Dhizaini yeNetwork yeKugovera Simba rePCB

Network yekugovera simba (PDN) ndiyo zvivakwa zvinopa voltage yakagadzikana kune yega yega IC iri pabhodhi rako. Kugadzira PDN inochengetedza target impedance kubva kuDC kusvika kumazana eMHz kunoda nzira yakarongeka yekusarudza VRM, saizi ye capacitor, uye plane geometry - hapana chimwe chazvo chinogona kuitwa nepfungwa chete.

Zviri Mukati

1. Magadzirirwo ePDN uye Matunhu Akajairwa
2. Kuverenga kweTarget Impedance
3. Kusarudzwa kweVRM uye Kukura kweBulk Capacitor
4. Kugona kwePlane uye Simulation yePDN
5. Kuyerwa kwePDN, Kusimbiswa uye Mibvunzo Inowanzo bvunzwa

Gwaro iri rinofukidza maitiro ese ekugadzira network yekugovera simba rePCB — kubva pakusarudza zvinangwa zve impedance kuburikidza nekusarudza VRM, saizi ye capacitor, simulation, uye post-fabrication validation. Kuti uwane hunyanzvi hwakakura hwesimba remagetsi hunosanganisira kubatanidza nzvimbo uye dhizaini yeplane, ona gwara guru rekugadzira simba rePCB.

1. Magadzirirwo ePDN uye Nzvimbo Dzinowanzo shandiswa

PDN yakazara inofukidza nzvimbo dzakasiyana-siyana dzemuviri, imwe neimwe ichipa inductance, resistance, uye capacitance kune impedance yese. Chinhu chakakosha ndechekuti hapana chikamu chimwe chete kana chinhu chekugadzira chinodzora impedance muhuwandu hwema frequency akazara. Domain yega yega ine huwandu hwema frequency ainoita painotungamira, uye imwe neimwe inoda kutariswa kwega kwega kwekugadzira.

Chinodiwa chebandwidth yePDN chinogadziriswa ne fastest current transient iyo mutoro unogona kugadzira:

f_Max = 0.5 / t_simuka
Kune processor ine nguva yekukwira kwesimba remagetsi ye1 ns: f_Max = 500 MHz.
Kune DDR5 pa6400 MT/s ine 100 ps edge rates: f_Max Inotambanukira ku5 GHz, ichida kutarisirwa kwakanyatsogadzirwa kwepakeji uye capacitance.

Chinangwa chekugadzira ndechekuchengetedza _chinangwa cheZ < Z nguva dzose kubva kuDC kusvika kuF _max . Chero mukana wefrequency apo PDN impedance inodarika _chinangwa cheZ inogona kukonzera kudonha kwevoltage, oscillation, kana logic failure pa switching frequency inoenderana.

2. Kuverenga Kudzivirira Kwakanangana

Target impedance ndiyo inonyanya kukosha pakugadzira PDN. Inoshandura voltage ripple tolerance kuita quantitative impedance budget iyo sarudzo yega yega yezvikamu uye sarudzo yelayout inofanira kuzadzisa.

Z_chinangwa = (V_zvitengeswa × ripple%) / I_peak
V_zvitengeswa: voltage yemagetsi inopihwa nemazita | ripple%: chikamu chepamusoro chinobvumidzwa cheripple | I_peak: peak instant current kubva kuIC datasheet

Nhamba idzi dzinoratidza huwandu hwakanyanya hwezvinodiwa zvePDN. GPU core rail pa0.1 mΩ inoda PDN yakakwana - mirioni yega yega yeparasitic inductance muPCB stackup, VRM output impedance, kana via array ine simba rinoyerwa. Kuwana zvinangwa izvi usati watanga kuronga kunodzivirira respins dzinodhura.

I _peak inoonekwa muIC datasheet semaximum supply current, peak operating current, kana se transient current waveforms muchikamu cheapplication. Kune maFPGA nema processors, maturusi ekufungidzira simba remutengesi (Xilinx Power Estimator, Intel VID) anopa ma values ​​akarurama kupfuura maximums edatasheet. Kana pasina kukosha kuripo, yera VRM output current ne current probe pane working system uye wedzera 20–30% margin yekushanda kwakaipisisa.

