MOSFET ubumenyi bwibanze bwibanze no kubishyira mubikorwa

Kubyimpamvu yo kubura uburyoMOSFETSntibikoreshwa, ntibisabwa kugera munsi yacyo.

Kuri ubu buryo bubiri bwo kuzamura-MOSFETs, NMOS ikoreshwa cyane. Impamvu nuko on-resistance ari nto kandi yoroshye kuyikora. Kubwibyo, NMOS isanzwe ikoreshwa muguhindura amashanyarazi hamwe na moteri ya moteri. Mu ntangiriro ikurikira, NMOS ikoreshwa cyane.

Hariho ubushobozi bwa parasitike hagati yipine eshatu za MOSFET. Ntabwo aribyo dukeneye, ahubwo biterwa nubushobozi buke bwo gukora. Kubaho kwa parasitike capacitance itera ibibazo cyane mugihe cyo gushushanya cyangwa guhitamo umuzunguruko, ariko ntaburyo bwo kubyirinda. Tuzabimenyekanisha birambuye nyuma.

Hariho diode ya parasitike hagati yumuyoboro nisoko. Ibi byitwa diode yumubiri. Iyi diode ningirakamaro cyane mugihe utwaye imizigo yinductive (nka moteri). Nukuvugako, diode yumubiri ibaho gusa muri MOSFET imwe kandi mubisanzwe ntabwo iboneka imbere muri chip yumuzingi.

 

2. Ibiranga imiyoboro myinshi

Kuyobora bisobanura gukora nka switch, bihwanye na switch ifunze.

Ikiranga NMOS nuko izafungura mugihe Vgs irenze agaciro runaka. Birakwiye gukoreshwa mugihe isoko yatanzwe (disiki yo hasi), mugihe voltage yumuryango igera kuri 4V cyangwa 10V.

Ibiranga PMOS nuko izafungura mugihe Vgs itarenze agaciro runaka, ikwiranye nibihe aho isoko ihurira na VCC (disiki yohejuru). Ariko, nahoPMOSIrashobora gukoreshwa byoroshye nkumushoferi wohejuru, NMOS mubusanzwe ikoreshwa mubashoferi bo murwego rwohejuru bitewe nini nini-irwanya, igiciro kinini, nubwoko buke bwo gusimbuza.

 

3. Igihombo kinini cya MOS

Yaba NMOS cyangwa PMOS, hariho on-resistance nyuma yo gufungura, ubu rero izakoresha ingufu kuriyi myigaragambyo. Iki gice cyingufu zikoreshwa cyitwa gutakaza imiyoboro. Guhitamo MOSFET hamwe na bike birwanya-kurwanya bizagabanya igihombo cyumuyoboro. Uyu munsi imbaraga nke MOSFET on-resistance muri rusange hafi ya miliohms icumi, kandi hariho na miliohms nyinshi.

Iyo MOSFET ifunguye kandi ikazimya, ntigomba kurangira ako kanya. Umuvuduko ukabije kuri MOS ufite inzira igabanuka, kandi umuyaga utemba ufite inzira yiyongera. Muri iki gihe ,.MOSFET'sigihombo nigicuruzwa cya voltage nubu, bita guhinduranya igihombo. Mubisanzwe guhinduranya igihombo ni kinini cyane kuruta igihombo cyo gutwara, kandi byihuse guhinduranya inshuro, niko igihombo kinini.

Ibicuruzwa bya voltage nubu mugihe cyo gutwara ni binini cyane, bitera igihombo kinini. Kugabanya igihe cyo guhinduranya birashobora kugabanya igihombo muri buri cyerekezo; kugabanya inshuro zo guhinduranya birashobora kugabanya umubare woguhindura kumwanya wigihe. Ubwo buryo bwombi burashobora kugabanya igihombo cyo guhindura.

Umuhengeri iyo MOSFET ifunguye. Birashobora kugaragara ko ibicuruzwa bya voltage nubu mugihe cyo gutwara ni binini cyane, kandi igihombo cyatewe nacyo kinini. Kugabanya igihe cyo guhinduranya birashobora kugabanya igihombo muri buri cyerekezo; kugabanya inshuro zo guhinduranya birashobora kugabanya umubare woguhindura kumwanya wigihe. Ubwo buryo bwombi burashobora kugabanya igihombo cyo guhindura.

