MOSFET amagqabantshintshi

I-MOSFET yamandla ikwahlulwe ngohlobo lwesiphambuka kunye nohlobo lwesango olugqunyiweyo, kodwa idla ngokubhekisa kuhlobo lwesango eligqunyiweyo iMOSFET (i-Metal Oxide Semiconductor FET), ekubhekiselwa kuyo njengamandla eMOSFET (Amandla eMOSFET). Umdibaniso wohlobo lwamandla entsimi yempembelelo transistor ngokuqhelekileyo ibizwa ngokuba yi-electrostatic induction transistor (Static Induction Transistor - SIT). Ibonakaliswe ngamandla ombane wesango ukulawula i-drain yangoku, isekethe yedrayivu ilula, ifuna amandla amancinci okuqhuba, isantya sokutshintsha ngokukhawuleza, isantya esiphezulu sokusebenza, ukuzinza kwe-thermal kungcono kunoGTR, kodwa umthamo wayo wangoku uncinci, umbane ophantsi, usebenza kuphela kumandla angekho ngaphezu kwe-10kW yezixhobo zombane zombane.

1. Ubume be-MOSFET yamandla kunye nomgaqo wokusebenza

Iintlobo ze-MOSFET zamandla: ngokungqinelana nejelo lokuqhuba linokwahlulwa libe yi-P-channel kunye ne-N-channel. Ngokwe-voltage yesango amplitude inokwahlulwa ibe; uhlobo lokuncipha; xa i-voltage yesango ingu-zero xa i-drain-source pole phakathi kobukho bomjelo wokuqhuba, iphuculwe; kwisixhobo setshaneli ye-N (P), amandla ombane esango mkhulu kuno (ngaphantsi) kunoziro phambi kobukho betshaneli yokuqhuba, amandla e-MOSFET omelezwa ubukhulu becala i-N-channel.

1.1 AmandlaI-MOSFETisakhiwo　　

Isakhiwo sangaphakathi seMOSFET samandla kunye neempawu zombane; conduction yayo kuphela abathwali polarity (polys) inxaxheba conductive, i transistor unipolar. Indlela yokuqhuba iyafana ne-MOSFET enamandla aphantsi, kodwa ubume bunomohluko omkhulu, i-MOSFET yamandla aphantsi sisixhobo sokuqhuba esithe tye, amandla e-MOSFET uninzi lwesakhiwo esithe nkqo sokuqhuba, esikwabizwa ngokuba yiVMOSFET (Vertical MOSFET) , ephucula kakhulu amandla ombane wesixhobo se-MOSFET kunye nokukwazi ukumelana nokumelana.

Ngokomahluko kulwakhiwo oluthe nkqo lwe-conductive, kodwa ikwahlulwe kusetyenziso lwe-V-shaped groove ukuphumeza ukuhanjiswa okuthe nkqo kwe-VVMOSFET kwaye inolwakhiwo oluthe nkqo lwe-MOSFET oluphindwe kabini lwe-VDMOSFET (i-Vertical Double-diffused.I-MOSFET), eli phepha lixoxwa ikakhulu njengomzekelo wezixhobo zeVDMOS.

Ii-MOSFET zamandla kwizakhiwo ezininzi ezidityanisiweyo, ezifana ne-International Rectifier (I-International Rectifier) ​​i-HEXFET isebenzisa iyunithi ene-hexagonal; Siemens (Siemens) SIPMOSFET usebenzisa iyunithi yesikwere; I-Motorola (Motorola) TMOS isebenzisa iyunithi yoxande ngolungiselelo lwemilo ye-"Pin".

1.2 Amandla omgaqo weMOSFET wokusebenza

Ukusikwa: phakathi kweepali zomthombo wedreyini kunye nonikezelo lwamandla olulungileyo, iipali zomthombo wesango phakathi kombane nguziro. isiseko sommandla we-p kunye nommandla we-N drift owenziwe phakathi kwe-PN junction J1 reverse bias, akukho msinga wangoku phakathi kweepali zomthombo wokuhambisa amanzi.

