Poyerekeza ndi LDO, dera la DC-DC ndi lovuta kwambiri komanso laphokoso, ndipo masanjidwe ndi zofunikira ndizokwera. Ubwino wa masanjidwewo umakhudza mwachindunji magwiridwe antchito a DC-DC, chifukwa chake ndikofunikira kumvetsetsa momwe DC-DC imapangidwira

1. Maonekedwe oipa
● EMI, DC-DC SW pini idzakhala ndi dv / dt yapamwamba, dv / dt yapamwamba idzayambitsa kusokoneza kwakukulu kwa EMI;
● Phokoso lapansi, mzere wapansi si wabwino, udzatulutsa phokoso lalikulu kwambiri pa waya pansi, ndipo phokosoli lidzakhudza mbali zina za dera;
● Kutsika kwamagetsi kumapangidwira pa wiring. Ngati mawaya ndi otalika kwambiri, kutsika kwamagetsi kumapangidwa pa waya, ndipo mphamvu ya DC-DC yonse idzachepetsedwa.

2. Mfundo zazikuluzikulu
● Sinthani dera lalikulu lamakono kukhala lalifupi momwe mungathere;
● Malo opangira ma siginecha ndi okwera-panopa (malo amagetsi) amayendetsedwa padera ndikulumikizidwa pamalo amodzi pa chip GND.

①Loop yachidule yosinthira
LOOP1 yofiyira pachithunzi pansipa ndi njira yomwe ikuyenda pano pomwe chitoliro cham'mbali cha DC-DC chili ndipo chitoliro chotsika chazimitsidwa. Green LOOP2 ndi njira yomwe ikuyenda panopa pamene chitoliro chapamwamba chatsekedwa ndipo chitoliro cham'mbali chotsika chikutsegulidwa;

Kuti malupu awiriwa akhale ang'onoang'ono momwe angathere ndikuyambitsa kusokoneza pang'ono, mfundo zotsatirazi ziyenera kutsatiridwa:

● Inductance pafupi ndi pini ya SW momwe zingathere;
● Lowetsani capacitance pafupi ndi pini ya VIN momwe mungathere;
● Pansi pa zolowetsa ndi zotulutsa zotulutsa ziyenera kukhala pafupi ndi pini ya PGND.
●Gwiritsani ntchito kuyala waya wamkuwa;

N’cifukwa ciani mungacite zimenezo?

● Mzere wabwino kwambiri komanso wautali kwambiri umawonjezera kutsekeka, ndipo pompopompo yayikulu imatulutsa mphamvu yamagetsi yamphamvu kwambiri pakuyimitsa kwakukulu kumeneku;
● Waya wabwino kwambiri komanso wautali kwambiri adzawonjezera inductance ya parasitic, ndipo phokoso lolumikizirana pa inductance lidzakhudza kukhazikika kwa DC-DC ndikuyambitsa mavuto a EMI.
● The parasitic capacitance ndi impedance idzawonjezera kutayika kwa kusintha ndi kutayika kwapang'onopang'ono ndikusokoneza mphamvu ya DC-DC.

②kukhazikitsa mfundo imodzi
Kuyika nsonga imodzi kumatanthawuza kuyika malo amodzi pakati pa malo olumikizirana ndi magetsi. Padzakhala phokoso lalikulu losinthira pamagetsi, kotero ndikofunikira kupewa kusokoneza ma siginecha ang'onoang'ono, monga pini ya FB.

● Malo apamwamba kwambiri: L, Cin, Cout, Cboot kugwirizana ndi intaneti ya nthaka yapamwamba;
● Pansi pakali pano: Css, Rfb1, Rfb2 padera yolumikizidwa ndi netiweki yapansi panthaka;

Zotsatirazi ndi masanjidwe a bolodi lachitukuko la TI. Chofiira ndi njira yamakono pamene chubu chapamwamba chikutsegulidwa, ndipo buluu ndi njira yamakono pamene chubu chapansi chikutsegulidwa. Masanjidwe otsatirawa ali ndi zabwino izi:

●GND ya ma capacitor olowetsa ndi kutuluka imalumikizidwa ndi mkuwa. Poika zidutswa, nthaka ya ziwirizi iyenera kuikidwa pamodzi momwe zingathere.
● Njira yamakono ya Dc-Dc-ton ndi Toff ndi yochepa kwambiri;
● Chizindikiro chaching'ono kumanja ndi malo amodzi, omwe ali kutali kwambiri ndi chikoka cha phokoso lalikulu lamakono kumanzere;

3. Zitsanzo

Kapangidwe ka dera la DC-DC BUCK laperekedwa pansipa, ndipo mfundo zotsatirazi zaperekedwa mu SPEC:
● Ma capacitor olowetsa, machubu apamwamba a MOS, ndi ma diode amapanga malupu ang'onoang'ono komanso aafupi momwe angathere;
● Lowetsani capacitance pafupi ndi pin Pin ya Vin;
● Onetsetsani kuti zolumikizira zonse ndi zazifupi komanso zachindunji, komanso kuti zotsutsa ndi zolipira zili pafupi kwambiri ndi chipangizocho;
●SW kutali ndi zizindikiro zomveka monga FB;
● Lumikizani VIN, SW, makamaka GND padera kudera lalikulu lamkuwa kuti muziziziritsa chip ndikuwongolera magwiridwe antchito komanso kudalirika kwanthawi yayitali;

4. Fotokozerani mwachidule

Kamangidwe ka dera la DC-DC ndikofunikira kwambiri, komwe kumakhudza mwachindunji bata ndi magwiridwe antchito a DC-DC. Nthawi zambiri, SPEC ya DC-DC chip ipereka chitsogozo cha masanjidwe, chomwe chingatchulidwe pakupanga.