Kuenzaniswa neLDO, dunhu reDC-DC rakanyanya kuomarara uye rine ruzha, uye marongero uye dhizaini zvinodiwa zvakakwirira. Hunhu hwekugadzirisa hunokanganisa zvakananga kushanda kweDC-DC, saka zvakakosha kuti unzwisise marongerwo eDC-DC

1. Yakashata marongero
● EMI, DC-DC SW pini ichava nepamusoro dv / dt, yakaenzana nepamusoro dv / dt ichakonzera kukanganisa kukuru kweEMI;
● Ruzha rwepasi, mutsara wepasi hauna kunaka, uchabudisa ruzha rwakakura rwekuchinja patambo yepasi, uye mheremhere iyi ichakanganisa zvimwe zvikamu zvedunhu;
● Kudonha kwemagetsi kunogadzirwa pane wiring. Kana iyo wiring yakanyanya kureba, kudonha kwemagetsi kuchagadzirwa pane wiring, uye kushanda kweiyo yose DC-DC kuchaderedzwa.

2. Mitemo yose
● Chinja dunhu rakakura riripo sepfupi sezvinobvira;
● Ivhu rechiratidzo uye yakakwira-ikozvino (simba pasi) inofambiswa zvakasiyana uye yakabatana mune imwe nzvimbo pane chip GND.

① Short switching loop
Iyo tsvuku LOOP1 mumufananidzo uri pazasi ndiyo inoyerera mafambiro kana DC-DC yakakwira-side pombi iripo uye pombi yepasi-padivi yakadzimwa. Green LOOP2 ndiyo nzira yekuyerera iripo kana pombi yeparutivi yakakwirira yakavharwa uye pombi yeparutivi yakaderera yakavhurwa;

Kuti zvishwe zviviri zvive zvidiki sezvinobvira uye kuunza kupindira kushoma, zvinotevera zvinofanirwa kuteverwa:

● Inductance sepedyo nepini yeSW sezvinobvira;
● Input capacitance pedyo neVIN pini sezvinobvira;
● Ivhu rekuisa uye kubuda capacitors rinofanira kuva pedyo nePGND pin.
●Shandisa nzira yekuisa waya yemhangura;

Nei ungadaro?

● Yakanyanya kunaka uye yakarebesa mutsara ichawedzera iyo impedance, uye yakakura ikozvino ichaburitsa yakakwira ripple voltage mune iyi impedance yakakura;
● Yakanyanya kunaka uye yakareba tambo ichawedzera parasitic inductance, uye coupling switch ruzha pane inductance inokanganisa kugadzikana kweDC-DC uye kukonzera EMI matambudziko.
● The parasitic capacitance uye impedance ichawedzera kuchinja kurasikirwa uye-ku-off kurasikirwa uye kukanganisa kushanda kweDC-DC.

②inzvimbo imwe chete
Single point grounding zvinoreva nzvimbo imwe chete yekudzika pakati pechiratidzo chepasi nepasi remagetsi. Pachave neruzha rwakakura rwekuchinja pamagetsi, saka zvakakosha kudzivirira kukanganisa kune masaini madiki masaini, senge FB mhinduro pini.

● High-current ground: L, Cin, Cout, Cboot inobatanidza kune network yepasi-yepasi;
● Yakaderera pasi ikozvino: Css, Rfb1, Rfb2 zvakasiyana yakabatana kune chiratidzo chepasi network;

Izvi zvinotevera marongero ebhodhi rekuvandudza reTI. Tsvuku ndiyo nzira yazvino kana chubhu yekumusoro yakavhurwa, uye bhuruu ndiyo nzira yazvino kana chubhu yepasi yakavhurwa. Iyo inotevera dhizaini ine zvinotevera zvakanakira:

● Iyo GND yekupinza uye kubuda capacitors yakabatana nemhangura. Pakuisa zvidimbu, pasi pezviviri zvinofanira kuiswa pamwe chete sezvinobvira.
● Nzira yezvino yeDc-Dc-ton neToff ipfupi kwazvo;
● Chiratidzo chiduku chiri kurudyi ndeye-single-point grounding, iyo iri kure nekukanganiswa kweiyo huru ikozvino kushandura ruzha kuruboshwe;

3. Mienzaniso

Kurongeka kweyakajairwa DC-DC BUCK dunhu rinopihwa pazasi, uye anotevera mapoinzi akapihwa muSPEC:
● Input capacitors, high-edge MOS tubes, uye diode zvinoumba kushandura zvishwe zviduku uye zvipfupi sezvinobvira;
● Input capacitance pedyo sezvinobvira kuVin Pin pini;
● Iva nechokwadi chokuti zvose zvinobatanidza mhinduro ipfupi uye zvakananga, uye kuti zvinopikisa mhinduro uye zvinhu zvinoripa zviri pedyo nechip sezvinobvira;
● SW kure nezviratidzo zvinonzwisisika zvakadai seFB;
● Unganidza VIN, SW, uye kunyanya GND zvakasiyana kune nzvimbo huru yemhangura kuti itonhodze chip uye kuvandudza kushanda kwemafuta uye kuvimbika kwenguva refu;

4. Pfupisa

marongerwo eDC-DC wedunhu akakosha kwazvo, ayo anokanganisa zvakananga kugadzikana kwekushanda uye kuita kweDC-DC. Kazhinji, SPEC yeDC-DC chip ichapa dhizaini kutungamira, iyo inogona kutaurwa kune dhizaini.