"MOSFET" ndi chidule cha Metal Oxide Semicoductor Field Effect Transistor. Ndi chipangizo chopangidwa ndi zinthu zitatu: zitsulo, okusayidi (SiO2 kapena SiN) ndi semiconductor. MOSFET ndi chimodzi mwazofunikira kwambiri pagawo la semiconductor. Kaya ili mu IC design kapena board-level circuit applications, ndiyochuluka kwambiri. Magawo akuluakulu a MOSFET akuphatikizapo ID, IDM, VGSS, V(BR)DSS, RDS(pa), VGS(th), etc. Kodi mukudziwa izi? OLUKEY Company, monga winsok Taiwanese wapakati mpaka-pamwamba-mapeto sing'anga ndi otsika magetsiMOSFETwothandizira, ali ndi gulu lalikulu lomwe ali ndi zaka pafupifupi 20 kuti akufotokozereni mwatsatanetsatane magawo osiyanasiyana a MOSFET!
Kufotokozera tanthauzo la magawo a MOSFET
1. Zofunikira kwambiri:
ID: Kuchuluka kwa drain-source current. Zimatanthawuza kuchuluka kwaposachedwa komwe kumaloledwa kudutsa pakati pa kukhetsa ndi gwero pomwe transistor yam'munda imagwira ntchito bwino. Kugwira ntchito kwa transistor ya field effect sikuyenera kupitirira ID. Parameter iyi imachepa pamene kutentha kwa mphambano kumawonjezeka.
IDM: Kuthamanga kwambiri kwa drain-source current. Parameter iyi idzachepa pamene kutentha kwa mphambano kumawonjezeka, kusonyeza kukana kwamphamvu komanso kumagwirizana ndi nthawi yothamanga. Ngati parameter iyi ndi yaying'ono kwambiri, dongosololi likhoza kukhala pachiwopsezo chophwanyidwa ndi pano pakuyesa kwa OCP.
PD: Mphamvu zazikuluzikulu zatha. Zimatanthawuza kutayika kwakukulu kwa mphamvu ya gwero lololedwa popanda kusokoneza ntchito ya transistor yam'munda. Akagwiritsidwa ntchito, mphamvu yeniyeni ya FET iyenera kukhala yochepa kuposa ya PDSM ndikusiya malire ena. Izi nthawi zambiri zimachepera pamene kutentha kwa mphambano kumawonjezeka
VDSS: Kuthamanga kwambiri kwa gwero lamagetsi. Mphamvu yamagetsi ya drain-source pamene madzi akukhetsa afika pamtengo wina (akukwera kwambiri) pansi pa kutentha kwina ndi pachipata-gwero lalifupi. Mphamvu ya drain-source pankhaniyi imatchedwanso avalanche breakdown voltage. VDSS ili ndi kutentha kwapakati. Pa -50°C, VDSS ndi pafupifupi 90% ya izo pa 25°C. Chifukwa cha ndalama zomwe nthawi zambiri zimasiyidwa pakupanga kwanthawi zonse, voteji ya avalanche ya MOSFET imakhala yayikulupo kuposa ma voliyumu omwe amavotera.
OLUKAYMalangizo Ofunda: Kuti mutsimikizire kudalirika kwazinthu, pansi pamikhalidwe yoyipa kwambiri yogwirira ntchito, tikulimbikitsidwa kuti voteji yogwira ntchito isapitirire 80 ~ 90% ya mtengo wake.
VGSS: Kuchuluka kwachipata-gwero kupirira voteji. Zimatanthawuza mtengo wa VGS pamene mphamvu yobwerera pakati pa chipata ndi gwero ikuyamba kuwonjezeka kwambiri. Kupitilira mtengo wamagetsiwa kumapangitsa kuwonongeka kwa dielectric pachipata cha oxide wosanjikiza, chomwe ndi kuwonongeka kowononga komanso kosasinthika.
TJ: Kutentha kwakukulu kogwirira ntchito. Nthawi zambiri ndi 150 ℃ kapena 175 ℃. Pansi pamikhalidwe yogwirira ntchito pamapangidwe a chipangizocho, ndikofunikira kupewa kupitilira kutentha uku ndikusiya malire ena.
