Choyamba, mtundu wa MOSFET ndi kapangidwe kake,MOSFETndi FET (wina ndi JFET), ikhoza kupangidwa kukhala mtundu wowongoleredwa kapena wocheperako, P-channel kapena N-channel mitundu yonse inayi, koma kugwiritsa ntchito ma MOSFET owonjezera a N-channel ndi ma MOSFET owonjezera a P, kotero Nthawi zambiri amatchedwa NMOS kapena PMOS amatanthauza mitundu iwiriyi. Pamitundu iwiriyi ya ma MOSFET otukuka, omwe amagwiritsidwa ntchito kwambiri ndi NMOS, chifukwa chake ndikuti kukana ndikochepa, komanso kosavuta kupanga. Chifukwa chake, NMOS nthawi zambiri imagwiritsidwa ntchito posinthira magetsi ndi ma drive drive.
Pachiyambi chotsatira, milandu yambiri imayendetsedwa ndi NMOS. mphamvu ya parasitic ilipo pakati pa zikhomo zitatu za MOSFET, chinthu chomwe sichifunikira koma chimachitika chifukwa cha zoletsa zopanga. 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.
MOSFETkusintha kwa chubu kutaya, kaya NMOS kapena PMOS, pambuyo conduction pa-kukana kulipo, kotero kuti panopa kuwononga mphamvu kukana uku, mbali imeneyi ya mphamvu kudyedwa amatchedwa conduction imfa. Kusankhidwa kwa ma MOSFET okhala ndi kukana pang'ono kudzachepetsa kutayika kwa kukana. Masiku ano, kukana kwa ma MOSFET otsika mphamvu nthawi zambiri kumakhala pafupifupi makumi a milliohm, ndipo ma milliohm ochepa amapezekanso.MOSFETs sayenera kutsirizidwa nthawi yomweyo pamene akuyatsa ndi kuzimitsa.Pali njira yochepetsera magetsi pamagetsi. malekezero awiri a MOSFET, ndipo pali njira yowonjezerapo yomwe ikudutsamo.Pa nthawiyi, kutayika kwa MOSFET ndizochokera ku magetsi ndi zamakono, zomwe zimatchedwa kutayika kwa kusintha. Kawirikawiri kutayika kwa kusintha kumakhala kwakukulu kwambiri kuposa kutayika kwa conduction, ndipo mofulumira kusintha kwafupipafupi, kutayika kwakukulu. Chopangidwa ndi voteji ndi chapano panthawi yomwe conduction ndi yayikulu kwambiri, zomwe zimapangitsa kutayika kwakukulu. Kufupikitsa nthawi yosinthira kumachepetsa kutayika pamayendedwe aliwonse; kuchepetsa kusintha kwafupipafupi kumachepetsa chiwerengero cha masinthidwe pa nthawi ya unit. Njira zonsezi zimachepetsa kutayika kwa kusintha.
Poyerekeza ndi bipolar transistors, amakhulupirira kuti palibe chapano chomwe chimafunikira kupanga aMOSFETkhalidwe, bola mphamvu ya GS ili pamwamba pa mtengo wina. Izi ndizosavuta kuchita, komabe, timafunikiranso liwiro. Monga mukuonera mu kapangidwe ka MOSFET, pali parasitic capacitance pakati pa GS, GD, ndi kuyendetsa MOSFET, kwenikweni, kulipiritsa ndi kutulutsa capacitance. Kulipiritsa capacitor kumafuna panopa, chifukwa kulipira capacitor nthawi yomweyo kumawoneka ngati dera lalifupi, kotero kuti nthawi yomweyo idzakhala yapamwamba. Chinthu choyamba kukumbukira posankha / kupanga dalaivala wa MOSFET ndi kukula kwa nthawi yofupikitsa yomwe ingaperekedwe.
