Yadda Ingantattun Kunshin MOSFETs ke Aiki

Lokacin zayyana wutar lantarki mai sauyawa ko da'irar tuƙi ta hanyar amfani da MOSFETs, yawancin mutane suna la'akari da juriya na MOS, matsakaicin ƙarfin lantarki, da sauransu, matsakaicin halin yanzu, da sauransu, kuma akwai da yawa waɗanda ke la'akari kawai waɗannan abubuwan. Irin waɗannan da'irori na iya aiki, amma ba su da kyau kuma ba a yarda da su azaman ƙirar samfuri na yau da kullun.

Mai zuwa shine ɗan taƙaitaccen abubuwan da MOSFET ke da shi daMOSFETda'irori na direba, waɗanda na yi nuni ga yawancin tushe, ba duka na asali ba. Ciki har da gabatarwar MOSFETs, halaye, tuƙi da da'irar aikace-aikace. Marufi MOSFET iri da junction MOSFET FET ne (wani JFET), ana iya ƙera shi zuwa nau'in haɓakawa ko raguwa, tashar P-tashar ko N-tashar duka nau'ikan guda huɗu, amma ainihin aikace-aikacen MOSFET N-tashar N-tashar MOSFET da haɓaka P. MOSFET tashar tashar, wanda yawanci ake kira NMOS, ko PMOS yana nufin waɗannan nau'ikan guda biyu.

Amma ga me yasa ba a yi amfani da nau'in ragewa MOSFETs ba, ba a ba da shawarar zuwa kasan sa ba. Don waɗannan nau'ikan MOSFET na haɓakawa guda biyu, NMOS an fi amfani dashi saboda ƙarancin juriya da sauƙin ƙirƙira. Don haka sauya wutar lantarki da aikace-aikacen tuƙi, gabaɗaya amfani da NMOS. gabatarwar mai zuwa, amma kuma ƙariNMOS- tushen.

MOSFETs suna da karfin parasitic tsakanin fil uku, wanda ba a buƙata, amma saboda iyakokin tsarin masana'antu. Kasancewar parasitic capacitance a cikin ƙira ko zaɓi na da'ira na drive ya zama wasu matsala, amma babu wata hanyar da za ta guje wa, sannan aka bayyana dalla-dalla. Kamar yadda kuke gani akan tsarin MOSFET, akwai diode parasitic tsakanin magudanar ruwa da tushen.

Wannan shi ake kira da body diode kuma yana da mahimmanci wajen tuki lodin inductive kamar injina. Af, diode jiki yana samuwa ne kawai a cikin mutumMOSFETskuma yawanci ba ya kasancewa a cikin guntun da'ira.MOSFET ON HalayeOn yana nufin yin aiki azaman canji, wanda yayi daidai da ƙulli.

Halayen NMOS, Vgs mafi girma fiye da wani ƙima za su gudanar, dacewa don amfani a cikin yanayin lokacin da tushen ya kasance ƙasa (ƙananan tuƙi), muddin ƙarfin ƙarfin ƙofar 4V ko 10V. Halayen PMOS, Vgs ƙasa da takamaiman ƙima za su gudanar, dacewa don amfani a cikin yanayin lokacin da aka haɗa tushen zuwa VCC (drive mai girma). Koyaya, kodayake ana iya amfani da PMOS cikin sauƙin azaman babban direba na ƙarshe, NMOS galibi ana amfani dashi a cikin manyan direbobi saboda babban juriya, farashi mai girma, da nau'ikan maye gurbin.

