Ngati dera la analogi (RF) ndi dera la digito (microcontroller) zimagwira ntchito bwino payekhapayekha, koma mukangoyika ziwirizo pa bolodi lomwelo ndikugwiritsa ntchito mphamvu yomweyo kuti mugwire ntchito limodzi, dongosolo lonselo likhoza kukhala losakhazikika.Izi makamaka chifukwa chizindikiro cha digito nthawi zambiri chimasinthasintha pakati pa nthaka ndi magetsi abwino (kukula kwa 3 V), ndipo nthawiyo imakhala yochepa kwambiri, nthawi zambiri ns mlingo.Chifukwa cha matalikidwe akuluakulu ndi nthawi yaying'ono yosinthira, zizindikiro za digitozi zimakhala ndi zigawo zambiri zomwe zimakhala zosagwirizana ndi kusintha kwafupipafupi.Mu gawo la analogi, chizindikiro chochokera pa mlongoti wokonza lupu kupita kumalo olandirira a chipangizo chopanda zingwe nthawi zambiri chimakhala chochepera 1μV.
Kusadzipatula kokwanira kwa mizere yodziwika bwino ndi mizere yazizindikiro zaphokoso ndi vuto lanthawi zonse.Monga tafotokozera pamwambapa, zizindikiro za digito zimakhala ndi kugwedezeka kwakukulu ndipo zimakhala ndi ma harmonics apamwamba kwambiri.Ngati mawaya a digito pa PCB ali moyandikana ndi ma siginecha amtundu wa analogi, ma harmonic okwera kwambiri amatha kuphatikizidwa kale.Ma node okhudzidwa a zida za RF nthawi zambiri amakhala sefa yozungulira ya gawo-lotsekeka (PLL), inductor yakunja yamagetsi yoyendetsedwa ndi oscillator (VCO), chizindikiro cha crystal reference ndi antenna terminal, ndipo magawo awa amayenera kuthandizidwa. ndi chisamaliro chapadera.
Popeza siginecha yolowera/yotulutsa imakhala ndi ma V angapo, mabwalo a digito nthawi zambiri amavomereza phokoso lamagetsi (osakwana 50 mV).Mabwalo a analogi amakhudzidwa ndi phokoso lamagetsi, makamaka ku ma burr voltages ndi ma frequency ena apamwamba kwambiri.Chifukwa chake, mawaya amagetsi pa board ya PCB okhala ndi ma RF (kapena ma analogi ena) ayenera kusamala kwambiri kuposa ma waya omwe ali pa bolodi wamba wa digito, ndipo njira zodziwikiratu ziyenera kupewedwa.Tiyeneranso kukumbukira kuti microcontroller (kapena dera lina la digito) lidzayamwa mwadzidzidzi zambiri zamakono kwa kanthawi kochepa mkati mwa wotchi iliyonse yamkati, chifukwa cha ndondomeko ya CMOS ya ma microcontrollers amakono.
Gulu lozungulira la RF liyenera kukhala ndi mzere wapansi wolumikizidwa ndi ma elekitirodi olakwika amagetsi, zomwe zitha kutulutsa zodabwitsa ngati sizikugwiridwa bwino.Izi zitha kukhala zovuta kwa wopanga ma digito kuti amvetsetse, chifukwa mabwalo ambiri a digito amagwira ntchito bwino ngakhale popanda wosanjikiza.Mu RF band, ngakhale waya waifupi amachita ngati inductor.Pafupifupi kuwerengeredwa, inductance pa mm kutalika ndi pafupifupi 1 nH, ndipo kuyamwa kwa 10 mm PCB mzere pa 434 MHz ndi pafupifupi 27 Ω.Ngati mzere wapansi sugwiritsidwa ntchito, mizere yambiri yapansi idzakhala yaitali ndipo dera silidzatsimikizira mawonekedwe a mapangidwe.
Izi nthawi zambiri zimanyalanyazidwa m'mabwalo omwe amakhala ndi ma radio frequency ndi magawo ena.Kuphatikiza pa gawo la RF, nthawi zambiri pamakhala ma analogi ena pa bolodi.Mwachitsanzo, ma microcontrollers ambiri ali ndi ma analogi-to-digital converters (ADCs) kuti athe kuyeza zolowetsa zaanalogi komanso mphamvu ya batri kapena magawo ena.Ngati mlongoti wa RF transmitter uli pafupi (kapena pa) PCB iyi, siginecha yotulutsa yothamanga kwambiri imatha kufikira ma analogi a ADC.Musaiwale kuti chingwe chilichonse chozungulira chimatha kutumiza kapena kulandira ma siginecha a RF ngati mlongoti.Ngati kulowetsa kwa ADC sikunasinthidwe bwino, siginecha ya RF imatha kudzisangalatsa yokha pakulowetsa kwa diode ya ESD kupita ku ADC, ndikupangitsa kuti ADC ipatuke.
