A cikin namu sassan sassan lantarki Mun riga mun yi magana sosai game da nau'ikan transistor na kasuwanci daban-daban. Yanzu lokaci ya yi da za a zurfafa zurfafa cikin transistor da ake amfani da shi sosai, dangin ne BJT transistor, wato bipolar transistors, wanda ke samuwa a cikin na'urorin lantarki da yawa waɗanda muke amfani da su a kullum.
Don haka zaka iya ƙarin koyo game da waɗannan transistor da bambance-bambancen da ke tattare da unipolar...
Menene semiconductor?
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da semiconductors Kayayyakin da ke da wutar lantarki tsakanin na conductors da na insulators. Ba kamar ƙarfe (masu jagoranci masu kyau) da waɗanda ba ƙarfe ba (insulators ko dielectrics), semiconductor sun mamaye matsayi na musamman wanda ke ba su damar sarrafa su don sarrafa wutar lantarki.
Su crystal tsarin, yawanci ƙunshi abubuwa kamar silicon ko germanium, yana da mahimmanci don fahimtar halayensa. Atom ɗin waɗannan kayan suna samar da tsari na crystalline wanda a cikinsa ake raba electrons tsakanin atom a cikin makaɗaɗan makamashi. Ƙungiyar valence tana ƙunshe da electrons waɗanda ke daure sosai da atoms, yayin da ƙungiyar conduction ta ƙunshi electrons waɗanda ke iya motsawa cikin yardar kaina.
da semiconductor kayan Suna da mahimmanci wajen kera na'urorin lantarki na ci gaba. Silicon, kasancewa ɗaya daga cikin na'urorin da aka fi amfani da su, yana ko'ina a cikin masana'antu kuma ya zama tushen kwakwalwan kwamfuta da microprocessors. Baya ga siliki, germanium wani abu ne na gama gari wanda aka yi amfani da shi a cikin tsoffin fasahar zamani. Semiconductor mahadi irin su gallium arsenide (GaAs) da phosphorene suma sun sami mahimmanci, musamman a cikin mitoci da aikace-aikacen optoelectronic. Wadannan kayan suna ba da damar ƙirƙirar na'urori irin su diodes masu fitar da haske (LEDs), transistor masu saurin gaske da na'urori masu auna firikwensin ci gaba, wanda ke nuna haɓakawa da ƙarfin semiconductor a sahun gaba na ƙirƙira na fasaha.
Masu ɗaukar kaya da tuƙi na lantarki
La ikon semiconductors don gudanar da wutar lantarki ya ta'allaka ne da ikonsa na samar da masu caji. Ana iya cajin masu ɗaukar caji mara kyau na electrons ko kuma ana cajin “ramuka,” wanda ke haifar da electrons waɗanda aka matsa daga valence band zuwa bandungiyar conduction.
Lokacin da aka yi amfani da wutar lantarki zuwa semiconductor, electrons iya matsawa daga valence band zuwa conduction band, samar da wutar lantarki. An san wannan al'amari da sarrafa lantarki kuma yana da mahimmanci ga aikin na'urorin lantarki.
Dopants (najasa)
Don haɓakawa da sarrafa kayan lantarki na semiconductors, Ana shigar da ƙazanta da gangan a cikin gilashin ta hanyar da ake kira doping. Dopant atom na iya zama nau'in mai ba da gudummawa (ƙara ƙarin electrons) ko na nau'in karɓa (ƙirƙirar ramuka), wato, na farko zai zama abin da ake kira semiconductor N-type kuma na biyu semiconductor na nau'in P.
Dopants suna gabatar da ƙarin matakan makamashi a cikin haramtacciyar band, ƙyale iko mafi girma akan tuƙi na lantarki. Wasu misalai na yau da kullun na dopants sune phosphorus (mai bayarwa) da boron (mai karɓa) don silicon. Ta wannan hanyar, ana iya ƙirƙirar zones ko junctions don ƙirƙirar na'urori irin su diode, wanda shine ainihin mahadar PN guda ɗaya, ko semiconductor, waɗanda galibi yankuna uku ne kamar yadda za mu gani nan gaba.
