Pali mitundu yambiri yaZithunzi za MOSFET, makamaka ogawidwa m'magulu a MOSFET ndi ma MOSFET otsekera zipata magulu awiri, ndipo onse ali ndi malo a N-channel ndi P-channel.
Metal-Oxide-Semiconductor Field-Effect Transistor, yomwe imatchedwa MOSFET, imagawidwa mumtundu wa MOSFET wochepetsera ndi mtundu wowonjezera wa MOSFET.
Ma MOSFET nawonso amagawidwa kukhala machubu a chipata chimodzi ndi zipata ziwiri. MOSFET yokhala ndi zipata ziwiri ili ndi zipata ziwiri zodziyimira pawokha za G1 ndi G2, kuchokera pakumanga kofanana ndi ma MOSFET a chipata chimodzi cholumikizidwa motsatizana, ndikusintha kwake komwe kukuchitika ndi magetsi a zipata ziwiri. Maonekedwe a ma MOSFET a zipata zapawiri amabweretsa kumasuka kwambiri akagwiritsidwa ntchito ngati ma amplifiers apamwamba kwambiri, kupeza ma amplifiers owongolera, osakaniza ndi ma demodulators.
1, MOSFETmtundu ndi kapangidwe
MOSFET ndi mtundu wa FET (mtundu wina ndi JFET), ukhoza kupangidwa kukhala mtundu wowongoleredwa kapena wocheperako, P-channel kapena N-channel mitundu inayi, koma kugwiritsa ntchito mwachidziwitso kwa MOSFET ya N-channel yokhayo komanso P- njira MOSFET, yomwe nthawi zambiri imatchedwa NMOS, kapena PMOS imatanthawuza mitundu iwiriyi. Ponena za chifukwa chiyani osagwiritsa ntchito ma MOSFET amtundu wa depletion, musalimbikitse kusaka komwe kumayambitsa. Pankhani ya ma MOSFET awiriwa, omwe amagwiritsidwa ntchito kwambiri ndi NMOS, chifukwa chake ndikuti kukana ndikochepa, komanso kosavuta kupanga. Chifukwa chake kusintha magetsi ndi ma drive drive application, nthawi zambiri amagwiritsa ntchito NMOS. mawu otsatirawa, komanso zambiri za NMOS. zikhomo zitatu za MOSFET parasitic capacitance alipo pakati pa zikhomo zitatu, zomwe si zosowa zathu, koma chifukwa cha zoletsa kupanga ndondomeko. Kukhalapo kwa parasitic capacitance pakupanga kapena kusankhidwa kwa dera loyendetsa galimoto kuti mupulumutse nthawi, koma palibe njira yopewera, ndiyeno mwatsatanetsatane mawu oyamba. Mu chithunzi cha MOSFET chojambula chikhoza kuwoneka, kukhetsa ndi gwero pakati pa diode ya parasitic. Izi zimatchedwa diode ya thupi, poyendetsa katundu womveka, diode iyi ndi yofunika kwambiri. Mwa njira, diode ya thupi imangopezeka mu MOSFET imodzi, nthawi zambiri osati mkati mwa chipangizo chophatikizika.
2, mawonekedwe a MOSFET
Kufunika kwa conduction kuli ngati kusinthana, kofanana ndi kutsekedwa kwa switch.NMOS, Vgs zazikulu kuposa mtengo wina womwe ungachite, woyenera kugwiritsidwa ntchito ngati gwero lakhazikika (galimoto yotsika), magetsi okhawo amafika pa 4V kapena 10V.PMOS makhalidwe, Vgs zosakwana mtengo wina adzachita, oyenera kugwiritsidwa ntchito pamene gwero chikugwirizana ndi VCC (high-end drive).
Komabe, ndithudi, PMOS ikhoza kukhala yosavuta kugwiritsa ntchito ngati dalaivala wapamwamba, koma chifukwa cha kukana, kutsika mtengo, mitundu yochepa ya kusinthanitsa ndi zifukwa zina, mu dalaivala wapamwamba, nthawi zambiri amagwiritsa ntchito NMOS.
3, MOSFETkusintha kusintha
Kaya ndi NMOS kapena PMOS, pambuyo pa kutsutsa kulipo, kotero kuti zamakono ziwononge mphamvu mu kukana uku, gawo ili la mphamvu zomwe zimagwiritsidwa ntchito zimatchedwa kutayika kwa kukana. Kusankha MOSFET yokhala ndi kukana pang'ono kudzachepetsa kutayika kwa kukana. MOSFET yamphamvu yotsika pa-kukana nthawi zambiri imakhala mu makumi a milliohms, ma miliohm angapo pamenepo. MOS mu nthawi ndi kudulidwa, sayenera kukhala mu nthawi yomweyo kumaliza voteji kudutsa MOS pali ndondomeko kugwa, panopa ikuyenda mwa njira kukwera, panthawiyi, imfa ya MOSFET ndi. mankhwala a voteji ndi panopa amatchedwa switching loss. Kawirikawiri kutayika kwa kusintha kumakhala kwakukulu kwambiri kuposa kutayika kwa conduction, ndipo mofulumira kusintha kwafupipafupi, kutayika kwakukulu. Chogulitsa chachikulu cha voltage ndi chapano panthawi ya conduction chimapangitsa kutayika kwakukulu. Kufupikitsa nthawi yosinthira kumachepetsa kutayika pamayendedwe aliwonse; kuchepetsa kusintha kwafupipafupi kumachepetsa chiwerengero cha masinthidwe pa nthawi ya unit. Njira zonse ziwiri zimatha kuchepetsa kutayika kwa kusintha.