I-Conductivity: Nge-voltage encomekayo ye-UGS esetyenzisiweyo phakathi kweetheminali zomthombo wesango, isango lifakwe i-insulated, ngoko akukho masango ahamba ngoku. Nangona kunjalo, amandla ombane afanelekileyo esango aya kutyhala imingxuma kwi-P-region engaphantsi kwayo, kwaye itsale ii-oligons-electrons kwi-P-region ukuya kumphezulu we-P-region ngaphantsi kwesango xa i-UGS inkulu kune-P. I-UT (i-voltage yokuvula i-voltage okanye i-threshold voltage), ukuxinwa kwee-electron phezu kwendawo ye-P phantsi kwesango kuya kuba ngaphezu koxinzelelo lwemingxuma, ukwenzela ukuba i-P-type semiconductor iguqulwe ibe yi-N-type kwaye ibe yi-inverted layer, kwaye i-inverted layer yenza i-N-channel kwaye yenza i-PN junction J1 ilahleke, i-drain kunye ne-source conductive.

1.3 Iimpawu eziSisiseko zeeMOSFET zaMandla

1.3.1 IiMpawu eziZimileyo.

Ubudlelwane phakathi kwe-ID yangoku kunye ne-UGS yombane phakathi komthombo wesango ibizwa ngokuba luphawu lokudluliselwa kwe-MOSFET, i-ID inkulu, ubudlelwane phakathi kwe-ID kunye ne-UGS buphantse bube ngumgca, kwaye ithambeka lejiko lichazwa njenge-Gfs edlulayo. .

Iimpawu ze-drain volt-ampere (iimpawu zemveliso) ze-MOSFET: ummandla we-cutoff (ohambelana nommandla osikiweyo we-GTR); ummandla wokwandisa (ohambelana nommandla wokwandisa we-GTR); ummandla ongahlaliyo (ohambelana nommandla wokugcwalisa we-GTR). Amandla e-MOSFET asebenza kwisimo sokutshintsha, oko kukuthi, atshintshela emva naphambili phakathi kommandla osikiweyo kunye nommandla ongeyo-saturation. I-MOSFET yamandla ine-parasitic diode phakathi kweetheminali ze-drain-source, kwaye isixhobo siqhuba xa i-voltage ebuyela umva isetyenziswa phakathi kweetheminali ze-drain-source. Ukuxhathisa kwi-state yamandla e-MOSFET ine-coefficient yeqondo lokushisa elihle, elilungele ukulinganisa okwangoku xa izixhobo zidibaniswe ngokufanayo.

1.3.2 Ukubonakaliswa kweempawu eziguqukayo;

isiphaluka sayo sovavanyo kunye nokutshintsha inkqubo yamaza.

Inkqubo yokuvula; vula ixesha lokulibaziseka td (on) - ixesha lexesha phakathi kwexesha lokuhamba phambili kunye nomzuzu apho uGS = UT kunye ne-iD iqala ukubonakala; ixesha lokunyuka kwe-ixesha apho i-uGS iphakama ukusuka e-UT ukuya kwi-voltage yesango i-UGSP apho i-MOSFET ingena kummandla ongagxiliyo; Ixabiso lemeko ezinzileyo ye-ID limiselwa ngamandla ombane okuhambisa amanzi, i-UE, kunye ne-drain Ubukhulu be-UGSP bunxulumene nexabiso lemeko ezinzileyo ye-ID. Emva kokuba i-UGS ifikelele kwi-UGSP, iyaqhubeka nokunyuka phantsi kwesenzo sokunyuka ide ifike kwindawo ezinzileyo, kodwa i-iD ayitshintshanga. Ixesha lokuvula itoni-Isixa sexesha lokulibaziseka lokuvula kunye nexesha lokunyuka.

Ixesha lokulibaziseka lokuvala td(off) -Ixesha apho i-ID iqala ukuhla ukuya kwiqanda ukusuka kwixesha ukuya phezulu ukuya kwi-zero, i-Cin ikhutshwa nge-Rs kunye ne-RG, kwaye i-uGS iwela kwi-UGSP ngokwegophe elichazayo.

Ixesha lokuwa tf- Ixesha lexesha ukusuka xa i-uGS iqhubeka nokuwa kwi-UGSP kunye ne-iD iyancipha de ishaneli inyamalale e-uGS <UT kunye ne-ID ewela kwi-zero. I-turn-off time toff- Isimbuku sexesha lokulibaziseka kunye nexesha lokuwa.

