Bipolar Transistor: switching circuits. Lub Circuit Court switching ntawm lub bipolar transistor nrog ib qho emitter

Ib tug ntawm lub peb-electrode hom semiconductor pab kiag li lawm yog bipolar transistors. ntawm lub Circuit Court yog nyob ntawm seb lawv muaj conductivity (qhov taub los yog electron) thiab kev khiav dej num.

kev faib

Transistors raug muab faib ua tej pawg:

1. Raws li cov ntaub ntawv: feem ntau siv gallium arsenide thiab silicon.
2. Raws li lub teeb liab zaus: tsawg (mus txog 3 MHz), medium (mus txog 30 MHz), siab (mus txog rau 300 MHz), ultra-high (saum toj no 300 MHz).
3. Rau siab tshaj plaws hwj chim dissipation: mus txog 0.3 W, mus txog 3 watts, ntau tshaj 3W.
4. Raws li lub hom ntaus ntawv: peb kev cob cog rua nrog lub semiconductor txheej los ntawm qho kev pauv qhov ncaj thiab rov qab txoj kev impurity conduction.

Yuav ua li cas ua lub transistors?

Cov txheej thiab puab khaubncaws sab nraud povtseg ntawm cov transistor yog kev cob cog rua rau cov hlau lead electrodes, feem hu ua lub emitter, collector thiab puag.

Lub emitter thiab collector yog tsis sib txawv ntawm txhua lwm yam conductivity, tab sis cov neeg kawm ntawv ntawm doping impurities ntawm lub yav tas yog tsawg. Qhov no saib kuas ib qho kev nce nyob rau hauv lub pub tso zis voltage.

Lub hauv paus, uas yog ib tug nruab nrab txheej muaj ib tug high kuj, raws li ua los ntawm ib tug semiconductor nrog ib tug tsis muaj zog doping. Nws muaj ib tug loj hu cheeb tsam nrog kev collector, uas pab txoj kev qhov kev tshem tawm los ntawm tshav kub generated vim rov qab tsis ncaj ncees rau txoj kev hloov, thiab tswj lub tso cai ntawm lub haiv neeg tsawg muaj - electrons. Txawm tias muaj tseeb hais tias cov kev hloov khaubncaws sab nraud povtseg yog raws li nyob rau hauv tib lub ntsiab cai, cov transistor yog asymmetric ntaus ntawv. By hloov qhov chaw huab khaubncaws sab nraud povtseg ntawm cov tib conductivity yuav tsis tau txais lub sib nug xov tsis muaj lub semiconductor ntaus ntawv.

Schematics ntawm bipolar transistors yuav tau kom nws nyob rau hauv ob lub xeev: nws yuav ua tau qhib los yog kaw. Nyob rau hauv lub active hom, thaum lub transistor qhib emitter offset txoj kev hloov no yog ua nyob rau hauv lub rau pem hauv ntej kev taw qhia. Muab ua piv txwv li no xav txog, piv txwv li, ib tug transistor ntawm npn hom, nws yuav tsum tau energized los ntawm lub qhov chaw, raws li qhia nyob rau hauv daim duab hauv qab no.

Lub ciam ntawm lub thib ob collector hlws ris thaum no yog kaw thiab ib tug tam sim no ntws los ntawm nws yuav tsum tsis txhob. Tab sis nyob rau hauv kev xyaum, cov lus rov tshwm sim vim hais tias ntawm lub kaw qhov chaw ntawm lub zaus rau txhua lwm yam thiab lawv kev sib nrig sib cawv. Txij li thaum lub emitter yog kev cob cog rua rau lub "rho tawm" roj teeb qhib txoj kev hloov tso cai electrons ntws mus rau hauv lub hauv paus cheeb tsam, nyob qhov twg lawv muaj ib nrab recombination nrog qhov - lub ntsiab nqa khoom. Tsim puag tam sim no kuv _b. Lub muaj zog nws yog, lub proportionately ntau zis tam sim no. Nyob rau txoj ntsiab cai no ua hauj lwm amplifiers siv bipolar transistors.

