MOSFET mwachidule

Mphamvu MOSFET imagawidwanso mu mphambano mtundu ndi insulated chipata mtundu, koma kawirikawiri makamaka amatanthauza insulated chipata mtundu MOSFET (Metal Oxide Semiconductor FET), amatchedwa mphamvu MOSFET (Mphamvu MOSFET). Transistor yamtundu wamtundu wamagetsi imatchedwa electrostatic induction transistor (Static Induction Transistor - SIT). Amadziwika ndi chipata chamagetsi kuti athe kuwongolera kukhetsa kwapano, kuyendetsa galimoto ndikosavuta, kumafuna mphamvu pang'ono yoyendetsa, kuthamanga kwachangu, kuthamanga kwambiri, kukhazikika kwamatenthedwe kuposaGTR, koma mphamvu yake yamakono ndi yaying'ono, yotsika voteji, nthawi zambiri imagwira ntchito ku mphamvu yosapitirira 10kW yamagetsi amagetsi.

1. Mphamvu ya MOSFET kapangidwe ndi mfundo ntchito

Mitundu yamphamvu ya MOSFET: molingana ndi njira yoyendetsera imatha kugawidwa mu P-channel ndi N-channel. Malinga ndi chipata voteji matalikidwe akhoza kugawidwa mu; mtundu wa kuchepa; pamene chipata voteji ndi ziro pamene kuda-gwero mzati pakati pa kukhalapo kwa kanjira, kumatheka; pa chipangizo cha N (P), voteji pachipata ndi chachikulu kuposa (zochepera) zero pasanakhale njira yoyendetsera, mphamvu ya MOSFET imakulitsidwa makamaka ndi njira ya N.

1.1 MphamvuMOSFETkapangidwe　　

Mphamvu ya MOSFET mkati ndi zizindikiro zamagetsi; conduction ake mmodzi polarity zonyamulira (polys) nawo conductive, ndi transistor unipolar. Makina oyendetsa ndi ofanana ndi MOSFET yamphamvu yotsika, koma kapangidwe kake kali ndi kusiyana kwakukulu, MOSFET yamphamvu yotsika ndi chipangizo cholumikizira chopingasa, mphamvu ya MOSFET yambiri pamapangidwe owongolera, omwe amadziwikanso kuti VMOSFET (Vertical MOSFET) , zomwe zimathandizira kwambiri mphamvu yamagetsi ya MOSFET komanso kuthekera kwanthawi yayitali.

Malinga ndi kusiyana kwa kapangidwe ka conductive, komanso kugawidwa mukugwiritsa ntchito poyambira V-woboola pakati kuti akwaniritse zowongoka za VVMOSFET ndipo ali ndi mawonekedwe owoneka bwino a MOSFET a VDMOSFET (Vertical Double-diffused.MOSFET), pepalali limakambidwa makamaka ngati chitsanzo cha zida za VDMOS.

Ma MOSFET amphamvu amitundu yambiri yophatikizika, monga International Rectifier (International Rectifier) ​​HEXFET pogwiritsa ntchito gawo la hexagonal; Siemens (Siemens) SIPMOSFET pogwiritsa ntchito square unit; Motorola (Motorola) TMOS pogwiritsa ntchito gawo lamakona anayi motengera mawonekedwe a "Pin".

1.2 Mphamvu MOSFET mfundo ya ntchito

Kudula: pakati pa mitengo yotengera kukhetsa komanso magetsi abwino, mitengo yolowera pachipata pakati pa voteji ndi ziro. p base region ndi dera la N drift lomwe linapangidwa pakati pa PN junction J1 reverse bias, palibe kuyenda kwaposachedwa pakati pa mitengo ya drain-source.

