Dabere na PCB okirikiri nhọrọ ukwuu nke ike ọkọnọ, akwụkwọ a na -ewebata usoro PCB kacha mma, atụ na usoro iji bulie arụmọrụ nke modul ike switcher dị mfe.

Mgbe ị na -eme atụmatụ okirikiri nhọrọ ọkụ ọkụ, ihe mbụ ị ga -echebara echiche bụ mpaghara akaghị aka nke abụọ na -agbanwe loops dị ugbu a. 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. Na loop 1 egosiri na onyonyo 1, onye na-eduzi onwe ya na-agafe agafe capacitor (Cin1) na-agafe na MOSFET n’ime ihe nrụpụta n’ime na mmepụta ihe mgbapụta (CO1) n’oge na-aga n’ihu na-aga n’ihu nke MOSFET dị elu, ma mesịa laghachi. input uzo capacitor.

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

Ọgụgụ 1 Eserese eserese nke loop na modul ike

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. Ike echekwara n’ime ihe nrụpụta n’ime na -agafere site na mgbapụta mgbapụta capacitor na MOSFEts dị ala tupu ịlaghachi na GND (lee ọgụgụ 1). Mpaghara ebe loops abụọ anaghị agbakọ ọnụ (gụnyere ókè n’etiti loops) bụ mpaghara nwere nnukwu DI/DT dị ugbu a. Capacitor input input (Cin1) na -arụ ọrụ dị mkpa n’iwebata ihe ntụgharị ugboro ugboro dị elu na iweghachi ugboro ugboro dị elu na ụzọ isi mmalite ya.

Ihe nrụpụta mgbapụta mmepụta ihe (Co1) anaghị ebu ọtụtụ AC ugbu a, mana ọ na-arụ ọrụ dị ka nzacha ugboro ugboro maka ịgbanwee mkpọtụ. Maka ebumnuche ndị a dị n’elu, ekwesịrị idobe ihe nrụnye na nrụpụta ihe ka o kwere mee na ntụtụ VIN na VOUT ha na modulu. Dị ka egosiri na eserese 2, enwere ike belata inductance nke njikọ ndị a na -eme site na ime ka eriri dị n’etiti ndị na -agafe agafe na ntụtụ VIN na VOUT ha dị nkenke na obosara.

Ọgụgụ 2 loop SWITCHER dị mfe

Mbelata inductance na nhazi PCB nwere nnukwu uru abụọ. Nke mbu, melite arụmọrụ akụrụngwa site na ịkwalite mbufe ume n’etiti Cin1 na CO1. Nke a na -agba mbọ hụ na modul ahụ nwere ezigbo ụzọ hf, na -ebelata ọnụ ọnụ ọkụ ọkụ inductive n’ihi oke DI/DT dị ugbu a. Ọ na -ebelata mkpọtụ ngwaọrụ na nrụgide voltaji iji hụ na ọ na -arụ ọrụ nke ọma. Nke abụọ, belata EMI.

Capacitors ejikọrọ na obere parasaiti inductance na -egosipụta njirimara impedance dị ala na ugboro ole dị elu, si otú a na -ebelata radieshon eduzi. A na -atụ aro ndị na -emepụta seramiiki (X7R ma ọ bụ X5R) ma ọ bụ ndị ọzọ nwere ụdị ESR dị ala. Mgbakwunye ntinye ike nwere ike banye naanị ma ọ bụrụ na etinyere capacitors na nso GND na 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.

A na -eleghara usoro nhazi sekit ugbu a anya, mana ọ na -arụ ọrụ dị mkpa n’ịkwalite imewe ike ọkọnọ. 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.

A ga-ejikọ ntụtụ ala (gụnyere mpe mpe mpe mpe akwa), ntinye na nrụpụta ihe, ihe nrụpụta dị nro, na ndị na-eguzogide nzaghachi na modul niile na akwa loop na PCB. Enwere ike iji akwa loop a dị ka ụzọ nloghachi nwere nnukwu inductance dị ugbu a yana dị ka ngwaọrụ mkpofu ọkụ tụlere n’okpuru.

FIG. 3 Ihe eserese nke modulu na PCB dị ka ihe na -egbochi ọkụ

Ekwesịrị idobe ihe nzaghachi nzaghachi ka o kwere mee na pin FB (nzaghachi) nke modul ahụ. 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. Dịka ọmụmaatụ, lee eserese PCB na tebụl data modul dị mkpa.

