Indlela yokukhetha ngokuchanekileyo ii-MOSFET zombane ezincinci

Amandla ombane amancinci Ukukhetha iMOSFET yinxalenye ebaluleke kakhuluI-MOSFETUkukhetha akulunganga kunokuchaphazela ukusebenza kunye neendleko zesekethe yonke, kodwa kwakhona kuya kuzisa ingxaki enkulu kwiinjineli, ukuba ungayikhetha njani ngokuchanekileyo iMOSFET?

Ukukhetha i-N-channel okanye i-P-channel Inyathelo lokuqala ekukhetheni isixhobo esichanekileyo kuyilo kukwenza isigqibo sokuba sisebenzise i-N-channel okanye i-P-channel MOSFET Kusetyenziso lwamandla oluqhelekileyo, i-MOSFET yenza iswiwi esecaleni ene-voltage ephantsi. I-MOSFET isekelwe kwaye umthwalo uqhagamshelwe kumandla ombane we-trunk. Kwi-low voltage side switch, i-N-channel MOSFET kufuneka isetyenziswe ngenxa yokuqwalaselwa kwamandla ombane afunekayo ukucima okanye ukuvula isixhobo.

Xa i-MOSFET iqhagamshelwe ebhasini kwaye umthwalo uphantsi, iswitshi yecala lombane ophezulu kufuneka isetyenziswe. IP-channel MOSFETs zidla ngokusetyenziswa kule topology, kwakhona kuqwalaselo lokuqhuba kombane. Qinisekisa ukalisho lwangoku. Khetha ireyithingi yangoku yeMOSFET. Ngokuxhomekeke kwisakhiwo sesekethe, eli nqanaba langoku kufuneka libe ngowona mzuzu uphezulu onokuwuthwala umthwalo phantsi kwazo zonke iimeko.

Ngokufanayo kwimeko yombane, umyili kufuneka aqinisekise ukuba okhethiweyoI-MOSFETinokumelana nolu mlinganiselo lwangoku, naxa inkqubo ivelisa imisinga ye-spike. Iimeko ezimbini zangoku ekufuneka ziqwalaselwe ziimowudi eziqhubekayo kunye ne-pulse spikes. Kwimo yokuqhuba eqhubekayo, i-MOSFET ikwimo ezinzileyo, xa ikhoyo ngoku idlula ngokuqhubekayo kwisixhobo.

I-Pulse spikes kuxa kukho ii-surges ezinkulu (okanye ii-spikes zangoku) ezihamba kwisixhobo. Emva kokuba ubuninzi bangoku phantsi kwezi meko sele buchongiwe, yinto nje yokukhetha ngokuthe ngqo isixhobo esinokumelana nalo mbane uphezulu. Ukumisela iiMfuno zeThermal Ukukhetha i-MOSFET kufuna ukubalwa kweemfuno ze-thermal zesistim. Umyili kufuneka athathele ingqalelo iimeko ezimbini ezahlukeneyo, eyona meko imbi kunye neyenyani. Kucetyiswa ukuba isibalo esibi kakhulu sisetyenziswe kuba sibonelela ngomda omkhulu wokhuseleko kwaye siqinisekisa ukuba inkqubo ayiyi kusilela. Kukwakho nemilinganiselo ethile ekufuneka iqwalaselwe kwiphepha ledatha le-MOSFET; njengokumelana ne-thermal phakathi kwe-semiconductor junction yesixhobo sephakheji kunye nokusingqongileyo, kunye neqondo lokushisa eliphezulu. Ukugqiba malunga nokutshintsha ukusebenza, inyathelo lokugqibela ekukhetheni i-MOSFET kukugqiba malunga nokutshintsha ukusebenza kwenkqubo.I-MOSFET.

Kukho iiparameters ezininzi ezichaphazela ukusebenza kokutshintsha, kodwa eyona nto ibalulekileyo yisango / i-drain, isango / umthombo, kunye ne-drain / source capacitance. Ezi capacitances zidala ilahleko zokutshintsha kwisixhobo kuba kufuneka zihlawulwe ngexesha lokutshintsha ngalunye. isantya sokutshintsha kwe-MOSFET ngoko siyancitshiswa kwaye ukusebenza kakuhle kwesixhobo kuyancipha. Ukubala ilahleko epheleleyo yesixhobo ngexesha lokutshintsha, umyili kufuneka abale iilahleko zokuvula (i-Eon) kunye neelahleko zokucima.

