Digital Oscilloscope Ua Haujlwm Txoj Cai thiab Cov Qauv
Nrog rau kev txhim kho cov cuab yeej siv hluav taws xob thiab kev hloov pauv, cov kev ntsuas kev ntsuas hluav taws xob tau dhau los ua ntau dua, hauv kev tsim hluav taws xob yuav pom tias qhov ntsuas ntawm ntau qhov tsis yog multimeter tuaj yeem muaj peev xwm, xws li microcontroller I / O chaw nres nkoj ntawm cov zis waveform lossis kev tsim cov amplifiers los ntsuas nws cov lus teb zaus thiab lwm yam. Yog li, oscilloscopes yog ib txwm zoo ib yam li multimeters, thiab tau dhau los ua cov cuab yeej tsim nyog rau cov kws tshaj lij hluav taws xob thiab cov neeg nyiam.
Kev qhia txog kev ua haujlwm thiab cov qauv
Qhov kho vajtse ib feem ntawm lub digital oscilloscope system yog cov ntaub ntawv ceev ceev kom tau txais cov ntaub ntawv. Nws tuaj yeem ua tiav ob-channel cov ntaub ntawv tawm tswv yim, txhua qhov piv txwv zaus tuaj yeem ncav cuag 60Mbit / s. Functionally, lub hardware system yuav muab faib mus rau hauv: teeb liab pem hauv ntej-kawg amplification (FET input amplifier) thiab txias module (variable nce amplifier), high-speed analogue-to-digital converter module (ADC tsav tsheb, ADC), FPGA logic tswj module , moos faib, kev sib piv siab ceev, MCU tswj module (DSP), cov ntaub ntawv sib txuas lus module, kua siv lead ua kua zaub (LCD). ), cov ntaub ntawv kev sib txuas lus module, LCD zaub, kov npo tswj, fais fab mov thiab roj teeb tswj thiab keyboard tswj thiab ntau qhov chaw.
Lub teeb liab tawm tswv yim hloov pauv los ntawm lub preamplifier thiab nce kev hloov pauv mus rau hauv qhov hluav taws xob input uas ua tau raws li qhov yuav tsum tau muaj ntawm A / D converter. Cov teeb liab digital hloov los ntawm A / D converter yog cached los ntawm FPGA los yog qhov tau txais lub cim xeeb FIFO, thiab tom qab ntawd xa mus rau lub khoos phis tawj los ntawm kev sib txuas lus rau kev ua cov ntaub ntawv tom ntej, lossis ncaj qha tswj los ntawm microcontroller yuav raug sau thiab tso tawm rau ntawm LCD. npo.
Cov khoom siv siv tau raws li hauv qab no
Hauv cov khoom no, qhov tseem ceeb tshaj plaws yog qhov programmed amplification (attenuation) circuit thiab A / D conversion circuit, vim hais tias ob lub circuits yog lub caj pas ntawm cov oscilloscope, lub programmed amplification (attenuation) Circuit Court txiav txim siab oscilloscope input bandwidth thiab ntsug daws teeb meem. , A / D hloov dua siab tshiab Circuit Court txiav txim siab oscilloscope txoj kev daws teeb meem kab rov tav, uas ncaj qha txiav txim siab qhov ua tau zoo ntawm oscilloscope ntawm ob qhov kev daws teeb meem. Ob qhov chaw ntawm lub voj voog yuav raug ntsuas cov teeb liab mus rau sab nraum qab ntawm cov txheej txheem ua haujlwm uas yuav tsum tau ua rau cov ntaub ntawv teeb liab, qhov no ntawm Circuit Court tuaj yeem siv rau hauv cov khoom siv hluav taws xob ua haujlwm siab ntxiv rau qee qhov me me ntawm cov khoom siv peripheral tsim ib qho yooj yim Circuit Court tsim, debugging kuj yooj yim heev. Qhov nyuaj tshaj plaws ntawm oscilloscope yuav tsum yog cov txheej txheem, uas yog, software. Lub software dais tag nrho cov ntaub ntawv ua thiab tswj cov dej num ntawm cov oscilloscope digital, suav nrog A / D sampling tswj, kab rov tav cheb ceev tswj, ntsug rhiab heev tswj, tso saib ua, peak-to-peak ntsuas, zaus ntsuas thiab lwm yam dej num. Nws tuaj yeem pom tau los ntawm kev siv lub microcontroller ntau heev ntawm kev ua lag luam niaj hnub no ua microprocessor thiab programming hauv C lus.