Nau'in Semiconductor: Na ciki da na waje
A gefe guda, don fahimtar BJT, yana da mahimmanci a san menene nau'ikan semiconductors Akwai su, kamar:
- Na ciki: Lokacin da ba a ƙara ƙazanta zuwa semiconductor ba, ana rarraba shi azaman na asali. A wannan yanayin, aikin wutar lantarki yana faruwa ne kawai ga masu samar da wutar lantarki (electron-rami nau'i-nau'i).
- na waje: Sakamakonsu ne na ganganci tare da ƙazanta. N-nau'in (korau) ana samun semiconducorors ta ƙara bashin mai ba da gudummawa, yayin da P-Typonductors an kafa su ne da ɗakunan da ya karɓa. Wadannan matakai suna ba da damar daidaita kayan lantarki na semiconductors bisa ga takamaiman bukatun aikace-aikacen.
Gabatarwa zuwa mahadar PN
La PN mahada Yana da mahimmancin ra'ayi a cikin na'urorin lantarki na semiconductor wanda ke kafa tushe don ƙirƙirar na'urori kamar diodes da transistor. Ana samun haɗin haɗin PN lokacin da yankuna biyu na kayan semiconductor suka taru. Waɗannan yankuna sune yanki na nau'in P (inda ƙaddamar da masu ɗaukar kaya masu inganci ko ramuka suka fi yawa) da yanki na nau'in N (inda ƙaddamar da masu ɗaukar kaya marasa ƙarfi ko electrons suka fi yawa). Canje-canje tsakanin waɗannan yankuna biyu yana haifar da keɓancewa na musamman tare da kayan lantarki na musamman.
La samuwar mahadar PN Yawancin lokaci yana faruwa ta hanyar da ake kira doping, inda aka shigar da ƙazanta da gangan a cikin kayan na'ura mai kwakwalwa. A yankin P-type, ana amfani da dopants masu karɓa (irin su boron), yayin da a yankin N, ana amfani da dopants masu ba da gudummawa (kamar phosphorus) kamar yadda na ambata a baya. Wannan tsari yana haifar da ƙwaƙƙwaran masu ɗaukar caji a duk faɗin mahaɗin, don haka kafa shinge mai yuwuwar.
Amma ga hali na wannan mahadar PN, yana da kaddarori na musamman lokacin da aka lalata su a wurare daban-daban:
- En gaba polarization, ana amfani da wutar lantarki ta hanyar da ta fi dacewa da gudana ta hanyar haɗin gwiwa. A wannan yanayin, masu ɗaukar caji suna motsawa ta hanyar shinge mai yuwuwar, suna ba da izinin tafiyar da wutar lantarki.
- Akasin haka, in baya polarization, Wutar lantarki da aka yi amfani da shi yana aiki da shinge mai yuwuwa, yana hana kwararar halin yanzu. A cikin wannan yanayin, haɗin PN yana aiki kamar diode, yana ba da damar gudanar da shi ta hanya ɗaya kuma yana toshe shi ta wata hanya.
Junction na PN shine tushen yawancin na'urorin lantarki. Diodes, alal misali, suna amfani da damar mallakar mahadar PN don ba da damar kwararar halin yanzu a wata hanya da toshe shi a ɗayan. Transistor, masu mahimmanci don dabaru na dijital da haɓaka sigina, ana kuma gina su ta amfani da mahaɗar PN daban-daban, kamar a cikin yanayin BJT waɗanda ke iya samun haɗin NPN ko PNP...
Menene transistor BJT?
