Complex, ifuna isilawuli esongezelelweyo sokuqhuba kunye neendleko eziphezulu;

②. Xa imveliso yangoku inkulu, ukusebenza kakuhle kuphezulu;

③. Xa kuthelekiswa neediode, ukuthembeka kwabo kuphantsi.

Kwizicelo ezisebenzayo, i-MOSFET ye-SSR yokulungiswa kwe-synchronous idla ngokususwa ukusuka kwinqanaba eliphezulu ukuya kwisiphelo esisezantsi ukuze kube lula ukuqhuba, njengoko kubonisiwe kuMfanekiso 5.

Iimpawu ze-MOSFET ephezulu ye-SSR yokulungiswa kwe-synchronous:

①. Ifuna i-bootstrap drive okanye idrayivu edadayo, enexabiso elikhulu;

②. I-EMI entle.

Iimpawu zokulungiswa okuhambelanayo kwe-SSR MOSFET ebekwe kwisiphelo esisezantsi:

① Ukuqhuba ngokuthe ngqo, ukuqhuba okulula kunye neendleko eziphantsi;

②. I-EMI embi.

3. Ulawulo oluphambili (oluphambili) kunye nolawulo lwesibini (olwesibini).

Umlawuli oyintloko we-PWM ubekwe kwicala eliphambili (eliphambili). Olu lwakhiwo lubizwa ngokuba licala eliphambili (eliphambili) ulawulo. Ukuze kuphuculwe ukuchaneka kwe-voltage ephumayo, izinga lokulawula umthwalo, kunye nezinga lokulawula umgca, icala eliphambili (eliphambili) lifuna i-optocoupler yangaphandle kunye ne-TL431 ukwenza ikhonkco lempendulo. I-bandwidth yenkqubo incinci kwaye isantya sokuphendula sicotha.

Ukuba umlawuli oyintloko we-PWM ubekwe kwicala lesibini (okwesibini), i-optocoupler kunye ne-TL431 inokususwa, kwaye i-voltage ephumayo inokulawulwa ngokuthe ngqo kwaye ilungiswe ngokuphendula ngokukhawuleza. Olu lwakhiwo lubizwa ngokuba lulawulo lwesibini (lwesibini).

Iimpawu zecala eliphambili (eliphambili) lolawulo:

①. I-Optocoupler kunye ne-TL431 ziyafuneka, kwaye isantya sokuphendula sicotha;

②. Isantya sokhuseleko lwemveliso sicotha.

③. Kwimo eqhubekayo yokulungiswa kwe-CCM, icala lesibini (lesibini) lifuna isignali yongqamaniso.

Iimpawu zolawulo lwesibini (olwesibini):

①. Imveliso ifunyenwe ngokuthe ngqo, akukho optocoupler kunye ne-TL431 efunekayo, isantya sokuphendula sikhawuleza, kwaye isantya sokukhusela isiphumo sikhawuleza;

②. Icala lesibini (lesibini) lokulungiswa okuhambelanayo I-MOSFET iqhutywa ngokuthe ngqo ngaphandle kwesidingo semiqondiso yongqamaniso; izixhobo ezongezelelweyo ezifana ne-pulse transformers, i-magnetic couplings okanye i-capacitive couplers iyadingeka ukuhambisa iimpawu zokuqhuba zecala eliphambili (eliphambili) le-MOSFET ephezulu.

③. Icala eliphambili (eliphambili) lifuna isiphaluka sokuqala, okanye icala lesibini (eli lesibini) linombane oncedisayo wokuqalisa.

4. Imowudi eqhubekayo ye-CCM okanye imo ye-DCM engapheliyo

Umguquleli we-flyback unokusebenza kwimowudi eqhubekayo ye-CCM okanye imo ye-DCM engapheliyo. Ukuba i-current in the second (yesibini) i-winding ifikelela kwi-0 ekupheleni komjikelo wokutshintsha, ibizwa ngokuba yi-discontinuous DCM mode. Ukuba i-current ye-second (yesibini) i-winding ayikho i-0 ekupheleni komjikelezo wokutshintsha, ibizwa ngokuba yimodi ye-CCM eqhubekayo, njengoko kuboniswe kwiMifanekiso 8 kunye ne-9.

Ingabonwa kwi-Figure 8 kunye ne-9 ukuba amazwe asebenzayo e-SSR yokulungiswa kwe-synchronous ahluke kwiindlela ezahlukeneyo zokusebenza ze-flyback converter, oko kuthetha ukuba iindlela zokulawula ukuvumelanisa ukuvumelanisa kwe-SSR nazo ziya kuhluka.

