3-A I-synchronous Step-Down Voltage Converter Isekethe ehlanganisiwe IC LMR33630BQRNXRQ1

1.

Umsebenzi wesiguquli sebhaka ukunciphisa i-voltage yokufaka futhi uyifanise nomthwalo.I-topology eyisisekelo yesiguquli sembabala siqukethe iswishi eyinhloko kanye neswishi ye-diode esetshenziswa ngesikhathi sekhefu.Uma i-MOSFET ixhunywe ngokuhambisana ne-continuity diode, ibizwa ngokuthi i-synchronous buck converter.Ukusebenza kahle kwalesi sakhiwo sesiguquli sembabala kungaphezulu kwalokho kweziguquli zembabala ezedlule ngenxa yokuxhumana okufanayo kwe-MOSFET yohlangothi oluphansi ne-Schottky diode.Umfanekiso 1 ubonisa uhlaka lwesiguquli sebhaka esivumelanayo, okuyisakhiwo esivame ukusetshenziswa kumakhompuyutha edeskithophu nawezincwadi zamanothi namuhla.

2.

Indlela yokubala eyisisekelo

Ama-transistor ashintsha i-Q1 ne-Q2 womabili ama-MOSFET wamandla wesiteshi se-N.lawa ma-MOSFET amabili ngokuvamile abizwa ngokuthi ama-switch aphezulu noma aphansi futhi i-MOSFET yohlangothi oluphansi ixhunywe ngokuhambisana ne-Schottky diode.Lawa ma-MOSFET amabili kanye ne-diode akha ishaneli yamandla eyinhloko yesiguquli.Ukulahlekelwa kulezi zingxenye nakho kuyingxenye ebalulekile yokulahlekelwa okuphelele.Ubukhulu besihlungi se-LC esiphumayo bunganqunywa i-ripple current kanye ne-ripple voltage.Ngokuya nge-PWM ethile esetshenziswa esimweni ngasinye, amanethiwekhi okumelana nempendulo u-R1 no-R2 angakhethwa futhi amanye amadivaysi anomsebenzi wokusetha okunengqondo wokusetha i-voltage ephumayo.I-PWM kufanele ikhethwe ngokwezinga lamandla kanye nokusebenza kokusebenza ngefrikhwensi oyifunayo, okusho ukuthi lapho imvamisa inyuswa, kudingeka kube namandla okushayela okwanele ukushayela amasango e-MOSFET, akha inani elincane lezingxenye ezidingekayo. okwesiguquli sebhaka esijwayelekile.

Umklami kufanele aqale ahlole izidingo, okungukuthi i-V input, i-V ephumayo kanye ne-I kanye nezidingo zokushisa zokusebenza.Lezi zidingo eziyisisekelo zibe sezihlanganiswa nokugeleza kwamandla, imvamisa, kanye nezidingo zosayizi womzimba ezitholiwe.

3.

Indima ye-topology ye-buck-boost

Ama-topology e-Buck-boost ayasebenza ngoba amandla kagesi okufakwayo angaba mancane, abe mkhulu, noma afane ne-voltage ephumayo kuyilapho idinga amandla okukhiphayo angaphezu kuka-50 W. Kumandla okukhiphayo angaphansi kuka-50 W, isiguquli se-inductor esisekupheleni okukodwa (SEPIC ) inketho engabizi kakhulu njengoba isebenzisa izingxenye ezimbalwa.

Iziguquli ze-Buck-boost zisebenza ngemodi yebhali lapho i-voltage yokufaka inkulu kune-voltage ephumayo futhi ikumodi yokukhulisa amandla lapho i-voltage yokufaka ingaphansi kwe-voltage ephumayo.Uma isiguquli sisebenza endaweni yokudlulisela lapho i-voltage yokufakwayo ikububanzi be-voltage ephumayo, kunemiqondo emibili yokubhekana nalezi zimo: kungaba izigaba zebhali ne-boost ziyasebenza ngesikhathi esifanayo, noma imijikelezo yokushintsha ishintshana phakathi kwendali. kanye nezigaba zokuthuthukisa, ngasinye ngokuvamile sisebenza kuhhafu wefrikhwensi evamile yokushintsha.Umqondo wesibili ungadala umsindo we-sub-harmonic ekuphumeni, kuyilapho ukunemba kwe-voltage ephumayo kungase kunganembeli kangako uma kuqhathaniswa nebhakede elivamile noma ukusebenza kwe-boost, kodwa isiguquli sizosebenza kahle kakhulu uma siqhathaniswa nomqondo wokuqala.