PCB Yila isantya esiphezulu sendlela yokungenisa isignali ye-analog

Ububanzi bomgca womgca, amandla anamandla okuchasana kunye nomgangatho ongcono wesignali (impembelelo yempembelelo yesikhumba). Kodwa kwangaxeshanye, imfuno ye-50Ω yokuphazamiseka kophawu kufuneka iqinisekiswe. Ibhodi ye-FR4 eqhelekileyo, ububanzi bomgca we-surface 6MIL impedance yi-50Ω. Ngokucacileyo oku akunakuhlangabezana neemfuno zomgangatho wophawu lwegalelo le-analog enesantya esiphezulu, ke siqhele ukusebenzisa umngxuma we-GND02 kwaye uyivumele ibhekisele kumaleko we-ART03. Ngale ndlela, isignali yokwahlukana ingabalwa njenge-12/10, kwaye umgca omnye ungabalwa njenge-18MIL. (Qaphela ukuba ububanzi bomgca bungaphezulu kwe-18MIL kwaye ke ukwandiswa akunantsingiselo)

Uyilo lwe-PCB olukwisantya esiphezulu se-analog yegalelo lendlela yendlela kunye nemithetho

I-CLINE egxininiswe eluhlaza kumfanekiso ibhekisela kumgca owodwa kunye nokwahlula igalelo le-analog yesantya esiphezulu se-ART03 layer. Ngelixa usenza oku, ezinye iinkcukacha kufuneka zijongwe:

(1) Inxalenye yokulinganisa ye-TOP layer kufuneka ifakwe, njengoko kuboniswe kumzobo ongentla. Kufuneka kuqatshelwe ukuba umgama ukusuka kubhedu lomhlaba ukuya kwigalelo le-analog CLINE kufuneka ibe yi-3W, oko kukuthi, i-AIRGAP ukusuka kumda wobhedu ukuya kwi-CLINE iphindwe kabini ububanzi bomgca. Ngokwezinye izibalo zethiyori ye-electromagnetic kunye nokulinganisa, intsimi yamagnetic kunye nentsimi yombane yemigca yesignali kwi-PCB isasazwa phakathi koluhlu lwe-3W. (Uphazamiseko lwengxolo oluvela kwiimpawu ezijikelezileyo lungaphantsi okanye lulingana no-1%).

(2) Ubhedu lwe-GND lwe-positive layer yendawo ye-analog nayo kufuneka ibekwe yodwa kwindawo ejikelezileyo yedijithali, oko kukuthi, zonke iileyile zibekwe zodwa.

(3) Ukugrunjwa kwe-GND02, sihlala sikhupha yonke le ndawo, ngoko ke umsebenzi ulula kwaye akukho ngxaki. Kodwa ngokuqwalasela iinkcukacha okanye ukuze senze ngcono, singakwazi ukuvala i-analog input wiring part, ngokuqinisekileyo, ngokufanayo ne-TOP layer, indawo ye-3W. Oku kunokuqinisekisa umgangatho wesignali kunye nokuthambeka kwebhodi. Isiphumo sokuqhubekeka simi ngolu hlobo lulandelayo:

Uyilo lwe-PCB olukwisantya esiphezulu se-analog yegalelo lendlela yendlela kunye nemithetho

Ngale ndlela, indlela yokubuya yesiginali ye-analog yesantya esiphezulu inokuphinda ifakwe kwakhona kwi-GND02 layer. Oko kukuthi, indlela yokubuya komhlaba oyifanisiweyo iba mfutshane.

(4) Ukubetha ngokungaqhelekanga inani elikhulu le-GND ngokujikeleza umqondiso we-analog onesantya esiphezulu ukwenza umqondiso we-analog ubuye ngokukhawuleza. Iyakwazi nokufunxa ingxolo.

I-PCB uyilo olunesantya esiphezulu semithetho ye-analog yokungenisa umzila

Umthetho 1: Isantya esiphezulu se-PCB ye-high-speeding signaling routing imithetho Kuyilo lwe-PCB olunesantya esiphezulu, ukuhanjiswa kwemigca yesignali ye-key-speed high-speed efana newotshi kufuneka ikhuselwe. Ukuba akukho khaka okanye inxalenye yayo kuphela, iya kubangela ukuvuza kwe-EMI. Kucetyiswa ukuba ucingo olukhuselekileyo lubekwe phantsi ngomngxuma kwi-1000 mil.