Conductivity: Ndi magetsi abwino a UGS omwe amagwiritsidwa ntchito pakati pa malo olowera pachipata, chipatacho chimatsekedwa, kotero palibe chipata chomwe chikuyenda. Komabe, voteji zabwino pachipata kukankhira kutali mabowo mu P-chigawo pansi pake, ndi kukopa oligons-ma elekitironi mu P-chigawo pamwamba pa P-chigawo pansi pa chipata pamene UGS ndi wamkulu kuposa UT (kutembenukira pa voteji kapena pakhomo voteji), ndende ya ma elekitironi padziko P-chigawo pansi pa chipata adzakhala kuposa ndende ya mabowo, kuti P-mtundu semiconductor. kutembenuzidwa kukhala mtundu wa N ndikukhala wosanjikiza wopindika, ndipo wosanjikiza wopindika umapanga njira ya N ndikupanga njira ya PN J1 kutha, kukhetsa ndi gwero loyendetsa.

1.3 Makhalidwe Ofunika a Mphamvu MOSFETs

1.3.1 Makhalidwe Okhazikika.

Ubale pakati pa ID yaposachedwa ndi ma voltage UGS pakati pa gwero lachipata amatchedwa mawonekedwe osinthira a MOSFET, ID ndi yayikulu, ubale pakati pa ID ndi UGS ndi pafupifupi mzere, ndipo otsetsereka kwa ma curve amatanthauzidwa ngati transconductance Gfs. .

Makhalidwe a drain volt-ampere (mawonekedwe otuluka) a MOSFET: chigawo chodulidwa (chogwirizana ndi gawo la GTR); machulukitsidwe dera (logwirizana ndi kukulitsa dera la GTR); chigawo chopanda machulukitsidwe (chogwirizana ndi dera la GTR). Mphamvu ya MOSFET imagwira ntchito posinthira, mwachitsanzo, imasintha mmbuyo ndi mtsogolo pakati pa chigawo chodulidwa ndi chigawo chopanda machulukitsidwe. Mphamvu ya MOSFET imakhala ndi diode ya parasitic pakati pa ma terminals a drain-source, ndipo chipangizocho chimagwira ntchito ngati voteji yakumbuyo ikugwiritsidwa ntchito pakati pa ma terminals a drain-source. Kukana kwapadziko lonse kwa mphamvu ya MOSFET kumakhala ndi kutentha kwabwino, komwe kumakhala koyenera kufananiza zomwe zilipo pomwe zida zilumikizidwa mofananira.

1.3.2 Makhalidwe Amphamvu;

mayendedwe ake oyeserera ndikusintha ma waveforms.

Njira yoyatsira; kuyatsa nthawi yochedwa td (pa) - nthawi yapakati pa mphindi yakutsogolo ndi mphindi yomwe uGS = UT ndi iD zimayamba kuwonekera; nthawi yokwera t- nthawi yomwe uGS imakwera kuchokera ku uT kupita ku magetsi a gate UGSP pomwe MOSFET imalowa m'dera losadzaza; mtengo wokhazikika wa iD umatsimikiziridwa ndi mphamvu yamagetsi ya drainage, UE, ndi drain Ukulu wa UGSP umagwirizana ndi mtengo wokhazikika wa iD. UGS ikafika ku UGSP, imapitilirabe kukwera mpaka itakhazikika, koma iD sinasinthidwe. Kuyatsa nthawi ton-Chiwerengero cha nthawi yochedwa kuyatsa ndi nthawi yokwera.

Nthawi yochedwa td(off) -Nthawi yomwe iD imayamba kutsika mpaka ziro kuyambira nthawi yopita ku ziro, Cin imatulutsidwa kudzera mu Rs ndi RG, ndipo uGS imagwera ku UGSP molingana ndi curve yowonekera.

Nthawi yotsika tf- Nthawi yochokera pamene uGS ikupitilira kutsika kuchokera ku UGSP ndipo iD imatsika mpaka tchanelo chizimiririka ku uGS <UT ndipo ID imatsika mpaka ziro. Turn-off time toff- Chiwerengero cha nthawi yochedwa ndi nthawi ya kugwa.

1.3.3 MOSFET kusintha liwiro.

MOSFET kusintha liwiro ndi Cin kulipiritsa ndi kutulutsa ali ndi ubale waukulu, wosuta sangathe kuchepetsa Cin, koma akhoza kuchepetsa galimoto dera mkati kukana Rs kuchepetsa nthawi zonse, kufulumizitsa kusintha liwiro, MOSFET okha kudalira madutsidwe polytronic, palibe oligotronic yosungirako zotsatira, motero njira yotsekera imakhala yofulumira kwambiri, nthawi yosinthira ya 10-100ns, maulendo ogwiritsira ntchito amatha kufika ku 100kHz kapena zambiri, ndiye wapamwamba kwambiri wa zida zazikulu zamagetsi zamagetsi.

