Yintoni i-MOSFET? Zeziphi iiparamitha eziphambili?

Xa uyila unikezelo lwamandla okutshintsha okanye isekethe yemoto drive usebenzisaIi-MOSFETs, izinto ezinjengokumelana ne-on-resistance, i-voltage ephezulu, kunye nobuninzi bangoku be-MOS ziqwalaselwa ngokubanzi.

Iityhubhu ze-MOSFET luhlobo lwe-FET enokwenziwa njengophuculo okanye uhlobo lokuncipha, i-P-channel okanye i-N-channel kwiintlobo ezi-4 zizonke. uphuculo lwe-NMOSFETs kunye nee-PMOSFET zophuculo zisetyenziswa ngokubanzi, kwaye ezi zimbini zidla ngokukhankanywa.

Ezi zimbini zisetyenziswa kakhulu yi-NMOS. isizathu kukuba ukuxhathisa conductive kuncinci kwaye kulula ukwenza. Ke ngoko, i-NMOS ihlala isetyenziswa ekutshintsheni unikezelo lwamandla kunye nezicelo zokuqhuba iimoto.

Ngaphakathi kwe-MOSFET, i-thyristor ifakwe phakathi kwe-drain kunye nomthombo, obaluleke kakhulu ekuqhubeni imithwalo ye-inductive efana ne-motor, kwaye ikhona kuphela kwi-MOSFET enye, kungekhona kwi-chip yesekethe edibeneyo.

I-Parasitic capacitance ikhona phakathi kwezikhonkwane ezintathu ze-MOSFET, kungekhona ukuba siyayifuna, kodwa ngenxa yokunciphisa inkqubo yokuvelisa. Ubukho be-parasitic capacitance buyenza ibe nzima ngakumbi xa uyila okanye ukhetha isiphaluka somqhubi, kodwa ayinakuphetshwa.

 

Iiparamitha eziphambili zeI-MOSFET

1, i-voltage evulekileyo ye-VT

I-voltage evulekileyo (eyaziwa ngokuba yi-voltage ye-threshold): ukwenzela ukuba i-voltage yesango efunekayo ukuqalisa ukwenza umjelo wokuqhuba phakathi komthombo we-S kunye ne-drain D; standard N-channel MOSFET, VT imalunga 3 ~ 6V; ngokuphuculwa kwenkqubo, ixabiso le-MOSFET VT lingancitshiswa libe yi-2 ~ 3V.

 

2, DC ukumelana igalelo RGS

Umlinganiselo wombane odibeneyo phakathi kwepali yomthombo wesango kunye nesango langoku Le mpawu ngamanye amaxesha ibonakaliswa yisango langoku elihamba ngesango, i-RGS ye-MOSFET inokugqithisa ngokulula i-1010Ω.

 

3. Khupha imvelaphi yokuphazamiseka kwamandla ombane e-BVDS.

Ngaphantsi kwemeko ye-VGS = i-0 (eyongeziweyo), kwinkqubo yokwandisa i-drain-source voltage, i-ID inyuka ngokukhawuleza xa i-VDS ibizwa ngokuba yi-drain-source breakdown voltage BVDS, i-ID inyuka ngokukhawuleza ngenxa yezizathu ezibini: (1) i-avalanche. Ukuqhekeka komgangatho wokuncipha kufutshane nombhobho, (2) ukuqhekeka kokungena phakathi kombhobho kunye neepali zomthombo, ezinye ii-MOSFETs, ezinobude obufutshane bomsele, zonyusa i-VDS ukwenzela ukuba umaleko we-drain kummandla wande ukuya kwindawo yomthombo, ukwenza ubude beChannel bube ngu-zero, oko kukuthi, ukuvelisa i-drain-source yokungena, ukungena, ininzi yabathwali kwindawo yomthombo iya kutsalwa ngokuthe ngqo kwintsimi yombane ye-depletion layer ukuya kwi-drain region, kubangele i-ID enkulu. .

 

4, isango lomthombo wokuphazamiseka kwamandla ombane BVGS

Xa i-voltage yesango inyuswa, i-VGS xa i-IG inyuswa ukusuka kwi-zero ibizwa ngokuba yi-voltage ye-bVGS yomthombo wesango.

 

5,I-transconductance ephantsi

Xa i-VDS ilixabiso elimiselweyo, umlinganiselo we-microvariation ye-drain yangoku ukuya kwi-microvariation ye-voltage yomthombo wesango ebangela ukuba utshintsho lubizwa ngokuba yi-transconductance, ebonisa amandla ombane womthombo wesango ukulawula i-drain yangoku, kwaye i-voltage ye-drain yangoku. iparameter ebalulekileyo ebonakalisa isakhono sokukhulisa iI-MOSFET.

 

6, on-ukumelana RON

Ukumelana ne-RON kubonisa umphumo we-VDS kwi-ID, i-inverse ye-slope yomgca we-tangent weempawu zombhobho kwindawo ethile, kwindawo yokuhluthwa, i-ID phantse ayitshintshi kunye ne-VDS, i-RON inkulu kakhulu. ixabiso, ngokubanzi kumashumi e-kilo-Ohms ukuya kumakhulu eekhilo-Ohms, kuba kwiisekethe zedijithali, ii-MOSFET zihlala zisebenza kwimeko ye-VDS eqhubayo = 0, ngoko ke ngeli nqanaba, i-RON yokuchasana inokuqikelelwa imvelaphi ye-RON ukuya kuqikelelo, yeMOSFET ngokubanzi, ixabiso le-RON ngaphakathi kwamakhulu ambalwa ohms.

 

I-7, i-inter-polar capacitance

I-Interpolar capacitance ikhona phakathi kwee-electrode ezintathu: isango lomthombo we-CGS, isango lokukhupha i-CGD kunye ne-drain source capacitance CDS-CGS kunye ne-CGD malunga ne-1 ~ 3pF, i-CDS imalunga ne-0.1 ~ 1pF.

 

8,Into yengxolo ephantsi

Ingxolo ibangelwa zizitenxo ekuhambeni kwabathwali kumbhobho. Ngenxa yobukho bayo, i-voltage engaqhelekanga okanye ukwahluka kwangoku kwenzeka kwimveliso nokuba akukho mqondiso uhanjiswa yi-amplifier. Ukusebenza kwengxolo kuvame ukubonakaliswa ngokwemeko yengxolo NF. Iyunithi yi-decibel (dB). Ixabiso elincinci, ingxolo encinci eyenziwa ityhubhu. I-low-frequency factor yengxolo yinto yengxolo elinganiswa kwi-low-frequency range. Ingxolo yetyhubhu yempembelelo yentsimi imalunga ne-dB embalwa, ngaphantsi kwe-bipolar triode.