4, MOSFET pagalimoto
Poyerekeza ndi ma transistors a bipolar, nthawi zambiri amaganiziridwa kuti palibe chomwe chikufunika kuti chipangitse MOSFET, kokha kuti magetsi a GS ali pamwamba pa mtengo wina. Izi ndizosavuta kuchita, komabe, timafunikiranso liwiro. Mu dongosolo la MOSFET mukhoza kuona kuti pali parasitic capacitance pakati GS, GD, ndi kuyendetsa MOSFET ndi, mu chiphunzitso, kulipiritsa ndi kutulutsa capacitance. Kulipiritsa capacitor kumafuna panopa, ndipo popeza kulipiritsa capacitor nthawi yomweyo kungawoneke ngati dera lalifupi, nthawi yomweyo idzakhala yapamwamba. Kusankha / kamangidwe ka MOSFET kuyendetsa chinthu choyamba kulabadira ndi kukula kwanthawi yayitali kwanthawi yayitali komwe kungaperekedwe. Chinthu chachiwiri choyenera kulabadira ndichakuti, chomwe chimagwiritsidwa ntchito kwambiri pamagalimoto apamwamba a NMOS, pakufunika ndikuti magetsi a pachipata ndiakulu kuposa magwero amagetsi. Mkulu-mapeto pagalimoto MOS chubu conduction gwero voteji ndi kuda voteji (VCC) chimodzimodzi, kotero chipata voteji kuposa VCC 4V kapena 10V. poganiza kuti mu dongosolo lomwelo, kuti tipeze voteji yokulirapo kuposa VCC, timafunikira dera lowonjezera lapadera. Madalaivala ambiri amaphatikizidwira pampu, kulabadira ayenera kusankha capacitor yoyenera yakunja, kuti apezeko pang'ono pang'onopang'ono kuyendetsa MOSFET. 4V kapena 10V zomwe zanenedwa pamwambapa zimagwiritsidwa ntchito MOSFET pamagetsi, kapangidwe kake, kufunikira kokhala ndi malire ena. Kukwera kwa voliyumu, kumapangitsanso kuthamanga kwa boma komanso kumachepetsa kukana kwa boma. Nthawi zambiri pamakhalanso ma MOSFET ang'onoang'ono amagetsi omwe amagwiritsidwa ntchito m'magulu osiyanasiyana, koma pamakina amagetsi amagetsi a 12V, 4V wamba paboma ndi yokwanira.
Magawo akuluakulu a MOSFET ndi awa:
1. chipata gwero kuwonongeka voteji BVGS - m'kati kuonjezera chipata gwero voteji, kuti chipata panopa IG ku ziro kuyamba lakuthwa kuwonjezeka VGS, lotchedwa chipata gwero kuwonongeka voteji BVGS.
2. voteji ya VT - voteji yoyatsa (yomwe imadziwikanso kuti voteji): kupanga gwero la S ndi kukhetsa D pakati pa chiyambi cha njira yopititsira patsogolo kumapanga mphamvu yamagetsi yofunikira; - yokhazikika N-channel MOSFET, VT pafupifupi 3 ~ 6V; - pambuyo ndondomeko kusintha, akhoza kupanga MOSFET VT mtengo mpaka 2 ~ 3V.
3. Kukhetsa kuwononga voteji BVDS - pansi pa chikhalidwe cha VGS = 0 (analimbitsa) , mu ndondomeko kuonjezera kukhetsa voteji kuti ID ayambe kuwonjezeka kwambiri pamene VDS amatchedwa kuda kusweka voteji BVDS - ID kuchuluka kwambiri chifukwa cha mbali ziwiri zotsatirazi:
(1) kusweka kwa chigumula chakusanjikiza kocheperako pafupi ndi electrode yokhetsa
(2) kugwetsa kwapakati-gwero lapakati - magetsi ena ang'onoang'ono a MOSFET, kutalika kwa njira yake kumakhala kochepa, nthawi ndi nthawi kuonjezera VDS kumapangitsa kuti dera lakumapeto liwonongeke nthawi ndi nthawi kuti likulitse dera la gwero. , kotero kuti kutalika kwa njira ya ziro, ndiko kuti, pakati pa kulowera kwa gwero, kulowetsa, malo oyambira onyamula ambiri, malo oyambira, akhale olunjika kuti athe kupirira kusanjikiza kocheperako kwa kuyamwa kwa gawo lamagetsi, kufika kudera lotayikira, zomwe zimapangitsa ID yayikulu.
4. DC athandizira kukana RGS-ie, chiŵerengero cha voteji anawonjezera pakati pa chipata gwero ndi chipata panopa, khalidwe nthawi zina anasonyeza mwa mawu a chipata panopa akuyenda pachipata MOSFET a RGS mosavuta upambana 1010Ω. 5.
5. Low-frequency transconductance gm mu VDS pamtengo wokhazikika wamikhalidwe, microvariance ya drain current ndi gate source voltage microvariance chifukwa cha kusinthaku imatchedwa transconductance gm, kuwonetsa kuwongolera kwamagetsi amagetsi pachipata. Kukhetsa kwapano ndikuwonetsa kuti kukulitsa kwa MOSFET kwa gawo lofunikira, nthawi zambiri m'magawo angapo mpaka ma mA / V. MOSFET imatha kupitilira 1010Ω mosavuta.
Nthawi yotumiza: May-14-2024