Zolumikizana zonse pansi pa nthaka ziyenera kukhala zazifupi momwe zingathere, ndipo pansi pa dzenje liyenera kuikidwa (kapena pafupi kwambiri ndi) pedi la chigawocho.Osalola kuti ma sign apansi agawane pobowo, zomwe zingayambitse kupambanitsa pakati pa mapadi awiriwa chifukwa cha kutsekeka komwe kumalumikizidwa ndi dzenje.Decoupling capacitor iyenera kuikidwa pafupi ndi pini momwe zingathere, ndipo kutsekemera kwa capacitor kuyenera kugwiritsidwa ntchito pa pini iliyonse yomwe ikufunika kudulidwa.Pogwiritsa ntchito ma capacitor apamwamba kwambiri a ceramic, mtundu wa dielectric ndi "NPO", "X7R" umagwiranso ntchito bwino pamapulogalamu ambiri.Phindu loyenera la capacitance yosankhidwa liyenera kukhala kuti mndandanda wake wa resonance ndi wofanana ndi ma frequency a signal.
Mwachitsanzo, pa 434 MHz, SMD-wokwera 100 pF capacitor idzagwira ntchito bwino, pafupipafupi, capacitive reactance ya capacitor ili pafupi 4 Ω, ndipo kutsekemera kwa dzenje kumakhala pamtunda womwewo.The capacitor ndi bowo mu mndandanda kupanga notch fyuluta pafupipafupi siginecha, kulola kuti bwino decouples.Pa 868 MHz, 33 p F capacitors ndi chisankho chabwino.Kuphatikiza pa RF decoupled capacitor yaying'ono yamtengo wapatali, capacitor yamtengo wapatali iyeneranso kuyikidwa pa chingwe chamagetsi kuti iwononge ma frequency otsika, imatha kusankha 2.2 μF ceramic kapena 10μF tantalum capacitor.
Mawaya a nyenyezi ndi njira yodziwika bwino pamapangidwe amtundu wa analogi.Mawaya a nyenyezi - Gawo lililonse pa bolodi limakhala ndi chingwe chake chamagetsi kuchokera kumalo opangira magetsi.Pamenepa, mawaya a nyenyezi amatanthawuza kuti zigawo za digito ndi RF za dera ziyenera kukhala ndi zingwe zawo zamagetsi, ndipo zingwe zamagetsizi ziyenera kugawidwa mosiyana pafupi ndi IC.Uku ndi kulekana ndi manambala
Njira yothandiza ya phokoso laling'ono komanso lamagetsi kuchokera ku gawo la RF.Ngati ma module okhala ndi phokoso lalikulu ayikidwa pa bolodi lomwelo, inductor (maginito mkanda) kapena kukana pang'ono (10 Ω) akhoza kulumikizidwa mndandanda pakati pa chingwe chamagetsi ndi gawo, ndi tantalum capacitor ya osachepera 10 μF. ziyenera kugwiritsidwa ntchito ngati kuphatikizika kwamagetsi kwa ma module awa.Ma module awa ndi madalaivala a RS 232 kapena owongolera magetsi osinthira.
Pofuna kuchepetsa kusokonezedwa kwa gawo la phokoso ndi gawo lozungulira la analogi, kuyika kwa gawo lililonse ladera pa bolodi ndikofunikira.Ma sensitive modules (zigawo za RF ndi tinyanga) ziyenera kusungidwa kutali ndi ma module a phokoso (microcontrollers ndi RS 232 madalaivala) kuti asasokonezedwe.Monga tafotokozera pamwambapa, ma siginecha a RF amatha kusokoneza ma module ena amtundu wa analogi monga ma ADC akatumizidwa.Mavuto ambiri amapezeka m'magulu otsika (monga 27 MHz) komanso kuchuluka kwa mphamvu zamagetsi.Ndi kachitidwe kabwino kamangidwe kochotsa mfundo zodziwikiratu ndi RF decoupling capacitor (100p F) yolumikizidwa pansi.
Ngati mukugwiritsa ntchito zingwe kulumikiza bolodi la RF kudera lakunja la digito, gwiritsani ntchito zingwe zopotoka.Chingwe chilichonse cha siginecha chiyenera kulumikizidwa ndi chingwe cha GND (DIN/ GND, DOUT/ GND, CS/ GND, PWR _ UP/ GND).Kumbukirani kulumikiza bolodi yozungulira ya RF ndi bolodi yoyendetsera ntchito ya digito ndi chingwe cha GND cha chingwe chopindika, ndipo kutalika kwa chingwe kuyenera kukhala kwaufupi momwe mungathere.Mawaya omwe amapereka mphamvu pa bolodi la RF ayeneranso kupotozedwa ndi GND (VDD/ GND).
