Zeziphi izizathu zokufudumeza kweMOSFET?

I-MOSFET ye-inverter isebenza kwimeko yokutshintsha kwaye yangoku ehamba nge-MOSFET iphezulu kakhulu. Ukuba i-MOSFET ayikhethwanga ngokufanelekileyo, i-amplitude yombane wokuqhuba ayinkulu ngokwaneleyo okanye ukuchithwa kobushushu besiphaluka akulunganga, kunokubangela ukuba i-MOSFET ishushu.

 

1, inverter MOSFET ukufudumeza kunzulu, kufuneka ingqaleloI-MOSFETukhetho

I-MOSFET kwi-inverter kwisimo sokutshintsha, ngokubanzi ifuna i-drain yayo yangoku ibe nkulu kangangoko, ukuxhathisa kuncinci kangangoko, ukuze ukwazi ukunciphisa ukuhla kwamandla ombane we-MOSFET, ngaloo ndlela unciphisa i-MOSFET ukusukela ekusetyenzisweni, ukunciphisa ubushushu.

Jonga incwadi ye-MOSFET, siya kufumanisa ukuba okukhona liphezulu ixabiso le-voltage yokumelana ne-MOSFET, kokukhona ukuxhathisa okukhulu, kunye nezo zine-drain ephezulu yangoku, ixabiso eliphantsi lokumelana ne-voltage ye-MOSFET, ukuxhathisa kwayo kungaphantsi kwamashumi iimiliyoni.

Ukucinga ukuba umthwalo wangoku we-5A, sikhetha i-inverter esetyenziswa ngokuqhelekileyo i-MOSFETRU75N08R kunye nokumelana nexabiso le-voltage ye-500V 840 ingaba, i-drain current yabo iku-5A okanye ngaphezulu, kodwa ukuchasana kwee-MOSFET ezimbini kwahlukile, qhuba okufanayo ngoku. , umahluko wabo wobushushu mkhulu kakhulu. I-75N08R kwi-resistance yi-0.008Ω kuphela, ngelixa i-on-resistance ye-840 I-on-resistance ye-75N08R yi-0.008Ω kuphela, ngelixa i-on-resistance ye-840 yi-0.85Ω. Xa umthwalo wangoku ohamba nge-MOSFET yi-5A, ukuhla kwamandla ombane we-75N08R's MOSFET yi-0.04V kuphela, kwaye ukusetyenziswa kwe-MOSFET ye-MOSFET yi-0.2W kuphela, ngelixa ukuhla kombane we-840's MOSFET kunokufikelela kwi-4.25W, kunye nokusetyenziswa ye-MOSFET iphezulu njenge-21.25W. Ukusuka koku, kunokubonwa ukuba ukuxhathisa kwe-MOSFET kwahlukile kwi-on-resistance ye-75N08R, kwaye isizukulwana sabo sobushushu sahluke kakhulu. Okuncinci ukuchasana kwe-MOSFET, ngcono, ukuxhathisa kwe-MOSFET, ityhubhu ye-MOSFET phantsi kokusetyenziswa okuphezulu ngoku inkulu kakhulu.

 

I-2, isiphaluka sokuqhuba i-voltage ye-voltage amplitude ayinkulu ngokwaneleyo

I-MOSFET sisixhobo sokulawula i-voltage, ukuba ufuna ukunciphisa ukusetyenziswa kwetyhubhu ye-MOSFET, ukunciphisa ubushushu, i-MOSFET gate drive voltage amplitude kufuneka ibe nkulu ngokwaneleyo, qhuba i-pulse edge ukuya kwithambeka, inokunciphisa i-voltage.I-MOSFETi-tube voltage drop, ukunciphisa ukusetyenziswa kwetyhubhu ye-MOSFET.

 

3, Ukutshatyalaliswa kobushushu be-MOSFET ayisosizathu silungileyo

Inverter MOSFET ukufudumeza kunzulu. Njengoko i-inverter MOSFET ityhubhu esetyenziswayo inkulu, umsebenzi ngokubanzi ufuna indawo enkulu eyaneleyo yangaphandle yendawo yokutshisa ubushushu, kwaye i-sink yobushushu yangaphandle kunye ne-MOSFET ngokwayo phakathi kwendawo yokutshisa ubushushu kufuneka inxibelelane ngokusondeleyo (ifuneka ngokubanzi ukuba igqunywe nge-thermal conductive. igrisi ye-silicone), ukuba i-sink yobushushu yangaphandle incinci, okanye nge-MOSFET ngokwayo ayisondelanga ngokwaneleyo kuqhagamshelwano lwe-sink yobushushu, kunokukhokelela ekufudumeni kwe-MOSFET.

Inverter MOSFET ukufudumeza serious kukho izizathu ezine zesishwankathelo.

Ukufudumeza okuncinci kwe-MOSFET yinto eqhelekileyo, kodwa ukufudumeza kunzulu, kwaye nokukhokelela kwi-MOSFET kutshiswe, kukho ezi zizathu zilandelayo:

 

1, ingxaki yoyilo lwesekethe

Vumela i-MOSFET isebenze kwimeko yokusebenza ehambelanayo, endaweni yemo yesekethe yokutshintsha. Ikwangomnye woonobangela bokufudumala kweMOSFET. Ukuba i-N-MOS yenza utshintsho, i-voltage ye-G kufuneka ibe yi-V embalwa ngaphezu kokunikezelwa kwamandla ngokupheleleyo, ngelixa i-P-MOS ichasene. Ayivulekanga ngokupheleleyo kwaye ukuhla kwamandla ombane kukhulu kakhulu okukhokelela kusetyenziso lwamandla, i-impedance ye-DC elinganayo inkulu, ukuhla kwe-voltage kuyanda, ngoko ke i-U * ndiyanyuka, ilahleko ithetha ubushushu. Le yeyona mpazamo iphephe kakhulu kuyilo lwesekethe.

 

2, i-frequency ephezulu kakhulu

Esona sizathu siphambili kukuba ngamanye amaxesha ukusukela ngokugqithisileyo umthamo, okukhokelela ekunyukeni rhoqo,I-MOSFETilahleko kwi enkulu, ngoko ke ubushushu kwandiswe.

 

3, akwanelanga uyilo thermal

Ukuba i-current iphezulu kakhulu, ixabiso eliqhelekileyo langoku le-MOSFET, lidla ngokufuna ukuchithwa kakuhle kobushushu ukuze kuphunyezwe. Ke i-ID ingaphantsi kobona buninzi bangoku, inokufudumeza kakubi, idinga isinki yobushushu eyaneleyo.

 

4, ukhetho lwe-MOSFET alulunganga

Isigwebo esingalunganga samandla, ukuchasana kwangaphakathi kwe-MOSFET akuqwalaselwa ngokupheleleyo, okukhokelela ekunyuseni kokutshintsha kokutshintsha.