Phunzirani za wotchi pa PCB
- 1. Kamangidwe
a, kristalo wa wotchi ndi maulendo okhudzana nawo ayenera kukonzedwa pakatikati pa PCB ndikukhala ndi mapangidwe abwino, osati pafupi ndi mawonekedwe a I / O.Dongosolo la wotchi silingapangidwe kukhala khadi la mwana wamkazi kapena mawonekedwe a bolodi la mwana wamkazi, liyenera kupangidwa pa bolodi la wotchi kapena bolodi yonyamula.
Monga momwe tawonetsera mu chithunzi chotsatira, bokosi lobiriwira gawo la mzere wotsatira ndi bwino kuti musayende pamzere
b, zida zokhazo zokhudzana ndi dera la wotchi mu PCB wotchi yozungulira dera, pewani kuyala mabwalo ena, ndipo musayike mizere ina yazizindikiro pafupi kapena pansi pa kristalo: Kugwiritsa ntchito ndege yapansi pansi pa dera lotulutsa koloko kapena kristalo, ngati pali zina. zizindikiro zimadutsa mu ndege, zomwe zimaphwanya ntchito ya ndege yopangidwa ndi mapu, ngati chizindikirocho chikudutsa pansi pa ndege, padzakhala phokoso laling'ono la pansi ndikukhudza kupitiriza kwa ndege yapansi, ndipo malupu apansi awa adzayambitsa mavuto pa maulendo apamwamba.
c.Kwa makhiristo a wotchi ndi mawotchi ozungulira, njira zotetezera zitha kutengedwa kuti zitetezedwe;
d, ngati chipolopolo cha wotchi ndi chitsulo, mapangidwe a PCB ayenera kuikidwa pansi pa mkuwa wa kristalo, ndikuonetsetsa kuti gawo ili ndi ndege yonse yapansi ili ndi magetsi abwino (kudzera pansi porous).
- Ubwino wopaka pansi pa makhiristo a wotchi:
Dera mkati mwa crystal oscillator imapanga RF yapano, ndipo ngati kristaloyo ili m'nyumba yachitsulo, pini yamagetsi ya DC ndikudalira kwa DC voltage reference ndi RF current loop reference mkati mwa kristalo, kutulutsa kwakanthawi komwe kumapangidwa ndi RF ma radiation a nyumba kudzera mu ndege yapansi.Mwachidule, chipolopolo chachitsulo ndi mlongoti wokhala ndi mapeto amodzi, ndipo chithunzi chapafupi, chosanjikiza chapansi ndipo nthawi zina zigawo ziwiri kapena kuposerapo ndizokwanira kulumikiza kwa RF panopa pansi.Pansi pa kristalo ndi bwinonso kutentha kutentha.Kuzungulira kwa wotchi ndi kristalo pansi kumapereka ndege yojambula, yomwe ingachepetse mawonekedwe wamba omwe amapangidwa ndi kristalo ndi wotchi yolumikizidwa, motero kuchepetsa ma radiation a RF.Ndege yapansi imatenganso njira yosiyanitsira RF pano.Ndege iyi iyenera kulumikizidwa ndi ndege yonse pansi ndi mfundo zingapo ndipo imafunikira mabowo angapo, omwe angapereke kutsekeka kochepa.Kuti muwonjezere mphamvu ya ndege yapansi iyi, dera la jenereta la wotchi liyenera kukhala pafupi ndi ndege yapansi iyi.
Makristalo okhala ndi Smt adzakhala ndi ma radiation ochulukirapo a RF kuposa makhiristo ovala zitsulo: Chifukwa makhiristo okwera pamwamba nthawi zambiri amakhala mapaketi apulasitiki, ma RF omwe ali mkati mwa kristalo amawala mumlengalenga ndikuphatikizidwa ndi zida zina.
1. Gawani njira ya wotchi
Ndikwabwino kulumikiza chizindikiro cham'mphepete mwachangu ndi chizindikiro cha belu ndi radial topology kuposa kulumikiza netiweki ndi gwero limodzi loyendetsa wamba, ndipo njira iliyonse iyenera kuyendetsedwa ndikuyimitsa miyeso molingana ndi mawonekedwe ake.
2, zofunika mzere kufala wotchi ndi PCB layering
Mfundo yoyendetsera wotchi: Konzani mawonekedwe athunthu a ndege pafupi ndi wotchiyo, chepetsa kutalika kwa mzere ndikuchita zowongolera.
- Mawaya olakwika ophatikizika ndi kusagwirizana kwa impedance kungayambitse:
1) Kugwiritsa ntchito mabowo ndi kulumpha mu mawaya kumatsogolera ku kukhulupirika kwa chithunzicho;
2) Kuthamanga kwamagetsi pa ndege ya fano chifukwa cha voteji pa pini ya chizindikiro cha chipangizo kusintha ndi kusintha kwa chizindikiro;
3), ngati mzerewo suganizira mfundo ya 3W, mawotchi osiyanasiyana amayambitsa crosstalk;
- Wiring wa chizindikiro cha wotchi
1, mzere wa wotchi uyenera kuyenda mkati mwa gulu la PCB lamitundu yambiri.Ndipo onetsetsani kuti mukutsatira mzere wa riboni;Ngati mukufuna kuyenda pamtunda wakunja, mzere wa microstrip wokha.
2, wosanjikiza wamkati akhoza kuonetsetsa wathunthu fano ndege, akhoza kupereka otsika-impedance RF kufala njira, ndi kupanga maginito flux kuthetsa maginito flux awo gwero kufala mzere, kuyandikira mtunda pakati pa gwero ndi kubwerera njira, ndi bwino degaussing.Chifukwa cha kuwonjezereka kwa demagnetization, chithunzi chilichonse chathunthu cha PCB cholimba kwambiri chimapereka kuponderezedwa kwa 6-8dB.
3, maubwino a bolodi lamitundu yambiri: pali wosanjikiza kapena zigawo zingapo zomwe zitha kuperekedwa kumagetsi athunthu ndi ndege yapansi, zitha kupangidwa kukhala njira yabwino yolumikizirana, kuchepetsa malo ozungulira, kuchepetsa njira yosiyanitsira. ma radiation, amachepetsa EMI, amachepetsa kuchuluka kwa chizindikiro ndi njira yobwereranso mphamvu, amatha kusunga kusasinthika kwa mzere wonse wa impedance, kuchepetsa kudutsa pakati pa mizere yoyandikana nayo.