Ukuba ixesha elifileyo alihoywa, xa usebenza kwimowudi ye-CCM eqhubekayo, ukulungiswa kwe-synchronous SSR inamazwe amabini:

①. Icala eliphambili (eliphambili) elinevoltage ephezulu ye-MOSFET livuliwe, kwaye icala lesibini (lesibini) lolungiso oluhambelanayo lwe-MOSFET lucinyiwe;

②. Icala eliphambili (eliphambili) elinombane ophezulu we-MOSFET licinyiwe, kwaye icala lesibini (lesibini) lolungiso oluhambelanayo lwe-MOSFET luvuliwe.

Ngokufanayo, ukuba ixesha elifileyo alihoywa, i-SSR yokulungiswa kwe-synchronous inamazwe amathathu xa isebenza kwimo ye-DCM engapheliyo:

①. Icala eliphambili (eliphambili) elinevoltage ephezulu ye-MOSFET livuliwe, kwaye icala lesibini (lesibini) lolungiso oluhambelanayo lwe-MOSFET lucinyiwe;

②. Icala eliphambili (eliphambili) elinombane ophezulu we-MOSFET licinyiwe, kwaye icala lesibini (lesibini) lolungiso oluhambelanayo lwe-MOSFET luvuliwe;

③. Icala eliphambili (eliphambili) elinombane ophezulu we-MOSFET licinyiwe, kwaye icala lesibini (lesibini) lolungiso oluhambelanayo lwe-MOSFET lucinyiwe.

5. Icala lesibini (lesibini) lokulungiswa kwe-synchronous SSR kwimo ye-CCM eqhubekayo

Ukuba isiguquli se-flyback esikhawulezayo sisebenza kwimowudi eqhubekayo ye-CCM, indlela yokulawula yecala eliphambili (ephambili), i-second side (yesibini) i-synchronous rectification MOSFET ifuna isignali yongqamaniso ukusuka kwicala eliphambili (eliphambili) ukulawula ukuvalwa.

Ezi ndlela zimbini zilandelayo zidla ngokusetyenziswa ukufumana isiginali ye-synchronous drive yecala lesibini (lesibini):

(1) Sebenzisa ngokuthe ngqo i-second (yesibini) i-winding, njengoko kuboniswe kuMzobo 10;

(2) Sebenzisa izinto ezongezelelweyo zokuzihlukanisa ezifana ne-pulse transformers ukuhambisa isignali ye-synchronous drive ukusuka kwicala eliphambili (eliyiprayimari) ukuya kwicala lesibini (lesibini), njengoko kuboniswe kuMfanekiso 12.

Ngokuthe ngqo usebenzisa i-second (yesibini) i-winding ukufumana isignali ye-synchronous drive, ukuchaneka kwesiginali ye-synchronous drive kunzima kakhulu ukuyilawula, kwaye kunzima ukufezekisa ukusebenza kakuhle kunye nokuthembeka. Ezinye iinkampani zide zisebenzise abalawuli bedijithali ukuphucula ukuchaneka kokulawula, njengoko kuboniswe kwi-Figure 11 Bonisa.

Ukusebenzisa i-pulse transformer ukufumana iimpawu zokuqhuba i-synchronous kunokuchaneka okuphezulu, kodwa ixabiso liphezulu kakhulu.

Indlela yokulawula yecala lesibini (yesibini) ngokuqhelekileyo isebenzisa i-pulse transformer okanye indlela yokudibanisa magnetic ukuhambisa isignali ye-synchronous drive ukusuka kwicala lesibini (isibini) ukuya kwicala eliphambili (eliphambili), njengoko kuboniswe kuMfanekiso 7.v

Sebenzisa ngokuthe ngqo i-second (yesibini) ukujikajika ukufumana isiginali ye-synchronous drive

Sebenzisa ngokuthe ngqo i-second (yesibini) ukujikajika ukufumana isignali ye-synchronous drive + ulawulo lwedijithali

6. Icala lesibini (okwesibini) ukulungiswa kwe-synchronous SSR kwimo ye-DCM engapheliyo

Ukuba intlawulo ekhawulezayo yokuguqula i-flyback isebenza kwimo ye-DCM engaqhubekiyo. Nokuba yeyiphi na indlela yolawulo yecala eliphambili (eliphambili) okanye indlela yolawulo yecandelo lesibini (lesibini), i-D kunye ne-S voltage drops ye-synchronous rectification MOSFET inokubonwa kwaye ilawulwe ngokuthe ngqo.