TSTG: kutentha kosungirako
Magawo awiriwa, TJ ndi TSTG, amawongolera kutentha kwapakati komwe kumaloledwa ndi malo ogwirira ntchito ndi kusungirako kwa chipangizocho. Mtundu wa kutenthawu wakhazikitsidwa kuti ukwaniritse zofunikira zochepa za moyo wa chipangizocho. Ngati chipangizocho chitsimikiziridwa kuti chikugwira ntchito mkati mwa kutentha uku, moyo wake wogwira ntchito udzakulitsidwa kwambiri.
2. Magawo osasunthika
Mayeso a MOSFET nthawi zambiri amakhala 2.5V, 4.5V, ndi 10V.
V(BR)DSS: Voltage yowononga magwero a Drain-source. Zimatanthawuza kuchulukitsitsa kwamagetsi komwe mphamvu ya transistor imatha kupirira pamene chipata cha gwero la VGS ndi 0. Ichi ndi chizindikiro chochepetsera, ndipo mphamvu yogwiritsira ntchito yomwe imagwiritsidwa ntchito kumunda wa transistor iyenera kukhala yochepa kuposa V(BR) DSS. Lili ndi makhalidwe abwino a kutentha. Choncho, mtengo wa chizindikiro ichi pansi pa kutentha kochepa uyenera kutengedwa ngati chitetezo.
△V(BR)DSS/△Tj: Kutentha kokwanira kwa voliyumu yowonongeka, nthawi zambiri 0.1V/℃
RDS (pa): Pazinthu zina za VGS (kawirikawiri 10V), kutentha kwapakati ndi kukhetsa kwapano, kukana kwakukulu pakati pa kukhetsa ndi gwero pamene MOSFET yatsegulidwa. Ndilo gawo lofunikira kwambiri lomwe limatsimikizira mphamvu zomwe zimagwiritsidwa ntchito pamene MOSFET yatsegulidwa. Izi nthawi zambiri zimawonjezeka pamene kutentha kwa mphambano kumawonjezeka. Choncho, mtengo wa chizindikiro ichi pa kutentha kwapamwamba kwambiri kogwirira ntchito uyenera kugwiritsidwa ntchito powerengera kutaya ndi kutsika kwa magetsi.
VGS (th): voteji yoyatsa (voltage). Pamene magetsi oyendetsa chipata chakunja a VGS adutsa VGS (th), zigawo zowonongeka za kukhetsa ndi zigawo zoyambira zimapanga njira yolumikizidwa. M'mapulogalamu, magetsi a pachipata pamene ID ndi yofanana ndi 1 mA pansi pa kukhetsa kwafupipafupi nthawi zambiri amatchedwa mphamvu yamagetsi. Izi nthawi zambiri zimachepera pamene kutentha kwa mphambano kumawonjezeka
IDSS: gwero lodzaza ndi madzi, gwero la madzi pamene magetsi a chipata VGS=0 ndi VDS ndi mtengo wake. Nthawi zambiri pamlingo wa microamp
IGSS: gate-source drive panopa kapena reverse current. Popeza kulowetsedwa kwa MOSFET ndikokulirapo, IGSS nthawi zambiri imakhala mulingo wa nanoamp.
3. Zosintha zamphamvu
gfs: transconductance. Zimatanthawuza chiŵerengero cha kusintha kwa kukhetsa komwe kumatulutsa panopa ndi kusintha kwa magetsi a gate-source. Ndilo muyeso wa mphamvu ya magetsi a gate-source kuwongolera kukhetsa kwapano. Chonde yang'anani tchati cha ubale wosamutsa pakati pa ma gf ndi VGS.
Qg: Chipata chonse cholipiritsa. MOSFET ndi chipangizo chamtundu wamagetsi. Njira yoyendetsera galimoto ndiyo kukhazikitsidwa kwa magetsi pachipata. Izi zimatheka polipira capacitance pakati pa gwero la chipata ndi kukhetsa kwa chipata. Mbali imeneyi ikambidwa mwatsatanetsatane pansipa.
