Zaɓin ƙaramin wutar lantarki MOSFET muhimmin sashi ne mai mahimmanci naMOSFETZaɓin ba shi da kyau na iya shafar inganci da farashin da'irar gabaɗaya, amma kuma zai kawo matsala mai yawa ga injiniyoyi, yadda za a zaɓi MOSFET daidai?
Zaɓin tashar N-channel ko P-tashar Mataki na farko na zaɓar na'urar daidai don ƙira shine yanke shawarar ko za a yi amfani da tashar N-channel ko MOSFET P-tashar A cikin aikace-aikacen wutar lantarki na yau da kullun, MOSFET yana zama maɓallin ƙaramin ƙarfin wutar lantarki lokacin MOSFET yana ƙasa kuma an haɗa nauyin da ƙarfin lantarki. A cikin ƙaramin ƙarfin wutan gefe, ya kamata a yi amfani da MOSFET ta tashar N-tashar saboda la'akari da ƙarfin lantarki da ake buƙata don kashe ko kunna na'urar.
Lokacin da MOSFET ta haɗa da bas ɗin kuma nauyin ya kasance ƙasa, za a yi amfani da babban canjin gefen wuta. P-tashar MOSFETs yawanci ana amfani da su a cikin wannan topology, kuma don la'akari da tuƙin wutar lantarki. Ƙayyade ƙimar halin yanzu. Zaɓi ƙimar MOSFET na yanzu. Dangane da tsarin kewayawa, wannan ƙimar na yanzu yakamata ya zama matsakaicin halin yanzu wanda kaya zai iya jurewa a ƙarƙashin kowane yanayi.
Hakazalika da yanayin ƙarfin lantarki, dole ne mai zane ya tabbatar da cewa an zaɓaMOSFETzai iya jure wa wannan kima na yanzu, ko da lokacin da tsarin ke haifar da igiyoyi masu karu. Abubuwa biyu na yanzu da za a yi la'akari da su sune yanayin ci gaba da bugun bugun jini. A cikin ci gaba da tafiyar da yanayin, MOSFET yana cikin kwanciyar hankali, lokacin da halin yanzu ke wucewa ta na'urar.
Ƙunƙarar bugun bugun jini shine lokacin da akwai manya-manyan tudu (ko spikes na halin yanzu) suna gudana ta cikin na'urar. Da zarar an ƙayyade iyakar halin yanzu a ƙarƙashin waɗannan sharuɗɗan, kawai batun zaɓin na'urar kai tsaye ce wacce za ta iya jure wannan matsakaicin halin yanzu. Ƙayyade buƙatun zafi Zaɓan MOSFET kuma yana buƙatar ƙididdige buƙatun zafi na tsarin. Dole ne mai zanen ya yi la'akari da yanayi biyu daban-daban, mafi munin yanayi da kuma gaskiyar lamarin. Ana ba da shawarar cewa a yi amfani da ƙididdige mafi munin yanayi saboda yana ba da mafi girman gefen aminci kuma yana tabbatar da cewa tsarin ba zai gaza ba. Har ila yau, akwai wasu ma'auni da za a sani a kan takardar bayanan MOSFET; kamar juriya na thermal tsakanin mahaɗar semiconductor na na'urar kunshin da muhalli, da matsakaicin zafin haɗuwa. Yanke shawarar canza aikin, mataki na ƙarshe na zaɓar MOSFET shine yanke shawara akan aikin sauya fasalin.MOSFET.
Akwai sigogi da yawa waɗanda ke shafar aikin sauyawa, amma mafi mahimmanci shine ƙofar / magudanar ruwa, kofa / tushe, da magudanar ruwa / iyawar tushen. Waɗannan ƙarfin ƙarfin suna haifar da asarar sauyawa a cikin na'urar saboda dole ne a caje su yayin kowane sauyawa. Don haka an rage saurin sauyawa na MOSFET kuma ingancin na'urar yana raguwa. Don ƙididdige jimlar asarar na'urar yayin sauyawa, dole ne mai ƙira ya ƙididdige asarar kunnawa (Eon) da asarar kashewa.