 

4. Umushoferi wa MOSFET

Ugereranije na bipolar transistors, muri rusange abantu bemeza ko ntamashanyarazi asabwa gufungura MOSFET, mugihe cyose ingufu za GS zirenze agaciro runaka. Ibi biroroshye gukora, ariko kandi dukeneye umuvuduko.

Birashobora kugaragara mumiterere ya MOSFET ko hariho ubushobozi bwa parasitike hagati ya GS na GD, kandi gutwara MOSFET mubyukuri ni kwishyuza no gusohora capacitor. Kwishyuza capacitor bisaba umuyoboro, kuko capacitor irashobora gufatwa nkumuzunguruko mugufi mugihe cyo kwishyuza, bityo umuyoboro uhita uzaba munini. Ikintu cya mbere ugomba kwitondera mugihe uhitamo / gushushanya umushoferi wa MOSFET numubare wigihe gito cyumuzunguruko ushobora gutanga. ?

Ikintu cya kabiri ugomba kumenya nuko NMOS, isanzwe ikoreshwa mugutwara imodoka yo mu rwego rwo hejuru, ikenera voltage yumuryango kugirango irusheho kuba isoko ya voltage iyo ifunguye. Iyo uruhande rwo hejuru rutwarwa na MOSFET rufunguye, voltage yinkomoko ni kimwe na voltage ya drain (VCC), bityo voltage yumuryango ni 4V cyangwa 10V iruta VCC muriki gihe. Niba ushaka kubona voltage nini kuruta VCC muri sisitemu imwe, ukeneye umuzenguruko udasanzwe. Abashoferi benshi bafite moteri yamashanyarazi. Twabibutsa ko ubushobozi bukwiye bwo hanze bugomba gutoranywa kugirango ubone amashanyarazi magufi ahagije yo gutwara MOSFET.

 

4V cyangwa 10V yavuzwe haruguru nugukingura voltage ya MOSFET ikunze gukoreshwa, kandi byanze bikunze hagomba kwemerwa mugihe runaka. Kandi hejuru ya voltage, nihuta umuvuduko wogutwara kandi ntoya irwanya imiyoboro. Ubu hariho MOSFETs hamwe na voltage ntoya yo gutwara ikoreshwa mubice bitandukanye, ariko muri sisitemu ya elegitoroniki ya 12V yimodoka, mubisanzwe gutwara 4V birahagije.

 

Kumashanyarazi ya MOSFET hamwe nigihombo cyayo, nyamuneka reba Microchip ya AN799 Ihuza Abashoferi ba MOSFET kuri MOSFETs. Birasobanutse neza, ntabwo rero nzandika byinshi.

 

Ibicuruzwa bya voltage nubu mugihe cyo gutwara ni binini cyane, bitera igihombo kinini. Kugabanya igihe cyo guhinduranya birashobora kugabanya igihombo muri buri cyerekezo; kugabanya inshuro zo guhinduranya birashobora kugabanya umubare woguhindura kumwanya wigihe. Ubwo buryo bwombi burashobora kugabanya igihombo cyo guhindura.

MOSFET ni ubwoko bwa FET (ubundi ni JFET). Irashobora gukorwa muburyo bwo kuzamura cyangwa kugabanuka, P-umuyoboro cyangwa N-umuyoboro, ubwoko 4 bwose. Ariko, gusa kuzamura-uburyo N-umuyoboro MOSFET ikoreshwa mubyukuri. no kuzamura-ubwoko bwa P-umuyoboro MOSFET, NMOS cyangwa PMOS mubisanzwe bivuga ubu bwoko bubiri.

 

5. Inzira ya porogaramu ya MOSFET?

Ikintu cyingenzi kiranga MOSFET nuburyo bwiza bwo guhinduranya, bityo ikoreshwa cyane mumuzunguruko usaba ibyuma bya elegitoronike, nko guhinduranya amashanyarazi na moteri ya moteri, ndetse no gucana amatara.