Programmed amplification (attenuation) Circuit Court thiab fais fab mov Circuit Court
Lub teeb liab yog tawm tswv yim los ntawm ib qho X10X1 oscilloscope sojntsuam mus rau hauv lub amplification (attenuation) circuit. Lub luag hauj lwm ntawm programmed amplification (attenuation) Circuit Court yog kom amplify los yog attenuate lub input teeb liab los kho, thiaj li hais tias cov zis teeb liab voltage nyob rau hauv lub input voltage yuav tsum tau ntawm lub converter A / D nyob rau hauv qhov ntau ntawm qhov zoo tshaj plaws kev ntsuas thiab kev soj ntsuam, yog li lub programmed amplifier circuit nyob rau hauv qhov teev bandwidth nce yuav tsum tiaj tus. Raws li lub oscilloscope Circuit Court muaj cov digital thiab analogue ob ntu, txhawm rau kom tsis txhob muaj kev cuam tshuam kev sib cuam tshuam, yog li cov khoom siv hluav taws xob digital thiab analogue ntawm cov khoom siv hluav taws xob sib cais, feem, muab cov txheej txheem ntawm ± 5V DC fais fab mov, thiab inductance. thiab capacitance ua los ntawm lim cais
Flash nco thiab moos Circuit Court
Vim hais tias lub A / D converter captures ib tug loj npaum li cas ntawm cov teeb liab cov ntaub ntawv, lub microcontroller lub internal flash nco tsis txaus siv, yog li lub Circuit Court yuav xaiv ib co lwm lub cim xeeb los siv, tab sis kuj yog ib txoj kev los sau cov LCD. Lub cim xeeb flash kuj tseem siv los ua lub cache rau kev sau ntawv LCD. Txhawm rau kom tau txais cov teeb liab siv moos, lub microcontroller tseem txuas nrog lub siv lead ua, uas yog siv los xam qhov tseeb zaus ntawm lub teeb liab sab nraud.
FPGA Control Unit
FPGAs yog ib qho kev cai ASICs uas tso cai rau cov neeg tsim hluav taws xob los tsim lawv tus kheej cov haujlwm tshwj xeeb. Tus tsim siv ob txoj kev sib txawv: schematic input thiab VHDL input. Lub chaw tswj hwm ua tiav feem ntau ntawm cov haujlwm tswj, muab cov kev tswj xyuas tsim nyog rau txhua qhov kev ua haujlwm kom ntseeg tau tias kev ua haujlwm raug ntawm tag nrho lub cev. Tshwj xeeb ua tiav cov haujlwm hauv qab no: zaus faib Circuit Court thiab tsim A / D converter tswj cov cim Cov ntaub ntawv tau txais qhov system muaj ntau qhov kev ntsuas, qhov zaus faib hluav taws xob yog tsim hauv FPGA kom ua tiav cov qauv sib txawv rau ntau zaus ntawm cov ntsuas ntsuas kom paub meej. tias cov ntaub ntawv khaws tseg yog qhov tseeb dua. Lub chav faib zaus yog siv los ntawm kev siv graphical input method thiab nws cov qauv sab hauv yog pom nyob rau hauv daim duab 4. Nyob rau hauv daim duab 4, kev siv T-trigger nyob rau hauv lub tswv yim yog 1, txhua lub moos ntug thaum cov zis yuav dhia mus cuag lub zaus division. . Nyob rau tib lub sijhawm, peb tuaj yeem pom tias cov tswv yim ntawm T-flip-flop yog tsim los ntawm qee qhov kev sib xyaw ua ke, uas yog lub moos gated. Rau cov moos gated, lub moos ua haujlwm tau ua tib zoo txheeb xyuas kom tsis txhob muaj qhov cuam tshuam ntawm burrs. Thaum lub moos gated tau lees paub tias tsis muaj qhov txaus ntshai burrs ntawm lub moos teeb liab thaum ob qho xwm txheej hauv qab no tau ntsib, lub moos gated tuaj yeem ua haujlwm zoo li lub moos ntiaj teb.
Rau kev tsim ntawm A / D converter, nws tswj lub teeb liab tsuas yog ob: moos input teeb liab CLK thiab pab kom cov zis teeb liab OE. CLK teeb liab ncaj qha los ntawm lub zog siv lead ua input 60M teeb liab, thaum OE teeb liab los ntawm FPGA sab hauv thiab CLK tib zaus thiab tib theem ntawm lub moos teeb liab inverted kom tau, yog li ntawd tsuas yog kom tau raws li qhov hloov dua siab tshiab ntawm A / D converter lub sij hawm. kev sib raug zoo.
Kev kub ceev A / D hloov dua siab tshiab; Circuit Court
Cov oscilloscope hauv Circuit Court tseem ceeb tshaj plaws yog A / D hloov dua siab tshiab Circuit Court, nws lub luag hauj lwm yog yuav tsum tau ntsuas lub teeb liab sampling thiab hloov mus rau hauv cov teeb liab mus rau hauv lub cim xeeb, hais tias nws yog ib tug digital oscilloscope caj pas tsis ntau dhau, vim hais tias nws ncaj qha txiav txim siab lub digital oscilloscope. tuaj yeem ntsuas ntawm qhov siab tshaj plaws, raws li Nyquist Theorem, qhov piv txwv zaus tsawg kawg yog 2 npaug ntawm qhov zaus siab tshaj plaws ntawm lub teeb liab yuav tsum tau ntsuas txhawm rau txhawm rau tsim cov teeb liab raug ntsuas. Hauv cov oscilloscopes digital, qhov piv txwv zaus yuav tsum yog tsawg kawg 5 mus rau 8 npaug ntawm qhov zaus ntawm lub teeb liab nyob rau hauv kev sim, txwv tsis pub lub teeb liab waveform tsis tuaj yeem pom.
