Hauv Kev Tshawb Nrhiav Kev Ua Tau Zoo: 9 Kauj Ruam

2024 Tus sau: John Day | [email protected]. Kawg hloov kho: 2024-01-30 09:26

BUCK Hloov ntawm "DPAK" Loj

Feem ntau, tus pib tsim qauv hluav taws xob lossis tus nyiam ua haujlwm peb xav tau tus tswj hluav taws xob hauv Circuit board luam tawm lossis lub khob cij. Hmoov tsis zoo los ntawm kev yooj yim, peb siv cov kab hluav taws xob tawm ncaj qha tab sis tsis muaj qhov phem tag nrho vim tias ib txwm nyob ntawm daim ntawv thov yog qhov tseem ceeb.

Piv txwv li hauv cov cuab yeej sib piv zoo ib yam (zoo li cov cuab yeej ntsuas) puas tau siv lub tshuab hluav taws xob tawm ncaj qha (kom txo teeb meem suab nrov). Tab sis hauv cov khoom siv hluav taws xob zoo li lub teeb LED, lossis tus tswj hwm ua ntej rau kab tswj kab theem (txhawm rau txhim kho kev ua tau zoo) yog qhov zoo dua los siv DC/DC BUCK hloov hluav taws xob tswj qhov hluav taws xob ua lub hauv paus tseem ceeb vim tias cov cuab yeej no ua haujlwm tau zoo dua uas tus tswj kab tawm nyob rau hauv cov zis tam sim no lossis thauj khoom hnyav.

Lwm qhov kev xaiv uas tsis zoo nkauj tab sis nrawm, yog siv DC / DC hloov pauv hauv cov qauv ua ntej thiab tsuas yog ntxiv lawv nyob rau sab saum toj ntawm peb cov ntawv luam tawm tab sis qhov no ua rau pawg thawj coj loj dua.

Kev daws teeb meem uas kuv hais qhia rau tus nyiam ua haujlwm lossis cov khoom siv hluav taws xob pib siv tus qauv DC/DC BUCK hloov pauv uas tus qauv uas yog saum npoo tab sis, txuag chaw.

Khoom siv

• 1 Thoob hloov pauv 3A --- RT6214.
• 1 Inductor 4.7uH/2.9A --- ECS-MPI4040R4-4R7-R
• 4 Capacitor 0805 22uF/25V --- GRM21BR61E226ME44L
• 2 Capacitor 0402 100nF/50V --- GRM155R71H104ME14D
• 1 Capacitor 0402 68pF/50V --- GRM1555C1H680JA01D
• 1 Resistor 0402 7.32k --- CRCW04027K32FKED
• 3 Resistor 0402 10k --- RC0402JR-0710KL

Kauj Ruam 1: Xaiv Qhov Ridder Zoo Tshaj

Xaiv DC/DC BUCK Converter

Thawj kauj ruam los tsim DC/DC Buck converter yog nrhiav qhov kev daws teeb meem zoo tshaj plaws rau peb daim ntawv thov. Kev daws teeb meem nrawm dua yog siv tus tswj kev hloov pauv tsis siv lub hloov pauv.

Qhov sib txawv ntawm ob txoj kev xaiv no muaj qhia hauv qab no.

Hloov txoj cai

1. Ntau zaus lawv yog monolithic.
2. Qhov ua tau zoo dua.
3. Lawv tsis txhawb nqa qhov tso tawm siab heev.
4. Lawv yooj yim dua kom ruaj khov (Tsuas yog xav tau ib qho RC Circuit).
5. Tus neeg siv tsis xav tau kev paub ntau ntxiv txog DC/DC hloov pauv los ua tus tsim hluav taws xob.
6. Tau teeb tsa ua ntej los ua haujlwm nkaus xwb hauv cov txheej txheem tshwj xeeb.
7. Tus nqi kawg yog qis dua.

Qhia hauv qab no piv txwv txo los ntawm Switching Regulator [Thawj daim duab ntawm cov kauj ruam no].