Packaging MOSFET sauya bututu asarar, ko NMOS ne ko PMOS, bayan gudanarwa akwai on-juriya, ta yadda na yanzu zai cinye makamashi a cikin wannan juriya, wannan bangare na makamashi cinye ana kiransa conduction asarar. Zaɓin MOSFET tare da ƙaramin juriya zai rage asarar gudanarwa. A zamanin yau, akan juriya na ƙaramin iko MOSFET gabaɗaya yana kusa da dubun milliohms, kuma akwai wasu miliyoyi kuma ana samun su.MOS ba dole ba ne a kammala shi nan take lokacin da yake gudanar da yankewa. Wutar lantarki a bangarorin biyu na MOS yana da tsari na raguwa, kuma halin yanzu yana gudana ta hanyarsa yana da tsari na karuwa. A wannan lokacin, asarar MOSFET shine samfurin ƙarfin lantarki da na yanzu, wanda ake kira hasara mai canzawa. Yawanci asarar sauyawa ya fi girma fiye da asarar gudanarwa, kuma da sauri saurin sauyawa, mafi girma asarar. Samfurin ƙarfin lantarki da na yanzu a lokacin da ake sarrafawa yana da girma sosai, yana haifar da asara mai yawa.

Rage lokacin sauyawa yana rage asarar a kowace gudanarwa; rage mitar sauyawa yana rage adadin masu sauyawa kowane lokaci naúrar. Duk waɗannan hanyoyin guda biyu na iya rage hasarar sauyawa. Samfurin ƙarfin lantarki da na yanzu a lokacin da ake sarrafawa yana da girma, kuma asarar da ta haifar ma babba ce. Rage lokacin sauyawa zai iya rage asarar a kowace gudanarwa; rage mitar sauyawa zai iya rage adadin masu sauyawa kowane lokaci naúrar. Duk waɗannan hanyoyin guda biyu na iya rage hasarar canji. Tuki Idan aka kwatanta da transistors na bipolar, gabaɗaya an yarda cewa babu wani halin yanzu da ake buƙatar kunna MOSFET da ke kunshe, matuƙar ƙarfin lantarki na GS yana sama da ƙima. Wannan yana da sauƙin yin, duk da haka, muna kuma buƙatar gudu. Za'a iya ganin tsarin MOSFET da aka lullube shi a gaban iyawar parasitic tsakanin GS, GD, kuma tuƙin MOSFET shine, a zahiri, caji da fitar da ƙarfin ƙarfin. Yin cajin capacitor yana buƙatar halin yanzu, saboda ana iya ganin cajin capacitor a matsayin ɗan gajeren lokaci, don haka halin yanzu na yanzu zai fi girma. Abu na farko da za a lura lokacin zabar / zana direban MOSFET shine girman gajeriyar da'irar halin yanzu wanda za'a iya bayarwa.

Abu na biyu da za a lura shi ne cewa, gabaɗaya ana amfani da su a cikin babban tuƙi na NMOS, ƙarfin wutar lantarki na ƙofar kan lokaci yana buƙatar girma fiye da ƙarfin tushen tushen. High-end drive MOSFET conduction tushen ƙarfin lantarki da lambatu ƙarfin lantarki (VCC) iri ɗaya, don haka ƙofar ƙarfin lantarki fiye da VCC 4 V ko 10 V. Idan a cikin wannan tsarin, don samun ya fi girma irin ƙarfin lantarki fiye da VCC, dole ne mu ƙware a. ƙarfafa da'irori. Yawancin direbobin motoci sun haɗa da famfunan caji, yana da mahimmanci a lura cewa yakamata ku zaɓi ƙarfin ƙarfin waje da ya dace, don samun isassun ɗan gajeren lokaci don fitar da MOSFET. 4V ko 10V yawanci ana amfani dashi a cikin wutar lantarki na MOSFET, ba shakka, ƙira yana buƙatar samun tazara. Mafi girman ƙarfin wutar lantarki, saurin kan-jihar gudun kuma ƙananan juriya na kan-jihar. A zamanin yau, akwai MOSFETs tare da ƙaramin on-jihar irin ƙarfin lantarki da ake amfani da su a fannoni daban-daban, amma a cikin tsarin lantarki na motoci na 12V, gabaɗaya 4V a kan-jihar ya isa.MOSFET da'ira da asararsa.