Tom qab lub hauv paus yog ib hom diffusive thauj ntawm electrons, vim hais tias muaj yog tsis muaj kev txiav txim ntawm hluav taws xob field. Vim me ntsis txheej thickness (microns) thiab ib tug loj qhov ntau ntawm cov concentration gradient ntawm negatively them hais, yuav luag tag nrho cov ntawm lawv lub caij nplooj zeeg mus rau hauv lub collector cheeb tsam, txawm hais tias tus puag kuj yog txaus loj. Muaj lawv tsiv mus nyob thim hluav taws xob field, txhawb lawv cov active thauj. Lub collector thiab emitter currents yog tshuam sib npaug zos, yog hais tias tsis negligible tsis them nyiaj los ntawm lub recombination nyob rau hauv lub puag: Kuv _e = Kuv _b + kuv _k.

Cov ciaj ciam ntawm transistors

1. Lub nce yam rau cov voltage U _eq / U _YUAV thiab tam sim no: β = kuv _{ib tug} / kuv _b (tiag tiag tus nqi). Feem ntau, cov coefficient β tsis pub tshaj 300, tab sis tej zaum yuav mus txog qhov tseem ceeb ntawm 800 thiab saum toj no.
2. Tswv yim impedance.
3. Lub zaus teb - ntawm cov transistor kev kawm mus txog ib tug predetermined zaus saum toj no uas transients nws tsis muaj lub sij hawm rau cov kev hloov ntawm lub thov teeb liab.

Bipolar Transistor: switching circuits, lag luam hom

Kev khiav hauj lwm hom txawv nyob ntawm yuav ua li cas rau hauv Circuit Court yog tuaj txoos ua ke. Teeb liab yuav tsum tau ua ntawv thov thiab tshem tawm ntawm ob lub ntsiab lus rau txhua tus cov ntaub ntawv, tab sis muaj tsuas yog peb pins. Nws li nram no yog tias ib tug electrode yuav tsum ob leeg yuav mus rau lub tswv yim thiab tso zis. Yog li ntawd muaj tej yam bipolar transistors. ntawm lub Circuit Court: RAU, OE thiab OK.

1. Tsav nrog OK

Lub Circuit Court switching ntawm lub bipolar transistor nrog ib qho collector: lub teeb liab yog noj rau resistor R _L, uas yog tseem muaj nyob rau hauv lub collector Circuit Court. Xws li ib tug kev twb kev txuas yog raug xa mus rau raws li ib tug ntau-collector.

Qhov kev xaiv no tsuas tsim ib tug tam sim no koj qhov nce. Qhov kom zoo dua ntawm lub emitter follower yog muab ib tug loj tswv yim impedance (10-500 ohms), uas tso cai rau yooj yim tswj cascades.

2. Tsav nrog RAU

Lub Circuit Court switching ntawm lub bipolar transistor nyob rau hauv ib qho puag: tuaj lub teeb liab los ntawm lub C ₁ thiab tom qab amplification yog muab tshem tawm nyob rau hauv lub tso zis ntawm cov collector Circuit Court, nyob rau hauv lub hauv paus electrode yog qhia. Nyob rau hauv cov ntaub ntawv no, ib tug voltage nce yog zoo li kev ua hauj lwm nrog cov MA.

Lub disadvantage yog ib tug me me tswv yim impedance (30-100 ohms), thiab Circuit Court nrog RAU yog siv raws li ib tug oscillator.

3. Daim duab nrog MA

Nyob rau hauv muaj ntau yam embodiments, thaum bipolar transistors siv, switching circuits feem ntau ua nrog ib tug ntau emitter. Cov mov voltage yog noj los ntawm ib tug load resistor R _L, thiab ib tug emitter kev cob cog rua rau qhov tsis zoo ncej ntawm ib tug sab nraud fais fab mov.