El transistor junction bipolar (BJT ko Bipolar Junction Transistor) Na'urar lantarki ce mai ƙarfi da ta ƙunshi mahaɗar PN guda biyu masu kusanci, yana ba da damar haɓakawa na yanzu, raguwar ƙarfin lantarki, da sarrafa kwararar halin yanzu ta tasha. Gudanarwa a cikin wannan nau'in transistor ya ƙunshi masu ɗaukar kaya na polarities biyu (tabbatattun ramuka da ƙananan electrons). Ana amfani da BJT sosai a cikin kayan lantarki na analog da wasu aikace-aikacen lantarki na dijital, kamar fasahar TTL ko BiCMOS.
La Tarihin bipolar transistor ya koma 1947, lokacin da John Bardeen da Walter Houser Brattain suka kirkiro transistor mai lamba-lamba a Kamfanin Wayar Hannu na Bell. Daga baya, William Shockley ya haɓaka transistor junction bipolar a cikin 1948. Ko da yake suna da mahimmanci shekaru da yawa, amfani da su ya ƙi yarda da fasahar CMOS a haɗaɗɗen da'irori na dijital.
Tsarin BJT ya ƙunshi yankuna uku:
- The emitter (sosai doped da kuma aiki azaman caji emitter)
- Tushen (narrows da raba emitter daga mai tarawa)
- Mai tarawa (mafi girma).
Jigon Epitaxial shine fasahar masana'anta gama gari. A cikin aiki na yau da kullun, mahaɗar tushen-emitter yana nuna son kai, yayin da mahaɗin mai tattara tushe ya koma baya. Ka'idar aiki ta ƙunshi Polarization kai tsaye polarization na tushen-emitter junction da juyar da polarization na tushe-masu tattara. Ana yin allurar lantarki daga emitter zuwa mai tarawa, yana ba da damar haɓaka sigina. BJT yana siffanta ta da ƙarancin shigarwar shigarta kuma ana iya ƙirƙira shi azaman tushen wutar lantarki mai sarrafa wutar lantarki ko tushen halin yanzu mai sarrafawa.
Bipolar transistor aiki
Dangane da aiki, muna da wannan a cikin junction transistor (BJT) a cikin tsarin NPN, Junction na tushe-emitter yana gaba da gaba kuma mahadar mai tara tushe tana juye juye.. Tashin hankali na thermal yana ba masu cajin caji daga emitter damar ketare shinge mai yuwuwar emitter-base kuma su isa wurin mai tarawa, ta hanyar wutar lantarki tsakanin tushe da mai tarawa. A cikin aiki na yau da kullun, mahaɗar tushe-emitter yana nuna son kai, yana barin electrons a yi allurar cikin yankin tushe kuma tafiya zuwa ga mai tarawa. Dole ne yankin tushe ya zama sirara don rage haɗuwar mai ɗaukar kaya kafin isa mahadar masu tara tushe. Ana iya sarrafa mai tattara-emitter halin yanzu ta hanyar tushe-emitter halin yanzu (ikon yanzu) ko kuma ta hanyar wutar lantarki mai tushe-emitter (ikon wutar lantarki). A cikin PNP transistor ita ce sauran hanyar kewaye ...
Bambance-bambance tare da transistor unipolar
Ana iya rarraba transistors zuwa manyan nau'ikan biyu: bipolar da unipolar. The key bambance-bambance Abin da muka samu tsakanin wadannan biyun shi ne:
- BJT ko bipolar: Kamar dai transistors unipolar, bipolar transistor suma suna da masu ɗaukar kaya masu inganci da marasa kyau, wato, tare da yankunan P da N a cikin tsarinsu. Dangane da polarization, ana iya yin polarized kai tsaye ko a baya, gwargwadon abin da ake buƙata, kuma suna iya zama nau'in NPN ko PNP. Dangane da yanayin aiki, suna iya aiki a yanayin aiki, yanayin yanke da yanayin jikewa. Ana sarrafa su a halin yanzu, kuma suna da riba na yanzu wanda harafin β (beta) ke wakilta. Asarar wutar lantarki a wannan yanayin ya fi na unipolar transistor kuma saurinsa gabaɗaya yana da hankali fiye da transistor unipolar. Sabili da haka, ana amfani da su sau da yawa a cikin amplifiers siginar analog da ƙananan sauyawa, da sauransu. BJTs sun fi kamuwa da surutu.
