Plaub thaj tsam ntawm MOSFET yog dab tsi?

Plaub thaj tsam ntawm N-channel txhim kho MOSFET

(1) Cov cheeb tsam sib txawv tsis sib xws (tseem hu ua thaj tsam unsaturated)

Ucs" Ucs (th) (tig-rau-voltage), uDs" UGs-Ucs (th), yog thaj av rau sab laug ntawm qhov preclamped kab nyob rau hauv daim duab uas lub channel qhib. Tus nqi ntawm UDs yog me me hauv cheeb tsam no, thiab cov channel tsis kam yog tswj los ntawm UGs. Thaum uGs yog qhov tseeb, ip thiab uDs rau hauv kev sib raug zoo, thaj tsam yog kwv yees li cov kab ncaj. Lub sij hawm no, lub teb nyhuv tube D, S ntawm qhov sib npaug ntawm qhov voltage UGS

Tswj los ntawm qhov voltage UGS kuj sib txawv.

(2) thaj tsam tam sim no tsis tu ncua (tseem hu ua cheeb tsam saturation, cheeb tsam amplification, cheeb tsam nquag)

Ucs ≥ Ucs (h) thiab Ubs ≥ UcsUssth), rau daim duab ntawm sab xis ntawm lub pre-pinch tawm khiav, tab sis tseem tsis tau tawg nyob rau hauv lub cheeb tsam, nyob rau hauv lub cheeb tsam, thaum lub uGs yuav tsum, ib yuav luag tsis. hloov nrog UDs, yog ib tug tas mus li-tam sim no yam ntxwv. Kuv tsuas yog tswj los ntawm UGs, ces lub MOSFETD, S yog sib npaug rau qhov voltage uGs tswj ntawm qhov tam sim no. MOSFET yog siv hauv amplification circuits, feem ntau ntawm kev ua haujlwm ntawm MOSFET D, S yog sib npaug rau qhov voltage uGs tswj qhov tam sim no. MOSFET siv nyob rau hauv amplification circuits, feem ntau ua hauj lwm nyob rau hauv lub cheeb tsam, thiaj li hu ua amplification cheeb tsam.

(3) Clip-off cheeb tsam (tseem hu ua cheeb tsam txiav tawm)

Clip-off cheeb tsam (tseem hu ua cheeb tsam txiav tawm) kom tau raws li ucs "Ues (th) rau daim duab nyob ze ntawm kab rov tav axis ntawm cheeb tsam, cov channel yog tag nrho clamped tawm, hu ua tag nrho clip tawm, io = 0 , lub raj tsis ua haujlwm.

(4) qhov chaw sib cais

Lub cheeb tsam tawg yog nyob rau hauv cheeb tsam ntawm sab xis ntawm daim duab. Nrog rau qhov nce UDs, PN kev sib tshuam yog raug rau ntau dhau qhov rov qab voltage thiab tawg, ip nce sharply. Lub raj yuav tsum tau ua haujlwm kom tsis txhob ua haujlwm hauv cheeb tsam tawg. Kev hloov cov yam ntxwv nkhaus tuaj yeem muab tau los ntawm qhov tso zis cov yam ntxwv nkhaus. Ntawm txoj kev siv los ua ib daim duab los nrhiav. Piv txwv li, nyob rau hauv daim duab 3 (a) rau Ubs = 6V ntsug kab, nws cov kev sib tshuam nrog ntau yam nkhaus sib xws rau i, Us qhov tseem ceeb hauv ib- Uss kev tswj xyuas txuas nrog txoj kab nkhaus, uas yog, kom tau txais cov yam ntxwv hloov pauv.

Parameters ntawmMOSFET

Muaj ntau qhov tsis sib xws ntawm MOSFET, suav nrog DC tsis, AC tsis txwv thiab txwv tsis pub, tab sis tsuas yog cov ntsiab lus hauv qab no yuav tsum muaj kev txhawj xeeb hauv kev siv ntau: saturated ntws-qhov tam sim no IDSS pinch-tawm voltage Up, (hluav taws xob hom raj thiab depletion -type insulated-gate tubes, los yog tig-on voltage UT (reinforced insulated-gate tubes), trans-conductance gm, leakage-source breakdown voltage BUDS, siab tshaj plaws dissipated zog PDSM, thiab siab tshaj plaws ntws-qhov chaw tam sim no IDSM.

(1) Saturated ntws tam sim no

Lub saturated ntws tam sim no IDSS yog cov ntws tam sim no nyob rau hauv ib qho kev sib tshuam los yog depletion hom insulated rooj vag MOSFET thaum lub rooj vag voltage UGS = 0.