 

Uyu munsi abashoferi ba MOSFET bafite byinshi basabwa:

1. Porogaramu ntoya ya voltage

Iyo ukoresheje amashanyarazi ya 5V, niba imiterere ya totem pole gakondo ikoreshwa muriki gihe, kubera ko transistor iba ifite voltage igabanuka ya 0.7V, voltage yanyuma ikoreshwa kumuryango ni 4.3V gusa. Muri iki gihe, duhitamo imbaraga z'irembo nominal

Hariho ingaruka runaka mugihe ukoresheje 4.5V MOSFET. Ikibazo kimwe nacyo kibaho mugihe ukoresheje 3V cyangwa ibindi bikoresho bitanga ingufu nkeya.

2. Porogaramu nini ya voltage

Iyinjiza voltage ntabwo ari agaciro gahamye, izahinduka hamwe nigihe cyangwa ibindi bintu. Ihinduka ritera voltage yo gutwara itangwa numuzunguruko wa PWM kuri MOSFET idahindagurika.

Kugirango MOSFETs itekane munsi yumubyigano muremure, MOSFETs nyinshi zubatswe mumashanyarazi kugirango zigabanye imbaraga za amplitude ya voltage yumuryango. Muri iki gihe, mugihe amashanyarazi yatanzwe yatanzwe arenze voltage yumuyoboro wa voltage, bizatera ingufu nini zihamye.

Muri icyo gihe, niba ukoresheje gusa ihame ryo kugabanya ingufu za voltage kugirango ugabanye voltage yumuryango, MOSFET izakora neza mugihe voltage yinjira ari ndende cyane, ariko mugihe voltage yinjira yagabanutse, voltage yumuryango izaba idahagije, bigatera imiyoboro ituzuye, bityo kongera ingufu zikoreshwa.

3. Porogaramu ya voltage ebyiri

Mubice bimwe na bimwe bigenzura, igice cya logique gikoresha voltage isanzwe ya 5V cyangwa 3.3V, mugihe igice cyamashanyarazi gikoresha voltage ya 12V cyangwa irenga. Umuvuduko wombi uhujwe nubutaka rusange.

Ibi bizamura icyifuzo cyo gukoresha umuzenguruko kugirango uruhande ruke rwa voltage rushobore kugenzura neza MOSFET kuruhande rwumuvuduko mwinshi. Muri icyo gihe, MOSFET kuruhande rwumuvuduko mwinshi nayo izahura nibibazo byavuzwe muri 1 na 2.

Muri ibi bihe bitatu, imiterere ya totem pole ntishobora kuba yujuje ibyasohotse bisohoka, kandi byinshi hanze ya tekinike ya MOSFET yumushoferi IC ntabwo bisa nkibirimo amarembo ya voltage agabanya imiterere.

 

Nashizeho rero uruziga rusanzwe rusanzwe kugirango mpuze ibyo bitatu bikenewe.

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Umushoferi uzunguruka kuri NMOS

Hano nzakora gusa isesengura ryoroshye ryumushoferi wa NMOS:

Vl na Vh nibikoresho byo hasi-byanyuma kandi bitanga ingufu zingana. Umuvuduko wombi urashobora kuba umwe, ariko Vl ntigomba kurenza Vh.

Q1 na Q2 bigize totem pole ihindagurika kugirango bagere ku bwigunge mugihe bareba ko imiyoboro ibiri ya shoferi Q3 na Q4 idafungura icyarimwe.

R2 na R3 bitanga amashanyarazi ya PWM. Muguhindura iyi nyandiko, umuzenguruko urashobora gukorerwa mumwanya aho ibimenyetso bya PWM byerekana neza.

Q3 na Q4 bikoreshwa mugutanga ibiyobora. Iyo ufunguye, Q3 na Q4 bifite gusa voltage ntoya ya Vce ugereranije na Vh na GND. Igabanuka rya voltage mubisanzwe ni 0.3V gusa, iri munsi cyane ya Vce ya 0.7V.

R5 na R6 nibirwanya ibitekerezo, bikoreshwa mugupima voltage yumuryango. Umuvuduko w'icyitegererezo utanga ibitekerezo bibi cyane kubitekerezo bya Q1 na Q2 kugeza Q5, bityo bikagabanya voltage yumuryango kugiciro gito. Agaciro gashobora guhinduka binyuze muri R5 na R6.

