In high-frequency PCB bhodhi, rudzi rwakakosha rwekuvhiringidza isimba rekupa ruzha. Nekunyatsoongorora maitiro uye zvinokonzeresa ruzha rwesimba pamabhodhi ePCB akakwira-frequency, munyori anoisa mberi mamwe anonyatsoshanda uye akareruka mhinduro musanganiswa neainjiniya maapplication.

Ongororo yemagetsi ekupa ruzha

Mutsindo wekupa simba (Power supply noise) zvinoreva ruzha rwunogadzirwa nemagetsi pachawo kana kukonzerwa nekuvhiringwa. Kukanganisa kunoratidzwa muzvikamu zvinotevera:

1) Ruzha rwakagovaniswa rwunokonzerwa neiyo inherent impedance yemagetsi pachayo. Mune ma-high-frequency circuits, magetsi emagetsi ane simba guru pane zviratidzo zvepamusoro-frequency. Nokudaro, magetsi akaderera-ruzha anotanga kudiwa. Ivhu rakachena rakakosha senzvimbo yemagetsi yakachena. Hunhu hwesimba hunoratidzwa semumufananidzo 1.

Simba waveform

Sezvinogona kuonekwa kubva kuMufananidzo 1, magetsi pasi pemamiriro ezvinhu akanaka haana impedance, saka hapana ruzha. Nekudaro, iyo chaiyo magetsi inopihwa ine imwe impedance, uye iyo impedance inogoverwa pane yese magetsi ekupa, saka, ruzha ruchave rwakanyanya pamusoro pemagetsi. Nokudaro, iyo impedance yemagetsi inofanira kuderedzwa zvakanyanya sezvinobvira, uye zvakanakisisa kuva nemagetsi akazvitsaurira uye pasi pasi. Mupamusoro-frequency circuit design, zvinowanzova nani kugadzira simba rekushandisa muchimiro chechidimbu pane chimiro chebhazi, kuitira kuti loop igare ichitevera nzira neine impedance shoma. Pamusoro pezvo, bhodhi remagetsi rinofanira kupawo chiratidzo chechiratidzo kune ese anogadzirwa uye anogamuchirwa masaini paPCB, kuitira kuti chiratidzo chechiratidzo chigone kudzikiswa, nekudaro kuderedza ruzha.

2) Common mode field interference. Zvinoreva ruzha pakati pemagetsi uye pasi. Iko kukanganisa kunokonzerwa neyakajairwa modhi voltage inokonzerwa ne loop yakaumbwa neyakakanganiswa dunhu uye yakajairika referensi yeimwe simba rekupa. Kukosha kwayo kunoenderana nehukama hwemagetsi uye magnetic field. Simba rinoenderana nesimba. Sezvakaratidzwa mumufananidzo 2.

Common mode kupindira

Pane iyi chiteshi, kudonha muIc kunokonzeresa yakajairika-modhi voltage munhevedzano yazvino loop, iyo inokanganisa chikamu chinogashira. Kana iyo magnetic field iri kutonga, kukosha kweiyo common mode voltage inogadzirwa munhevedzano yepasi loop ndeye:

Common mode voltage

Muchidimbu (1), ΔB ndiyo shanduko yemagnetic flux density, Wb/m2; S ndiyo nzvimbo, m2.

Kana iri munda wemagetsi, kana kukosha kwemunda wemagetsi kuchizivikanwa, iyo induced voltage ndeye

Inductive voltage

Equation (2) inowanzoshanda kuL=150/F kana pasi, uko F iri frequency yemafungu emagetsi muMHz.

Chiitiko chemunyori ndeichi: Kana muganho uyu ukapfuudzwa, kuverenga kweiyo yakanyanya induced voltage inogona kurerutswa ku:

Maximum induced voltage

3) Differential mode field interference. Zvinoreva kukanganisa pakati pemagetsi emagetsi uye ekuisa uye kubuda magetsi emagetsi. Mune chaiyo PCB dhizaini, munyori akaona kuti chikamu chayo muruzha rwemagetsi idiki, saka hazvifanirwe kukurukura nezvazvo pano.

4) Inter-line kupindira. Zvinoreva kukanganisa pakati petambo dzemagetsi. Kana paine mutual capacitance C uye mutual inductance M1-2 pakati pemaseketi maviri akasiyana akafanana, kana paine voltage VC uye yazvino IC mune yekukanganisa sosi wedunhu, iyo yakakanganiswa dunhu ichaonekwa:

A. The voltage yakabatanidzwa kuburikidza capacitive impedance iri

Voltage yakabatanidzwa kuburikidza ne capacitive impedance

Mune formula (4), RV ndiyo inofananidzwa kukosha kwepedyo-kuguma kushorwa uye kure-kumagumo kushorwa kwedunhu rakakanganiswa.

B. Series kuramba kuburikidza inductive coupling

Series kuramba kuburikidza inductive coupling

Kana paine ruzha rwemhando yakajairika mune yekukanganisa sosi, iyo mutsara-kune-mutsara kukanganisika kazhinji inotora chimiro cheyakajairwa modhi uye yekusiyanisa maitiro.

5) Simba rekubatanidza mutsara. Zvinoreva chiitiko chekuti mushure mekunge AC kana DC tambo yemagetsi yaiswa pasi pekukanganiswa kwemagetsi, tambo yemagetsi inoendesa kukanganiswa kune mamwe maturusi. Uku ndiko kukanganisa kusina kunanga kwesimba rekupa ruzha kune yakakwirira-frequency circuit. Izvo zvinofanirwa kucherechedzwa kuti ruzha rwemagetsi emagetsi haaite kugadzirwa pacharwo, asi runogona kunge rwuri ruzha rwunokonzerwa nekupindira kwekunze, uye wobva wawedzera ruzha urwu neruzha rwunogadzirwa pacharwo (radiation kana conduction) kukanganisa mamwe maseketi. kana midziyo.