(1) Ukuvula i-MOSFET yolungiso oluhambelanayo

Xa i-voltage ye-VDS yohlengahlengiso oluhambelanayo lwe-MOSFET lutshintsha ukusuka kokulungileyo ukuya kokubi, idiode yeparasitic yangaphakathi iyavula, kwaye emva kokulibaziseka okuthile, uhlengahlengiso oluhambelanayo lwe-MOSFET luyavula, njengoko kubonisiwe kuMfanekiso 13.

(2) Ukucima ulungelelwaniso lwe-MOSFET

Emva kokuba ulungelelwaniso lolungiso lwe-MOSFET luvuliwe, VDS=-Io*Rdson. Xa umbane wesibini (okwesibini) ojikajikayo wehla ukuya ku-0, oko kukuthi, xa i-voltage ye-VDS yophawu lwangoku itshintsha ukusuka kwi-negative ukuya ku-0, uhlengahlengiso oluhambelanayo lwe-MOSFET luyacima, njengoko kubonisiwe kuMfanekiso 13.

Ukuvula kunye nokucima ukulungiswa okuhambelanayo kwe-MOSFET kwimowudi ye-DCM engaqhubekiyo

Kwizicelo ezisebenzayo, uhlengahlengiso oluyi-synchronous MOSFET luyacima phambi kokuba umsinga ojikajikayo wesibini (owesibini) ufikelele ku-0 (VDS=0). Amaxabiso ombane wesalathiso akhoyo ngoku abekwe ziichips ezahlukeneyo ahlukile, njenge -20mV, -50mV, -100mV, -200mV, njl.

I-voltage yesalathiso yangoku yenkqubo ilungisiwe. Ixabiso elikhulu elipheleleyo le-voltage yesalathiso yangoku, encinci impazamo yokuphazamiseka kunye nokuchaneka okungcono. Nangona kunjalo, xa umthwalo wemveliso yangoku i-Io iyancipha, ukulungiswa kwe-synchronous MOSFET kuya kucinywa kwisiphumo esikhulu sangoku, kwaye i-diode yayo yangaphakathi ye-parasitic iya kuqhuba ixesha elide, ngoko ke ukusebenza kuyancipha, njengoko kubonisiwe kuMfanekiso 14.

Ivoltheji yereferensi yokuva yangoku kunye nokulungiswa okuhambelanayo kwexesha lokucinywa kweMOSFET

Ukongeza, ukuba ixabiso elipheleleyo le-voltage yesalathiso yangoku lincinci kakhulu. Iimpazamo zenkqubo kunye nokuphazamiseka kunokubangela uhlengahlengiso oluhambelanayo lwe-MOSFET lucime emva kokuba umsinga womoya wesibini (wesibini) ugqithise ku-0, okukhokelela ekungeneni okubuyela umva kwangoku, okuchaphazela ukusebenza kakuhle kunye nokuthembeka kwenkqubo.

Izibonakaliso ezichanekileyo ezichanekileyo zangoku zinokuphucula ukusebenza kakuhle kunye nokuthembeka kwenkqubo, kodwa iindleko zesixhobo ziya kwanda. Ukuchaneka kophawu lwangoku lokubona lunxulumene nezi zinto zilandelayo:
①. Ukuchaneka kunye nokukhukuliseka kweqondo lokushisa lombane wesalathiso wangoku;
②. I-voltage ye-bias kunye ne-offset voltage, i-bias yangoku kunye ne-offset yangoku, kunye nokunyuka kweqondo lokushisa kwe-amplifier yangoku;
③. Ukuchaneka kunye nokukhukuliseka kweqondo lobushushu kwi-on-voltage Rdson ye-synchronous rectification MOSFET.

Ukongeza, ngokwembono yenkqubo, inokuphuculwa ngolawulo lwedijithali, ukutshintsha ivolthi yesalathiso yangoku, kunye nokutshintsha uhlengahlengiso oluhambelanayo lombane wokuqhuba weMOSFET.

Xa umthwalo wemveliso yangoku i-Io iyancipha, ukuba i-voltage yokuqhuba yamandla e-MOSFET iyancipha, i-voltage ye-MOSFET yokuvula i-Rdson iyanda. Njengoko kuboniswe kwi-Figure 15, kunokwenzeka ukuba ugweme ukuvalwa kwangaphambili kwe-synchronous rectification MOSFET, ukunciphisa ixesha lokuqhuba i-parasitic diode, kunye nokuphucula ukusebenza kakuhle kwenkqubo.