Hanyuma, R1 itanga igipimo fatizo cyibanze kuri Q3 na Q4, naho R4 itanga amarembo agezweho ya MOSFET, akaba aribwo rugabano rwa Buzimu bwa Q3 na Q4. Nibiba ngombwa, capacitor yihuta irashobora guhuzwa ugereranije na R4.

Uyu muzunguruko utanga ibintu bikurikira:

1. Koresha voltage yo hepfo na PWM kugirango utware MOSFET yo murwego rwo hejuru.

2. Koresha ikimenyetso gito cya amplitude PWM kugirango utware MOSFET ifite amarembo maremare asabwa.

3. Umupaka ntarengwa wa voltage yumuryango

4. Kwinjiza no gusohora imipaka igezweho

5. Ukoresheje rezistoriste ikwiye, gukoresha ingufu nke cyane birashobora kugerwaho.

6. Ikimenyetso cya PWM gihinduwe. NMOS ntabwo ikeneye iyi mikorere kandi irashobora gukemurwa no gushyira inverter imbere.

Mugihe utegura ibikoresho byimukanwa nibicuruzwa bidafite umugozi, kunoza imikorere yibicuruzwa no kongera ubuzima bwa bateri nibibazo bibiri abashushanya bakeneye guhura nabyo. Abahindura DC-DC bafite ibyiza byo gukora neza, ibisohoka binini, hamwe na quiescent nkeya, bigatuma bikenerwa cyane no gukoresha ibikoresho byimuka. Kugeza ubu, inzira nyamukuru mu iterambere rya tekinoroji ya DC-DC ihindura ni: (1) Ikoranabuhanga ryihuta cyane: Nkuko guhinduranya inshuro byiyongera, ubunini bwihinduranya nabwo buragabanuka, ubwinshi bwamashanyarazi nabwo bwiyongera cyane, kandi igisubizo cyingirakamaro kiratunganijwe. . Guhindura inshuro za DC-DC zihindura imbaraga zizamuka kurwego rwa megahertz. . ibisabwa kubitunganya nibikoresho bya elegitoroniki byoroshye.

Iterambere ryikoranabuhanga ryashyize imbere ibisabwa hejuru mugushushanya amashanyarazi ya chip. Mbere ya byose, nkuko guhinduranya inshuro zikomeza kwiyongera, ibisabwa bihanitse bishyirwa kumikorere yibintu. Muri icyo gihe, ibice byo guhinduranya ibintu bigomba gutangwa kugirango harebwe niba ibintu byo guhinduranya bikora bisanzwe muguhindura imirongo kugeza kuri MHz. Icya kabiri, kubikoresho bya elegitoroniki bikoreshwa na elegitoronike, voltage ikora yumuzunguruko iba mike (gufata bateri ya lithium nkurugero, voltage ikora ni 2.5 ~ 3.6V), kubwibyo rero, imbaraga zakazi za chip yamashanyarazi ziri hasi.

 

MOSFET ifite imbaraga nke cyane zo kurwanya kandi ikoresha ingufu nke. MOSFET ikoreshwa kenshi nka power power muri chip-DC izwi cyane. Nyamara, kubera ubushobozi bwa parasitike nini ya MOSFET, ubushobozi bw irembo rya NMOS ihinduranya imiyoboro muri rusange ni hejuru ya picofarad mirongo. Ibi birashyira imbere ibyangombwa bisabwa kugirango igishushanyo mbonera gikora cyane DC-DC ihinduranya imiyoboro ya moteri.

Mubishushanyo bito bya ULSI bishushanyije, hariho imiyoboro itandukanye ya CMOS na BiCMOS ukoresheje bootstrap yo kuzamura ibikoresho no gutwara imiyoboro nkimitwaro minini ya capacitive. Iyi mizunguruko irashobora gukora mubisanzwe hamwe numuyoboro wamashanyarazi uri munsi ya 1V, kandi irashobora gukora kumurongo wa megahertz mirongo cyangwa na megahertz amagana hamwe nubushobozi bwumutwaro wa 1 kugeza 2pF. Iyi ngingo ikoresha bootstrap itera umuzenguruko kugirango ishushanye umuzenguruko wa disiki ifite ubushobozi bunini bwo gutwara ibintu bikwiranye na voltage nkeya, guhinduranya inshuro nyinshi kuzamura DC-DC. Umuzunguruko wakozwe ushingiye kubikorwa bya Samsung AHP615 BiCMOS kandi bigenzurwa na simulation ya Hspice. Iyo voltage yo gutanga ari 1.5V naho ubushobozi bwumutwaro ni 60pF, inshuro ikora irashobora kugera kuri 5MHz.

