IiCapacitors zidlala indima ebalulekileyo kuyilo lwePCB enesantya esiphezulu kwaye zisoloko zisesona sixhobo sisetyenziswa kakhulu kwiPCBS. Kwi-PCB, ii-capacitors zihlala zihlulwe zibe yi-filter capacitors, i-decoupling capacitors, i-capacitors yokugcina amandla, njl.
I-1.I-capacitor yokuphuma kwamandla, i-capacitor yokucoca
Ngokuqhelekileyo sibhekisela kwi-capacitor yegalelo kunye neesekethe zemveliso yemodyuli yamandla njenge-filter capacitor. Ukuqonda okulula kukuba i-capacitor iqinisekisa ukuzinza kwegalelo kunye nokunikezelwa kwamandla okuphuma. Kwimodyuli yamandla, i-capacitor yokucoca kufuneka ibenkulu phambi kokuba encinci. Njengoko kubonisiwe kumfanekiso, i-capacitor yokucoca ibekwe enkulu kwaye incinci kwicala lotolo.
Xa uqulunqa ukunikezelwa kwamandla, kufuneka kuqatshelwe ukuba i-wiring kunye nesikhumba sobhedu zibanzi ngokwaneleyo kwaye inani lemingxuma yanele ukuqinisekisa ukuba umthamo wokuhamba uhlangabezana neemfuno. Ububanzi kunye nenani lemingxuma ivandlakanywa ngokubambisana nekhoyo ngoku.
Amandla okufaka amandla
I-capacitor yegalelo lamandla yenza i-loop yangoku kunye ne-loop yokutshintsha. Le loop yangoku iyahluka nge-amplitude enkulu, i-Iout amplitude. I-frequency yi-frequency switching. Ngexesha lenkqubo yokutshintsha i-chip ye-DCDC, i-current eveliswa yi-loop yangoku iyatshintsha, kubandakanywa ngokukhawuleza i-di/dt.
Kwimodi ye-BUCK ehambelanayo, indlela eqhubekayo yangoku kufuneka idlule kwi-pin ye-GND ye-chip, kunye ne-input capacitor kufuneka idibaniswe phakathi kwe-GND kunye ne-Vin ye-chip, ngoko indlela ingaba mfutshane kwaye inzima.
Ummandla wale ring yangoku incinci ngokwaneleyo, ngcono i-radiation yangaphandle yale ring yangoku iya kuba.
2.Ukuqhawula i-capacitor
Iphini yamandla ye-IC enesantya esiphezulu idinga i-decoupling capacitors eyaneleyo, ngokukodwa enye ipini nganye. Kuyilo lwangempela, ukuba akukho ndawo ye-decoupling capacitor, inokususwa ngokufanelekileyo.
I-decoupling capacitance ye-pin yonikezelo lwamandla ye-IC idla ngokuba yincinci, njenge-0.1μF, 0.01μF, njl. Iphakheji ehambelanayo nayo incinci, njengephakheji ye-0402, iphakheji ye-0603 njalo njalo. Xa ubeka i-decoupling capacitors, la manqaku alandelayo kufuneka aqatshelwe.
(1)Yibeke kufutshane kangangoko kwiphini yonikezelo lombane, kungenjalo isenokungabi nasiphumo sokuqhawula. Ngokwethiyori, i-capacitor ine-radius ethile yokuqhawula, ngoko umgaqo wokusondela kufuneka uphunyezwe ngokungqongqo.
(2)I-capacitor yokuqhawuka kwisikhonkwane sonikezelo lombane kufuneka ibemfutshane kangangoko, kwaye ilothe kufuneka ibengqindilili, ngokuqhelekileyo ububanzi bomgca yi-8 ~ 15mil (1mil = 0.0254mm). Injongo yokuqina kukunciphisa i-lead inductance kunye nokuqinisekisa ukusebenza kombane.
(3) Emva kokunikezelwa kwamandla kunye nezikhonkwane zomhlaba ze-capacitor decoupling zikhokelwa ngaphandle kwe-welding pad, imingxuma ye-punch ekufutshane kwaye idibanise nombane kunye nenqwelomoya yomhlaba. Ilothe nayo kufuneka ijiye, kwaye umngxuma ube mkhulu kangangoko. Ukuba umngxuma onomngxuma oyi-10mil ungasetyenziswa, makungasetyenziswa umngxuma oyi-8mil.
(4)Qinisekisa ukuba i-loop yokudibanisa incinci kangangoko
I-3.I-capacitor yokugcina amandla
Indima ye-capacitor yokugcina amandla kukuqinisekisa ukuba i-IC inokubonelela ngamandla ngexesha elifutshane xa usebenzisa umbane. Umthamo we-capacitor yokugcina amandla ngokuqhelekileyo mkhulu, kwaye iphakheji ehambelanayo nayo inkulu. Kwi-PCB, i-capacitor yokugcina amandla ingaba kude nesixhobo, kodwa ingabi kude kakhulu, njengoko kuboniswe kumfanekiso. Ugcino lwamandla oluqhelekileyo lwe-capacitor fan-hole mode luboniswe kumfanekiso.
Imigaqo yemingxuma yeefeni kunye neentambo zezi zilandelayo:
(1) Ilothe imfutshane kwaye ingqindilili kangangoko kunokwenzeka, ukuze kubekho inductance encinci yeparasitic.
(2)Ii-capacitors zokugcina amandla, okanye izixhobo ezine-overcurrent enkulu, punch imingxuma emininzi kangangoko kunokwenzeka.
(3) Ngokuqinisekileyo, ukusebenza kakuhle kombane komngxuma wefeni ngumngxuma wediski. Ubunyani bufuna ukuqwalaselwa ngokubanzi