1.3.3 Isantya sokutshintsha kweMOSFET.

Isantya sokutshintsha kwe-MOSFET kunye nokutshaja kwe-Cin kunye nokukhutshwa kunobudlelwane obukhulu, umsebenzisi akanako ukunciphisa i-Cin, kodwa unokunciphisa ukunyanzeliswa kwesekethe yangaphakathi yokuqhuba i-Rs ukunciphisa ixesha elingaguqukiyo, ukukhawulezisa isantya sokutshintsha, i-MOSFET ixhomekeke kuphela kwi-polytronic conductivity, akukho siphumo sokugcina i-oligotronic, kwaye ke inkqubo yokuvala ikhawuleza kakhulu, ixesha lokutshintsha le-10-100ns, i-frequency yokusebenza inokufikelela kwi-100kHz okanye ngaphezulu, yeyona iphezulu izixhobo zombane zamandla aphambili.

Izixhobo ezilawulwa yintsimi zifuna phantse akukho galelo langoku ekuphumleni. Nangona kunjalo, ngexesha lenkqubo yokutshintsha, i-input capacitor kufuneka ihlawuliswe kwaye ikhutshwe, esafuna umlinganiselo othile wamandla okuqhuba. Ukuphakama kwe-frequency switching, amandla amakhulu okuqhuba afunekayo.

1.4 Ukuphuculwa kwentsebenzo emandla

Ukongeza kwisicelo sesixhobo ukuqwalasela amandla ombane wesixhobo, okwangoku, amaza, kodwa kufuneka ube yincutshe ekusetyenzisweni kwendlela yokukhusela isixhobo, hayi ukwenza isixhobo kutshintsho lwethutyana kumonakalo. Ngokuqinisekileyo i-thyristor yindibaniselwano yee-bipolar transistors ezimbini, ezidityaniswa ne-capacitance enkulu ngenxa yendawo enkulu, ngoko ke amandla ayo e-dv/dt asengozini ngakumbi. Kwi-di/dt ikwanengxaki eyandisiweyo yommandla wokuqhuba, ngoko ke ikwabeka imida engqongqo.

Imeko ye-MOSFET yamandla yahluke kakhulu. I-dv/dt yayo kunye ne-di/dt isakhono isoloko iqikelelwa ngokwesakhono nge-nanosecond (kunokuba nge-microsecond nganye). Kodwa ngaphandle koku, inemida yokusebenza eguqukayo. Oku kunokuqondwa ngokwesiseko sesiseko se-MOSFET yamandla.

Ubume be-MOSFET yamandla kunye nesekethe ehambelana nayo. Ukongeza kwi-capacitance phantse yonke indawo yesixhobo, kufuneka kuthathelwe ingqalelo ukuba i-MOSFET ine-diode edibeneyo ngokufana. Ukusuka kwindawo ethile yokujonga, kukho kwakhona i-transistor ye-parasitic. (Kanye njengokuba i-IGBT nayo ine-thyristor ye-parasitic). Ezi zizinto ezibalulekileyo kuphononongo lokuziphatha okuguquguqukayo kwee-MOSFETs.

Okokuqala kuzo zonke i-intrinsic diode encanyathiselwe kulwakhiwo lwe-MOSFET inekhono elithile le-avalanche. Oku kuvamise ukubonakaliswa ngokwesakhono esinye se-avalanche kunye nokubanakho ukuphinda-phindwa kwe-avalanche. Xa i-reverse di/dt inkulu, i-diode iphantsi kwe-pulse spike ekhawuleza kakhulu, enokuthi ingene kummandla we-avalanche kwaye inokuba nokonakalisa isixhobo xa isakhono saso se-avalanche sigqithile. Njengayo nayiphi na i-PN junction diode, ukuphonononga iimpawu zayo eziguqukayo kunzima kakhulu. Zihluke kakhulu kwingcamango elula ye-PN junction eqhuba kwicala eliya phambili kunye nokuthintela kwicala elingasemva. Xa ikhoyo ngoku ihla ngokukhawuleza, i-diode ilahlekelwa amandla ayo okuthintela umva kwixesha elithile elibizwa ngokuba lixesha lokubuyisela umva. kukho kwakhona ixesha apho i-PN junction ifuneka ukuba iqhube ngokukhawuleza kwaye ayibonisi ukuchasana okuphantsi kakhulu. Nje ukuba kubekho inaliti eya phambili kwi-diode kumandla e-MOSFET, abathwali abambalwa abatofwayo nabo bongeza kubunzima be-MOSFET njengesixhobo se-multitronic.

Iimeko ezidlulayo zihambelana ngokusondeleyo neemeko zomgca, kwaye lo mba kufuneka unikwe ingqwalasela eyaneleyo kwisicelo. Kubalulekile ukuba nolwazi olunzulu lwesixhobo ukwenzela ukuba kube lula ukuqonda kunye nohlalutyo lweengxaki ezihambelanayo.