- FET ko unipolar: Unipolar ko filin tasirin transistor suma suna amfani da masu ɗaukar kaya, amma a nan muna da electrons ko ramuka, ya danganta da nau'in. Babban polarization anan shine baya, kuma hanyoyin aiki galibi suna cikin jikewa. A wannan yanayin muna da transistor masu sarrafa wutar lantarki. Ribar da ake samu a halin yanzu ana wakilta a cikin wannan yanayin ta hanyar transconductance, asarar wutar lantarki ba ta da ƙasa a cikin masu bipolar, kuma suna da sauri. Saboda wannan dalili, ana amfani da su sau da yawa don sauyawa mai girma da kuma da'irori na dijital. Unipolar ba su da sauƙi ga hayaniya.
Nau'in BJT (NPN da PNP)
Kamar yadda na yi tsokaci a sassa da dama na labarin, akwai manyan iri biyu na BJT transistor:
- NPN Transistor: Sun kasance ɓangare na ɗaya daga cikin mahimman nau'ikan transistor guda biyu, inda haruffan "N" da "P" ke nuna yawancin masu cajin da ke cikin yankuna daban-daban na na'urar. A halin yanzu, yawancin transistor na biyu na nau'in NPN ne, tunda motsin electrons ya fi na "ramuka" a cikin semiconductor, don haka yana ba da damar igiyoyi masu girma da kuma saurin aiki. Tsarin NPN transistor ya ƙunshi Layer na P-doped semiconductor abu, wanda ake kira "base," wanda ke tsakanin layuka biyu na kayan N-doped. fitarwa na da yawa. Alamar transistor ta NPN ta ƙunshi kibiya mai nuni zuwa tashar emitter da kuma alkiblar halin yanzu yayin aiki na na'urar.
- PNP TransistorNau'i na biyu na transistor bipolar, suna da haruffa "P" da "N" waɗanda ke nufin yawancin cajin a yankuna daban-daban na na'urar. Ko da yake ba a gama kowa ba a yau, PNP transistors sun ƙunshi Layer na N-doped semiconductor abu tsakanin nau'i biyu na kayan P-doped. A cikin aiki na yau da kullum, mai tarawa yana haɗi zuwa ƙasa, kuma emitter yana da alaƙa da ingantaccen tashar tushe. wutar lantarki ta hanyar lodin lantarki na waje. Karamin halin yanzu da ke kwarara cikin tushe yana ba da damar mafi girman halin yanzu don gudana daga emitter zuwa mai tarawa. Kibiya akan alamar transistor PNP tana kan tashar emitter kuma tana nuna al'adar halin yanzu yayin aiki na na'urar. Duk da ƙarancin yaɗuwar su, NPN transistor an fi son a mafi yawan yanayi saboda ingantaccen aikin su.
Kuna iya ganin duk cikakkun bayanai a cikin hotunan da ke sama.
Abubuwan da aka bayar na BJT
Bipolar junction transistor (BJTs) ana amfani da su a cikin nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in iri) ana amfani da su aikace-aikace a cikin kayan lantarki, Na riga na yi tsokaci kan wasu lokuta a baya, amma a nan na nuna muku jeri tare da wasu manyan aikace-aikace ko amfani da waɗannan transistor:
- Ƙara sigina: Ana amfani da BJT da yawa don haɓaka sigina masu rauni, kamar waɗanda suke daga na'urori masu auna firikwensin ko makirufo, a cikin da'irar sauti da mitar rediyo.
- Tafiya: Ana amfani da su don sarrafa canjin halin yanzu a cikin da'irori na dijital da dabaru, irin su na'urorin lantarki, don aiwatar da ƙofofin dabaru.