3. Kusarudzwa kweVRM uye Kukura kweBulk Capacitor

VRM inotonga PDN impedance kubva kuDC kuenda ku feedback loop bandwidth yayo. Pasi pe loop bandwidth, VRM inodzora zvinobuda, ichipa milliohm-range impedance. Pa crossover frequency, impedance inosvika — iyi ndiyo shanduko yakakosha yekutonga. Pamusoro pe loop bandwidth, VRM output impedance inokwira uye bulk capacitors inotora nzvimbo.

Mapombi emagetsi ane simba remagetsi ari pamusoro pe20–30 A anoda magadzirirwo eVRM akawanda. Mapombi akawanda anosiya ma switching cycles awo, zvichideredza output current ripple nenhamba yezvikamu, zvichibvumira output inductors diki, uye zvichigovera thermal load pamidziyo yakawanda yemagetsi. Kune maAI accelerator PCB anoda 200+ A supplies, magadzirirwo eVRM ezvikamu 8–16 ndiwo akajairwa.

Kukura kweBulk Capacitor

Ma "bulk capacitor" anobatanidza musiyano we "impedance" pakati peVRM loop bandwidth ne "frequency range" apo ceramic dracoupling inotora nzvimbo. "Bulk capacitance" shoma yekudzivirira "impedance" kuti isakwire pamusoro pe "Z _target " paVRM crossover ndeiyi:

C_guru = 1 / (2π × f_crossover × Z_chinangwa)
Muenzaniso: Z_chinangwa = 5 mΩ, f_crossover = 200 kHz → C_guru = 159 µF zvishoma

Kune madhizaini edhijitari anomhanya zvakanyanya, maMLCC arrays makuru anofarirwa nekuda kwekusanganiswa kwawo kweESR yakaderera, ESL yakaderera, uye capacitance yakagadzikana kana tichienzanisa nefrequency netembiricha. Parallel array yeMLCC values ​​dzakawanda — semuenzaniso, imwe 100 µF iri pamwe chete ne10 µF yakati wandei — inopa bandwidth yakakura inoshanda yekubatanidza kupfuura mhando imwe chete yecapacitor hombe yemhando yega yega.

4. Kugona kwePlane uye Simulation yePDN

Mapurani emhangura ePCB anoratidza capacitance yakagoverwa pakati pemagetsi ari pedyo nepasi. Capacitance iyi inoshanda kupfuura 100 MHz — apo ma capacitor akasiyana-siyana ave inductive uye asingachabatsiri mukupatsanurwa kwePDN.

C_Plane = ε₀ × ε_r × A / d
ε₀ = 8.854 × 10⁻¹² F/m | ε_r = 4.3 (FR-4) | A = nzvimbo yendege inopindirana (m²) | d = ukobvu hwe dielectric (m)
Muenzaniso: Bhodhi re100×100 mm, 4 mil FR-4 pakati peGND nePWR planes → C_Plane ≈ 3.8 nF

Kunyange zvazvo 3.8 nF iri diki zvachose, inoparadzirwa zvakaenzana munzvimbo yese yebhodhi uye ine inductance yakaderera kwazvo pamafrequencies akakwira. Kuti uwedzere kugona kweplane: shandisa 3–4 mil prepreg pakati peGND nePWR planes (kwete 10+ mil core); wedzera nzvimbo yemhangura inopindirana uye dzivisa kucheka kweplane kusingakoshi; uye funga nezvezvinhu zve capacitance zvakapinzwa zvine high-ε _r (zvakadai seSanmina C-Ply) zvemabhodhi ane Z _target iri pasi pe5 mΩ pamusoro pe100 MHz - zvinhu izvi zvinogona kuwedzera kugona kweplane ne100× kupfuura standard FR-4.

Nzira dzeKutevedzera dzePDN

Kutevedzera kwePDN kunoratidza kuti network yakagadzirwa inowana chinangwa chekupindira usati wagadzira. Nzira nhatu dzinoshandiswa mukuita, mukuwedzera kurongeka kwekururama:

• Muenzaniso wakarungwa wakavakirwa paSpreadsheet: Inogadzirisa zvikamu zvePDN sema network eRLC akatevedzana. Inokurumidza uye inoziva matambudziko makuru ekugadzira, asi inorasikirwa nemhedzisiro yeplane resonances uye mhedzisiro yenzvimbo. Yakanakira kusarudza kwekutanga kweVRM uye kufungidzira huwandu hwema capacitor.
• Kutevedzera kweS-parameter PDN (Ansys SIwave, Cadence Sigrity, HyperLynx PI): Kutevedzera kwakazara kweEM kwemapuraneti ePCB. Kunotora peaks dzeresonance yeplane, anti-resonance nulls, mhedzisiro yekupatsanurwa kweplane, uye kugadzirisa capacitor placement. Zvinodiwa kana Z_chinangwa iri pasi pe10 mΩ.
• Kutevedzera nguva nedhomini: Inoshandisa mapurofayiri emagetsi eIC chaiwo kubva kumamodeli emagetsi eBIS kana ma waveforms akayerwa. Inopa fungidziro yekudonha kwemagetsi zvakananga pasi pemamiriro chaiwo ekuchinja. Nzira chaiyo yekuongorora kusaina kwemagetsi kwakaipisisa.

