Phukusi Lalikulu la MOSFET Driver Circuit

Choyamba, mtundu wa MOSFET ndi kapangidwe kake, MOSFET ndi FET (wina ndi JFET), imatha kupangidwa kukhala mtundu wowongoleredwa kapena wocheperako, P-channel kapena N-channel mitundu inayi, koma kugwiritsa ntchito kwenikweni kwa N -channel MOSFETs ndi ma P-channel MOSFET owonjezera, omwe nthawi zambiri amatchedwa NMOSFET, kapena PMOSFET amatanthauza NMOSFET yomwe imatchulidwa kawirikawiri, kapena PMOSFET imatanthawuza mitundu iwiriyi. Pamitundu iwiriyi ya ma MOSFET otukuka, ma NMOSFET amagwiritsidwa ntchito kwambiri chifukwa chokana kukana komanso kupanga mosavuta. Chifukwa chake, ma NMOSFET nthawi zambiri amagwiritsidwa ntchito posinthira magetsi ndi ma drive drive, ndipo mawu oyamba otsatirawa amayang'ananso ma NMOSFET. parasitic capacitance ilipo pakati pa zikhomo zitatu zaMOSFET, zomwe sizikufunika, koma chifukwa cha zofooka za kupanga. Kukhalapo kwa parasitic capacitance kumapangitsa kuti zikhale zovuta kupanga kapena kusankha dera loyendetsa. Pali parasitic diode pakati pa kukhetsa ndi gwero. Izi zimatchedwa diode ya thupi ndipo ndizofunikira pakuyendetsa katundu wolowera monga ma motors. Mwa njira, diode ya thupi imapezeka mu MOSFETs payekha ndipo nthawi zambiri sapezeka mkati mwa IC chip.

 

  

 

Tsopano aMOSFETpagalimoto otsika-voteji ntchito, pamene ntchito 5V magetsi, nthawi ino ngati inu ntchito chikhalidwe totem mzati dongosolo, chifukwa transistor kukhala za 0,7V voteji dontho, chifukwa chenicheni chomaliza anawonjezera pa chipata pa voteji yekha. 4.3 V. Panthawiyi, timasankha voteji yachipata cha 4.5V cha MOSFET pa kukhalapo kwa zoopsa zina. Vuto lomwelo limachitika mukamagwiritsa ntchito 3V kapena zina zotsika mphamvu zamagetsi. Magetsi apawiri amagwiritsidwa ntchito m'mabwalo owongolera pomwe gawo lamalingaliro limagwiritsa ntchito voteji ya digito ya 5V kapena 3.3V ndipo gawo lamagetsi limagwiritsa ntchito 12V kapena kupitilira apo. Ma voltages awiriwa amalumikizidwa pogwiritsa ntchito malo amodzi. Izi zimayika kufunikira kogwiritsa ntchito dera lomwe limalola kuti mbali yotsika yamagetsi izitha kuwongolera bwino MOSFET kumbali yamagetsi apamwamba, pomwe MOSFET yomwe ili pamtunda wamagetsi amakumana ndi zovuta zomwe zatchulidwa mu 1 ndi 2.

 

Pazochitika zonse zitatu, mawonekedwe a totem pole sangathe kukwaniritsa zofunikira, ndipo ma driver ambiri a MOSFET omwe ali pashelufu sakuwoneka kuti akuphatikiza mawonekedwe oletsa magetsi. Mphamvu yolowera simtengo wokhazikika, imasiyana ndi nthawi kapena zinthu zina. Kusiyanaku kumapangitsa kuti magetsi oyendetsa operekedwa ku MOSFET ndi dera la PWM akhale osakhazikika. Pofuna kuti MOSFET ikhale yotetezeka ku ma voltages apamwamba, ma MOSFET ambiri ali ndi zowongolera magetsi kuti achepetse mphamvu yamagetsi a chipata. Pamenepa, pamene magetsi oyendetsa galimoto aperekedwa kuposa magetsi oyendetsa magetsi, amachititsa kuti magetsi azigwiritsidwa ntchito nthawi imodzi, ngati mutagwiritsa ntchito mfundo ya resistor voltage divider kuti muchepetse voteji pachipata, padzakhala kuchuluka kwambiri. input voltage, ndiMOSFETimagwira ntchito bwino, pomwe magetsi olowera amachepetsedwa pomwe voteji yachipata sichikukwanira kuti ipangitse kuwongolera kocheperako, potero kumawonjezera kugwiritsa ntchito mphamvu.

 

Dera lodziwika bwino pano kokha kuti mayendedwe oyendetsa a NMOSFET afufuze mosavuta: Vl ndi Vh ndi magetsi otsika komanso otsika kwambiri, ma voltages awiriwa amatha kukhala ofanana, koma Vl sayenera kupitilira Vh. Q1 ndi Q2 kupanga inverted totem pole, ntchito kuzindikira kudzipatula, ndipo nthawi yomweyo kuonetsetsa kuti awiri dalaivala chubu Q3 ndi Q4 sadzakhala nthawi yomweyo conduction. R2 ndi R3 amapereka PWM voteji R2 ndi R3 kupereka PWM voteji Buku, posintha buku, mukhoza kulola ntchito dera mu PWM chizindikiro waveform ndi otsetsereka ndi malo owongoka. Q3 ndi Q4 amagwiritsidwa ntchito kupereka pagalimoto panopa, chifukwa pa nthawi, Q3 ndi Q4 wachibale Vh ndi GND ndi zochepa chabe Vce voteji dontho, voteji dontho nthawi zambiri yekha 0.3V kapena choncho, otsika kwambiri. kuposa 0.7V Vce R5 ndi R6 ndi zotsutsana ndi mayankho, zomwe zimagwiritsidwa ntchito pachipata cha R5 ndi R6 ndizotsutsa zomwe zimagwiritsidwa ntchito poyesa magetsi a chipata, omwe amadutsa pa Q5 kuti apange malingaliro oipa pa Q1 ndi Q2, motero kuchepetsa voteji pachipata pa mtengo wotsirizira. Mtengo uwu ukhoza kusinthidwa ndi R5 ndi R6. Pomaliza, R1 imapereka malire a maziko apano ku Q3 ndi Q4, ndipo R4 imapereka malire a chipata chapano kwa MOSFETs, komwe ndikuchepetsa kwa Ice wa Q3Q4. Ma capacitor othamanga amatha kulumikizidwa molingana pamwamba pa R4 ngati kuli kofunikira.