STM32 ADC?????????????????????????
STM32?????е?????о???????????α?????????ADC???.?????????????:
???ADC???????в???????????????б???????????????ADC??λ???????ADC?????????????λ??????????ù?STM32 ADC?????????????ο?????й???12λADC??????????? 
ST???????α???????ADC????д?????????AN2834?????????????????????ADC????????????????ADC?????????????????ADC?????????????????????????????????????ADC?????????????????????Щ??μ?С???????????顣 ???????????????????????????????????????????????????????www.st.com????AN2834????????? ??????????STM32??ADC?????????????????????????????????????????????????????·???????????????????????????????????ADC?????????????????????????????????????????????????????????????????????????????????? ???????????迹?????
????ADC???????????????ADC????????????????е???RAIN??ADC????AIN??????е?????????????????????????????????CADC???????????????е?????RADC????? ???????CADC??Ч?????ɡ?RADC +RAIN?????????????????tc = (RADC + RAIN) ×CADC????????????????????С??CADC???RADC +RAIN?????????ts < tc????ADC?????????????С?????????? ????????????????(RADC+RAIN)?????????????????????????????????????STM32?????RADC????????????????裬???????????????????о?????????????и???????????????????????????????????????RAIN???????仯????糣???????????о??????????????? ???tc?????CADC??????????????Vc = VAIN?????1/2LSB ??? Vc??????????CADC????? tc = (RADC + RAIN) × CADC ??CADC?????????????? ???????????????PCB?????????ADC????? ??ADC?????????????????????????????????????????????????????????????(?μ????)????????????????????????????磬??????????(CAIN +Cp)??????????????????????ADC??????????????????(CAIN + Cp)??????????????????????????(????????????????????????CAIN??Cp?????) 
??????·???????б??????????????????????????????????????????????VAIN?????????????????????????仯??????仯???(FAIN)?????????????????10RC???????10 × RAIN × (CAIN +Cp)?? TAIN = ??????????? =1/FAIN ?????TAIN ≥ 10 x RAIN x (CAIN + CP) ????FAIN ≤ 1 / [10 x RAIN x (CAIN+ CP)] ???磺RAIN = 25kΩ??CAIN = 7pF??CP = 3pF???? FAINmax = 1 / [10 x 25x103 x (7 +3)x10-12] ??????????????FAIN??max??= 400kHz?? ??????????????????????(??????迹)???????????????400kHz??????ADC?????????????????? ??????????????迹???? ?????????????迹??AD??????????ADC??????????????????????????????????迹??????????????????????1/2 LSB?? ??????????9?е???????????????????????????????粻????????? 
?????????? = VAIN – Vc ??Vc????????????CADC??????? 
????tS???????? tS = TS / fADC??????TS????ADC??????????λ??????????? ?? ?????????tS?????VAIN = VREF+????????????VAIN< VREF+???????????????CADC??0V?????VAIN??VAIN = VREF+????????VAIN < VREF+?????????????????VAIN = VREF+??????????????????迹???????????????????????1/2LSB. 
Rmax = (RAIN + RADC)max ????N ?? ADC ????? 12 ???????????????? 
??STM32F103о?????????????Ts=7.5, fADC=14MHz,Cadc=12pF,RadcMax=1K,??????1/2LSB???????????????迹???RAIN(max) = 6.4 k? ?????????????????????????????????????????ADC????????????????Ч???????????????ADC???????????????????????????????????????????????????迹?? ?????????????????????С???????迹Ч???????????????????迹???????????迹??RAIN??RADC??????????????????????????????????????????????? ????????RadcMax??Cadc??????о?????????ADC????????????STM32F103????????????????????????????????????????????????AN2834???????в?????????????ADC????????,????????????????? 
????admin ?????????2019-01-03
