Chii chinonzi MOSFET? Ndezvipi zvakakosha parameters?

Paunenge uchigadzira switching power supply kana mota drive wedunhu uchishandisaMOSFETs, zvinhu zvakadai se-on-resistance, maximum voltage, uye yakanyanya ikozvino yeMOS zvinowanzoonekwa.

MOSFET machubhu imhando yeFET inogona kugadzirwa senge yekusimudzira kana kupera simba, P-channel kana N-channel yemhando ina. kusimudzira NMOSFETs uye kukwidziridzwa PMOSFETs anowanzo shandiswa, uye maviri aya anowanzo kutaurwa.

Aya maviri anonyanya kushandiswa ndeyeNMOS. chikonzero ndechekuti conductive resistance idiki uye iri nyore kugadzira. Naizvozvo, NMOS inowanzo shandiswa mukuchinja magetsi uye mota drive application.

Mukati meMOSFET, thyristor inoiswa pakati pemvura uye sosi, iyo yakakosha mukutyaira inductive mitoro yakadai semotor, uye inongowanikwa mune imwechete MOSFET, isingawanzo mumubatanidzwa wedunhu chip.

Parasitic capacitance iripo pakati pemapini matatu eMOSFET, kwete kuti isu tinoida, asi nekuda kwekugumira kwekugadzira maitiro. Kuvapo kweparasitic capacitance kunoita kuti zvinyanye kuomesesa pakugadzira kana kusarudza mutyairi wedunhu, asi haigone kudzivirirwa.

 

Iyo huru parameters yeMOSFET

1, yakavhurika voltage VT

Vhura voltage (inozivikanwawo sechikumbaridzo voltage): kuitira kuti gedhi regedhi rinodiwa kuti ritange kugadzira conductive chiteshi pakati peiyo S uye dhiza D; mwero N-channel MOSFET, VT inenge 3 ~ 6V; kuburikidza nekuvandudzwa kwemaitiro, kukosha kweMOSFET VT kunogona kudzikiswa kusvika pa2 ~ 3V.

 

2, DC yekuisa kuramba RGS

Chiyero chemagetsi akawedzerwa pakati pegedhi source pole uye gedhi razvino Ichi chimiro chinomboratidzwa negedhi ikozvino inoyerera nepagedhi, iyo MOSFET's RGS inogona kudarika 1010Ω nyore.

 

3. Drain source breakdown BVDS voltage.

Pasi pemamiriro eVGS = 0 (yakakwidziridzwa), mukuwedzera kweiyo drain-source voltage, ID inowedzera zvakanyanya kana VDS ichinzi iyo drain-source breakdown voltage BVDS, ID inowedzera zvakanyanya nekuda kwezvikonzero zviviri: (1) avalanche. kuparara kwedepletion layer padhuze nekudonhedza, (2) kuparara kwekupinda pakati pemvura yekudonhedza uye matanda emvura, mamwe maMOSFET, ane hurefu hwemugero, anowedzera VDS kuitira kuti dhizaini iri munzvimbo yekudonha iwedzere kusvika kunzvimbo inobva, kuita kuti Channel urefu huve zero, ndiko kuti, kugadzira kudonhedza-source kupinza, kupinda, vazhinji vevatakuri vari munzvimbo yetsime vanokwezvwa zvakananga nemunda wemagetsi weiyo depletion layer kunharaunda yekudonhedza, zvichikonzera ID hombe. .

 

4, gedhi tsime kuputsa voltage BVGS

Kana gedhi regedhi rawedzerwa, iyo VGS kana IG yawedzerwa kubva pazero inonzi gedhi sosi yekuputsa voltage BVGS.

 

5,Low frequency transconductance

Kana VDS iri yakakosha kukosha, chiyero cheiyo microvariation yekudonha ikozvino kune microvariation yegedhi sosi voltage iyo inokonzera shanduko inonzi transconductance, iyo inoratidza kugona kwegedhi sosi voltage kudzora kudonha ikozvino, uye i yakakosha parameter inoratidza kugona kweamplification yeMOSFET.

 

6, pa-kupikisa RON

On-resistance RON inoratidza mhedzisiro yeVDS paID, ndiyo inverse yemateru e tangent mutsara wedhivha maitiro pane imwe nzvimbo, munzvimbo yekusatutsira, ID inenge isingachinji neVDS, RON yakakura kwazvo. kukosha, kazhinji mumakumi e-kilo-Ohms kusvika kumazana e-kilo-Ohms, nekuti mumaseketi edhijitari, MOSFETs anowanzo shanda mudunhu reiyo conductive VDS = 0, saka panguva ino, iyo-inopikisa RON inogona kuenzaniswa ne mabviro eRON kusvika kufungidzira, kune general MOSFET, RON kukosha mukati memazana mashoma ohms.

 

7, inter-polar capacitance

Interpolar capacitance iripo pakati pemaelectrodes matatu: gedhi source capacitance CGS, gedhi drain capacitance CGD uye drain source capacitance CDS-CGS uye CGD ingangoita 1 ~ 3pF, CDS ingangoita 0.1 ~ 1pF.

 

8,Low frequency noise factor

Ruzha rwunokonzerwa nekusafamba zvakanaka kwevatakuri mupombi. Nekuda kwekuvapo kwayo, isingaite vhezheni kana misiyano yazvino inoitika pakubuda kunyangwe pasina chiratidzo chinounzwa neamplifier. Kuita ruzha kunowanzo kuratidzwa maererano neiyo noise factor NF. Iyo unit ndeye decibel (dB). Iyo idiki kukosha, iyo shoma ruzha iyo chubhu inoburitsa. The low-frequency noise factor is noise factor inoyerwa mu low-frequency range. Iyo ruzha chinhu chemumunda chinokonzera chubhu chinenge dB shoma, shoma pane yebipolar triode.