Uyawazi umjikelezo womshayeli we-MOSFET?

Isekethe yomshayeli we-MOSFET iyingxenye ebalulekile yokwakhiwa kwamandla kagesi kanye nesekethe, enesibopho sokuhlinzeka ngamakhono okushayela anele ukuze kuqinisekiswe ukuthi i-MOSFET ingasebenza kahle nangokwethembeka. Okulandelayo ukuhlaziya okuningiliziwe kwamasekhethi abashayeli be-MOSFET:

I. Indima yesekethe yedrayivu

Nikeza umthamo owanele wokushayela:Njengoba isignali yedrayivu ivame ukunikezwa isilawuli (isb. i-DSP, i-microcontroller), i-voltage yedrayivu kanye neyamanje ingase inganele ukuvula i-MOSFET ngokuqondile, ngakho-ke isekethe yedrayivu iyadingeka ukuze ihambisane nekhono lokushayela.

Qinisekisa izimo ezinhle zokushintsha:Umjikelezo womshayeli udinga ukuqinisekisa ukuthi ama-MOSFET awasheshi kakhulu futhi awanensi kakhulu ngesikhathi sokushintshwa ukuze kugwenywe izinkinga ze-EMI kanye nokulahlekelwa kokushintsha ngokweqile.

Qinisekisa ukwethembeka kwedivayisi:Ngenxa yokuba khona kwepharamitha ye-parasitic yedivayisi yokushintsha, ama-spikes e-voltage-current angase akhiqizwe ngesikhathi sokuqhuba noma ukucisha, futhi isifunda somshayeli sidinga ukucindezela lezi zipikili ukuze kuvikelwe isekethe kanye nedivayisi.

II. Izinhlobo zamasekethe okushayela

 

Umshayeli ongayedwa

I-Direct Drive:Indlela elula yokushayela i-MOSFET ukuxhuma isignali yokushayela ngqo esangweni le-MOSFET. Le ndlela ifanele izikhathi lapho amandla okushayela anele futhi isidingo sokuhlukaniswa singekho phezulu.

Umjikelezo we-Bootstrap:Ngokusebenzisa isimiso sokuthi i-voltage ye-capacitor ayikwazi ukuguqulwa kungazelelwe, i-voltage iphakama ngokuzenzakalelayo lapho i-MOSFET ishintsha isimo sayo sokushintsha, ngaleyo ndlela ishayela i-MOSFET enamandla kakhulu. umshayeli IC, njengamasekhethi eBUCK.

Umshayeli Oyedwa

Ukuhlukaniswa kwe-Optocoupler:Ukuhlukaniswa kwesignali yedrayivu kusuka kumjikelezo oyinhloko kufinyelelwa ngama-optocouplers. I-Optocoupler inezinzuzo zokuhlukaniswa kukagesi kanye nekhono eliqinile lokulwa nokuphazamiseka, kodwa impendulo yemvamisa ingase ibe nomkhawulo, futhi ukuphila nokuthembeka kungase kuncishiswe ngaphansi kwezimo ezinzima.

Ukuhlukaniswa kwe-Transformer:Ukusetshenziswa kwama-transformers ukufeza ukuhlukaniswa kwesignali yokushayela kusuka kumjikelezo oyinhloko. Ukuhlukaniswa kwe-Transformer kunezinzuzo zokuphendula okuhle kwe-high-frequency, i-voltage ephezulu yokuhlukanisa, njll., kodwa umklamo uyinkimbinkimbi futhi ungenwa kalula yimingcele ye-parasitic.

Okwesithathu, ukuklama amaphuzu wesifunda sokushayela

Drive Voltage:Kufanele kuqinisekiswe ukuthi i-voltage yokushayela iphezulu kune-threshold voltage ye-MOSFET ukuze kuqinisekiswe ukuthi i-MOSFET ingakwazi ukuqhuba ngendlela enokwethenjelwa. Ngesikhathi esifanayo, i-voltage yokushayela akufanele ibe phezulu kakhulu ukugwema ukulimaza i-MOSFET.

Shayela okwamanje:Nakuba ama-MOSFET engamadivayisi ashayelwa yi-voltage futhi engadingi idrayivu eqhubekayo yamanje, inani eliphakeme lamanje lidinga ukuqinisekiswa ukuze kuqinisekiswe isivinini esithile sokushintsha. Ngakho-ke, isifunda somshayeli kufanele sikwazi ukuhlinzeka ngenani eliphakeme lamanje.

I-Drive Resistor:I-resistor yedrayivu isetshenziselwa ukulawula isivinini sokushintsha nokucindezela ama-spikes amanje. Ukukhethwa kwevelu ye-resistor kufanele kusekelwe kumjikelezo othize kanye nezici ze-MOSFET. Ngokuvamile, inani le-resistor akufanele libe likhulu kakhulu noma libe lincane kakhulu ukuze kugwenywe ukuthikameza umphumela wokushayela nokusebenza kwesifunda.

Isakhiwo se-PCB:Phakathi nokuhlelwa kwe-PCB, ubude bokuqondanisa phakathi kwesekethe yomshayeli nesango le-MOSFET kufanele bufinyezwe ngangokunokwenzeka, futhi ububanzi bokuqondanisa kufanele bunyuswe ukuze kuncishiswe umthelela we-inductance ye-parasitic kanye nokumelana nomphumela wokushayela. Ngesikhathi esifanayo, izingxenye ezibalulekile ezifana ne-dris resistors kufanele zibekwe eduze kwesango le-MOSFET.

IV. Izibonelo zezicelo

Amasekethe abashayeli be-MOSFET asetshenziswa kakhulu kumadivayisi ahlukahlukene kagesi namasekethe, njengokushintshwa kwezinto zamandla, ama-inverter, namadrayivu ezimoto. Kulezi zinhlelo zokusebenza, ukuklama nokwenza kahle kwamasekhethi abashayeli kubalulekile ukuthuthukisa ukusebenza nokuthembeka kwamadivayisi.

Kafushane, isekethe yokushayela ye-MOSFET iyingxenye ebalulekile yama-electronics kanye nokwakhiwa kwesekethe. Ngokuklama ngokunengqondo isekethe yomshayeli, ingaqinisekisa ukuthi i-MOSFET isebenza ngokujwayelekile nangokuthembekile, ngaleyo ndlela ithuthukise ukusebenza nokuthembeka kwayo yonke isekethe.