Kanggo riset lan pangembangan sumber daya ganti, Desain PCB occupies a very important position. A bad PCB has poor EMC performance, high output noise, weak anti-interference ability, and even basic functions are defective.

Rada beda karo PCBS hardware liyane, PCBS ngalih bisa duwe ciri khas dhewe-dhewe. Artikel iki bakal mbahas babagan sawetara prinsip dhasar kabel PCB sing paling penting kanggo ngoper sumber daya adhedhasar pengalaman teknik.

1, spacing

Jarak baris kudu dipikirake kanggo produk voltase dhuwur. Jarak sing bisa memenuhi persyaratan peraturan keamanan sing cocog mesthine paling apik, nanging kakehan produk sing ora butuh sertifikasi, utawa ora bisa entuk sertifikasi, jarak kasebut ditemtokake dening pengalaman. Jembar jarak apa sing cocog? Kudu nimbang produksi manawa kanggo njamin kebersihan permukaan papan, asor lingkungan, polusi liyane ngenteni kahanan kepiye.

For the mains input, even if the board surface can be guaranteed clean and sealed, MOS tube drain source electrode close to 600V, less than 1mm is actually more dangerous!

2. Komponen ing pojok papan

For the patch capacitance or other easily damaged devices at the edge of PCB, the PCB splitter direction must be taken into consideration when placing. The figure shows the comparison of the stress on the devices under various placement methods.

FIG. 1 Comparison of stress on the device when the plate is split

Bisa dingerteni manawa piranti kasebut mesthine ora adoh lan sejajar karo ujung splitter, yen komponen kasebut bisa uga rusak amarga PCB splitter.

3. Loop area

Whether input or output, power loop or signal loop, should be as small as possible. Daur ulang listrik ngasilake lapangan elektromagnetik, sing bakal nyebabake karakteristik EMI sing ora apik utawa gangguan output sing gedhe; At the same time, if received by the control ring, it is likely to cause an exception.

Saliyane, yen area loop daya luwih gedhe, induktansi parasit sing padha uga bakal nambah, sing bisa nambah puncak gangguan saluran.

4. Kabel kunci

Amarga efek DI / DT, induktansi ing simpul dinamis kudu dikurangi, saupama digawe lapangan elektromagnetik sing kuat. Yen pengin nyuda induktansi, pokoke pengin nyuda dawa kabel, mundhak tumindak jembar iku sithik.

5. Kabel sinyal

Kanggo kabeh bagean kontrol, kudu dipikirake kabel adoh saka bagean daya. Yen kalorone cedhak amarga watesan liyane, garis kontrol lan garis listrik ora kudu sejajar, yen bisa nyebabake operasi suplai listrik sing ora normal, kejut.

In addition, if the control line is very long, a pair of back and forth lines should be close to each other, or the two lines should be placed on the two sides of the PCB facing each other, so as to reduce the loop area and avoid interference by the electromagnetic field of the power part. GAMBAR 2 nggambarake cara nuntun garis sinyal sing bener lan salah ing antarane A lan B.

Gambar 2 Cara nuntun kabel sinyal sing bener lan salah.

Mesthine, garis sinyal kudu nyuda koneksi liwat bolongan!

6, copper

Kadhangkala mbikak tembaga pancen ora perlu lan malah kudu dihindari. If the copper was large enough and its voltage varied, it might act as an antenna, radiating electromagnetic waves around it. Saliyane, gampang njupuk swara.

Umume, peletakan tembaga mung diidini ing simpul statis, kayata simpul “ground” ing mburi output, sing bisa nambah capacitance output kanthi efektif lan nyaring sawetara sinyal swara.

7, pemetaan,

For a circuit, copper can be laid on one side of the PCB, which automatically maps to the wiring on the other side of the PCB to minimize the impedance of the circuit. Kayane sekumpulan impedimen kanthi nilai impedansi sing beda-beda disambungake kanthi paralel, lan saiki kanthi otomatis bakal milih dalan kanthi impedansi paling murah sing bisa dilalekake.

Sampeyan bisa ngawat-ngawati sisih kontrol sirkuit ing sisih, lan nyelehake tembaga ing simpul “lemah” ing sisih liyane, lan sambungake loro-lorone liwat bolongan.

8. Diode rectifier output

Yen diode penerus output cedhak karo output, mula ora diselehake sejajar karo output. Yen ora, kolom elektromagnetik sing digawe ing diode bakal nembus menyang loop sing dibentuk dening output tenaga lan beban eksternal, saengga output output sing diukur bakal nambah.

GAMBAR 3 Penempatan dioda sing bener lan ora bener

9, kabel lemah,

Kabel kabel lemah kudu ngati-ati banget. Yen ora, EMS, EMI lan kinerja liyane bisa uga saya parah. Kanggo ngoper “ground” PCB, paling ora rong poin ing ngisor iki: (1) lemah listrik lan ground signal, kudu ana siji sambungan; (2) Ora kudu ana gelung dhasar.

10. Y capacitance

Input lan output asring disambungake karo kapasitor Y, kadang amarga sawetara sebab, bisa uga ora bisa digantung ing kapasitor input, elinga ing wektu iki, kudu disambungake menyang simpul statis, kayata terminal voltase dhuwur.

11, liyane

Nalika ngrancang PCB saka pasokan listrik nyata, bisa uga ana sawetara masalah liyane sing kudu dipikirake, kayata “varistor kudu cedhak karo sirkuit sing dilindhungi”, “induksi mode umum kanggo nambah untu sing ngeculake”, “pasokan listrik VCC chip kudu nambah kapasitor ”lan liya-liyane. Kajaba iku, kabutuhan perawatan khusus, kayata foil tembaga, tameng, lsp., Uga kudu dipikirake ing tahap desain PCB.

Kadhangkala asring nemoni sawetara prinsip sing saling bertentangan, kanggo ketemu salah sawijine ora bisa ketemu karo sing liyane, iki perlune para insinyur kanggo ngetrapake pengalaman sing ana, miturut kabutuhan proyek sing nyata, temtokake kabel sing paling cocog!