Chinthu chachiwiri chomwe muyenera kudziwa ndichakuti, chomwe chimagwiritsidwa ntchito kwambiri pagalimoto yapamwamba ya NMOS, mphamvu yamagetsi yapanthawi yake iyenera kukhala yayikulu kuposa mphamvu yamagetsi. Mkulu-mapeto pagalimoto MOSFET pa gwero voteji ndi kuda voteji (VCC) chomwecho, ndiye chipata voteji kuposa VCC 4V kapena 10V. ngati mu dongosolo lomwelo, kuti tipeze voteji yokulirapo kuposa VCC, tifunika ukadaulo wowongolera dera. Madalaivala ambiri oyendetsa magalimoto ali ndi mapampu ophatikizika, ndikofunikira kudziwa kuti muyenera kusankha luso loyenera lakunja kuti mupeze nthawi yayitali yokwanira kuyendetsa MOSFET. 4V kapena 10V ndiye MOSFET yomwe imagwiritsidwa ntchito kwambiri pamagetsi, kapangidwe kake, muyenera kukhala ndi malire ena. Kukwera kwa voliyumu, kumapangitsanso kuthamanga kwa boma komanso kumachepetsa kukana kwa boma. Tsopano palinso ma MOSFET ang'onoang'ono amagetsi omwe amagwiritsidwa ntchito m'magawo osiyanasiyana, koma mu 12V galimoto zamagetsi zamagetsi, nthawi zambiri 4V pa-state ndiyokwanira.MOSFETs chodziwika kwambiri ndi kusintha kwa zinthu zabwino, kotero zimagwiritsidwa ntchito kwambiri mu kufunikira kwa mabwalo osinthira pakompyuta, monga kusinthira magetsi ndi kuyendetsa galimoto, komanso kuyatsa kwamagetsi. Kuchita kumatanthauza kuchita ngati kusintha, komwe kuli kofanana ndi kutsekedwa kwa switch.NMOS makhalidwe, Vgs zazikulu kuposa mtengo wina zidzachititsa, zoyenera kugwiritsidwa ntchito pamene gwero lakhazikitsidwa (otsika-kumapeto pagalimoto), bola ngati chipata voteji ya 4V kapena 10V.PMOS makhalidwe, Vgs zosakwana mtengo adzachititsa, oyenera ntchito pa nkhani pamene gwero chikugwirizana ndi VCC (high-mapeto pagalimoto). Komabe, ngakhale PMOS itha kugwiritsidwa ntchito mosavuta ngati dalaivala wapamwamba kwambiri, NMOS nthawi zambiri imagwiritsidwa ntchito pamadalaivala apamwamba chifukwa chakukaniza kwakukulu, kukwera mtengo, ndi mitundu yochepa yosinthira.
Tsopano MOSFET galimoto otsika-voteji ntchito, pamene ntchito 5V magetsi, nthawi ino ngati inu ntchito chikhalidwe totem pole dongosolo, chifukwa transistor kukhala pafupifupi 0.7V voteji dontho, chifukwa chomaliza kwenikweni anawonjezera pa chipata pa voteji ndi 4.3 V. Panthawiyi, timasankha mwadzina chipata voteji 4.5V wa 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 ya voteji izitha kuyendetsa bwino MOSFET pamtunda wapamwamba, pamene MOSFET yomwe ili pamtunda wamagetsi idzakumana ndi mavuto omwe atchulidwa mu 1 ndi 2. mawonekedwe a totem pole sangathe kukwaniritsa zofunikira, ndipo ma driver ambiri a MOSFET IC akuwoneka kuti akuphatikiza mawonekedwe oletsa magetsi pachipata. 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.
Pachifukwa ichi, pamene magetsi oyendetsa galimoto amaperekedwa kuposa magetsi a chowongolera, amachititsa kuti magetsi azigwiritsidwa ntchito nthawi yomweyo, ngati mutagwiritsa ntchito mfundo ya resistor voltage divider kuti muchepetse mphamvu yamagetsi, padzakhalanso voteji yolowera kwambiri, MOSFET imagwira ntchito bwino, pomwe magetsi olowera amachepetsedwa pomwe voteji yachipata sichikukwanira kuti ipangitse kuyendetsa bwino, motero kumawonjezera kugwiritsa ntchito mphamvu.
Pafupifupi dera wamba pano kokha kwa NMOS dalaivala dera kuchita kusanthula kosavuta: Vl ndi Vh ndi otsika mapeto ndi mkulu-mapeto magetsi, motero, ma voltages awiri akhoza kukhala ofanana, koma Vl sayenera kupitirira Vh. Q1 ndi Q2 kupanga inverted totem pole, ntchito kukwaniritsa kudzipatula, ndipo nthawi yomweyo kuonetsetsa kuti awiri oyendetsa machubu Q3 ndi Q4 sadzakhala pa nthawi yomweyo. R2 ndi R3 amapereka PWM voteji Buku, ndi kusintha bukuli, inu mukhoza kupanga dera ntchito bwino, ndi voteji pachipata sikokwanira chifukwa conduction bwinobwino, motero kuonjezera mowa mphamvu. R2 ndi R3 imapereka mawonekedwe amagetsi a PWM, posintha izi, mutha kulola kuti ntchito yozungulira mu mawonekedwe a PWM ikhale yotsetsereka komanso yowongoka. 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 mayankho resistors kwa chipata voteji zitsanzo, pambuyo zitsanzo voteji, voteji pachipata ntchito ngati resistor ndemanga kwa voteji pachipata, ndi voteji chitsanzo ntchito voteji pachipata. R5 ndi R6 ndi zotsutsa zomwe zimagwiritsidwa ntchito poyesa magetsi a pachipata, omwe amadutsa pa Q5 kuti apange maganizo oipa pazitsulo za Q1 ndi Q2, motero amachepetsa mphamvu yamagetsi pamtengo wotsika. 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 ndiko kuchepetsa Ice wa Q3Q4. Ma capacitor othamanga amatha kulumikizidwa molingana pamwamba pa R4 ngati kuli kofunikira.