AC teeb liab los ntawm lub tswv yim davhlau ya nyob twg nkag mus rau hauv emitter thiab puag electrodes (V _{nyob rau hauv),} thiab nws yuav loj nyob rau hauv qhov ntau (V _CE) nyob rau hauv lub collector Circuit Court. Cov yooj yim Circuit Court hais: ib tug transistor, ib tug resistor R _L thiab tso zis hauv lub amplifier Circuit Court nrog ib tug sab nraud fais fab mov. Koom haum pab: capacitor C ₁ uas txwv tsis pub cov zaj ntawm ncaj qha tam sim no nyob rau hauv lub pub Circuit Court ntawm lub tswv yim teeb liab, thiab ib tug resistor R _1, ntawm uas transistor opens.

Lub collector voltage ntawm cov transistor Circuit Court thiab tso zis hauv lub resistor R _L ua ke sib npaug zos magnitude _{EMF: V CC = kuv C R L} + V CE.

Yog li, V _{nyob rau hauv} lub me me teeb liab ntawm lub tswv yim yog muab los ntawm cov variation ntawm DC hwj chim rau AC tso zis inverter transistor tswj. Lub tswvyim muab ib qho kev nce nyob rau hauv lub tswv yim tam sim no 20-100 lub sij hawm, thiab lub voltage - nyob rau hauv 10-200 lub sij hawm. Raws li, lub hwj chim kuj yuav tsub kom.

Tsis muaj tswvyim: ib tug me me tswv yim kuj (500-1000 ohms). Vim li no, muaj teeb meem nyob rau hauv lub tsim ntawm amplification theem. Lub tso zis kuj yog 2-20 ohms.

Cov kos duab qhia yuav ua li cas lub bipolar transistor. Yog hais tias koj tsis noj ntxiv txiav txim rau lawv cov kev kawm yuav raug heev cuam tshuam los ntawm lwm influences, xws li overheating thiab teeb liab zaus. Tsis tas li ntawd, lub emitter grounding tsim harmonic distortion ntawm cov qhov tso zis. Yuav kom txhim kho kev ntseeg, hauv Circuit Court yog kev cob cog rua feedbacks, ntxaij lim dej, thiab hais txog. N. Nyob rau hauv rooj plaub no tus tau txo, tab sis tus ntaus ntawv yuav ntau npaum.

hom ntawm cov lag luam

Lub transistor muaj nuj nqi muaj feem xyuam rau tus nqi ntawm cov kev cob cog rua voltage. Tag nrho cov hom yuav tsum tau qhia yog tias peb ua Circuit Court ntawm lub bipolar transistor muab yav tas los nrog ib tug ntau emitter.

1. Lub cut-off hom

Qhov no hom yog tsim thaum lub V _YUAV voltage txo rau 0.7 V. Nyob rau hauv cov ntaub ntawv no, lub emitter hlws ris yog kaw thiab tam sim no collector yog tsis tuaj kawm ntawv, vim tsis muaj free electrons nyob rau hauv lub hauv paus. Yog li, cov transistor blocks.

2. Active hom

Yog hais tias ib tug voltage yog thov rau lub hauv paus uas yog txaus los mus qhib lub transistor, muaj ib tug me me tswv yim tam sim no thiab ib tug muaj zog zis, nyob ntawm seb qhov ntau ntawm cov koj qhov nce. Ces tus transistor yuav ua hauj lwm raws li ib tug amplifier.

3. saturation hom

Nws txawv los ntawm lub active hom ntawd hais tias cov transistor yog siab qhib, thiab tus collector tam sim no nce mus txog lub siab tshaj plaws tau muaj nqis. Nws nce yuav tsuas yuav tiav los ntawm kev hloov lub applied electromotive quab yuam los yog load nyob rau hauv lub tso zis Circuit Court. Thaum hloov puag tam sim no collector yog tsis tau hloov. saturation regime tsiag ntawv los ntawm qhov tseeb hais tias tus transistor yog qhib, thiab ntawm no nws ua hauj lwm pab raws li ib tug mus yog muab rau. Schematics ntawm bipolar transistors los ntawm combining cut-off thiab saturation hom cia koj mus tsim nrog lawv hluav taws xob hauv lub lag luam.