Hloov maub los

1. Yuav tsum muaj ntau yam sab nrauv xws li MOSFETs thiab Diodes.
2. Lawv nyuaj dua thiab cov neeg siv xav tau kev paub ntau ntxiv txog DC/DC hloov pauv los ua tus tsim hluav taws xob.
3. Lawv tuaj yeem siv ntau dua topologies.
4. Txhawb nqa cov zis tam sim no siab heev.
5. Tus nqi kawg yog siab dua.

Qhia hauv qab no ib daim ntawv thov ib txwm muaj ntawm Switching Controller [Daim duab thib ob ntawm cov kauj ruam no]

• Xav txog cov ntsiab lus hauv qab no.

  1. Nqi.
  2. Chaw [Lub zog tso tawm yog nyob ntawm qhov no].
  3. Hwj chim tso zis.
  4. Ua tau zoo.
  5. Nyuaj.

Hauv qhov no, Kuv siv Richtek RT6214 [A rau hom txuas mus yog qhov zoo dua rau qhov hnyav, thiab qhov kev xaiv B uas nws ua haujlwm nyob rau hauv hom tsis tu ncua uas yog qhov zoo dua rau lub teeb thauj khoom thiab txhim kho kev ua haujlwm ntawm qhov tso zis tsawg tam sim no] uas yog DC /DC Buck Converter monolithic [thiab yog li peb tsis xav tau ib qho khoom siv sab nraud xws li Power MOSFETs thiab diodes Schottky vim tias tus hloov pauv tau suav nrog MOSFET hloov pauv thiab lwm yam MOSFET uas ua haujlwm xws li Diode].

Cov ncauj lus kom ntxaws tuaj yeem nrhiav tau ntawm cov kab txuas hauv qab no: Buck_converter_guide, Sib piv Buck Converter Topologies, Buck Converter Xaiv Cov Qauv

Kauj Ruam 2: Tus Inductor Yog Koj Tus Phooj Ywg Zoo Tshaj Plaws hauv DC/DC Converter

Nkag siab qhov inductor [Kev tshuaj xyuas ntawm cov ntawv]

Xav txog qhov chaw ntawm kuv lub Circuit Court, Kuv siv ECS-MPI4040R4-4R7-R nrog muaj 4.7uH, nominal tam sim no ntawm 2.9A, thiab tam sim no saturation ntawm 3.9A thiab DC tsis kam 67m ohms.

Nominal tam sim no

Tus nominal tam sim no yog tus nqi tam sim no uas tus inductor tsis poob cov khoom xws li inductance thiab tsis muaj qhov tseem ceeb nce qhov kub ib puag ncig.

Saturation tam sim no

Qhov saturation tam sim no hauv qhov inductor yog tus nqi tam sim no uas tus inductor poob nws lub zog thiab tsis ua haujlwm kom khaws lub zog hauv qhov chaw sib nqus.

Loj vs Kuj

Nws tus cwj pwm ib txwm muaj qhov chaw thiab kev tiv thaiv yog nyob ntawm ib leeg vim tias yog xav tau txuag chaw peb xav tau kom txuag chaw txo tus nqi AWG hauv cov hlau nplaum hlau thiab yog tias kuv xav poob qhov tsis kam kuv yuav tsum nce AWG tus nqi hauv cov hlau nplaum hlau.

Tus kheej-resonance zaus

Tus kheej-resonance zaus tau ua tiav thaum qhov hloov pauv tau tso tseg qhov inductance thiab tsuas yog tam sim no muaj cov kab mob parasitic. Ntau lub chaw tsim khoom pom zoo kom tswj kev hloov pauv zaus inductor tsawg kawg kaum xyoo hauv qab ntawm tus kheej-resonance zaus. Piv txwv

Tus kheej-resonance zaus = 10MHz.

f-hloov = 1MHz.