Uyilo lwe-PCB olukwisantya esiphezulu se-analog yegalelo lendlela yendlela kunye nemithetho

Umthetho we-2: Umzila wesignali yesantya esiphezulu semigaqo evaliweyo

Ngenxa yoxinzelelo olwenyukayo lweebhodi zePCB, iinjineli ezininzi ze-PCB LOKUBEKELA ziqhele ukwenza impazamo kwinkqubo yothungelwano, oko kukuthi, uthungelwano lwemiqondiso enesantya esiphezulu njengemiqondiso yewotshi, evelisa iziphumo ezivaliweyo xa uhambisa ii-PCB ezinomaleko amaninzi. Njengomphumo welophu evaliweyo, i-antenna ye-loop iya kuveliswa, eya kwandisa i-radiated intensity ye-EMI.

Uyilo lwe-PCB olukwisantya esiphezulu se-analog yegalelo lendlela yendlela kunye nemithetho

Umthetho 3: Umqondiso wesantya esiphezulu uhambisa imithetho evulekileyo ye-loop

Umthetho we-2 ukhankanya ukuba i-loop evaliweyo yemiqondiso yesantya esiphezulu iya kubangela i-EMI radiation, kodwa i-loop evulekileyo iya kubangela imitha ye-EMI.

Uthungelwano lweempawu zesantya esiphezulu ezifana neempawu zewotshi, kanye ukuba isiphumo se-open-loop senzeka xa i-PCB ye-multilayer ihanjiswa ngendlela, kuya kuveliswa i-eriyali yomgca, eyandisa ubunzulu bemitha ye-EMI.

Uyilo lwe-PCB olukwisantya esiphezulu se-analog yegalelo lendlela yendlela kunye nemithetho

Umgaqo 4: Umgaqo wokuqhubekeka kokuphazamiseka kophawu lwesantya esiphezulu

Kwiimpawu zesantya esiphezulu, i-impedance yeempawu kufuneka ibe yinto eqhubekayo xa utshintshela phakathi kweengqimba, ngaphandle koko kuya kwandisa i-EMI radiation. Ngamanye amazwi, ububanzi be-wiring yoluhlu olufanayo kufuneka buqhubeke, kwaye i-impedance ye-wiring yemigangatho eyahlukeneyo kufuneka iqhubeke.

Uyilo lwe-PCB olukwisantya esiphezulu se-analog yegalelo lendlela yendlela kunye nemithetho

Umthetho 5: Imithetho yendlela yocingo yoyilo lwePCB enesantya esiphezulu

I-wiring phakathi kwemigangatho emibini emeleneyo kufuneka ilandele umgaqo wocingo oluthe nkqo, ngaphandle koko kuya kubangela i-crosstalk phakathi kwemigca kunye nokwandisa i-EMI radiation.

Ngamafutshane, iileyile ze-wiring ezikufutshane zilandela izikhokelo ze-wiring ezithe tye kunye nezithe nkqo, kwaye i-wiring ethe nkqo inokucinezela i-crosstalk phakathi kwemigca.

Uyilo lwe-PCB olukwisantya esiphezulu se-analog yegalelo lendlela yendlela kunye nemithetho

Umthetho 6: Imithetho yesakhiwo se-Topological kuyilo lwePCB olunesantya esiphezulu

Kwi-high-speed PCB design, ulawulo lwe-impedance yeempawu zebhodi yesekethe kunye noyilo lwesakhiwo se-topological phantsi kweemeko zomthwalo omninzi zichaza ngokuthe ngqo impumelelo okanye ukungaphumeleli kwemveliso.

Umzobo ubonisa i-daisy chain topology, enenzuzo ngokubanzi xa isetyenziswe kwi-Mhz embalwa. Kuyacetyiswa ukuba kusetyenziswe i-symmetrical structure emile okwenkwenkwezi kwicala elingasemva kuyilo lwePCB olunesantya esiphezulu.

Uyilo lwe-PCB olukwisantya esiphezulu se-analog yegalelo lendlela yendlela kunye nemithetho

Umgaqo 7: Umgaqo we-resonance wobude bokulandelela

Jonga ukuba ubude bomgca wesignali kunye nokuphindaphindwa komqondiso kukwenza iresonance, oko kukuthi, xa ubude bocingo buyinani elipheleleyo le-wavelength yesignali eyi-1/4, iingcingo ziya kuvakala, kwaye iresonance iya kukhupha amaza ombane. kwaye ibangele ukuphazamiseka.