Tag nrho cov hom ntawm cov lag luam yog nyob ntawm seb qhov xwm ntawm cov zis yam ntxwv qhia nyob rau hauv lub teeb.

Lawv muaj peev xwm qhia, yog hais tias nws yog tuaj txoos ua ke thaiv daim duab ntawm lub bipolar transistor nrog OE.

Yog hais tias koj muab tso rau hauv ntsug axis thiab tus kab rov tav feem sawv cev rau lub siab tshaj plaws collector tam sim no thiab cov nqi ntawm cov mov voltage V _CC, thiab ces txuas lub xaus rau txhua lwm yam, tau ib tug load kab (liab). Nws yog piav los ntawm qhov _{qhia: Kuv C = (V CC -} V CE) / R C. Los ntawm cov duab nws hais ntxiv hais tias lub operating point uas txiav txim seb tus collector tam sim no kuv _C thiab cov voltage V _CE, yuav tsum moog raws load kab los ntawm lub hauv qab mus nrog ua puag tam sim no kuv _B.

Zone V _CE ntawm lub axis thiab tus thawj tso zis yam ntxwv (tsaus) qhov twg kuv _B = 0 characterizes cutoff hom. Nyob rau hauv no rov qab tam sim no kuv _C yog negligible thiab cov transistor yog kaw.

Lub uppermost yam ntxwv nyob rau hauv lub taw tes A tshuam cov kab load, tom qab uas, nrog ntxiv nce _{nyob rau hauv lub} collector tam sim no kuv tsis tau hloov. Saturation cheeb tsam nyob rau hauv lub teeb yog tus duab ntxoo thaj tsam ntawm lub axis kuv _C thiab cov steepest yam ntxwv.

Yuav ua li cas puas muaj tus transistor nyob rau hauv ntau hom?

Lub transistor ua hauj lwm nrog nce mus nce los los yog qhov teeb txhab khoom mus rau lub tswv yim Circuit Court.

Bipolar Transistor: switching circuits, lub hwj chim

Feem ntau transistor ua hauj lwm pab raws li ib tug amplifier. Lub alternating tswv yim teeb liab ua rau ib tug kev hloov nyob rau hauv nws cov zis tam sim no. Koj yuav thov tau lub tswvyim nrog OK los yog nrog tus MA. Nyob rau hauv lub tso zis Circuit Court rau lub teeb liab yuav tsum tau load. Feem ntau siv ib tug resistor mounted nyob rau hauv lub collector tso zis Circuit Court. Yog hais tias zoo xaiv, tso zis voltage nqi yog ho ntau dua li cov tswv yim.

amplifier ua hauj lwm zoo los ua piv txwv nyob rau hauv lub sij hawm kos duab.

Thaum lub hloov dua siab tshiab mem tes Pib ntsais koj teeb, ib hom yog tib yam li ntawd rau cov sinusoidal. Zoo converting lawv harmonic Cheebtsam txiav txim los ntawm lub zaus yam ntxwv ntawm transistors.

Ua hauj lwm nyob rau hauv switching hom

Transistor keyboards no yog tsim rau cov neeg tsis-hu switching sib txuas nyob rau hauv hluav taws xob circuits. Lub hauv paus ntsiab lus yog lub stepwise hloov nyob rau hauv cov kuj ntawm lub transistor. Bipolar hom yog zoo suited rau cov uas yuav tsum tau ntawm lub ntsiab ntaus ntawv.

xaus

Semiconductor ntsiab siv nyob rau hauv circuits rau converting hluav taws xob Pib ntsais koj teeb. Ntau yam thiab loj faib pub dav siv ntawm bipolar transistors. switching circuits txiav txim lawv zog thiab hom ntawm cov lag luam. Ntau nyob ntawm tus yam ntxwv.

Lub ntsiab Circuit Court switching bipolar transistors ua kom nrov loj, hloov thiab ua kom muaj tswv yim Pib ntsais koj teeb, thiab hloov circuits.