Li-capacitor li na le karolo ea bohlokoa moralong oa PCB oa lebelo le holimo 'me hangata ke sesebelisoa se sebelisoang haholo ho PCBS.Ho PCB, li-capacitor hangata li arotsoe ka li-filter capacitor, li-decoupling capacitor, li-capacitor tsa polokelo ea matla, joalo-joalo.
1.Power output capacitor, filter capacitor
Hangata re bua ka capacitor ea li-circuits tsa ho kenya le tse hlahisoang tsa mojule oa matla e le "filter capacitor".Kutloisiso e bonolo ke hore capacitor e tiisa botsitso ba matla a ho kenya le ho tsoa.Moduleng oa matla, capacitor ea filthara e lokela ho ba kholo pele e nyane.Joalo ka ha ho bonts'itsoe setšoantšong, capacitor ea filthara e beoa e kholo ebe e nyane ka lehlakoreng la motsu.
Ha ho etsoa tlhahiso ea matla, hoa lokela ho hlokomeloa hore marang-rang le letlalo la koporo li pharaletse ka ho lekaneng 'me palo ea likoti e lekane ho netefatsa hore matla a phallo a finyella tlhokahalo.Bophara le palo ea likoti li hlahlojoa hammoho le hona joale.
Matla a ho kenya matla
Motlakase oa ho kenya matla o etsa loop ea hona joale e nang le switching loop.Loop ena ea hona joale e fapana ho ea ka amplitude e kholo, Iout amplitude.Leqhubu ke maqhubu a ho fetoha.Nakong ea ts'ebetso ea ho fetola chip ea DCDC, hona joale e hlahisoang ke loop ena ea hona joale e fetoha, ho kenyelletsa le di/dt e potlakileng.
Ka mokhoa oa synchronous BUCK, tsela e tsoelang pele ea hona joale e lokela ho feta pineng ea GND ea chip, 'me capacitor ea ho kenya e lokela ho kopanngoa pakeng tsa GND le Vin ea chip, kahoo tsela e ka ba e khutšoanyane le e teteaneng.
Sebaka sa selikalikoe sena sa hona joale se senyenyane ka ho lekaneng, ho molemo hore mahlaseli a ka ntle a lesale lena la hona joale a be molemo.
2.Decoupling capacitor
Pini ea matla ea IC e lebelo le phahameng e hloka li-capacitor tse lekaneng tsa ho kopanya, haholo-holo pini e le 'ngoe.Ka moralo oa 'nete, haeba ho se na sebaka sa decoupling capacitor, e ka hlakoloa ha ho loketse.
The decoupling capacitance ea Pin phepelo ea matla a IC hangata e nyenyane, tse kang 0.1μF, 0.01μF, joalo-joalo Pakete e tsamaisanang le eona e batla e le nyane, joalo ka sephutheloana sa 0402, sephutheloana sa 0603 joalo-joalo.Ha u beha li-decoupling capacitors, lintlha tse latelang li lokela ho hlokomeloa.
(1) Beha haufi ka hohle kamoo ho ka khonehang ho phini ea phepelo ea motlakase, ho seng joalo e ka 'na ea se be le phello ea ho kopanya.Ka khopolo, capacitor e na le radius e itseng ea ho fokotsa, kahoo molao-motheo oa ho atamela o lokela ho kenngoa ts'ebetsong ka thata.
2Sepheo sa ho tenya ke ho fokotsa inductance ea lead le ho netefatsa ts'ebetso ea phepelo ea motlakase.
3Loto le eona e lokela ho ba motenya, 'me lesoba le be leholo kamoo ho ka khonehang.Haeba lesoba le nang le lesoba la 10mil le ka sebelisoa, lesoba la 8mil ha lea lokela ho sebelisoa.
(4) Netefatsa hore loop ea ho kopanya e nyane kamoo ho ka khonehang
3.Capacitor ea polokelo ea matla
Karolo ea capacitor ea polokelo ea matla ke ho netefatsa hore IC e ka fana ka matla ka nako e khutšoanyane ha e sebelisa motlakase.Bokhoni ba capacitor ea polokelo ea matla ka kakaretso bo boholo, 'me sephutheloana se tsamaisanang le sona se seholo.Ho PCB, capacitor ea polokelo ea matla e ka ba hole le sesebelisoa, empa eseng hole haholo, joalo ka ha ho bonts'itsoe setšoantšong.Mokhoa o tloaelehileng oa polokelo ea matla a capacitor fan-hole o bontšoa setšoantšong.
Melao-motheo ea likoti tsa fan le likhoele ke tse latelang:
(1) Loto e khutšoanyane ebile e teteaneng ka hohle kamoo ho ka khonehang, e le hore ho be le inductance e nyenyane ea parasitic.
(2) Bakeng sa li-capacitor tsa polokelo ea matla, kapa lisebelisoa tse nang le overcurrent e kholo, phunya masoba a mangata kamoo ho ka khonehang.
(3) Ehlile, ts'ebetso e ntle ka ho fetisisa ea motlakase ea lesoba la fan ke lesoba la disc.'Nete e hloka ho nahanoa ka botlalo