E faavae i le PCB faʻatulagaina o le paoa sapalai, o lenei pepa faʻalauiloaina le sili PCB faʻatulaga metotia, faʻataʻitaʻiga ma metotia e faʻaleleia ai le faʻatinoina o le faigofie switch switch module.

A o fuafuaina le paoa sapalai sapalai, o le muamua iloiloga o le tino matasele eria o le lua fesuiaʻi loops nei. Although these loop regions are largely invisible in the power module, it is important to understand the respective current paths of the two loops because they extend beyond the module. I le matasele 1 o loʻo faʻaalia i le Ata 1, o le taimi nei o loʻo faʻatautaia e le tagata lava ia auala sao bypass capacitor (Cin1) e ui atu i le MOSFET i le tagata e faʻaulufale i totonu ma faʻatosina mai auala gaosimea (CO1) i le taimi e faʻaauau ai le faʻatonutonuina o le maualuga o le MOSFET, ma e toe foʻi lava i le o le mea e alu ai i le auala uila

Schematic diagram of loop in the power module www.elecfans.com

Ata 1 Schematic ata o matasele i le paoa module

Loop 2 is formed during the turn-off time of the internal high-end MOSFEts and the turn-on time of the low-end MOSFEts. O le malosiaga e teu i totonu o totonu e tafe atu i totonu o le output bypass capacitor ma maualalo pito MOSFEts ae le i toe foʻi atu i le GND (tagai Ata 1). O le itulagi e lua faʻataʻamilo e le fesiliaʻi le tasi le isi (e aofia ai le tuaoi i le va o matasele) o le itulagi ma maualuga DI / DT nei. O le input bypass capacitor (Cin1) o loʻo avea ma sao taua i le tuʻuina atu o le maualuga taimi i le taimi nei i le tagata liliu ma toe faʻafoʻi le maualuga o taimi nei i ona auala auala.

O le gaosiga o le capacitor bypass capacitor (Co1) e le o tele sana avega i le taimi nei, ae e avea o se faamama maualuga mo le fesuiaʻi o leo. Mo mafuaʻaga ua taʻua i luga, e tatau ona tuʻu latalata i ai mea e faʻaulu ai ma mea e faʻatino ai a latou VIN ma VOUT pine i luga ole module. E pei ona faʻaalia i le Ata 2, o le faʻaaogaina na faia e nei fesoʻotaʻiga e mafai ona faʻaititia ile faia o uaea i le va o le bypass capacitors ma a latou VIN ma VOUT pine e puʻupuʻu ma lautele pe a mafai.

Ata 2 matasele Suiga matasele

Faʻaitiitia le faʻasolosolo i totonu o le PCB faʻataʻatiaga e lua sili aoga. Muamua, faʻaleleia atili le faʻatinoina o mea e ala ile faʻalauiloaina ole malosiʻaga i le va o le Cin1 ma le CO1. O lenei e mautinoa ai o le module o loʻo iai se auala lelei o le faʻatafunaina o Hf, faʻaitiitia ai le faʻaosoina o le uila ona o le maualuga o le taimi nei DI / DT. E faʻaitiitia ai foʻi le leo o le masini ma le faʻamama o le uila ina ia mautinoa ai le masani ona faʻatino. Lua, faʻaititia le EMI.

Capacitors fesoʻotaʻi ma laʻititi parasite inductance faʻaalia maualalo impedance uiga i maualuga alualu i luma, lea faʻaititia faia radiation. Keramika capacitors (X7R poʻo X5R) poʻo isi maualalo ituaiga ESR capacitors e fautuaina. E faʻatoa mafai ona faʻaulu mea faʻaopoopo faʻaopoopo peʻa tuʻu iai ni capacitor faʻaopoopo e latalata i le pito o le GND ma le VIN. The Power module of the SIMPLE SWITCHER is uniquely designed to have low radiation and conducted EMI. However, follow the PCB layout guidelines described in this article to achieve higher performance.

E masani ona tuʻulafoaʻia le faʻataʻamilosaga o auala i le taimi nei, ae e tele lona sao ile faʻaogaina o le eletise. In addition, ground wires to Cin1 and CO1 should be shortened and widened as much as possible, and bare pads should be directly connected, which is especially important for input capacitor (Cin1) ground connections with large AC currents.

Eleele pine (aofia ai le leai ni lapisi), sao ma galuega faʻatino capacitors, vaivai-amata capacitors, ma tali mai tali i le module tatau ona fesoʻotaʻi uma i le matasele vaega i luga o le PCB. Lenei lapisi faʻapipiʻi mafai ona faʻaaogaina o se toe foʻi auala ma sili atu maualalo inductance nei ma o se vevela dissipation masini talanoaina i lalo.