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

Aro Ntanetị Mgbasa Ọkụ

Ọdịdị kọmpat nke modulu, mgbe ọ na -enye uru eletrik, nwere mmetụta na -adịghị mma na nhazi mkpofu ọkụ, ebe a na -ewepụ ike nha anya site na obere oghere. 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. Mpekere ahụ na -enyere aka inye ike ikuku dị oke ala site na MOSFE dị n’ime, nke na -ebutekarị oke ọkụ, na PCB.

Mkpuchi ọkụ (θJC) site na njikọ semiconductor ruo na ngwugwu mpụga nke ngwaọrụ ndị a bụ 1.9 ℃/W. Ka ị na-enweta uru θJC na-eduga ụlọ ọrụ dị mma, obere θJC dị ala enweghị isi mgbe oke ikuku (θCA) nke ngwugwu dị na ikuku dị oke oke! Ọ bụrụ na-enyeghị ụzọ mgbapụ ọkụ ọkụ dị ala na ikuku gbara ya gburugburu, okpomọkụ ga-agbakọba na paịlị na-enweghị ntụpọ, enweghị ike ịgbasa ya. Yabụ kedu ihe na -ekpebi θCA? Ihe njikwa PCB na mgbanye ọkụ metụtara ya na -achịkwa nguzogide ọkụ sitere na paịda na -enweghị ikuku.

Ugbu a maka ileba anya ngwa ngwa ka esi emepụta PCB dị mfe na -enweghị ntù, eserese 3 na -egosi modulu na PCB dị ka ihe na -egbochi ọkụ. N’ihi na ihe na -egbochi ọkụ dị n’etiti njikọta na elu nke ngwugwu dị elu dịtụ elu ma e jiri ya tụnyere impedance thermal site na nkwụsị ruo na mpe mpe akwa, anyị nwere ike ileghara ụzọ mgbapụta θJA anya n’oge atụmatụ mbụ nke nguzogide na -ekpo ọkụ site na nkwụsị ruo ikuku gbara ya gburugburu (θJT).

Nzọụkwụ mbụ na nhazi mkpofu ọkụ bụ ikpebi oke ike a ga -ekesa. Enwere ike ịgbakọ ike nke modulu (PD) na -eji ngwa eserese (η) nke edepụtara na tebụl data.

Anyị na -eji ihe mgbochi okpomọkụ nke oke okpomọkụ dị n’ime imewe, TAmbient, yana oke ọkwa njikọta, TJuncTIon (125 ° C), iji chọpụta nguzogide ọkụ chọrọ maka ngwugwu ngwugwu na PCB.

N’ikpeazụ, anyị jiri mgbatị dị mfe karịa nke mbufe ọkụ na-ebugharị n’elu PCB (ya na nku ọla kọpa 1-ounce na-adịghị emebi emebi na ọtụtụ oghere nsị ọkụ n’elu ma na ala ala) iji chọpụta mpaghara efere achọrọ maka mgbasa ọkụ.

Ịmata mpaghara PCB achọrọ anaghị eburu n’uche ọrụ nke oghere mgbasa ọkụ na -ebufe okpomọkụ site na akwa igwe (ngwugwu ejikọtara na PCB) na akwa ala ala. Ala ala na -eje ozi dị ka akwa elu nke abụọ site na nke convection nwere ike ibufe okpomọkụ na efere. Ọ dịkarịa ala, a ga -eji oghere jụrụ oyi 8 ruo 10 mee ka atụmatụ ebe bọọdụ ahụ dị irè. A na -atụle nguzogide ọkụ ọkụ nke igwe ọkụ ọkụ site na nha anya na -esote.

Ihe atụ a na-emetụta oghere a na-ahụkarị nke dayameta mils 12 na ogwe ọla kọpa 0.5 oz. A ga -ahazi ọtụtụ oghere ịkụ ọkụ dị ka o kwere mee na mpaghara niile dị n’okpuru paịlị na -enweghị oghere, oghere ndị a na -etinye ọkụ kwesịrị ịhazi oghere nwere oghere nke 1 ruo 1.5mm.

ọgwụgwụ

Igwe ọkụ ọkụ SIMPLE SWITCHER na -enye ihe ọzọ maka atụmatụ ọkọnọ ike dị mgbagwoju anya yana ụdị PCB jikọtara ya na ndị ntụgharị DC/DC. Ọ bụ ezie na ewepụla ihe ịma aka nhazi, ụfọdụ ọrụ injinịa ka kwesịrị ime ka ebuli arụmọrụ modul site na ịgafe nke ọma yana imebe ikpo ọkụ.