Xyoo caum = cav [puag 10] (Tus kheej - Resonance zaus / f - hloov pauv)

Kaum xyoo = log [puag 10] (10MHz / 1MHz)

Xyoo = 1

Yog tias koj xav paub ntau ntxiv ntawm inductors, thov txheeb xyuas cov txuas hauv qab no: Tus kheej_resonance_inductor, Saturation_current_vs nominal_current

Kauj Ruam 3: Tus Inductor Yog Lub Plawv

Xaiv Qhov Zoo Tshaj Plaws Inductor

Tus inductor yog lub plawv ntawm DC / DC hloov pauv, yog li nws yog ib qho tseem ceeb heev uas yuav tsum khaws cov ntsiab lus hauv qab no hauv siab txhawm rau ua tiav qhov ntsuas hluav taws xob zoo.

Qhov tso tawm tam sim no ntawm tus tswj hwm qhov hluav taws xob, lub npe tam sim no, tam sim no saturation, thiab ripple tam sim no

Hauv qhov no, cov chaw tsim khoom muab cov kab zauv los laij cov khoom siv hluav taws xob zoo raws li qhov ripple tam sim no, qhov hluav taws xob tso tawm, qhov hluav taws xob nkag, hloov pauv zaus. Qhov sib npaug yog qhia hauv qab no.

L = Vout (Vin-Vout) / Vin x f-hloov x ripple tam sim no.

Ripple tam sim no = Vout (Vin-Vout) / Vin x f-hloov x L.

IL (ncov) = Iout (Max) + ripple tam sim no / 2.

Ua ntawv thov qhov sib npaug ntawm ripple tam sim no ntawm kuv tus inductor [Cov txiaj ntsig muaj nyob hauv Kauj Ruam dhau los] cov txiaj ntsig tau qhia hauv qab no.

Vin = 9V

VA = 5 V

f-Hloov = 500kHz.

L = 4,7uH.

Ib = 1.5A

Lub tswv yim ripple tam sim no = 1.5A * 50%

Lub tswv yim ripple tam sim no = 0.750A

Ripple tam sim no = 5V (9V - 5V) / 9V x 500kHz x 4.7uH

Ripple tam sim no = 0.95A*

IL (ncov) = 1.5A + 0.95A / 2

IL (ncov) = 1.975A **

*Pom zoo siv lub ripple tam sim no ze rau 20% - 50% ntawm cov zis tam sim no. Tab sis qhov no tsis yog txoj cai dav dav vim tias nws nyob ntawm lub sijhawm teb ntawm tus tswj kev hloov pauv. Thaum peb xav tau lub sijhawm teb nrawm peb yuav tsum siv qhov qis inductance vim tias lub sijhawm them nyiaj ntawm cov khoom siv hluav taws xob luv thiab thaum peb xav tau lub sijhawm teb qeeb peb yuav tsum siv lub inductance siab vim tias lub sijhawm them nqi ntev thiab nrog qhov no, peb txo EMI.

** Cov chaw tsim khoom pom zoo tsis pub tshaj qhov siab tshaj tam sim no uas txhawb nqa lub cuab yeej kom muaj kev nyab xeeb ntau. Hauv qhov no, qhov siab tshaj plaws tam sim no yog 4.5A.

Cov txiaj ntsig no tuaj yeem sab laj hauv qhov txuas hauv qab no: Datasheet_RT6214, Datasheet_Inductor

Kauj Ruam 4: Yav Tom Ntej Yog Tam Sim No

Siv REDEXPERT txhawm rau xaiv qhov zoo tshaj inductor rau koj cov nyiaj hloov pauv

REDEXPERT yog cov cuab yeej zoo thaum koj xav paub dab tsi yog qhov inductor zoo tshaj plaws rau koj cov nyiaj hloov pauv, txhawb kev hloov pauv, sepic hloov pauv, thiab lwm yam. Hauv cov cuab yeej no, peb tuaj yeem pom hauv kab ntawv qhov kub nce ntxiv vs tam sim no thiab qhov poob ntawm inductance vs tam sim no hauv qhov inductor. Nws tsuas yog xav tau cov tswv yim tsis yooj yim xws li qhia hauv qab no.