ATA 3 Schematic diagram o le module ma le PCB o se faʻalavelave faʻafuaseʻi

O le tali atu i tali e tatau foi ona tuʻu i le latalata e mafai ai i le FB (manatu faʻaalia) pine o le module. To minimize the potential noise extraction value at this high impedance node, it is critical to keep the line between the FB pin and the feedback resistor’s middle tap as short as possible. Available compensation components or feedforward capacitors should be placed as close to the upper feedback resistor as possible. Mo se faʻataʻitaʻiga, vaʻai le PCB layout diagram i le talafeagai module data table.

For AN example layout of LMZ14203, see the application guide document AN-2024 provided at www.naTIonal.com.

Manatu Faʻateʻa o le Faʻateʻa o le vevela

O le faʻatulagaina puʻupuʻu o modules, a o tuʻuina atu penefiti eletise, ei ai se aafiaga le lelei i luga o le vevela dissipation mamanu, lea tutusa malosiaga faʻateʻaina mai laiti Spaces. To address this problem, a single large bare pad is designed on the back of the Power module package of the SIMPLE SWITCHER and is electrically grounded. O le pad e fesoasoani e tuʻuina mai le paʻu maualalo o le afi mai le MOSFEts i totonu, e masani ona faʻateleina le tele o le vevela, i le PCB.

O le impedance vevela (θJC) mai le soʻoga semiconductor i le pito i fafo o nei masini o 1.9 ℃ / W. A o le mauaina o se alamanuia-taʻitaʻia θJC taua e lelei, o le maualalo θJC aoga leai se uiga pe a o le vevela afifiina (θCA) o le fafo afifi i le ea e sili sili! Afai e leai se maualalo-impedance vevela dissipation ala e tuuina atu i le siosiomaga ea, o le vevela o le a faaputuputu i luga o le leai se ie ma e le mafai ona faʻaleaogaina. Ole a la le mea e iloa ai le θCA? O le teteʻe vevela mai le leai o se ie i le ea ua faʻatonutonuina atoa e le PCB mamanu ma fesoʻotaʻi vevela magoto.

Lenei mo se vave vaʻai i le auala e mamanuina ai se faigofie PCB aunoa fins, ata 3 faʻataʻitaʻia le module ma PCB o vevela afifiina. Talu ai o le vevela impedance i le va o le fauga ma le pito i luga o le pito i fafo afifi e fai lava si maualuga pe a faatusatusa i le vevela impedance mai le fauga i le leai se pa, e mafai ona tatou le amanaiaina le θJA vevela faʻasalalauina ala i le taimi o le muamua fuafuaina o le vevela teteʻe mai le fauga i le ea lata ane (θJT).

O le laasaga muamua i le faʻaseseina o le vevela mamanu o le fuafua le aofaʻi o le paoa e faʻateʻaina. O le paoa faʻaumatia e le module (PD) mafai ona faigofie fuafua e faʻaaoga ai le lelei le kala (η) lomia i le laulau faʻamatalaga.

Ona matou faʻaaogaina lea o le vevela tapulaa o le maualuga vevela i le mamanu, TAmbient, ma le fuaina faʻatulagaina vevela, TJuncTIon (125 ° C), e fuafua ai le vevela teteʻe manaʻomia mo afifi afifi i luga o le PCB.

Mulimuli ane, na matou faʻaaogaina se faʻafaigofieina faʻatatauina o le maualuga faʻasologa vevela vevela luga o le PCB luga (ma le faʻaleagaina 1-aunese ‘apamemea apamemea ma tele vevela sosolo pu i luga uma o le pito i luga ma lalo fola) e fuafua ai le ipu eria manaʻomia mo vevela dissipation.

O le manaomia PCB eria latalata e le amanaʻiaina le matafaioi faia e le vevela dissipation pu e faʻaliliu ai le vevela mai le pito i luga uamea vaega (o le afifi e fesoʻotaʻi i le PCB) i le pito i lalo uʻamea vaega. O le vaega pito i lalo e avea o se vaega lona lua luga luga lea convection mafai faʻaliliu vevela mai le ipu. Le itiiti ifo 8 i le 10 malulu pu e tatau ona faʻaaoga mo le laupapa eria latalata ina ia aoga. O le teteʻe vevela o le vevela magoto ua latalata i le faʻatusa lea.

Lenei latalata faʻatatau i se masani ala-lua o 12 mils diameter ma 0.5 oz apamemea tafatafa. E pei o le tele o le vevela magoto pu pe a mafai e tatau ona fuafuaina i totonu o le eria atoa i lalo o le leai se ie, ma o nei vevela magoto pu e tatau ona fausia ai se faʻavasega ma le va o le 1 i le 1.5mm.

faaiuga

O le SIMPLE SWITCHER mana module maua ai se isi auala faigata i sapalai o sapalai o le paoa ma faʻatulagaina masani PCB e fesoʻotaʻi ma DC / DC liliu. E ui na aveʻese faʻafitauli faʻatulagaina, o nisi inisinia galuega e manaʻomia lava ona faia e faʻaleleia ai le faʻatinoina o le module ma le lelei aloese ma le vevela faʻaseseina mamanu.