NMOS vs PMOS
A FET (Field Effect Transistor) yog ib qho khoom siv hluav taws xob tswj qhov uas nws lub peev xwm nqa tam sim no hloov pauv los ntawm kev siv hluav taws xob. Ib hom kev siv FET feem ntau yog Hlau Oxide Semiconductor FET (MOSFET). MOSFET yog dav siv nyob rau hauv kev sib xyaw circuits thiab kev kub ceev hloov daim ntawv thov. MOSFET ua hauj lwm los ntawm inducing ib tug conduction channel ntawm ob tug hu ua qhov chaw thiab cov ntws los ntawm kev siv ib tug voltage ntawm oxide-insulated gate electrode. Muaj ob yam tseem ceeb ntawm MOSFET hu ua nMOSFET (feem ntau hu ua NMOS) thiab pMOSFET (feem ntau hu ua PMOS) nyob ntawm seb cov neeg nqa khoom ntws los ntawm cov channel.
NMOS yog dab tsi?
Raws li tau hais ua ntej, NMOS (nMOSFET) yog hom MOSFET. NMOS transistor yog tsim los ntawm n-hom qhov chaw thiab ntws thiab p-hom substrate. Thaum muaj hluav taws xob siv rau lub rooj vag, qhov hauv lub cev (p-hom substrate) raug tsav tawm ntawm lub rooj vag. Qhov no tso cai rau kev tsim cov n-hom channel ntawm qhov chaw thiab cov dej ntws thiab ib qho tam sim no yog nqa los ntawm cov khoom siv hluav taws xob los ntawm qhov chaw mus rau qhov ntws los ntawm qhov induced n-hom channel. Cov rooj vag logic thiab lwm yam khoom siv digital siv siv NMOSs tau hais tias muaj NMOS logic. Muaj peb hom kev ua haujlwm hauv NMOS hu ua kev txiav tawm, triode thiab saturation. NMOS logic yog ib qho yooj yim los tsim thiab tsim khoom. Tab sis circuits nrog NMOS logic rooj vag dissipate lub zog zoo li qub thaum lub voj voog nyob twj ywm, txij li DC tam sim no ntws los ntawm lub rooj vag logic thaum cov zis qis.
PMOS yog dab tsi?
Raws li tau hais ua ntej, PMOS (pMOSFET) yog hom MOSFET. PMOS transistor yog tsim los ntawm p-type source thiab ntws thiab n-hom substrate. Thaum lub qhov hluav taws xob zoo yog siv los ntawm qhov chaw thiab lub rooj vag (tsis zoo voltage ntawm lub rooj vag thiab qhov chaw), p-hom channel yog tsim los ntawm qhov chaw thiab qhov ntws nrog cov polarities opposite. Ib qho tam sim no yog nqa los ntawm qhov los ntawm qhov chaw mus rau qhov ntws los ntawm qhov induced p-hom channel. Qhov hluav taws xob siab ntawm lub rooj vag yuav ua rau PMOS tsis ua, thaum lub qhov rooj tsis tshua muaj hluav taws xob yuav ua rau nws ua. Cov rooj vag logic thiab lwm yam khoom siv digital siv siv PMOS tau hais tias muaj PMOS logic. PMOS thev naus laus zis yog tus nqi qis thiab muaj lub suab nrov tiv thaiv zoo.
NMOS thiab PMOS yog dab tsi?
NMOS yog tsim nrog n-hom qhov chaw thiab ntws thiab p-hom substrate, thaum PMOS yog tsim nrog p-hom qhov chaw thiab ntws thiab n-hom substrate. Hauv NMOS, cov nqa khoom yog cov khoom siv hluav taws xob, thaum nyob hauv PMOS, cov cab kuj yog qhov. Thaum muaj hluav taws xob siab siv rau lub rooj vag, NMOS yuav ua, thaum PMOS yuav tsis. Tsis tas li ntawd, thaum muaj hluav taws xob tsawg siv rau hauv lub rooj vag, NMOS yuav tsis ua thiab PMOS yuav ua. NMOS raug suav hais tias yog ceev tshaj PMOS, txij li cov neeg nqa khoom hauv NMOS, uas yog cov khoom siv hluav taws xob, taug kev ob zaug sai dua qhov, uas yog cov nqa hauv PMOS. Tab sis PMOS cov cuab yeej tiv thaiv lub suab nrov dua li NMOS cov cuab yeej. Tsis tas li ntawd, NMOS ICs yuav me dua PMOS ICs (uas muab tib lub luag haujlwm), txij li NMOS tuaj yeem muab ib nrab ntawm cov impedance muab los ntawm PMOS (uas muaj tib lub geometry thiab kev ua haujlwm).
