Yuav ua li cas piv txwv tus nqi yuav tsum tau ntsuas ntau hom kev taw qhia nrog oscilloscope?
Peb muab lub teeb liab rau oscilloscope los ntawm kev sojntsuam. Tom qab ntsuas lub teeb liab dhau los ntawm kev nthuav dav, attenuation thiab lwm yam teeb liab txias circuits nyob rau pem hauv ntej kawg ntawm oscilloscope, lub high-speed ADC analog-rau-digital converter ua teeb liab sampling thiab digital quantization. Tus nqi piv txwv ntawm oscilloscope yog qhov hloov pauv ntawm analog-rau-digital ntawm cov teeb liab tawm tswv yim. Qhov zaus ntawm lub sijhawm piv txwv thaum hloov dua siab tshiab yog, nyob rau hauv layman cov ntsiab lus, lub sij hawm piv txwv. Ib qho piv txwv yog sau nyob rau txhua lub sij hawm sampling. Piv txwv li, tus nqi piv txwv ntawm 1GSa / s txhais tau hais tias oscilloscope muaj peev xwm sau tau 1 billion sampling ntsiab lus ib ob. Lub sijhawm no, nws lub sijhawm piv txwv yog 1 nanosecond.
Rau lub sijhawm tiag tiag oscilloscopes, cov qauv siv sijhawm tiag tiag yog siv tam sim no. Lub npe hu ua real-time sampling yog los ua cov qauv ntsuas nrawm nrawm ntawm qhov sib npaug ntawm qhov ntsuas waveform teeb liab, thiab tom qab ntawd rov tsim kho lossis rov ua dua lub waveform raws li cov qauv no txuas ntxiv mus. Nyob rau hauv lub sij hawm tiag tiag sampling txheej txheem, nws yog ib qho tseem ceeb heev kom paub tseeb tias tus nqi piv txwv ntawm oscilloscope yog sai npaum li cas tshaj qhov kev hloov ntawm lub teeb liab ntsuas.
Yog li yuav ceev npaum li cas? Txoj cai Nyquist hauv kev ua cov teeb liab digital hais tias yog tias qhov bandwidth ntawm lub teeb liab ntsuas raug txwv, ces thaum sampling thiab quantizing lub teeb liab, yog tias tus nqi piv txwv yog ntau tshaj ob npaug ntawm bandwidth ntawm lub teeb liab raug ntsuas, nws tuaj yeem ua tiav tag nrho Reconstruct lossis rov qab tau cov ntaub ntawv nqa hauv lub teeb liab yam tsis muaj aliasing.
Tom ntej no, peb yuav ua kom lub sij hawm lub suab me me, kom tus nqi piv txwv yuav loj dua. Peb yuav kho tus nqi coj mus kuaj kom txog rau thaum tus nqi piv txwv yog 2 zaug thiab 10 npaug ntawm lub teeb liab zaus los soj ntsuam cov teeb liab hloov, uas yog, 2MSa/s thiab 10MSa/s. Lub teeb liab ntawm sab laug hauv daim duab hauv qab no yog qhov piv txwv ntawm 2MSa / s. Koj tuaj yeem pom tias qhov zaus ntawm lub teeb liab tau hloov rov qab mus rau 1MHz, uas yog qhov tseeb zaus ntawm cov teeb liab. Tab sis tus thawj sine nthwv dej tau dhau los ua daim duab peb sab yoj, thiab lub waveform tau hloov pauv. Thaum tus nqi piv txwv hloov mus rau 10MSa / s, uas yog lub teeb liab ntawm sab xis ntawm daim duab hauv qab no, koj tuaj yeem pom tias lub teeb liab tau los ze zog mus rau sine yoj, tab sis nws tseem tsis zoo nkauj heev.
