Mashandiro Akawedzerwa Package MOSFETs Anoshanda

Paunenge uchigadzira switching power supply kana mota dhiraivha wedunhu uchishandisa encapsulated MOSFETs, vanhu vazhinji vanofunga nezve-kupokana kweMOS, iyo yakanyanya voltage, nezvimwewo, iyo yakanyanya ikozvino, nezvimwewo, uye kune vazhinji vanongofunga zvinhu izvi chete. Maseketi akadaro anogona kushanda, asi haana kunaka uye haatenderwe seyakagadzirirwa chigadzirwa magadzirirwo.

Inotevera ipfupiso diki yezvakakosha zveMOSFET uyeMOSFETmutyairi maseketi, ayo andinotaura kune akati wandei masosi, kwete ese epakutanga. Kusanganisira kuunzwa kweMOSFETs, maitiro, dhiraivha uye maseketi ekushandisa. Packaging MOSFET marudzi uye junction MOSFET iFET (imwe JFET), inogona kugadzirwa kuva yakakwidziridzwa kana kupera simba, P-channel kana N-channel akazara emhando ina, asi iko kushandiswa kweiyo chete yakagadziridzwa N-channel MOSFET uye yakagadziridzwa P. -Channel MOSFET, saka inowanzonzi NMOS, kana PMOS inoreva marudzi maviri aya.

Kana zviri zvekuti sei usingashandise depletion type MOSFETs, hazvikurudzirwe kusvika pazasi payo. Kune aya marudzi maviri ekusimudzira MOSFETs, NMOS inonyanya kushandiswa nekuda kwekudzikira kwayo-kupokana uye kureruka kwekugadzira. Saka kushandura magetsi uye mota drive application, kazhinji shandisa NMOS. sumo inotevera, asiwo zvimweNMOS-based.

MOSFETs ine parasitic capacitance pakati pemapini matatu, izvo zvisingadiwe, asi nekuda kwekukanganisa kwekugadzira maitiro. Kuvapo kweparasitic capacitance mukugadzira kana kusarudzwa kwedhiraivha yedhiraivha kuve imwe dambudziko, asi hapana nzira yekudzivisa, uye zvino inotsanangurwa zvakadzama. Sezvauri kuona pane iyo MOSFET schematic, pane parasitic diode pakati pekudonhedza uye kunobva.

Izvi zvinonzi body diode uye zvakakosha pakutyaira inductive mitoro yakadai semotor. Nenzira, diode yemuviri inongowanikwa mumunhuMOSFETsuye kazhinji haisipo mukati meiyo integrated circuit chip.MOSFET ON CharacteristicsOn zvinoreva kuita sechishanduko, iyo yakaenzana nekuvhara kushandura.

NMOS maitiro, Vgs yakakura kupfuura imwe kukosha ichaitisa, yakakodzera kushandiswa muchiitiko kana sosi yakadzikwa (yakaderera-kuguma drive), chero bedzi gedhi voltage ye4V kana 10V. PMOS maitiro, Vgs isingasviki imwe kukosha ichaitisa, yakakodzera kushandiswa mune iyo nyaya kana sosi yakabatana neVCC (yepamusoro-yekupedzisira drive). Nekudaro, kunyangwe PMOS ichigona kushandiswa zviri nyore semutyairi wekupedzisira, NMOS inowanzo shandiswa mumadhiraivha ekupedzisira nekuda kwehukuru hwekupokana, mutengo wepamusoro, uye mashoma ekutsiva marudzi.