Xa ixabiso le-vGS lincinci, ukukwazi ukufunxa i-electron akunamandla, ukuvuza-umthombo phakathi kwe-conductive channel presents, i-vGS yanda, ifakwe kwi-P substrate yangaphandle yomgangatho we-electron ekunyukeni, xa i-vGS ifikelela kwindawo. ixabiso elithile, ezi electron esangweni kufutshane P substrate inkangeleko yenza umaleko obhityileyo of N-uhlobo, kunye nezimbini N + zone eqhagamshelweyo Xa vGS ifikelela ixabiso elithile, ezi electron Isango elikufuphi nembonakalo ye-substrate ye-P liyakwenza umaleko obhityileyo we-N, kwaye uqhagamshelwe kwimimandla emibini ye-N +, kwidrain - umthombo wenza i-N-type conductive channel, uhlobo lwalo lokuqhuba kunye nechasana ne-P substrate, eyenza umaleko ochasene nohlobo. I-vGS inkulu, indima yembonakalo ye-semiconductor yomelele ngakumbi kwintsimi yombane, ukufunxwa kwee-electron ngaphandle kwe-substrate ye-P, ngakumbi i-channel conductive iyancipha, iyancipha ukuxhathisa kwetshaneli. Oko kukuthi, i-N-channel MOSFET kwi-vGS <VT, ayikwazi ukwenza i-channel conductive, ityhubhu ikwimeko yokunqunyulwa. Logama nje vGS ≥ VT, kuphela xa ukwakhiwa kwetshaneli. Emva kokuba ishaneli yenziwe, i-drain current iveliswa ngokudibanisa i-vDS ye-voltage phambili phakathi kwe-drain - source.

Kodwa i-Vgs iyaqhubeka ikhula, masithi IRFPS40N60KVgs = 100V xa i-Vds = 0 kunye ne-Vds = 400V, iimeko ezimbini, umsebenzi wetyhubhu ukuzisa yintoni umphumo, ukuba utshiswe, imbangela kunye nendlela yangaphakathi yenkqubo yindlela yokwandisa iVgs iya kunciphisa. I-Rds (on) iyanciphisa ilahleko yokutshintsha, kodwa kwangaxeshanye iya kwandisa i-Qg, ukuze ilahleko yokujika ibe nkulu, ichaphazele ukusebenza kakuhle Umbane weMOSFET GS ngeVgg ukuya kwiCgs ukutshaja nokunyuka, ufike kumbane wolondolozo lweVth, iMOSFET iqalisa ukuqhutywa; Ukunyuka kwangoku kwe-MOSFET DS, i-Millier capacitance kwisithuba ngenxa yokukhutshwa kwe-DS capacitance kunye nokukhutshwa, ukutshaja kwe-GS capacitance ayinayo impembelelo enkulu; Qg = Cgs * Vgs, kodwa intlawulo iya kuqhubeka ukwakha.

Umbane we-DS we-MOSFET wehla ukuya kumbane ofanayo kunye ne-Vgs, amandla e-Millier anyuka kakhulu, i-voltage yangaphandle yokuqhuba iyayeka ukutshaja i-Millier capacitance, i-voltage ye-GS capacitance ihlala ingatshintshi, i-voltage kwi-Millier capacitance iyanda, ngelixa amandla ombane kwi-DS capacitance iyaqhubeka nokuhla; I-voltage ye-DS ye-MOSFET iyancipha ukuya kwi-voltage ekuqhubeni okugcweleyo, i-Millier capacitance iba yincinci I-voltage ye-DS ye-MOSFET ihla iye kwi-voltage kwi-saturation conduction, i-Millier capacitance iba yincinci kwaye ihlawuliswa kunye ne-GS capacitance nge-drive yangaphandle. i-voltage, kunye ne-voltage kwi-GS capacitance iphakama; imijelo yokulinganisa i-voltage yi-3D01 yasekhaya, i-4D01, kunye ne-series ye-3SK ye-Nissan.

I-G-pole (isango) ukuzimisela: sebenzisa i-diode gear ye-multimeter. Ukuba unyawo kunye nezinye iinyawo ezimbini phakathi kwe-voltage ye-positive kunye ne-negative voltage zinkulu kune-2V, oko kukuthi, umboniso "1", olu nyawo lusango G. Kwaye utshintshe ipeni ukulinganisa ezinye iinyawo ezimbini, ukuhla kwe-voltage kuncinci ngelo xesha, ipeni elimnyama lixhunywe kwi-D-pole (i-drain), ipeni ebomvu ixhunyiwe kwi-S-pole (umthombo).