Kev sib tham luv luv ntawm qhov sib txawv ntawm analog oscilloscopes thiab digital oscilloscopes
Txhawm rau nce qhov bandwidth ntawm analog oscilloscopes, oscilloscope hlab, ntsug amplification thiab kab rov tav scanning yuav tsum tau nce siab. Txhawm rau txhim kho qhov bandwidth ntawm lub oscilloscope digital, koj tsuas yog yuav tsum tau txhim kho qhov kev ua tau zoo ntawm lub hauv ntej-kawg A / D converter, thiab tsis muaj cov cai tshwj xeeb rau oscilloscope raj thiab scanning circuit. Ntxiv rau cov oscilloscopes tuaj yeem ua rau tag nrho kev siv lub cim xeeb, khaws cia thiab ua haujlwm, nrog rau ntau qhov ua rau thiab ua kom muaj peev xwm ua ntej. Hauv xyoo 1980s, cov oscilloscopes digital dheev tshwm sim thiab ua tiav ntau qhov txiaj ntsig. Lawv muaj peev xwm los hloov cov analog oscilloscopes. Analog oscilloscopes muaj tseeb thim rov qab los ntawm lub rooj zaum pem hauv ntej mus rau keeb kwm yav dhau.
Txawm li cas los xij, qee qhov nta ntawm analog oscilloscopes tsis muaj nyob rau hauv digital oscilloscopes: kev ua haujlwm yooj yim - txhua qhov haujlwm yog nyob ntawm lub vaj huam sib luag, thiab cov lus teb waveform yog raws sijhawm. Digital oscilloscopes feem ntau xav tau lub sijhawm ua haujlwm ntev dua. High ntsug daws teeb meem - nruam thiab infinite. Qhov kev daws teeb meem ntawm cov oscilloscopes feem ntau tsuas yog 8 mus rau 10 khoom. Cov ntaub ntawv hloov tshiab sai sai - ntau pua txhiab tus waveforms raug ntes ib ob, thiab cov oscilloscopes digital ntes tau kaum ob ntawm waveforms ib ob. Real-time bandwidth thiab real-time zaub - lub bandwidth ntawm nruam waveforms yog tib yam li ntawm ib waveforms. Qhov bandwidth ntawm digital oscilloscopes yog ze ze rau qhov piv txwv. Thaum tus nqi piv txwv tsis siab, yuav tsum muaj kev xam interpolation, uas yuav yooj yim ua rau tsis meej pem waveforms.
Hauv luv luv, analog oscilloscopes muab engineers nrog waveforms uas lawv tuaj yeem pom thiab ntseeg tau, tso cai rau lawv sim nrog kev ntseeg siab nyob rau hauv ib qho kev qhia bandwidth. Ntawm cov tib neeg lub ntsej muag, qhov muag tsis pom kev yog qhov rhiab heev. Lub vijtsam waveform yog tam sim ntawd cuam tshuam rau lub hlwb rau kev txiav txim, thiab txawm tias hloov maj mam tuaj yeem pom. Yog li ntawd, analog oscilloscopes yog nrov heev ntawm cov neeg siv.
Cov oscilloscopes thawj zaug nce tus nqi piv txwv, los ntawm qhov piv txwv thawj zaug sib npaug li ob zaug ntawm qhov bandwidth mus rau tsib los yog kaum zaug, thiab qhov cuam tshuam tau qhia rau sine wave sampling kuj txo los ntawm 100% mus rau 3% lossis txawm tias 1%. Tus nqi piv txwv ntawm qhov bandwidth ntawm 1GHz yog 5GHz, lossis txawm tias 10GHz. Thib ob, nce tus nqi hloov tshiab ntawm cov oscilloscopes mus rau tib theem li analog oscilloscopes, mus txog 400, 000 waveforms ib ob, uas yuav yooj yim dua rau kev soj ntsuam qee lub sijhawm thiab ntes glitch pulses.