Ukunciphisa amandla ombane okuqhuba iVGS kunye nokucima uhlengahlengiso oluhambelanayo lweMOSFET

Inokubonwa kwi-Figure 14 ukuba xa umthamo wemveliso yangoku i-Io iyancipha, i-voltage ye-reference reference yangoku iyancipha. Ngale ndlela, xa imveliso yangoku i-Io inkulu, i-voltage ephezulu yokukhangela i-reference isetyenziselwa ukuphucula ukuchaneka kolawulo; xa imveliso yangoku i-Io iphantsi, i-voltage yereferensi yokufumanisa esezantsi isetyenziswa. Inokuphucula ixesha lokuqhuba le-MOSFET yokulungiswa okuhambelanayo kunye nokuphucula ukusebenza kakuhle kwenkqubo.

Xa le ndlela ingasentla ingasetyenziselwa ukuphuculwa, i-Schottky diode inokudityaniswa ngokunxuseneyo kuzo zombini iziphelo ze-synchronous rectification MOSFET. Emva kokuba ulungelelwaniso lolungiso lwe-MOSFET lucinywe kwangaphambili, i-diode ye-Schottky yangaphandle inokudityaniswa kwi-freewheeling.

7. Ulawulo lwesibini (olwesibini) lwe-CCM+DCM hybrid mode

Okwangoku, kukho izisombululo ezibini eziqhelekileyo ezisetyenziswayo zokutshaja ngokukhawuleza kwefowuni:

(1) Icala eliphambili (eliphambili) ulawulo kunye nemodi yokusebenza ye-DCM. Icala lesibini (lesibini) uhlengahlengiso olungqameneyo I-MOSFET ayifuni mqondiso wongqamaniso.

(2) Ulawulo lweSekondari (olwesibini), i-CCM+DCM exutywe imo yokusebenza (xa umthamo wemveliso uyancipha, ukusuka kwi-CCM ukuya kwi-DCM). Icala lesibini (lesibini) lolungiso oluhambelanayo I-MOSFET iqhutywa ngokuthe ngqo, kwaye imigaqo yayo yokuvula kunye nokucinywa kwayo iboniswe kuMfanekiso 16:

Ukuvula uhlengahlengiso lwe-synchronous MOSFET: Xa amandla ombane e-VDS yolungiso oluyi-synchronous i-MOSFET itshintsha ukusuka ku-positive ukuya kwe-negative, i-diode yayo yangaphakathi ye-parasitic iyavula. Emva kokulibaziseka okuthile, ulungelelwaniso lolungiso lwe-MOSFET luyavula.

Ukucima ulungelelwaniso lwe-MOSFET:

① Xa i-voltage ephumayo ingaphantsi kwexabiso elibekiweyo, isignali yewotshi ye-synchronous isetyenziselwa ukulawula ukucinywa kwe-MOSFET kunye nokusebenza kwimowudi ye-CCM.

② Xa i-voltage ephumayo inkulu kunexabiso elimiselweyo, isignali yewashi ye-synchronous ikhuselwe kwaye indlela yokusebenza iyafana nemodi ye-DCM. Isiginali ye-VDS=-Io*Rdson ilawula ukuvalwa kohlengahlengiso lwe-MOSFET.

Icala lesibini (eliyesibini) lilawula uhlengahlengiso oluhambelanayo nokucima i-MOSFET

Ngoku, wonke umntu uyayazi indima edlalwa yiMOSFET kuyo yonke i-QC yokutshaja ngokukhawuleza!

Malunga no Olukey

Iqela eliphambili lika-Olukey ligxile kumacandelo iminyaka engama-20 kwaye likomkhulu eShenzhen. ishishini Main: MOSFET, MCU, IGBT kunye nezinye izixhobo. Iimveliso ze-arhente eziphambili ziyi-WINSOK kunye ne-Cmsemicon. Iimveliso zisetyenziswa kakhulu kushishino lomkhosi, ulawulo lwamashishini, amandla amatsha, iimveliso zonyango, i-5G, i-Intanethi yeZinto, amakhaya ahlakaniphileyo, kunye neemveliso ezahlukeneyo zombane zabathengi. Ukuxhomekeka kwiinzuzo ze-arhente yehlabathi jikelele yokuqala, sisekelwe kwimarike yaseTshayina. Sisebenzisa iinkonzo zethu ezibanzi ezinenzuzo ukwazisa amacandelo ahlukeneyo obuchwepheshe obuphezulu be-elektroniki kubathengi bethu, sincedisa abavelisi ekuveliseni iimveliso ezikumgangatho ophezulu kunye nokubonelela ngeenkonzo ezibanzi.