(2) Clip-off voltage

Lub pinch-off voltage UP yog lub rooj vag voltage nyob rau hauv junction-type lossis depletion-type insulated-gate MOSFET uas tsuas yog txiav tawm ntawm qhov ntws thiab qhov chaw. Raws li qhia hauv 4-25 rau N-channel raj UGS tus ID nkhaus, tuaj yeem nkag siab pom qhov tseem ceeb ntawm IDSS thiab UP

MOSFET plaub cheeb tsam

(3) Tig voltage

Lub turn-on voltage UT yog lub rooj vag voltage nyob rau hauv ib tug reinforced insulated-gate MOSFET uas ua rau lub inter-drain-qhov chaw xwb conductive.

(4) Transconductance

Lub transconductance gm yog lub peev xwm tswj tau ntawm lub qhov rooj qhov hluav taws xob UGS ntawm qhov ntws tam sim no ID, piv txwv li, qhov sib piv ntawm qhov hloov pauv ntawm qhov ntws tam sim no ID mus rau qhov hloov pauv ntawm lub qhov rooj qhov hluav taws xob UGS. 9m yog ib qho tseem ceeb parameter hnyav lub amplification muaj peev xwm ntawm lubMOSFET.

(5) Tshem tawm qhov hluav taws xob tawg

Cov dej ntws tawm qhov hluav taws xob tawg BUDS hais txog lub qhov rooj qhov hluav taws xob qhov hluav taws xob UGS qee yam, MOSFET ib txwm ua haujlwm tuaj yeem lees txais qhov siab tshaj plaws ntws qhov hluav taws xob. Qhov no yog qhov txwv tsis pub, ntxiv rau MOSFET kev khiav hauj lwm voltage yuav tsum tsawg dua BUDS.

(6) Lub zog siab tshaj plaws dissipation

Lub zog siab tshaj plaws dissipation PDSM kuj yog qhov txwv tsis pub, hais txog qhovMOSFETkev ua tau zoo tsis deteriorate thaum lub siab tshaj plaws permissible to qhov hluav taws xob dissipation. Thaum siv MOSFET cov tswv yim siv hluav taws xob yuav tsum tsawg dua li PDSM thiab tawm ntawm cov npoo.

(7) Qhov dej ntws siab tshaj plaws tam sim no

Qhov siab tshaj tawm tam sim no IDSM yog lwm qhov txwv tsis pub, hais txog kev ua haujlwm ib txwm muaj ntawm MOSFET, qhov dej ntws tawm ntawm qhov siab tshaj plaws tam sim no tso cai hla dhau ntawm MOSFET txoj haujlwm tam sim no yuav tsum tsis pub tshaj IDSM.

MOSFET Txoj Cai Ua Haujlwm

Lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm MOSFET (N-channel txhim kho MOSFET) yog siv VGS los tswj tus nqi ntawm "inductive charge", txhawm rau hloov cov xwm txheej ntawm cov channel conductive tsim los ntawm cov "inductive charge", thiab tom qab ntawd kom ua tiav lub hom phiaj. ntawm kev tswj cov dej ntws tam sim no. Lub hom phiaj yog los tswj cov dej ntws tam sim no. Hauv kev tsim cov raj, los ntawm cov txheej txheem ntawm kev ua kom muaj ntau qhov zoo ions hauv txheej txheej insulating, yog li nyob rau sab nraud ntawm lub interface tuaj yeem raug ntxias ntau dua cov nqi tsis zoo, cov nqi tsis zoo no tuaj yeem raug ntxias.

Thaum lub rooj vag voltage hloov, tus nqi ntawm tus nqi induced nyob rau hauv lub channel kuj hloov, qhov dav ntawm cov conductive channel kuj hloov, thiab yog li cov ntws tam sim no ID hloov nrog lub rooj vag voltage.

MOSFET lub luag haujlwm

I. MOSFET tuaj yeem siv rau amplification. Vim hais tias ntawm lub siab input impedance ntawm MOSFET amplifier, lub coupling capacitor tuaj yeem muaj peev xwm me dua, tsis tas siv electrolytic capacitor.

Qhov thib ob, qhov siab input impedance ntawm MOSFET yog qhov tsim nyog rau kev hloov pauv impedance. Feem ntau siv nyob rau hauv multi-theem amplifier input theem rau impedance conversion.

MOSFET tuaj yeem siv los ua qhov hloov pauv hloov tau.

Plaub, MOSFET tuaj yeem siv tau yooj yim los ua qhov chaw tam sim no.

Thib tsib, MOSFET tuaj yeem siv los ua hluav taws xob hloov.