Iyada oo ku saleysan PCB qaabeynta korontada, warqadani waxay soo bandhigaysaa habka qaabeynta PCB -ga ugu fiican, tusaalooyin iyo farsamooyin si kor loogu qaado wax -qabadka module -ka korontada fudud.

Markaad qorshaynayso khariidadda korontada, tixgelinta ugu horraysa waa aagga loop jireed ee labada beddelashada loopyada hadda jira. 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. Wareegga 1 ee lagu muujiyey Jaantuska 1, hadda is-qabsiga is-dhexgalka awoodda wax-ku-oolka (Cin1) wuxuu dhex maraa MOSFET gudaha gudaha inductor-ka iyo soo-saaridda ka-soo-baxa soo-saare (CO1) inta lagu jiro waqtiga gudbinta joogtada ah ee MOSFET-ka sare, ugu dambayntiina wuxuu ku soo noqdaa capacitor -ka gudbinta soo -gelinta.

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

Jaantuska 1 Jaantuska jadwalka ee loop -ka ee module -ka awoodda

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. Tamarta lagu kaydiyo gudaha inductor -ka gudaha waxay ku dhex socotaa soo -saare dhaafsiiyaha korantada iyo MOSFEts -ka dhammaadkiisa ka hor intaadan ku noqon GND (fiiri sawirka 1). The region where two loops do not overlap each other (including the boundary between loops) is the region with high DI/DT current. Awoodda gudbinta soo -gelinta (Cin1) ayaa kaalin muhiim ah ka siineysa soo -noqnoqodka sare ee beddelka iyo ku -soo -noqoshada hirarka soo noqnoqda ee ugu sarreeya dariiqa isha.

Awood-dhaafiyaha soo-saarka soo-saarka (Co1) ma siddo wax badan oo AC ah, laakiin wuxuu u shaqeeyaa sidii shaandheyn aad u sarreeya oo loogu beddelo buuqa. Sababaha kor ku xusan awgood wax -soo -saarka iyo soo -saareyaasha waa in la dhigaa sida ugu dhow ee suurtogalka ah ee musmaarradooda VIN iyo VOUT ee ku jira cutubka. Sida lagu muujiyey Jaantuska 2, inductance -ka ay sameeyeen iskuxirradan waa la yareyn karaa iyadoo laga dhigayo xarigga u dhexeeya capacitors -ka iyo VIN -ka iyo musmaarrada VOUT -ga sida ugu gaaban oo ballaadhan.

Sawirka 2 Loop SWITCHER SIMPLE

Yareynta kicinta ee qaabeynta PCB waxay leedahay laba faa’iidooyin oo waaweyn. Marka hore, hagaaji wax -qabadka qaybta iyada oo kor loo qaadayo wareejinta tamarta ee u dhaxaysa Cin1 iyo CO1. Tani waxay xaqiijineysaa in modulku leeyahay marin wanaagsan oo hf ah, oo yareynaya meelaha ugu sarreeya ee danab -dhaliyaha iyadoo ay ugu wacan tahay DI/DT oo sarreeya. Waxa kale oo ay yareysaa buuqa aaladda iyo cadaadiska danab si loo hubiyo hawlgalka caadiga ah. Marka labaad, yaree EMI.

Capacitors -ka ku xiran indctance -ka dulin -yar -yar ayaa muujiya astaamaha impedance -ka hooseeya ee jadwalka sare, sidaas darteedna waxay yareysaa shucaaca la sameeyay. Awoodda dhoobada (X7R ama X5R) ama kaabayaasha nooca ESR kale oo hooseeya ayaa lagula talinayaa. Kordhiyeyaasha wax -soo -gelinta ee dheeraadka ah ayaa soo geli kara ciyaarta haddii awood -dheereyaal dheeraad ah la dhigo meel u dhow dhammaadka GND iyo 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.

Qorshaynta dariiqa hadda jira ayaa inta badan la dayacaa, laakiin waxay kaalin muhiim ah ka qaadataa hagaajinta naqshada korontada. 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.

Musmaarrada dhulka ku jira (oo ay ku jiraan suufka qaawan), soo-geliyaasha iyo soo-saareyaasha wax-soo-saarka, capacitors-ka-bilowga ah, iyo iska-caabbinta jawaab-celinta ee modul-ka waa inay dhammaantood ku xirmaan lakabka loop ee PCB-ga. Lakabka loop -kan waxaa loo isticmaali karaa waddo soo laabasho leh oo leh dareen -kicinta aadka u hooseysa iyo aaladda kala -daadinta kuleylka ee hoos lagu falanqeeyey.

FIG. 3 Jaantuska jadwalka ee moduleka iyo PCB -ga oo ah caqabad kuleyl

Soo -celiyaha jawaab -celinta waa in sidoo kale la dhigaa sida ugu dhow ee suurtogalka ah FB (warcelin) pin ee cutubka. 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. For an example, see the PCB layout diagram in the relevant module data table.

