Izimbangela Nokuvinjelwa Kokwehluleka Kwe-MOSFET

Izimbangela ezimbili eziyinhlokoof I-MOSFET ukwehluleka:

Ukuhluleka kwe-voltage: okungukuthi, i-voltage ye-BVdss phakathi kwe-drain kanye nomthombo idlula i-voltage elinganiselwe ye-MOSFET futhi ifinyelela umthamo othile, okwenza i-MOSFET ihluleke.

Ukwehluleka Kwegesi Yesango: Isango linenkinga yokukhuphuka kwamandla kagesi okungavamile, okuholela ekuhlulekeni kongqimba lwesango lomoya-mpilo.

Izimbangela Nokuvinjelwa Kokwehluleka Kwe-MOSFET

Goqa iphutha (ukwehluleka kwe-voltage)

Uyini ngempela umonakalo we-avalanche? Kalula nje,i-MOSFET imodi yokwehluleka edalwe yi-superposition phakathi kwama-voltages ebhasi, ama-voltages abonisa i-transformer, ama-spike voltages avuzayo, njll. kanye ne-MOSFET. Ngamafuphi, ukwehluleka okuvamile okwenzeka lapho i-voltage esigxotsheni somthombo we-drain ye-MOSFET idlula inani layo elishiwo likagesi futhi ifinyelela umkhawulo othile wamandla.

Izinyathelo zokuvimbela ukulimala kwe-avalanche:

-Yehlisa umthamo ngendlela efanele. Kulo mkhakha, kuvame ukuncishiswa ngo-80-95%. Khetha ngokusekelwe emigomeni yewaranti yenkampani nezinto eziza kuqala ngomugqa.

-I-voltage ye-reflective inengqondo.

-RCD, TVS ukumuncwa isekethe design kunengqondo.

-Izintambo eziphezulu zamanje kufanele zibe zinkulu ngangokunokwenzeka ukuze kuncishiswe i-inductance ye-parasitic.

-Khetha isango eliphikisayo elifanele Rg.

-Engeza i-RC damping noma i-Zener diode absorption ukuze uthole amandla aphezulu njengoba kudingeka.

Izimbangela Nokuvinjelwa Kokwehluleka Kwe-MOSFET(1)

Ukuhluleka kweSango Voltage

Kunezimbangela ezintathu eziyinhloko zamagridi aphezulu ngokungavamile: ugesi omile ngesikhathi sokukhiqiza, ukuthuthwa nokuhlanganisa; i-high voltage resonance ekhiqizwa imingcele ye-parasitic yemishini namasekethe ngesikhathi sokusebenza kwesistimu yamandla; kanye nokudluliselwa kwamandla kagesi aphezulu nge-Ggd kuya kugridi ngesikhathi sokushaqeka kwamandla kagesi aphezulu (iphutha elivame kakhulu phakathi nokuhlolwa kokushaya kombani).

Izinyathelo zokuvimbela amaphutha kagesi wesango:

Ukuvikelwa kwe-overvoltage phakathi kwesango nomthombo: Uma i-impedance phakathi kwesango nomthombo iphezulu kakhulu, ukushintsha okungazelelwe ku-voltage phakathi kwesango nomthombo kuhlanganiswe nesango ngokusebenzisa amandla phakathi kwama-electrode, okuholela ekulawuleni kwamandla kagesi e-UGS aphezulu kakhulu, okuholela ekulawuleni ngokweqile kwesango. Ukulimala okuhlala njalo kwe-oxidative. Uma i-UGS iku-voltage yesikhashana evumayo, idivayisi ingase futhi ibangele amaphutha. Ngalesi sisekelo, i-impedance yesekethe yedrayivu yesango kufanele incishiswe ngokufanelekile futhi i-resistor yokudambisa noma i-voltage yokuzinzisa engu-20V kufanele ixhunywe phakathi kwesango nomthombo. Kufanele kuqashelwe ngokukhethekile ukuze kuvinjelwe ukusebenza komnyango ovulekile.

Ukuvikelwa kwe-overvoltage phakathi kwamashubhu akhiphayo: Uma kukhona i-inductor kusekethe, izinguquko ezingazelelwe ekuvuzeni kwamanje (di/dt) lapho iyunithi ivaliwe kuzophumela ekudubuleni kwamandla kagesi avuzayo ngaphezu kwamandla kagesi, okubangela ukulimala kweyunithi. Ukuvikela kufanele kuhlanganise i-Zener clamp, RC clamp, noma i-RC suppression circuit.