Momwe Phukusi Lowonjezera la MOSFET limagwirira ntchito

Popanga makina osinthira magetsi kapena ma drive oyendetsa magalimoto pogwiritsa ntchito ma MOSFET otsekedwa, anthu ambiri amawona kukana kwa MOS, mphamvu yayikulu kwambiri, etc., kuchuluka kwapano, ndi zina zambiri, ndipo pali ambiri omwe amangoganizira izi. Mabwalo oterowo amatha kugwira ntchito, koma siabwino kwambiri ndipo samaloledwa ngati mapangidwe okhazikika.

Zotsatirazi ndi chidule chachidule cha zoyambira za MOSFET ndiMOSFETmayendedwe oyendetsa, omwe ndimatchula magwero angapo, osati onse oyambirira. Kuphatikizira kukhazikitsidwa kwa ma MOSFET, mawonekedwe, ma drive ndi mabwalo ogwiritsira ntchito. Kupaka mitundu ya MOSFET ndi mphambano MOSFET ndi FET (JFET ina), imatha kupangidwa kukhala mtundu wowongoleredwa kapena wocheperako, P-channel kapena N-channel mitundu inayi, koma kugwiritsa ntchito kwenikweni kwa N-channel MOSFET yokhayo komanso P. -channel MOSFET, yomwe nthawi zambiri imatchedwa NMOS, kapena PMOS imatanthawuza mitundu iwiriyi.

Ponena za chifukwa chiyani osagwiritsa ntchito ma MOSFET amtundu wa depletion, sizovomerezeka kuti mufike pansi pake. Pamitundu iwiriyi ya ma MOSFET owonjezera, NMOS imagwiritsidwa ntchito kwambiri chifukwa chokana kukana komanso kuphweka kwake. Chifukwa chake kusintha magetsi ndi ma drive drive application, nthawi zambiri amagwiritsa ntchito NMOS. mawu oyamba otsatirawa, komanso zambiriNMOS-zokhazikika.

MOSFETs ali ndi parasitic capacitance pakati pa zikhomo zitatu, zomwe sizikufunika, koma chifukwa cha kuchepa kwa kupanga. Kukhalapo kwa parasitic capacitance pakupanga kapena kusankhidwa kwa dera lagalimoto kukhala vuto lina, koma palibe njira yopewera, kenako ndikufotokozedwa mwatsatanetsatane. Monga mukuonera pa MOSFET schematic, pali parasitic diode pakati kukhetsa ndi gwero.

Izi zimatchedwa diode ya thupi ndipo ndizofunikira pakuyendetsa katundu wolowera monga ma motors. Mwa njira, diode ya thupi imapezeka mwa munthu payekhaZithunzi za MOSFETndipo nthawi zambiri sichipezeka mkati mwa chipangizo chophatikizika chophatikizika.MOSFET ON CharacteristicsOn amatanthauza kuchita ngati chosinthira, chomwe chili chofanana ndi kutseka kwa switch.

Makhalidwe a NMOS, ma Vgs ochulukirapo kuposa mtengo wina adzachita, oyenera kugwiritsidwa ntchito ngati gwero lakhazikika (galimoto yotsika), bola mphamvu ya chipata cha 4V kapena 10V. Makhalidwe a PMOS, Vgs zosakwana mtengo wina adzachita, zoyenera kugwiritsidwa ntchito ngati gwero likulumikizidwa ndi VCC (magalimoto apamwamba). Komabe, ngakhale PMOS itha kugwiritsidwa ntchito mosavuta ngati dalaivala wapamwamba kwambiri, NMOS nthawi zambiri imagwiritsidwa ntchito pamadalaivala apamwamba chifukwa chakukaniza kwakukulu, kukwera mtengo, ndi mitundu yochepa yosinthira.