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

Talooyinka Naqshadeynta Kulaylka

Qaab -dhismeedka isku -dhafan ee cutubyada, inta ay bixinayaan faa’iidooyinka korantada, waxay saamayn taban ku yeelanayaan naqshadeynta kala -firdhinta kulaylka, halkaasoo awoodda u dhiganta laga gooyo Meelaha yaryar. 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. Suufku wuxuu gacan ka geystaa bixinta ka -hortagga kuleylka aadka u hooseeya ee MOSFEts -ka gudaha, kaas oo sida caadiga ah ku dhaliya kuleylka badan, PCB -ga.

Is -beddelka kuleylka (θJC) laga bilaabo isgoyska semiconductor -ka ilaa xirmada dibadda ee aaladahaan waa 1.9 ℃/W. In kasta oo la gaadhayo qiimaha θJC ee warshadu hoggaamiso ayaa habboon, qiimaha lowJC ee hooseeya wax macno ah ma samaynayso marka kuleylka kuleylka (θCA) ee xirmada dibadda ee hawada aad u weyn! Haddii aan la siin dariiqa kala-firdhinta kulaylka-yar-yar ee hawada ku xeeran, kulaylku wuxuu ku ururayaa suufka qaawan oo lama kala bixin karo. Haddaba maxaa go’aaminaya θCA? The thermal resistance from bare pad to air is completely controlled by the PCB design and associated heat sink.

Hadda si dhakhso ah loo fiiriyo sida loo naqshadeeyo PCB -ga fudud oo aan lahayn baalal, sawirka 3 wuxuu muujinayaa modul -ka iyo PCB -ga inay yihiin caqabad kuleyl. Sababtoo ah ka -hortagga kuleylka ee u dhexeeya isgoyska iyo xagga sare ee xirmada dibedda ayaa aad u sarreeya marka la barbardhigo ka -hortagga kuleylka laga bilaabo isgoyska ilaa suufka qaawan, waxaan iska indho -tiri karnaa dariiqa kala -daadinta θJA inta lagu jiro qiyaasta ugu horreysa ee iska -caabbinta kuleylka laga bilaabo isgoyska ilaa hawada ku xeeran (θJT).

Tallaabada ugu horreysa ee naqshadeynta kala -firdhinta kuleylka ayaa ah in la go’aamiyo xaddiga awoodda la siideynayo. Awoodda uu isticmaalay cutubka (PD) si fudud ayaa loo xisaabin karaa iyadoo la adeegsanayo garaafka wax -ku -oolnimada (η) ee lagu daabacay miiska xogta.

Waxaan markaa adeegsaneynaa caqabadaha heerkulka ee heerkulka ugu sarreeya ee naqshadeynta, TAmbient, iyo heerkulka isgoyska lagu qiimeeyay, TJuncTIon (125 ° C), si loo go’aamiyo iska caabbinta kuleylka ee looga baahan yahay modules -ka baakaysan ee PCB.

Ugu dambayntii, waxaan isticmaalnay qiyaasta la fududeeyay ee wareejinta kuleylka ugu badan ee dusha PCB (oo leh 1-wiqiyadood oo baalal naxaas ah ah iyo godad badan oo kuleylka ku dul yaal dabaqyada sare iyo hoose labadaba) si loo go’aamiyo aagga saxanka looga baahan yahay kala-daadinta kuleylka.

Qiyaasta aagga PCB -ga ee loo baahan yahay ma tixgelinayso doorka ay ka ciyaaraan godadka kala -firdhinta kulaylka oo ka wareejiya kuleylka lakabka birta sare (xirmada waxay ku xiran tahay PCB) ilaa lakabka birta hoose. Lakabka hoose wuxuu u adeegaa sida lakabka sare ee labaad kaas oo ka -soo -wareejintu kulaylka ka soo wareejin karto saxanka. Ugu yaraan 8 ilaa 10 godad qaboojin waa in loo adeegsadaa qiyaasta aagga guddiga si ay u noqoto mid ansax ah. Ka -hortagga kuleylka ee weelka kuleylka waxaa lagu qiyaasaa isla’egta soo socota.

Qiyaastaani waxay quseysaa daloolka caadiga ah ee dhexroorka 12 mils oo leh 0.5 oz oo ah derbiga naxaasta ah. Inta ugu badan ee daloollada godka kuleylka ah waa in lagu naqshadeeyaa aagga oo dhan oo ka hooseeya suufka qaawan, iyo godadkan kuleylku waa inay sameystaan ​​isugeyn leh 1 ilaa 1.5mm.

gabagabeyn

Module -ka korontada ee SIMPLE SWITCHER wuxuu siiyaa beddel naqshadaha korontada qalafsan iyo qaababka PCB ee caadiga ah ee la xiriira beddelayaasha DC/DC. In kasta oo caqabadaha qaab -dhismeedka la tirtiray, haddana qaar ka mid ah shaqada injineernimada ayaa weli loo baahan yahay in la sameeyo si loo wanaajiyo waxqabadka module -ka oo leh marin -u -helid wanaagsan iyo naqshadeynta kala -daadinta kuleylka.