Asebenza kanjani ama-MOSFETs

Isimiso sokusebenza se-MOSFET sisekelwe kakhulu ezintweni zayo zesakhiwo esiyingqayizivele kanye nemiphumela yenkundla kagesi. Okulandelayo yincazelo enemininingwane yokuthi ama-MOSFET asebenza kanjani:

I. Isakhiwo esiyisisekelo se-MOSFET

I-MOSFET iqukethe ikakhulukazi isango (G), umthombo (S), umsele (D), kanye ne-substrate (B, ngezinye izikhathi exhunywe emthonjeni ukuze yakhe idivayisi yamatheminali amathathu). Kuma-MOSFET okuthuthukisa isiteshi se-N, i-substrate ivamise ukuba yi-silicon esezingeni eliphansi le-P lapho izifunda ezimbili ezihlotshiswe kakhulu ze-N zenziwa ukuze zisebenze njengomthombo nokukhipha amanzi, ngokulandelana. Ingaphezulu le-substrate yohlobo lwe-P limbozwe ifilimu elincane kakhulu le-oxide (i-silicon dioxide) njengengqimba evikelayo, futhi i-electrode idwetshwa njengesango. Lesi sakhiwo senza isango livalwe kusukela ku-P-type semiconductor substrate, i-drain kanye nomthombo, ngakho-ke ibizwa nangokuthi i-insulated-gate field effect tube.

II. Isimiso sokusebenza

Ama-MOSFET asebenza ngokusebenzisa amandla kagesi omthombo wesango (VGS) ukuze alawule ukugeleza kwamanzi (ID). Ngokucacile, lapho i-voltage yomthombo wesango ephozithivu esetshenzisiwe, i-VGS, inkulu kunoziro, inkambu kagesi ephezulu nenegethivu ephezulu izovela kungqimba lwe-oxide ngaphansi kwesango. Le nkambu kagesi iheha ama-electron amahhala ku-P-region, okubangela ukuthi aqongelele ngaphansi kongqimba lwe-oxide, kuyilapho exosha izimbobo ku-P-region. Njengoba i-VGS ikhula, amandla enkundla kagesi ayanda futhi ukugxila kwama-electron amahhala akhangayo kuyanda. Lapho i-VGS ifinyelela ku-threshold voltage (VT) ethile, ukuhlangana kwama-electron amahhala aqoqwe esifundeni kukhulu ngokwanele ukuze kwakhe indawo entsha yohlobo lwe-N (N-channel), esebenza njengebhuloho elixhuma idrayivu nomthombo. Kuleli qophelo, uma i-voltage ethile yokushayela (VDS) ikhona phakathi komsele nomthombo, i-ID yamanje yokukhipha iqala ukugeleza.

III. Ukwakhiwa nokushintshwa kwesiteshi sokuqhuba

Ukwakhiwa kwesiteshi esiqhubayo kuyisihluthulelo sokusebenza kwe-MOSFET. Uma i-VGS inkulu kune-VT, isiteshi esiqhubayo siyasungulwa futhi i-ID yamanje yokudonsa ithintwa yi-VGS kanye ne-VDS.VGS ithinta i-ID ngokulawula ububanzi nokuma kwesiteshi esiqhubayo, kuyilapho i-VDS ithinta i-ID ngokuqondile njenge-voltage yokushayela. kubalulekile ukuqaphela ukuthi uma isiteshi sokuqhuba singasungulwa (okungukuthi, i-VGS ingaphansi kwe-VT), khona-ke noma ngabe i-VDS ikhona, i-ID yamanje yokudonsa ayiveli.

IV. Izici ze-MOSFETs

I-impedance ephezulu yokufaka:I-impedance yokufaka ye-MOSFET iphezulu kakhulu, iseduze nokungapheli, ngoba kukhona ungqimba oluvikelayo phakathi kwesango nesifunda sokukhipha umthombo kanye nesango lamanje elibuthakathaka.

I-impedance yokukhipha okuphansi:Ama-MOSFET angamadivayisi alawulwa yi-voltage lapho i-source-drain current ingashintsha khona nge-voltage yokufaka, ngakho-ke i-impedance yawo yokuphuma incane.

Ukugeleza njalo:Lapho isebenza endaweni ye-saturation, i-current ye-MOSFET cishe ayithinteki izinguquko ku-voltage wokukhipha umthombo, ehlinzeka ngokuqhubekayo okuhle kakhulu.

Ukuzinza okuhle kwezinga lokushisa:Ama-MOSFET anezinga lokushisa elibanzi lokusebenza ukusuka ku--55°C kuya cishe ku-+150°C.

V. Izicelo kanye nezigaba

Ama-MOSFET asetshenziswa kakhulu kumasekethe edijithali, kumasekethe e-analogue, amasekhethi kagesi neminye imikhakha. Ngokohlobo lomsebenzi, ama-MOSFET angahlukaniswa abe izinhlobo zokuthuthukisa kanye nokuncipha; ngokohlobo lwesiteshi esiqhutshwayo, zingahlukaniswa zibe yisiteshi esingu-N kanye nesiteshi esingu-P. Lezi zinhlobo ezahlukene zama-MOSFET zinezinzuzo zazo ezimweni ezihlukene zohlelo lokusebenza.

Kafushane, umgomo wokusebenza we-MOSFET uwukulawula ukwakheka nokushintshwa kweshaneli eqhubayo ngokusebenzisa i-voltage yomthombo wesango, yona elawula ukugeleza kwamanzi okudonsa amanzi. I-impedance yayo ephezulu yokufaka, i-impedance ephansi yokukhipha, ukuzinza okuqhubekayo kwamanje kanye nezinga lokushisa kwenza ama-MOSFET abe ingxenye ebalulekile kumasekethe kagesi.