- Amplifiers na wuta: Ana amfani da su a matakan haɓaka ƙarfi a cikin tsarin sauti da RF (mitar rediyo) amplifiers. A haƙiƙa, ɗaya daga cikin aikace-aikacen farko da aka ƙera waɗannan transistor don wannan shine, ya maye gurbin bututun injin da ya gabata.
- Hanyoyin makamashi: Ana iya saita su don fitar da na yau da kullun, wanda ke da amfani a wasu da'irori da aikace-aikace na yanzu. Hakanan zaka same su a cikin tsarin sarrafa wutar lantarki ko da'irori don kula da wutar lantarki akai-akai a fitowar wutar lantarki.
- Oscillators: Ana amfani da su a cikin da'irori na oscillator don samar da sigina na lokaci-lokaci, kamar a cikin janareta na igiyar igiyar ruwa.
- Ƙarawa RF: A cikin tsarin sadarwa, ana amfani da BJT a matakan haɓaka siginar mitar rediyo.
- Girma da daidaitawa mitar: Ana amfani da su a cikin da'irar daidaitawa don canza halayen sauti ko siginar RF. Hakanan za'a iya aiwatar da su a wasu na'urori masu auna firikwensin ko na'urar ganowa don aiwatar da siginar.
Yadda ake duba transistor BJT
Duba transistor BJT yana da mahimmanci don tabbatar da aikinsa yadda ya kamata. Idan kana son sanin yadda ake yin shi, za ku buƙaci multimeter ko multimeter kawai wanda ke da wannan aikin don bincika transistors na bipolar. Kuma hanyar da za a ci gaba abu ne mai sauqi qwarai, kawai ku bi waɗannan matakan:
- BJT NPN: Da farko dole ne ka gano Emitter (E), Base (B) da Collector (C) tashoshi ko fil ɗin da transistor ɗinka ya haɗa. Dangane da samfurin, zaku iya tuntuɓar bayanan bayanan don ƙarin cikakkun bayanai, kodayake yana da sauƙin sani. Da zarar kun gano tashoshi da multimeter a hannu, abu na gaba shine kawai saka fil ɗin daidai a cikin ramummuka don wannan dalili. Idan multimeter ɗinku ba shi da wannan aikin, zaku iya amfani da wannan madadin:
- Sanya multimeter a yanayin gwajin transistor, wato, juya dabaran don zaɓar alamar don auna wutar lantarki ta DC (V —).
- Taɓa fil ɗin da ake so tare da binciken multimeter:
- Lokacin da ka duba BE ko Base-Emitter junction, ya kamata ka ga ƙarfin karantawa akan allon tsakanin 0.6 da 0.7v, dangane da transistor.
- Lokacin da ka duba BC ko Base-Collector junction, ka taɓa waɗannan sauran tashoshi kuma karatun ƙarfin lantarki ya kamata ya yi kama da na sama.
- Don bincika riba na yanzu (hFE), kunna bugun kiran zaɓi zuwa aikin hFE. Kuma ta hanyar taɓa emitter da tushe, da emitter da mai tarawa tare da bincike don sanin ribar hFE, wanda zai zama alakar da ke tsakanin su biyun.
- BJT PNP: a cikin wannan yanayin, tabbatarwa yana kama da, kawai a akasin hanyar NPN.
Idan sakamakon da aka samu yana da ƙima a waje da tsammanin, transistor zai nuna cewa baya aiki ko yana da lahani kuma yana buƙatar maye gurbinsa.
Inda zan sayi BJT
Idan kanaso ka siya arha transistor BJT, Kuna iya yin shi a kowane kantin sayar da kayan lantarki ko dandamali na kan layi na musamman. Wuri ɗaya da zaku sami waɗannan na'urorin BJT yana kan Amazon, kuma muna ba da shawarar waɗannan:
