Iyo yakakosha magetsi ekupa chimiro chekukurumidza kuchajaQC inoshandisa flyback + yechipiri side (yechipiri) synchronous rectification SSR. Kune vashanduri veflyback, zvinoenderana nemhinduro yesampling nzira, inogona kukamurwa kuita: yekutanga divi (yekutanga) mutemo uye yechipiri divi (yechipiri) mutemo; zvinoenderana nenzvimbo yePWM controller. Inogona kukamurwa kuita: yekutanga divi (yekutanga) kutonga uye yechipiri divi (yechipiri) kutonga. Zvinoita sekuti haina chekuita neMOSFET. Saka,Olukeyinofanirwa kubvunza: MOSFET yakavanzwa kupi? Yakaita basa rei?
1. Chikamu chekutanga (chekutanga) kugadzirisa uye chikamu chechipiri (chechipiri) kugadzirisa
Kugadzikana kwemagetsi ekubuda kunoda chinongedzo chemhinduro kutumira ruzivo rwayo kuPWM main controller kuti igadzirise shanduko mune yekupinza voltage uye inobuda mutoro. Zvinoenderana neakasiyana emhinduro sampling nzira, inogona kukamurwa kuita yekutanga divi (yekutanga) gadziriso uye yechipiri divi (yechipiri) kugadzirisa, sezvakaratidzwa muFigure 1 uye 2.
Chiratidzo chemhinduro chepuraimari side (yekutanga) regulation haitorwe zvakananga kubva kune inobuda voltage, asi kubva kune yekubatsira mhepo kana yekutanga yekutanga mhepo inochengetedza humwe hukama hwakaenzana neinobuda voltage. Hunhu hwayo ndeiyi:
① Nzira yemhinduro isina kunanga, mwero wakashata wekutonga uye kusarongeka kwakashata;
②. Zviri nyore uye zvakaderera mutengo;
③. Hapana chikonzero chekuzviparadzanisa optocoupler.
Chiratidzo chemhinduro chechipiri chedivi (chechipiri) mutemo chinotorwa zvakananga kubva kune yakabuda voltage uchishandisa optocoupler uye TL431. Hunhu hwayo ndeiyi:
① Yakananga mhinduro nzira, yakanaka chiyero chemutoro, mutsara wemutsetse mwero, uye yakanyanya kurongeka;
②. Kugadziriswa kwedunhu kwakaoma uye kunodhura;
③. Izvo zvinodiwa kuparadzanisa optocoupler, iyo ine matambudziko ekukwegura nekufamba kwenguva.
2. Chikamu chechipiri (chechipiri) diode rectification uyeMOSFETsynchronous kugadzirisa SSR
Rutivi rwechipiri (rwechipiri) rweflyback convert rinowanzoshandisa diode rectification nekuda kwehombe yakabuda ikozvino yekuchaja nekukurumidza. Kunyanya kuchaja yakananga kana flash kuchaja, iyo inobuda ikozvino yakakwira se5A. Kuti uvandudze kushanda zvakanaka, MOSFET inoshandiswa pachinzvimbo cheiyo diode seyakagadziridza, inonzi yechipiri (yechipiri) synchronous rectification SSR, sezvakaratidzwa muFigure 3 uye 4.
Hunhu hwechikamu chechipiri (chechipiri) diode kugadzirisa:
①. Nyore, hapana yekuwedzera dhiraivha inodiwa, uye mutengo wakaderera;
② Kana iyo yakabuda ikozvino yakakura, kushanda kwakaderera;
③. Kuvimbika kwepamusoro.
Zvimiro zvechikamu chechipiri (chechipiri) MOSFET synchronous rectification:
①. Yakaomarara, inoda yakawedzera dhiraivha controller uye mutengo wakakwira;
②. Kana iyo yakabuda ikozvino yakakura, kushanda kwakakwirira;
③. Kuenzaniswa ne diode, kuvimbika kwavo kwakaderera.
Mumashandisirwo anoshanda, iyo MOSFET yeiyo synchronous rectification SSR inowanzotamiswa kubva kumucheto wepamusoro kuenda kumucheto wakaderera kuti ufambise kutyaira, sezvakaratidzwa muFigure 5.
Hunhu hweiyo yepamusoro-yekupedzisira MOSFET ye synchronous rectification SSR:
①. Inoda bootstrap drive kana floating drive, iyo inodhura;
②. EMI yakanaka.
Hunhu hwekuyananisa kugadzirisa SSR MOSFET yakaiswa pamucheto wakaderera:
① Direct drive, nyore dhiraivha uye mutengo wakaderera;
②. Murombo EMI.
3. Primary side (primary) control and second side (secondary) control
Iyo PWM main controller inoiswa padivi pekutanga (yekutanga). Chimiro ichi chinodaidzwa kuti primary side (primary) control. Kuti uvandudze kurongeka kweiyo voltage inobuda, chiyero chekutonga kwemutoro, uye mutsara wekutonga mwero, iyo yekutanga divi (yekutanga) kutonga inoda yekunze optocoupler uye TL431 kuti igadzire chinongedzo chemhinduro. Iyo system bandwidth idiki uye kumhanya kwekupindura kunononoka.
Kana iyo PWM main controller yakaiswa padivi rechipiri (yechipiri), iyo optocoupler uye TL431 inogona kubviswa, uye inobuda voltage inogona kudzorwa zvakananga uye kugadziriswa nekukurumidza kupindura. Chimiro ichi chinonzi chechipiri (secondary) control.
Zvimiro zvechikamu chekutanga (yekutanga) kutonga:
①. Optocoupler uye TL431 inodiwa, uye kukurumidza kwekupindura kunononoka;
②. Iko kumhanya kwekudzivirira kwekubuda kunononoka.
③. Mune synchronous rectification inoenderera mberi modhi CCM, iyo yechipiri divi (yechipiri) inoda chiratidzo chekuyananisa.
Zvimiro zvechipiri (chechipiri) kutonga:
①. Izvo zvinobuda zvinoonekwa zvakananga, hapana optocoupler uye TL431 inodiwa, kukurumidza kwekupindura kunokurumidza, uye kubuda kwekudzivirira kunokurumidza;
②. Iyo yechipiri divi (yechipiri) synchronous rectification MOSFET inotyairwa zvakananga pasina kudiwa kwemasaini masaini; mamwe maturusi akadai semapulse transformers, magineti couplings kana capacitive couplers anodiwa kufambisa masaini ekutyaira edivi rekutanga (primary) high-voltage MOSFET.
③. Rutivi rwekutanga (yekutanga) inoda dunhu rekutanga, kana rechipiri divi (rechipiri) rine simba rekubatsira rekutanga.
4. Inoenderera mberi CCM mode kana discontinuous DCM mode
Iyo flyback inoshandura inogona kushanda mukuenderera mberi kweCCM modhi kana discontinuous DCM modhi. Kana iyo iripo mune yechipiri (yechipiri) inotenderera inosvika 0 pakupera kwekuchinja kutenderera, inonzi discontinuous DCM mode. Kana iyo yazvino yeyechipiri (yechipiri) inotenderera isiri 0 pakupera kwekuchinja kutenderera, inonzi inoenderera CCM mode, sezvakaratidzwa muFigure 8 uye 9.
Zvinogona kuonekwa kubva kuMufananidzo 8 uye Mufananidzo 9 kuti nyika dzekushanda dze synchronous rectification SSR dzakasiyana nenzira dzakasiyana-siyana dzekushandura flyback converter, izvo zvinorevawo kuti nzira dzekutonga dze synchronous rectification SSR dzichavawo dzakasiyana.
Kana nguva yekufa ikafuratirwa, kana uchishanda mukuenderera kweCCM modhi, iyo synchronous rectification SSR ine maviri anoti:
①. Rutivi rwekutanga (yekutanga) yakakwira-voltage MOSFET inobatidzwa, uye chikamu chechipiri (chechipiri) synchronous rectification MOSFET inodzimwa;
②. Rutivi rwekutanga (yekutanga) yakakwira-voltage MOSFET inodzimwa, uye chikamu chechipiri (chechipiri) synchronous rectification MOSFET inobatidzwa.
Saizvozvo, kana nguva yekufa ikafuratirwa, iyo synchronous rectification SSR ine matunhu matatu kana ichishanda mu discontinuous DCM mode:
①. Rutivi rwekutanga (yekutanga) yakakwira-voltage MOSFET inobatidzwa, uye chikamu chechipiri (chechipiri) synchronous rectification MOSFET inodzimwa;
②. Rutivi rwekutanga (yekutanga) yakakwira-voltage MOSFET yakadzimwa, uye chikamu chechipiri (chechipiri) synchronous rectification MOSFET inobatidzwa;
③. Rutivi rwekutanga (yekutanga) yakakwira-voltage MOSFET inodzimwa, uye chikamu chechipiri (chechipiri) synchronous rectification MOSFET inodzimwa.
5. Chikamu chechipiri (chechipiri) synchronous rectification SSR mune inopfuurira CCM mode
Kana iyo inokurumidza-chaji flyback inoshandura ichishanda mune inoenderera yeCCM modhi, iyo yekutanga divi (yekutanga) yekudzora nzira, yechipiri divi (yechipiri) synchronous rectification MOSFET inoda chiratidzo chekuyananisa kubva kudivi rekutanga (yekutanga) kudzora kudzima.
Idzi nzira mbiri dzinotevera dzinowanzo shandiswa kuwana iyo synchronous drive chiratidzo chechikamu chechipiri (chechipiri):
(1) Shandisa zvakananga yechipiri (yechipiri) mhepo, sezvinoratidzwa mumufananidzo 10;
(2) Shandisa zvimwe zvikamu zvekuzviparadzanisa nevamwe senge pulse transformers kuendesa iyo synchronous drive chiratidzo kubva kudivi rekutanga (yepuraimari) kuenda kune yechipiri divi (yechipiri), sezvakaratidzwa mumufananidzo 12.
Yakananga kushandisa yechipiri (yechipiri) mhepo kuti uwane iyo synchronous drive chiratidzo, iko kurongeka kweiyo synchronous drive chiratidzo kwakaoma kudzora, uye zvakaoma kuwana optimized kunyatsoshanda uye kuvimbika. Mamwe makambani anotoshandisa vatongi vedhijitari kuti vavandudze kudzora kurongeka, sezvakaratidzwa muMufananidzo 11 Ratidza.
Kushandisa pulse transformer kuti uwane synchronous kutyaira masaini kune yakanyanya kurongeka, asi mutengo wakakwira.
Iyo yechipiri yedivi (yechipiri) yekudzora nzira inowanzo shandisa pulse transformer kana magineti coupling nzira kuendesa iyo synchronous drive chiratidzo kubva kudivi rechipiri (chechipiri) kuenda kudivi rekutanga (yekutanga), sezvakaratidzwa mumufananidzo 7.v
6. Chikamu chechipiri (chechipiri) synchronous rectification SSR mune discontinuous DCM mode
Kana iyo yekukurumidza kuchaja flyback inoshandura ichishanda mune discontinuous DCM modhi. Zvisinei nerutivi rwekutanga (yekutanga) nzira yekudzora kana yechipiri nzira (yechipiri) yekudzora nzira, iyo D uye S voltage madonhwe eiyo synchronous rectification MOSFET inogona kunyatsoonekwa uye kudzorwa.
(1) Kubatidza iyo synchronous rectification MOSFET
Kana iyo voltage yeVDS yeiyo synchronous rectification MOSFET yachinja kubva kune yakanaka kuenda kune yakaipa, iyo yemukati parasitic diode inotendeuka, uye mushure mekumbononoka, iyo synchronous rectification MOSFET inobatidzwa, sezvakaratidzwa mumufananidzo 13.
(2) Kudzima iyo synchronous rectification MOSFET
Mushure meiyo synchronous rectification MOSFET yavhurwa, VDS=-Io*Rdson. Kana iyo yechipiri (yechipiri) inotenderera ikozvino inoderera kusvika ku0, ndiko kuti, kana voltage yeazvino yekuona chiratidzo VDS ichichinja kubva kune yakaipa kuenda ku0, iyo synchronous rectification MOSFET inodzima, sezvakaratidzwa mumufananidzo 13.
Mumashandisirwo anoshanda, iyo synchronous rectification MOSFET inodzima isati yechipiri (yechipiri) inofenda yazvino yasvika 0 (VDS=0). Ikozvino yekuona mareferensi voltage maitiro akaiswa nemachipi akasiyana akasiyana, senge -20mV, -50mV, -100mV, -200mV, nezvimwe.
Ikozvino yekuona referensi voltage yehurongwa inogadziriswa. Iyo yakakura kukosha kwakazara kweiyo ikozvino yekuona referensi voltage, iyo diki yekukanganisa kukanganisa uye zviri nani kurongeka. Nekudaro, kana iyo inobuda mutoro wazvino Io inodzikira, iyo synchronous rectification MOSFET inodzima pane yakakura kubuda ikozvino, uye yayo yemukati parasitic diode ichaita kwenguva yakareba, saka kushanda zvakanaka kunodzikiswa, sezvakaratidzwa mumufananidzo 14.
Mukuwedzera, kana iyo yakakwana kukosha kweiyo ikozvino yekuona referensi voltage idiki zvakanyanya. Kukanganisa kweSystem uye kupindira kunogona kuita kuti iyo synchronous rectification MOSFET idzima mushure meyechipiri (yechipiri) mhepo inovhuvhuta inodarika 0, zvichikonzera reverse inflow ikozvino, kukanganisa kushanda uye kuvimbika kwehurongwa.
High-chaiyo ikozvino yekuona zviratidzo zvinogona kuvandudza kushanda uye kuvimbika kwegadziriro, asi mutengo wechigadzirwa uchawedzera. Iko kurongeka kweiyo ikozvino yekuona chiratidzo kune hukama kune zvinotevera zvinhu:
①. Kurongeka uye tembiricha kudonha kwezvino yekuona referensi voltage;
②. Iyo bias voltage uye offset voltage, bias ikozvino uye offset ikozvino, uye tembiricha inodonha yeazvino amplifier;
③. Iko kurongeka uye tembiricha kudonha kweiyo-voltage Rdson yeiyo synchronous rectification MOSFET.
Uye zvakare, kubva pamaonero ehurongwa, inogona kuvandudzwa kuburikidza nedhijitari kutonga, kushandura ikozvino yekuona referensi voltage, uye kushandura synchronous rectification MOSFET yekutyaira voltage.
Kana iyo inobuda mutoro wazvino Io inodzikira, kana iyo yekutyaira voltage yesimba MOSFET ikadzikira, inoenderana MOSFET yekutendeuka-on voltage Rdson inowedzera. Sezvinoratidzwa muMufananidzo 15, zvinokwanisika kudzivirira kutanga kuvharwa kweiyo synchronous rectification MOSFET, kuderedza conduction nguva yeparasitic diode, uye kuvandudza kushanda kwehurongwa.
Inogona kuoneka kubva kuMufananidzo 14 kuti kana iyo yakabuda mutoro ikozvino Io inoderera, ikozvino yekuona referensi voltage inodererawo. Nenzira iyi, kana iyo yakabuda ikozvino Io yakakura, yakakwira ikozvino yekuona referensi voltage inoshandiswa kuvandudza kurongeka kwekutonga; kana iyo yakabuda ikozvino Io yakaderera, yakaderera ikozvino yekuona referensi voltage inoshandiswa. Iyo inogona zvakare kuvandudza iyo conduction nguva yeiyo synchronous rectification MOSFET uye kugadzirisa mashandiro ehurongwa.
Kana iyo nzira iri pamusoro isingashandiswe kuvandudza, maSchottky diode anogona zvakare kubatanidzwa mukufanana pamativi ese ari maviri eiyo synchronous rectification MOSFET. Mushure meiyo synchronous rectification MOSFET yakadzimwa pachine nguva, yekunze Schottky diode inogona kusungirirwa mahara.
7. Sekondari (secondary) control CCM+DCM hybrid mode
Parizvino, pane maviri anowanzo shandiswa mhinduro dzekuchaja nharembozha nekukurumidza:
(1) Primary side (primary) control uye DCM inoshanda mode. Sekondari yedivi (yechipiri) synchronous rectification MOSFET haidi chiratidzo chekuyananisa.
(2) Sekondari (yechipiri) kutonga, CCM + DCM yakasanganiswa yekushanda mode (apo iyo inobuda mutoro ikozvino inoderera, kubva kuCCM kuenda kuDCM). Iyo yechipiri divi (yechipiri) synchronous rectification MOSFET inofambiswa zvakananga, uye yayo yekuvhura uye yekudzima misimboti yekudzima inoratidzwa muMufananidzo 16:
Kuvhura iyo synchronous rectification MOSFET: Kana iyo voltage yeVDS yeiyo synchronous rectification MOSFET yachinja kubva kune yakanaka kuenda kune yakaipa, yemukati parasitic diode inotendeuka. Mushure mekunonoka kumwe, iyo synchronous rectification MOSFET inovhura.
Kudzima iyo synchronous rectification MOSFET:
① Kana magetsi ekubuda ari pasi pemutengo wakatarwa, chiratidzo chewachi chinoshandiswa kudzora kudzima kweMOSFET uye kushanda muCCM modhi.
② Kana iyo yakabuda voltage yakakura kudarika kukosha kweseti, iyo synchronous clock signal inodzivirirwa uye nzira yekushanda yakafanana neDCM mode. Iyo VDS = -Io * Rdson siginecha inodzora kuvharika kweiyo synchronous rectification MOSFET.
Zvino, munhu wese anoziva kuti MOSFET inoita basa rei mukukurumidza kuchaja QC!
About Olukey
Chikwata chikuru chaOlukey chakatarisana nezvikamu zvemakore makumi maviri uye chine muzinda muShenzhen. Bhizinesi guru: MOSFET, MCU, IGBT uye mamwe madivayiri. Iwo makuru ejenti zvigadzirwa WINSOK uye Cmsemicon. Zvigadzirwa zvinoshandiswa zvakanyanya muindasitiri yemauto, kutonga kwemaindasitiri, simba idzva, zvigadzirwa zvekurapa, 5G, Internet yezvinhu, dzimba dzakangwara, uye zvakasiyana zvigadzirwa zvemagetsi zvevatengi. Tichivimba nemabhenefiti eiyo yekutanga yepasi rose mumiriri, isu takavakirwa pamusika weChinese. Isu tinoshandisa edu akazara anobatsira masevhisi kuunza akasiyana epamusoro-tekinoroji emagetsi zvikamu kune vatengi vedu, kubatsira vagadziri mukugadzira zvigadzirwa zvemhando yepamusoro uye nekupa masevhisi akazara.
Nguva yekutumira: Zvita-14-2023