Packaging MOSFET switching chubhu kurasikirwa, ingave NMOS kana PMOS, mushure mekuitisa pane-kupokana kuripo, kuti yazvino inopedza simba mukupokana uku, ichi chikamu chesimba rinopedzwa chinonzi conduction kurasikirwa. Kusarudza MOSFET ine diki pa-resistance kunoderedza kurasikirwa kwekuita. Mazuvano, kusamira kwemagetsi madiki eMOSFET kunowanzoita makumi emamiriyoni, uye mamiriyoni mashoma aripowo.MOS haifanirwe kupedzwa nekukasira kana ichiita nekudzimwa.Votigeti iri kumativi ese eMOS ine magetsi nzira yekuderera, uye ikozvino inoyerera kuburikidza nayo ine nzira yekuwedzera.Munguva ino, kurasikirwa kweMOSFET ndicho chigadzirwa chemagetsi uye ikozvino, iyo inonzi inoshandura kurasikirwa. Kazhinji kurasikirwa kwekuchinja kwakakura zvakanyanya kudarika kurasikirwa kwekuita, uye nekukurumidza kuchinja kwekuchinja, kunowedzera kurasikirwa. Chigadzirwa chemagetsi uye chazvino panguva yekufambisa chakakura kwazvo, zvichikonzera kurasikirwa kukuru.

Kupfupisa nguva yekuchinja kunoderedza kurasikirwa pane imwe neimwe conduction; kudzikisa kushandura frequency kunoderedza huwandu hwekuchinja pane imwe unit nguva. Nzira mbiri idzi dzinogona kuderedza kurasikirwa kwekuchinja. Chigadzirwa chemagetsi uye chazvino panguva yekufambisa chakakura, uye kurasikirwa kunoguma kwakakurawo. Kupfupisa nguva yekuchinja kunogona kuderedza kurasikirwa pane imwe neimwe conduction; kuderedza kushanduka kwekuchinja kunogona kuderedza nhamba yekuchinja pane imwe nguva yeyuniti. Nzira mbiri idzi dzinogona kuderedza kurasikirwa kwekuchinja. Kutyaira Kuenzaniswa nebipolar transistors, zvinotendwa kuti hapana ikozvino inodikanwa kuti ubatidze MOSFET yakarongedza, chero bedzi GS voltage iri pamusoro pehumwe kukosha. Izvi zviri nyore kuita, zvisinei, tinodawo kukurumidza. Chimiro cheMOSFET yakavharidzirwa inogona kuonekwa muhupo hweparasitic capacitance pakati peGS, GD, uye kutyaira kweMOSFET ndiko, iko kubhadharisa uye kubudiswa kwesimba. Kuchaja iyo capacitor inoda ikozvino, nekuti kubhadharisa iyo capacitor pakarepo inogona kuoneka sepfupi pfupi, saka iyo pakarepo ikozvino ichave yakakura. Chinhu chekutanga chekucherechedza kana uchisarudza / kugadzira mutyairi weMOSFET saizi yekanguva pfupi-yedunhu ikozvino inogona kupihwa.

Chechipiri chekucherechedza ndechekuti, chinowanzo shandiswa mu-high-end drive NMOS, iyo-on-nguva gedhi voltage inoda kuve yakakura kupfuura iyo sosi voltage. High-end drive MOSFET conduction source voltage uye drain voltage (VCC) zvakafanana, saka magetsi egedhi kupfuura VCC 4 V kana 10 V. Kana mune imwecheteyo system, kuti tiwane guru guru kupfuura VCC, tinofanira hunyanzvi kusimudzira matunhu. Vazhinji vatyairi vemota vakabatanidza pombi yekuchaja, zvakakosha kuti uzive kuti iwe unofanirwa kusarudza iyo yakakodzera yekunze capacitance, kuitira kuti uwane yakakwana pfupi-yedunhu ikozvino kutyaira iyo MOSFET. 4V kana 10V inowanzoshandiswa mu-on-state voltage yeMOSFET, hongu, dhizaini inoda kuve neimwe margin. Kukwira kwevoltage, ndiko kukurumidza kwe-on-state kumhanya uye kuderera kwe-on-state kuramba. Mazuvano, kune maMOSFET ane madiki pa-state voltage anoshandiswa munzvimbo dzakasiyana, asi mumagetsi emagetsi e12V, kazhinji 4V pa-state inokwana.MOSFET drive circuit uye kurasikirwa kwayo.