Qgs: Kuchulukira kwa chipata
Qgd: chipata-to-drain charge (potengera zotsatira za Miller). MOSFET ndi chipangizo chamtundu wamagetsi. Njira yoyendetsera galimoto ndiyo kukhazikitsidwa kwa magetsi pachipata. Izi zimatheka polipira capacitance pakati pa gwero la chipata ndi kukhetsa kwa chipata.
Td (pa): nthawi yochedwa conduction. Nthawi yoyambira pomwe magetsi amakwera mpaka 10% mpaka VDS ikatsikira mpaka 90% ya matalikidwe ake.
Tr: nthawi yowuka, nthawi yotulutsa VDS kuchokera ku 90% mpaka 10% ya matalikidwe ake.
Td (kuzimitsa): Nthawi yochedwa yozimitsa, nthawi yoyambira pomwe mphamvu yolowera imatsikira mpaka 90% mpaka VDS ikakwera mpaka 10% yamagetsi ake ozimitsa.
Tf: Nthawi yakugwa, nthawi yotulutsa voteji VDS kukwera kuchokera ku 10% mpaka 90% ya matalikidwe ake.
Ciss: Kuthekera kolowetsa, chepetsani kukhetsa ndi gwero lalifupi, ndikuyesa mphamvu pakati pa chipata ndi gwero ndi chizindikiro cha AC. Ciss = CGD + CGS (CDS yochepa). Zimakhudza mwachindunji kuyatsa ndi kuzimitsa kuchedwa kwa chipangizocho.
Coss: Kuthekera kotulutsa, chepetsani chipata ndi gwero, ndikuyesa mphamvu pakati pa kukhetsa ndi gwero ndi chizindikiro cha AC. Coss = CDS +CGD
Crss: Reverse transmission capacitance. Ndi gwero lolumikizidwa pansi, mphamvu yoyezera pakati pa kukhetsa ndi chipata Crss=CGD. Chimodzi mwazinthu zofunika kwambiri zosinthira ndi nthawi yokwera ndi kugwa. Crss=CGD
The interelectrode capacitance ndi MOSFET induced capacitance ya MOSFET agawidwa mu input capacitance, output capacitance and feedback capacitance ndi ambiri opanga. Makhalidwe omwe atchulidwa ndi amagetsi okhazikika a drain-to-source. Ma capacitances awa amasintha pamene mphamvu yamagetsi ya drain-source imasintha, ndipo mtengo wa capacitance uli ndi zotsatira zochepa. Mtengo wa capacitance wolowera umangopereka chizindikiritso cha kuyitanitsa komwe kumafunikira ndi dera la dalaivala, pomwe chidziwitso chowongolera pachipata ndichothandiza kwambiri. Imawonetsa kuchuluka kwa mphamvu zomwe chipatacho chimayenera kulipira kuti chifike pamagetsi enaake.
4. Kuwonongeka kwa chigumukire magawo
Kuwonongeka kwa avalanche ndi chizindikiro cha kuthekera kwa MOSFET kupirira kuchulukirachulukira kumadera akumidzi. Ngati voteji iposa mphamvu ya gwero la kukhetsa, chipangizocho chidzakhala chopanda phokoso.
EAS: Mphamvu imodzi yowononga mphamvu. Izi ndi malire malire, kusonyeza pazipita avalanche kusweka mphamvu kuti MOSFET akhoza kupirira.
IAR: avalanche current
KUTU: Mphamvu Zobwerezabwereza za Avalanche Breakdown
5. Mu vivo diode magawo
NDI: Continuous maximum freewheeling current (kuchokera gwero)
ISM: pulse maximum freewheeling panopa (kuchokera gwero)
VSD: kutsika kwamagetsi kutsogolo
Trr: sinthani nthawi yochira
Qrr: Bwezerani kubwezeretsanso ndalama
Ton: Nthawi yopititsa patsogolo. (Zachidziwikire)
MOSFET nthawi yoyatsa ndi kumasulira kwa nthawi yozimitsa
Panthawi yofunsira, zotsatirazi ziyenera kuganiziridwa:
1. Makhalidwe abwino a kutentha kwa V (BR) DSS. Khalidweli, lomwe ndi losiyana ndi zida za bipolar, zimawapangitsa kukhala odalirika ngati kutentha kwanthawi zonse kumakwera. Koma muyeneranso kulabadira kudalirika kwake pakuyamba kuzizira kozizira.