5. Kuyerwa kwePDN, Kusimbiswa uye Mibvunzo Inowanzo bvunzwa

Mushure mekugadzirwa kwePCB, simbisai PDN impedance musati magadzira system yese kuti musimbise kuti mhedzisiro yesimulation inowanikwa muhardware. Kusiyana pakati pesimulation nekuyera kunowanzo konzerwa nema component models asina kururama, unmodeled parasitic inductance muvias kana connectors, kana plane resonances inoshandurwa ne dielectric properties chaiyo.

Kuyerwa kweVNA yePort 1

Pima S11 panzvimbo yeIC power pin neVRM nemacapacitor akapatsanurwa, IC yabviswa. S11 inoshanduka kuita impedance:

Z = Z₀ × (1 + S11) / (1 − S11)
Z₀ = 50 Ω (VNA port impedance). Kune Z < 100 mΩ, shandisai 2-port shunt-through measurement kuti muve nekururama kwakadzika pamitengo yakaderera ye impedance.

Kusimbiswa kweDomain yeNguva

Kana sisitimu yagadzirwa zvizere, shandisa probe yesimba remagetsi (20 MHz bandwidth minimum, 1 GHz inosarudzwa) paIC power pin pasi pemutoro wekushanda wakazara. Simbisa: ripple yesimba repamusoro-soro iri mukati mebhajeti reripple rinobvumirwa; hapana kudonha kwemhepo kunopfuura specification yesimba rekushanda; uye frequency yeripple yekuchinjana inoonekwa uye iri mukati meamplitude inotarisirwa.

Mibvunzo Inonyanya Kubvunzwa

Chii chinokonzera PDN impedance ine anti-resonance peak?

Chinorwisa resonance peak chinoitika apo impedance yemhando imwe ye capacitor (inova inductive pamusoro peSRF yayo) inosangana ne impedance yemhando inotevera ye capacitor (ichiri capacitive). Impedances inowedzera panzvimbo pe cancel pamharadzano iyi, zvichigadzira peak inogona kudarika Z _target . Kuidzvinyirira nekushandisa ma capacitor ane ma values ​​akasiyana zvishoma kuparadzira resonance frequency, kuwedzera resistive damping capacitors mu parallel, kana kusarudza ma capacitor types ane ESR yakakwira pa crossover frequency.

Ndingashandisa mabheya eferrite here kupatsanura zvikamu zvePDN?

Mabheya eFerrite akakodzera kuparadzanisa mareya eAnalog kana RF kubva kunzwi redigital switching riri pamusoro pe10–100 MHz. Usashandise mabheya eFerrite akatevedzana ane nzira dzemagetsi dzemagetsi dzinopa simba rakawanda — kupindira kwawo kunokonzera kudzikira kukuru kwemagetsi pasi pemutoro, uye maitiro asina kurongeka anogona kukonzera kusagadzikana kweVRM.

Ndinoda mangani maVRM phases?

Gwaro rinowanzo shandiswa i10–15 A pachikamu chimwe nechimwe chemagadzirirwo akajairwa eFET VRM. Kune 60 A CPU rail, shandisa 4–6 phases. Kune GPU kana AI accelerator rails pa200 A+, 12–16 phases ndizvo zvakajairika. Mazhinji phases anoderedza kubuda kwemhepo, anobvumira ma inductors madiki, uye anovandudza transient response bandwidth pamutengo we greater controller uye FET count.

Kuti uwane misoro ine chekuita nekuvimbika kwesimba, ona gwara redu rekuisa capacitor , matekiniki ekugadzira plane yemagetsi , kuderedza ruzha panguva imwe chete , uye dhizaini yePCB stackup yakawanda . Highleap Electronics inopa ongororo yePDN dhizaini uye kugadzirwa kwePCB nekukurumidza. Kumbira mutengo wepurojekiti yako.