Countermeasures yekubvisa magetsi ekupa ruzha kukanganisa

Tichifunga nezve kuratidzwa kwakasiyana uye zvikonzero zvekuvhiringidza kwemagetsi ekupa ruzha zvakaongororwa pamusoro, mamiriro ayo anoitika anogona kuparadzwa nenzira yakanangwa, uye kukanganiswa kweruzha rwemagetsi emagetsi kunogona kudzvinyirirwa. Mhinduro ndeidzi: 1) Chenjerera kune kuburikidza nemaburi pabhodhi. Iyo kuburikidza neburi inoda kuvhura pane simba layer kuti ichengetwe kusiya nzvimbo kuti buri ripfuure. Kana kuvhurwa kwechigadziko chesimba chakanyanya kukura, zvichange zvichikanganisa chiratidzo chechiratidzo, chiratidzo chichamanikidzwa kudarika, nzvimbo yechiuno ichawedzera, uye ruzha ruchawedzera. Panguva imwecheteyo, kana mamwe masaini mitsara akaiswa padhuze nekuvhurwa uye kugovera iyi loop, iyo yakajairika impedance inokonzeresa crosstalk. Ona Mufananidzo 3.

Bypass nzira yakajairika yechiratidzo chedunhu

2) Waya dzepasi dzakakwana dzinodiwa kune waya dzekubatanidza. Chiratidzo chega chega chinoda kuve neyayo yakatsaurwa yechiratidzo loop, uye iyo loop nzvimbo yechiratidzo uye loop idiki sezvinobvira, kureva kuti, chiratidzo uye loop inofanira kufanana.

3) Isai simba rekupa ruzha sefa. Inogona kunyatso kudzvinyirira ruzha mukati memagetsi ekupa uye kuvandudza anti-kupindira uye kuchengetedzwa kwehurongwa. Uye inzira mbiri-redhiyo frequency sefa, isingangogone kusefa kupindira kweruzha kwakaunzwa kubva kutambo yemagetsi (kudzivirira kupindira kubva kune mamwe maturusi), asi zvakare kusefa ruzha rwunogadzirwa pacharwo (kudzivisa kukanganiswa nemimwe michina. ), uye kukanganisa serial modhi yakajairika. Zvose zvine inhibitory effect.

4) Simba rekuparadzanisa transformer. Kupatsanura iyo simba loop kana yakajairika modhi yepasi loop yechiratidzo tambo, inogona kunyatso patsanura yakajairika modhi loop ikozvino inogadzirwa mune yakakwirira frequency.

5) Mugadziri wemagetsi. Kuwanazve magetsi ekuchenesa kunogona kuderedza zvakanyanya ruzha rwemagetsi emagetsi.

6) Wiring. Iyo yekupinza uye inobuda mitsara yemagetsi haifanirwe kuiswa pamucheto weiyo dielectric board, zvikasadaro zviri nyore kugadzira radiation uye kukanganisa mamwe maseketi kana michina.

7) Iyo analog uye yedhijitari magetsi anofanirwa kuparadzaniswa. High-frequency midziyo inowanzo terera kune ruzha rwedhijitari, saka izvo zviviri zvinofanirwa kupatsanurwa uye kubatanidzwa pamwe chete pamusuwo wemagetsi. Kana iyo chiratidzo ichida kutenderedza ese analog uye edhijitari zvikamu, loop inogona kuiswa pane iyo chiratidzo span kuti ideredze iyo loop nzvimbo. Sezvinoratidzwa Mufananidzo 4.

Isa chiuno pachiratidzo chekuyambuka kuti uderedze nzvimbo yechiuno

8) Dzivisa kupindirana kwemagetsi akasiyana emagetsi pakati peakasiyana akaturikidzana. Vadzikame zvakanyanya sezvinobvira, zvikasadaro ruzha rwemagetsi runobatanidzwa zviri nyore kuburikidza neparasitic capacitance.

9) Kuzvitsaura zvinonzwisisika zvikamu. Zvimwe zvikamu, zvakadai sechikamu-chakakiyiwa zvishwe (PLL), zvinonzwa zvakanyanya kune ruzha rwemagetsi. Vachengetedze kure kure nemagetsi sezvinobvira.

10) Isa tambo yemagetsi. Kuti uderedze chiratidzo chechiratidzo, ruzha runogona kuderedzwa nekuisa tambo yemagetsi pamucheto wemutsara wechiratidzo, sezvakaratidzwa mumufananidzo 5.

Isa tambo yemagetsi pedyo nemutsara wechiratidzo

11) Kuti udzivise ruzha rwemagetsi emagetsi kubva pakukanganisa bhodhi redunhu uye ruzha rwakaunganidzwa rwunokonzerwa nekupindira kwekunze kune magetsi, bypass capacitor inogona kubatanidzwa pasi munzira yekukanganisa (kunze kwemwaranzi), kuitira kuti. ruzha runogona kuvharirwa pasi kudzivirira Kupindira nemimwe michina nemichina.

Simba rekupa ruzha rinogadzirwa zvakananga kana zvisina kunanga kubva kune magetsi uye rinokanganisa dunhu. Pakudzvinyirira maitiro ayo padunhu, mutemo mukuru unofanirwa kuteverwa. Kune rumwe rutivi, ruzha rwekupa magetsi runofanira kudzivirirwa zvakanyanya sezvinobvira. Kufuridzirwa kwedunhu, kune rumwe rutivi, kunofanirawo kuderedza simba rekunze kwenyika kana dunhu pamagetsi emagetsi, kuitira kuti arege kuwedzera ruzha rwemagetsi.