Packaging MOSFET switching chubu loss, kaya ndi NMOS kapena PMOS, pambuyo pa conduction pali on-resistance ilipo, kotero kuti yapano idzawononga mphamvu pakukana uku, gawo ili lamphamvu lomwe limagwiritsidwa ntchito limatchedwa conduction loss. Kusankha MOSFET yokhala ndi kukana pang'ono kudzachepetsa kutayika kwa conduction. Masiku ano, kukana kwa mphamvu yaing'ono ya MOSFET nthawi zambiri kumakhala pafupifupi mamiliyoni makumi ambiri, ndipo mamiliyoni ochepa amapezekanso.MOS sayenera kutsirizidwa nthawi yomweyo pamene ikuyendetsa ndikudula. Magetsi kumbali zonse za MOS ali ndi mphamvu njira yochepetsera, ndipo yomwe ikudutsamo imakhala ndi njira yowonjezera.Panthawiyi, kutayika kwa MOSFET ndikochokera ku magetsi ndi magetsi, omwe amatchedwa. kusintha kwa kutentha. Kawirikawiri kutayika kwa kusintha kumakhala kwakukulu kwambiri kuposa kutayika kwa conduction, ndipo mofulumira kusintha kwafupipafupi, kutayika kwakukulu. Chopangidwa ndi voteji ndi chapano panthawi yomwe conduction ndi yayikulu kwambiri, zomwe zimapangitsa kutayika kwakukulu.

Kufupikitsa nthawi yosinthira kumachepetsa kutayika pamayendedwe aliwonse; kuchepetsa kusintha kwafupipafupi kumachepetsa chiwerengero cha masinthidwe pa nthawi ya unit. Njira ziwirizi zitha kuchepetsa kutayika kwa kusintha. Chopangidwa ndi magetsi komanso chapano panthawi yoyendetsa ndi yayikulu, ndipo kutayika kwake kumakhalanso kwakukulu. Kufupikitsa nthawi yosinthira kungachepetse kutayika pamayendedwe aliwonse; kuchepetsa kusintha kwafupipafupi kungachepetse chiwerengero cha masinthidwe pa nthawi ya unit. Njira ziwirizi zitha kuchepetsa kutayika kwa kusintha. Kuyendetsa Poyerekeza ndi ma transistors a bipolar, amakhulupirira kuti palibe chapano chomwe chimafunikira kuyatsa MOSFET yopakidwa, bola mphamvu ya GS ili pamwamba pamtengo wina. Izi ndizosavuta kuchita, komabe, timafunikiranso liwiro. Mapangidwe a MOSFET otsekedwa amatha kuwoneka pamaso pa parasitic capacitance pakati pa GS, GD, ndi kuyendetsa kwa MOSFET, kwenikweni, kulipiritsa ndi kutulutsa capacitance. Kulipiritsa capacitor kumafuna panopa, chifukwa kulipira capacitor nthawi yomweyo kumawoneka ngati dera lalifupi, kotero kuti nthawi yomweyo idzakhala yaikulu. Chinthu choyamba kukumbukira posankha / kupanga dalaivala wa MOSFET ndi kukula kwa nthawi yofupikitsa yomwe ingaperekedwe.

Chinthu chachiwiri chomwe muyenera kudziwa ndichakuti, chomwe chimagwiritsidwa ntchito kwambiri pagalimoto yapamwamba ya NMOS, mphamvu yamagetsi yapanthawi yake iyenera kukhala yayikulu kuposa mphamvu yamagetsi. Mkulu-mapeto pagalimoto MOSFET conduction gwero voteji ndi kuda voteji (VCC) chimodzimodzi, kotero chipata voteji kuposa VCC 4 V kapena 10 V. Ngati mu dongosolo lomwelo, kupeza voteji lalikulu kuposa VCC, tiyenera mwapadera mu kulimbikitsa ma circuits. Madalaivala ambiri oyendetsa magalimoto ali ndi mapampu ophatikizika, ndikofunikira kudziwa kuti muyenera kusankha luso lakunja loyenera, kuti mupeze nthawi yayitali yokwanira kuyendetsa MOSFET. 4V kapena 10V imagwiritsidwa ntchito kwambiri pamagetsi amtundu wa MOSFET, zachidziwikire, kapangidwe kake kamayenera kukhala ndi malire ena. Kukwera kwa voliyumu, kumapangitsanso kuthamanga kwa boma komanso kumachepetsa kukana kwa boma. Masiku ano, pali ma MOSFET okhala ndi magetsi ang'onoang'ono a boma omwe amagwiritsidwa ntchito m'madera osiyanasiyana, koma m'makina amagetsi amagetsi a 12V, nthawi zambiri 4V on-state ndi yokwanira.MOSFET drive circuit ndi kutayika kwake.