• Kev tawm tswv yim
• tso zis hluav taws xob
• cov zis tam sim no
• hloov zaus
• ripple tam sim no

Qhov txuas yog qhov txuas ntxiv: REDEXPERT Simulator

Kauj Ruam 5: Peb Xav Tau Tseem Ceeb

Xam cov txiaj ntsig tso tawm

Nws yog qhov yooj yim heev los xam qhov hluav taws xob tso tawm, peb tsuas yog xav tau txhawm rau txheeb xyuas qhov faib hluav taws xob faib los ntawm cov zauv hauv qab no. Tsuas yog peb xav tau R1 thiab txhais qhov hluav taws xob tso tawm.

Vref = 0.8 [RT6214A/BHGJ6F].

Vref = 0.765 [RT6214A/BHRGJ6/8F]

R1 = R2 (Vout - Vref) / Vref

Qhia hauv qab qhov piv txwv siv RT6214AHGJ6F.

R2 = 10k.

Qhov hnyav = 5.

Cov = 0.8.

R1 = 10k (5 - 0.8) / 0.8.

R1 = 52.5k

Kauj Ruam 6: Cov cuab yeej zoo rau Tus Tsim Hluav Taws Xob Zoo

Siv cov cuab yeej ntawm cov chaw tsim khoom

Kuv siv cov cuab yeej simulation muab los ntawm Richtek. Hauv ib puag ncig no, koj tuaj yeem pom tus cwj pwm ntawm DC/DC hloov pauv hauv kev txheeb xyuas-lub xeev ruaj khov, kev tshuaj xyuas ib ntus, pib tshuaj xyuas.

Thiab cov txiaj ntsig tuaj yeem sab laj hauv cov duab, cov ntaub ntawv, thiab kev sim video.

Kauj Ruam 7: Ob Qhov Zoo Tshaj Ib Leeg

PCB Tsim hauv Dav Dav Dav thiab Fusion 360

Kev tsim PCB yog ua rau Eagle 9.5.6 hauv kev koom tes nrog Fusion 360 Kuv ua haujlwm sib xyaw 3D tsim nrog PCB tsim kom tau txais kev pom tiag tiag ntawm kev tsim Circuit Court.

Qhia hauv qab cov ntsiab lus tseem ceeb los tsim PCB hauv Eagle CAD.

• Lub tsev qiv ntawv tsim.
• Schematic tsim.
• PCB tsim lossis Layout tsim
• Tsim kom muaj tiag 2D saib.
• Ntxiv 3D qauv rau ntaus ntawv hauv kev tsim qauv.
• Synchronize Eagle PCB rau Fusion 360.

Nco tseg: Txhua qhov tseem ceeb tau piav qhia los ntawm cov duab uas koj pom thaum pib ntawm cov theem no.

Koj tuaj yeem rub tawm qhov Circuit Court no ntawm GitLab chaw cia khoom:

Kauj Ruam 8: Ib Qhov Teeb Meem, Ib Txoj Kev Kho

Puas tau sim txiav txim siab txhua qhov kev hloov pauv

Qhov yooj yim tshaj plaws tsis tau zoo dua … Kuv tau hais rau kuv tus kheej qhov no thaum kuv qhov project cua sov txog li 80ºC. Yog, yog tias koj xav tau cov zis tawm tam sim no, tsis txhob siv cov cai tswj kab vim tias lawv tso tawm ntau lub zog.

Kuv qhov teeb meem … qhov tso tawm tam sim no. Kev daws teeb meem… siv DC/DC hloov pauv los hloov cov kab hluav taws xob tawm ncaj qha hauv pob DPAK.

Vim qhov no kuv hu ua Buck DPAK project

Kauj Ruam 9: Xaus

DC / DC cov hloov pauv yog cov txheej txheem ua haujlwm tau zoo rau kev tswj hwm qhov hluav taws xob ntawm qhov siab heev tam sim no, txawm li cas los xij ntawm cov dej ntws qis lawv feem ntau tsis muaj txiaj ntsig tab sis tsis muaj txiaj ntsig zoo dua li tus tswj kab tawm.

Niaj hnub no nws yooj yim heev uas tuaj yeem tsim DC / DC hloov pauv ua tsaug rau qhov tseeb uas cov tuam ntxhab tau pab txhawb txoj hauv kev uas lawv tau tswj hwm thiab siv.