Thib peb, ntau cov txheej txheem siv los ua kom lub teeb liab ua kom muaj peev xwm ua tau, thiab qhov kev ntsuas qhov ntsuas tsis tau hloov kho los ntawm ntau cov ntawv qhia zaub mov tau txhim kho kom yooj yim kho pob qhov rooj, lossis txawm tias tag nrho tsis siv neeg ntsuas, thiab yooj yim siv raws li analog oscilloscope. Thaum kawg, cov oscilloscope digital, zoo li analog oscilloscope, muaj qhov screen persistence hom zaub, uas muab lub waveform lub xeev peb-dimensional, uas yog, nws qhia lub amplitude, lub sij hawm thiab kev faib ntawm lub amplitude nyob rau hauv lub sij hawm ntawm lub teeb liab. Cov oscilloscopes nrog cov haujlwm no yog hu ua digital phosphor oscilloscopes lossis digital persistence oscilloscopes.
Analog oscilloscopes siv cathode ray oscilloscopes los tso saib waveforms. Lub bandwidth ntawm oscilloscope yog tib yam li cov analog oscilloscope, uas yog, qhov ceev ntawm electron txav hauv oscilloscope yog proportional rau lub teeb liab zaus. Qhov siab dua qhov teeb liab zaus, qhov ceev ntawm electron ceev. Lub oscilloscope screen Lub ci ci yog inversely proportional rau qhov ceev ntawm electron beam. Lub waveform tsawg zaus muaj qhov siab siab thiab lub siab zaus waveform muaj qhov siab qis. Nws yog ib qho yooj yim kom tau txais cov ntaub ntawv thib peb ntawm lub teeb liab los ntawm kev siv lub teeb ci lossis greyscale ntawm lub vijtsam fluorescent. Yog tias txoj kab ntsug ntawm lub vijtsam yog siv los sawv cev amplitude thiab kab rov tav axis yog lub sijhawm, ces lub vijtsam ci tuaj yeem sawv cev qhov hloov pauv ntawm cov teeb liab amplitude faib lub sijhawm. Qhov no lub sij hawm-dependent fluorescence afterglow (grayscale scaling) nyhuv yog pab tau rau kev soj ntsuam sib xyaw thiab sporadic waveforms. Analog cia oscilloscope yog ib qho khoom sawv cev ntawm hom kev mob siab oscilloscope. Qhov kev ua tau zoo tshaj plaws mus txog 800MHz bandwidth thiab tuaj yeem sau cov xwm txheej ceev ceev ntawm li 1ns.
Cov oscilloscope digital tsis muaj qhov ua haujlwm tsis tu ncua vim tias nws yog digital ua thiab tsuas muaj ob lub xeev, siab lossis qis. Raws li txoj cai, lub waveform kuj qhia "yog" thiab "tsis yog". Txhawm rau kom ua tiav ntau theem kev ci ntsa iab xws li analog oscilloscope, yuav tsum siv cov duab ua haujlwm siab nti. Piv txwv li, TEK siv DPX processor nti, uas muaj ntau yam haujlwm xws li kev nrhiav tau cov ntaub ntawv, ua duab thiab khaws cia. DPX nti yog tsim los ntawm 1.3 lab transistors. Nws txais yuav 0.65um CMOS txheej txheem, cov qauv xa mus rau cov kav dej, thiab cov qauv piv txwv ntawm 2GS/s.
Nws yog ob qho tib si cov ntaub ntawv tau txais nti thiab raster scanner, simulating cov yam ntxwv luminescence ntawm oscilloscope screen phosphor, siv 16 brightness theem khaws cov waveform ntawm 500 * 200 pixel LCD monochrome lossis xim zaub txhua 0.33 vib nas this. Hloov tshiab ib zaug. Txij li thaum analog cia oscilloscopes tsuas yog tso siab rau cov duab thaij duab los sau cov waveforms, lawv tsis yooj yim heev rau cov ntaub ntawv khaws cia. Piv txwv li, liab sawv cev rau lub waveform nrog ntau tshaj qhov tshwm sim, thiab xiav sawv cev rau lub waveform nrog qhov tsawg tshaj plaws qhov tshwm sim, kom nws pom tseeb ntawm ib nrais muag. Txij li cov oscilloscopes digital tau mus txog qib 1GHz bandwidth thiab ua ke nrog fluorescent cov yam ntxwv, lawv qhov kev ua tau zoo tag nrho yog zoo dua li analog cia oscilloscopes.