Popanga zida zonyamulika ndi zinthu zopanda zingwe, kuwongolera magwiridwe antchito ndi kukulitsa nthawi yogwiritsira ntchito batire ndi zinthu ziwiri zomwe opanga ayenera kuyang'anizana nazo. DC-DC converters ali ndi ubwino wakuchita bwino kwambiri, kutulutsa kwakukulu pakali pano komanso kutsika kocheperako, komwe kuli koyenera kwambiri kulimbikitsa kunyamula. zipangizo.
Ma converter a DC-DC ali ndi ubwino wochita bwino kwambiri, kutulutsa kwakukulu kwaposachedwa komanso kutsika kwaposachedwa, komwe kuli koyenera kwambiri kupatsa mphamvu zida zonyamula. Pakalipano, zomwe zikuchitika pakupanga teknoloji ya DC-DC converter design ikuphatikizapo: teknoloji yapamwamba kwambiri: ndi kuwonjezeka kwa ma frequency osinthika, kukula kwa kusintha kosinthika kumachepetsedwanso, mphamvu yamagetsi yawonjezeka kwambiri, ndi mphamvu. kuyankha kwawongoleredwa. Wamng'ono
Mphamvu ya DC-DC yosinthira ma frequency idzakwera mpaka pamlingo wa megahertz. Ukadaulo wamagetsi otsika: Ndi chitukuko chopitilira ukadaulo wopanga ma semiconductor, ma microprocessors ndi kunyamula zida zamagetsi zamagetsi akutsika komanso kutsika, zomwe zimafunikira mtsogolo kutembenuza kwa DC-DC kumapereka mphamvu yotsika yopangira magetsi kuti igwirizane ndi ma microprocessor ndi zida zamagetsi zamagetsi, zomwe amafuna mtsogolo DC-DC Converter angapereke otsika linanena bungwe voteji kuti agwirizane ndi microprocessor.
Zokwanira kuti apereke magetsi otsika kuti agwirizane ndi ma microprocessors ndi zida zonyamula zamagetsi. Kutukuka kwaukadaulo kumeneku kumapereka zofunika zapamwamba pamapangidwe a ma chip amagetsi. Choyamba, ndi kuwonjezeka kwafupipafupi kusinthasintha, ntchito ya zigawo zosinthira zimayikidwa patsogolo
Zofunikira zazikulu pakuchita kwa chinthu chosinthira, ndipo ziyenera kukhala ndi chosinthira chosinthira kuti chiwonetsetse kuti chinthu chosinthira pakusintha pafupipafupi mpaka pamlingo wa megahertz wantchito yabwinobwino. Kachiwiri, pazida zamagetsi zoyendetsedwa ndi batri, mphamvu yamagetsi yamagetsi yamagetsi ndi yotsika (mwachitsanzo, ngati mabatire a lithiamu).
Lithium mabatire Mwachitsanzo, voteji ntchito 2.5 ~ 3.6V), kotero mphamvu kotunga Chip kwa voteji m'munsi.
MOSFET ili ndi kukana kotsika kwambiri, kugwiritsa ntchito mphamvu pang'ono, mu chipangizo chamakono chodziwika bwino cha DC-DC MOSFET ngati chosinthira mphamvu. Komabe, chifukwa chachikulu cha parasitic capacitance ya MOSFETs. Izi zimayika zofunikira pakupanga ma switching ma driver oyendetsa ma chubu kuti apange ma frequency osinthira a DC-DC. Pali ma CMOS osiyanasiyana, mabwalo amalingaliro a BiCMOS omwe amagwiritsa ntchito bootstrap boost structure ndi mabwalo oyendetsa ngati katundu wamkulu wa capacitive pamapangidwe otsika a ULSI. Mabwalowa amatha kugwira ntchito moyenera pansi pazigawo zosakwana 1V voteji, ndipo amatha kugwira ntchito molingana ndi kuchuluka kwa 1 ~ 2pF pafupipafupi amatha kufikira ma megabits kapena mazana a megahertz. Mu pepala ili, bootstrap boost circuit imagwiritsidwa ntchito popanga mphamvu yayikulu yoyendetsa galimoto, yoyenera kutsika kwamagetsi, kusinthasintha kwafupipafupi kumathandizira DC-DC converter drive circuit. Magetsi otsika ndi PWM kuyendetsa ma MOSFET apamwamba. chizindikiro chaching'ono cha matalikidwe a PWM choyendetsa zofunikira zamagetsi apamwamba a MOSFET.
Nthawi yotumiza: Apr-12-2024