Lokacin da ƙimar vGS tayi ƙanƙanta, ikon ɗaukar electrons ba shi da ƙarfi, yayyo - tushen tsakanin har yanzu babu tashar tashar da ke gabatarwa, haɓaka vGS, tunawa a cikin P substrate surface Layer na electrons akan karuwa, lokacin da vGS ya kai wani darajar, waɗannan abubuwan wayoyin a ƙofar kusa da p substrate bayyanar sun ƙunshi wani darajar, waɗannan wayoyin a cikin bayyanar da ke kusa da bayyanar pubstrate za su iya zama a N-type bakin ciki Layer, da kuma alaka da biyu N + yankin, a cikin magudana - tushen kunshi N-type conductive tashar, ta conductive irin da kuma akasin P substrate, kunshi anti-type Layer. vGS ya fi girma, rawar da semiconductor bayyanar da karfi filin lantarki, da sha electrons zuwa na waje na P substrate, da mafi conductive tashar ne thicker, da ƙananan tashar juriya. Wato, N-channel MOSFET a vGS <VT, ba zai iya zama tashar sarrafawa ba, bututu yana cikin yanayin yankewa. Muddin lokacin vGS ≥ VT, kawai lokacin da abun da ke ciki na tashar. Bayan an kafa tashar, ana samar da magudanar ruwa ta hanyar ƙara vDS na gaba tsakanin magudanar ruwa - tushen.
Amma Vgs ya ci gaba da karuwa, bari mu ce IRFPS40N60KVgs = 100V lokacin da Vds = 0 da Vds = 400V, yanayi biyu, aikin bututu don kawo abin da tasiri, idan ya ƙone, dalilin da tsarin ciki na tsarin shine yadda za a ƙara Vgs zai rage. Rds (akan) yana rage asarar canzawa, amma a lokaci guda zai ƙara Qg, don haka asarar kunnawa ya zama mafi girma, yana rinjayar ingancin MOSFET GS ta Vgg zuwa Cgs caji da tashi, ya isa ga ƙarfin ƙarfin kulawa Vth. , MOSFET fara gudanarwa; MOSFET DS karuwa a halin yanzu, Millier capacitance a cikin tazara saboda fitarwa na DS capacitance da fitarwa, GS capacitance caji ba shi da tasiri sosai; Qg = Cgs * Vgs, amma cajin zai ci gaba da haɓakawa.
Wutar lantarki ta DS ta MOSFET tana faɗuwa zuwa irin ƙarfin lantarki kamar Vgs, ƙarfin Millier yana ƙaruwa sosai, ƙarfin wutar lantarki na waje yana dakatar da cajin ƙarfin Millier, ƙarfin ƙarfin GS ɗin ya kasance baya canzawa, ƙarfin lantarki akan ƙarfin Millier yana ƙaruwa, yayin da ƙarfin lantarki yana ƙaruwa. akan ƙarfin DS yana ci gaba da raguwa; Wutar lantarki na DS na MOSFET yana raguwa zuwa ƙarfin lantarki a cikakkiyar gudanarwa, ƙarfin Millier ya zama ƙarami. ƙarfin lantarki, da ƙarfin lantarki akan ƙarfin GS yana tashi; Tashoshin ma'aunin wutar lantarki sune na gida 3D01, 4D01, da Nissan's 3SK series.
Ƙaddamar da G-pole (ƙofa): yi amfani da gear diode na multimeter. Idan ƙafa da sauran ƙafa biyun da ke tsakanin ma'aunin ma'aunin inganci da na ɗabi'a sun fi 2V, wato nunin “1”, wannan ƙafar ita ce ƙofar G. Sannan a musanya alƙalami don auna sauran ƙafa biyun. raguwar wutar lantarki kadan ne a wancan lokacin, baƙar alkalami yana haɗa da D-pole (magudanar ruwa), alƙalamin ja yana haɗa zuwa S-pole (source).
Lokacin aikawa: Afrilu-26-2024