Zipangizo zoyendetsedwa m'munda zimafuna pafupifupi osalowetsapo panthawi yopuma. Komabe, panthawi yosinthira, capacitor yolowera iyenera kulipitsidwa ndikutulutsidwa, yomwe imafunikirabe mphamvu yoyendetsa. Kukwera kwapang'onopang'ono kosinthira, mphamvu yoyendetsa imafunikanso.

1.4 Kuchita bwino kwamphamvu

Kuwonjezera pa chipangizo ntchito kuganizira chipangizo voteji, panopa, pafupipafupi, komanso ayenera kudziwa mu ntchito mmene kuteteza chipangizo, osati kupanga chipangizo mu zosakhalitsa kusintha kuwonongeka. Zoonadi thyristor ndi kuphatikiza kwa ma transistors awiri a bipolar, kuphatikizapo mphamvu yaikulu chifukwa cha dera lalikulu, kotero kuti mphamvu yake ya dv / dt imakhala yovuta kwambiri. Kwa di/dt ilinso ndi vuto lalitali lachigawo cha conduction, kotero imayikanso malire akulu.

Nkhani ya mphamvu MOSFET ndi yosiyana kwambiri. Kuthekera kwake kwa dv/dt ndi di/dt nthawi zambiri kumaganiziridwa malinga ndi kuthekera kwa nanosecond (osati pa microsecond). Koma ngakhale izi, ili ndi zoletsa zogwira ntchito. Izi zitha kumveka molingana ndi kapangidwe kake ka mphamvu ya MOSFET.

Kapangidwe ka mphamvu ya MOSFET ndi dera lofanana nalo. Kuphatikiza pa capacitance pafupifupi mbali iliyonse ya chipangizocho, ziyenera kuganiziridwa kuti MOSFET ili ndi diode yolumikizidwa mofanana. Kuchokera kumbali ina, palinso parasitic transistor. (Monga IGBT imakhalanso ndi thyristor ya parasitic). Izi ndi zinthu zofunika pakuphunzira za machitidwe amphamvu a MOSFET.

Choyamba, diode yamkati yomwe imalumikizidwa ndi kapangidwe ka MOSFET imakhala ndi mphamvu zina. Izi nthawi zambiri zimawonetsedwa potengera kuthekera kwa chigumula chimodzi komanso kuthekera kobwerezabwereza. Reverse di/dt ikakhala yayikulu, diode imayendetsedwa ndi kugunda kwachangu kwambiri, komwe kumatha kulowa m'dera la avalanche ndikuwononga chipangizocho chikadutsa mphamvu yake. Monga momwe zimakhalira ndi diode iliyonse ya PN, kuyang'ana mawonekedwe ake ndizovuta kwambiri. Ndiosiyana kwambiri ndi lingaliro losavuta la mphambano ya PN yomwe ikuyendetsa kutsogolo ndikutchinga kumbuyo. Pamene pano ikutsika mofulumira, diode imataya mphamvu yake yotsekereza kwa nthawi yotchedwa reverse recovery time. palinso nthawi yomwe mgwirizano wa PN umafunika kuti uzichita mofulumira ndipo susonyeza kutsutsa kochepa kwambiri. Mukakhala jekeseni wopita patsogolo mu diode mu mphamvu ya MOSFET, zonyamulira zochepa zomwe zimabayidwa zimawonjezeranso zovuta za MOSFET ngati chipangizo cha multitronic.

Mikhalidwe yocheperako imagwirizana kwambiri ndi mizere ya mzere, ndipo mbali iyi iyenera kuyang'aniridwa mokwanira pakugwiritsa ntchito. Ndikofunika kukhala ndi chidziwitso chozama cha chipangizochi kuti muthe kumvetsetsa ndi kusanthula mavuto omwe akugwirizana nawo.