2. Makhalidwe oipa a kutentha kwa V (GS) th. Kuthekera kwa zipata kudzachepera pang'ono pomwe kutentha kwa mphambano kumawonjezeka. Ma radiation ena amachepetsanso kuthekera kwa izi, mwinanso kutsika kwa 0. Izi zimafuna mainjiniya kulabadira kusokoneza ndi kuyambitsa zabodza kwa ma MOSFET pamikhalidwe iyi, makamaka pamapulogalamu a MOSFET okhala ndi mwayi wochepa. Chifukwa cha khalidweli, nthawi zina zimakhala zofunikira kupanga mphamvu zowonongeka kwa dalaivala wa pakhomo kuti zikhale zovuta (kutanthauza N-mtundu, P-mtundu ndi zina zotero) kuti mupewe kusokoneza ndi kuyambitsa zabodza.
3.Positive kutentha coefficient makhalidwe a VDSon/RDSo. Makhalidwe omwe VDSon/RDSon amawonjezeka pang'ono pamene kutentha kwa mphambano kumawonjezeka kumapangitsa kuti zitheke kugwiritsa ntchito MOSFET mwachindunji mofanana. Zipangizo za bipolar ndizosiyana kwambiri pankhaniyi, chifukwa chake kugwiritsa ntchito kwawo limodzi kumakhala kovuta. RDSon iwonjezekanso pang'ono pomwe ID ikuwonjezeka. Makhalidwe awa komanso mawonekedwe abwino a kutentha kwa mphambano ndi pamwamba pa RDSon amathandizira MOSFET kupewa kuwonongeka kwachiwiri ngati zida za bipolar. Komabe, ziyenera kudziwidwa kuti zotsatira za mbaliyi ndizochepa. Mukagwiritsidwa ntchito mofananira, kukankha-koka kapena mapulogalamu ena, simungadalire kwathunthu pakudzilamulira nokha. Mfundo zina zofunika zikufunikabe. Khalidweli limafotokozanso kuti kutayika kwa ma conduction kumakhala kokulirapo pakatentha kwambiri. Choncho, chidwi chapadera chiyenera kuperekedwa pakusankhidwa kwa magawo powerengera zotayika.
4. Makhalidwe oipa a kutentha kwa ID, kumvetsetsa kwa magawo a MOSFET ndi zizindikiro zake zazikulu za ID zidzachepa kwambiri pamene kutentha kwapakati kumawonjezeka. Khalidweli limapangitsa kuti nthawi zambiri zizikhala zofunikira kuganizira magawo ake a ID pa kutentha kwakukulu panthawi yopanga.
5. Makhalidwe olakwika a kutentha kwa mphamvu ya avalanche IER/EAS. Pambuyo pa kutentha kwapakati kumawonjezeka, ngakhale MOSFET idzakhala ndi V (BR) DSS yaikulu, ziyenera kuzindikiridwa kuti EAS idzachepetsedwa kwambiri. Ndiko kunena kuti, kuthekera kwake kupirira ma avalanches pansi pa kutentha kwakukulu kumakhala kochepa kwambiri kusiyana ndi kutentha kwabwino.
6. Kuthekera kochititsa ndi kubweza kuchira kwa parasitic diode mu MOSFET sikuli bwino kuposa ma diode wamba. Sichiyembekezeredwa kuti chigwiritsidwe ntchito ngati chonyamulira chachikulu chamakono mu chipika pamapangidwe. Ma diode otsekereza nthawi zambiri amalumikizidwa motsatizana kuti awononge ma diode a parasitic m'thupi, ndipo ma diode ena ofanana amagwiritsidwa ntchito kupanga chonyamulira chamagetsi. Komabe, imatha kuonedwa ngati chonyamulira pakuchita kwakanthawi kochepa kapena zofunikira zina zazing'ono zamakono monga kukonzanso kogwirizana.
7. Kuwonjezeka kofulumira kwa mphamvu ya kukhetsa kungayambitse kusokoneza kwa chipata, kotero kuti izi ziyenera kuganiziridwa m'mapulogalamu akuluakulu a dVDS/dt (mabwalo othamanga kwambiri).