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Ibiranga MOSFET biranga

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1. Ibiranga imiterere

Nkikintu cyo guhinduranya, MOSFET nayo ikora muri leta ebyiri: kuzimya cyangwa kuri. Kubera ko MOSFET ari igikoresho kigenzurwa na voltage, imikorere yacyo igenwa cyane cyane n irembo-isoko ya voltage uGS.

 

Ibiranga akazi ni ibi bikurikira:

※ uGS ＜ gufungura voltage UT: MOSFET ikorera ahantu haciwe, imiyoboro y'amazi iDS ni 0, ibisohoka voltage uDS≈UDD, kandi MOSFET iri muri "off".

※ uGS> Kuzimya voltage UT: MOSFET ikorera mukarere kayobora, imiyoboro y'amazi iDS = UDD / (RD + rDS). Muri byo, rDS ni imiyoboro irwanya isoko iyo MOSFET ifunguye. Ibisohoka voltage UDS = UDD? RdS / (RD + rDS), niba rDS ＜＜ RD, uDS≈0V, MOSFET iri muri "kuri" leta.

2. Ibiranga imbaraga

MOSFET nayo ifite inzira yinzibacyuho mugihe ihinduranya hagati ya reta na reta, ariko ibiranga imbaraga zayo ahanini biterwa nigihe gisabwa cyo kwishyuza no gusohora ubushobozi bwayobye bujyanye numuzunguruko, hamwe no gukusanya amafaranga no gusohora mugihe umuyoboro ubwawo urimo kandi uzimye Igihe cyo gutandukana ni gito cyane.

Iyo kwinjiza voltage ui ihindutse kuva hejuru ikagera hasi kandi MOSFET ihinduka kuva kuri leta ikajya kuri leta, amashanyarazi UDD yishyuza ubushobozi bwa CL yataye umurongo binyuze muri RD, kandi igihe cyo kwishyuza gihoraho τ1 = RDCL. Kubwibyo, ibisohoka voltage uo ikeneye kunyura mubukererwe runaka mbere yo guhinduka kuva murwego rwo hasi ikagera kurwego rwo hejuru; iyo kwinjiza voltage ui ihinduka kuva hasi ikagera hejuru kandi MOSFET ihinduka kuva kuri reta ikajya kuri leta, amafaranga kuri capacitance yazimiye CL anyura muri rDS Gusohora bibaho hamwe nigihe cyo gusohora gihoraho τ2≈rDSCL. Birashobora kugaragara ko ibisohoka voltage Uo nayo ikenera gutinda mbere yuko ishobora kwimuka kurwego rwo hasi. Ariko kubera ko rDS ari nto cyane kurenza RD, igihe cyo guhinduka kuva guhagarikwa kugeza kugitwara ni kigufi kuruta igihe cyo guhinduka kuva kwiyobora kugera.

Kubera ko imiyoboro y-imiyoboro irwanya rDS ya MOSFET iyo ifunguye ni nini cyane kuruta kwiyuzuzanya kwuzuye kwa rCES ya transistor, kandi irwanya imiyoboro yo hanze RD nayo nini kuruta iyakusanyirizaga RC ya transistor, igihe cyo kwishyuza no gusohora ya MOSFET ni ndende, ikora MOSFET Umuvuduko wo guhinduranya uri munsi ya transistor. Nyamara, mumuzunguruko wa CMOS, kubera ko umuzunguruko wumuriro hamwe numuzunguruko usohora byombi ari imiyoboro idahwitse, uburyo bwo kwishyuza no gusohora birihuta cyane, bigatuma umuvuduko mwinshi wo guhinduranya umuzunguruko wa CMOS.