Umgaqo ngokubanzi nokusebenza ADC

Makhe sijonge uluhlu ephambili lwemiba kunganxulunyaniswa kumthetho converters analog-to-digital (ADCs) kweentlobo ezahlukeneyo. akhawunti silandelelaniswe kakuhle, balancing ezilandelelanayo - oyena nobangela la mazwi? Yintoni na umgaqo osebenza ngayo ADC le microcontroller? Ezi kunye neminye imiba kuya kuxoxwa kwi-sikhokelo weli nqaku. Owokuqala abathathu baya kuzinikela ingcamango jikelele, kwaye isihlokwana owesine uya kufunda ukuba zisebenza njani. Unako ukuhlangabezana uncwadi ADC neDAC amagama ezahlukeneyo. Umgaqo esebenza ngayo ezi zixhobo yahluke kancinane, ngoko musa siphambanise kuzo. Ngoko ke, eli nqaku liza kuqwalaselwa ukuguquka lwemiqondiso ukusuka analog digital, lo gama i-DAC isebenza umva.

definition

Phambi kokuba kuqwalaselwe kumthetho ADC, masifumanise ukuba yintoni le divayisi. Analog ku converters digital zizixhobo ukuba ubuninzi emzimbeni iguqulelwa ibe ukumelwa yamanani engqinelanayo. I parameter zokuqala ukwenza phantse nantoni na - ngoku, ombane, capacitance, ukumelana, njengokujikeleza shaft, umyinge ukubetha njalo njalo. Kodwa ukuze babe ukuqiniseka, siza kusebenza noguqulo enye kuphela. Le "ikhowudi ombane". Ukukhetha le fomati msebenzi ngengozi. Emva kokuba ADC (umgaqo ukusebenza kwalo sixhobo) kunye neempawu zayo zixhomekeke kakhulu loluphi uhlobo ingqiqo womlinganiselo. Oku kuthetha ukuba inkqubo ngokuthelekisa ixabiso elithile umgangatho lusekiwe ngaphambili.

iimpawu ADC

I-bit engundoqo ekunokuthiwa, kunye lokuguqulwa. Okokuqala ichazwe apha naphaya, kwaye eyesibini - in iisampulu ngomzuzwana. converters Modern analog-to-digital babe bit-24 okanye isantya ukuguqulwa, okutshabalalayo neeyunithi GSPS. Qaphela ukuba ADC nga ngaxeshanye kukunika ukusetyenziswa omnye kuphela iimpawu zakhe. enkulu Ukusebenza labo, nzima ukusebenza kunye nefowuni, kwaye kuyabiza kakhulu ngokwayo. Kodwa inzuzo isenokuba ukufumana komsebenzi eziyimfuneko ubunzulu besuntswana ngokuncama isantya sixhobo.

iintlobo ADC

Siseko ukusebenza yahluka phakathi kwamaqela awohlukeneyo amacebo. Siqwalasela ezi ndidi zilandelayo:

1. Ekubeni ukuguqulwa ngqo.
2. Nge isilinganiselo ezilandelelanayo.
3. Xa iinguqu ngaxeshanye.
4. Analog-to-digital Converter nge balancing isigxina (ogudle-kelly).
5. Ukuhlanganiswa ADC.

Kukho ezinye iintlobo ezininzi yokuthutha kwaye zidibene, ezo mpawu zabo ezizodwa izakhiwo ezahlukeneyo. Kodwa ezo iisampuli, nto leyo iya kuqwalaselwa kwi-sikhokelo amanqaku umdla kuba zidlala indima engumzekelo izixhobo injongo yaso Okukodwa ezinjalo. Ngoko ke, makhe sihlolisise kumthetho ADC, kwakunye ukuxhomekeka ngecebo elibonakalayo.

analog ngqo converters digital

Baye baba kakhulu zithandwa kwi-imi- 60-70 kwinkulungwane yokugqibela. Xa uhlobo leesekethe ezihlangeneyo ziveliswa kunye 80s. Kuyinto elula kakhulu, nkqu izixhobo zamandulo ukuze kuqhayisa yamanani ezibalulekileyo. umthamo wazo uqobo 6-8 amasuntswana, nesantya azifane idlula 1 GSPS.

Umgaqo ukusebenza kwalo hlobo ADC kukuba kwizimvo ezinikwe plus of comparators umqondiso igalelo ngaxeshanye. Kwi indlela yesiphelo ombane ezimbi lixabiso elithile. Kwaye ngoko ke isixhobo imisela ukusebenza kwayo. Oku kwenziwa kubulelwe reference ombane. Makhe sicinge ukuba isixhobo apho 8 comparators. Xa ukondla ½ le reference ombane yenziwe-4 kuphela kubo. Ifayile ekhowudiweyo kuqala kwakhiwa code yokubini, nto leyo irejista output kunye latches. anokunceda kunye nobuthathaka kuthiwe ukuba lo mgaqo of operation ikuvumela ukuba ukudala izixhobo-high speed. Kodwa ukufumana ubude igama ofunekayo kufuneka ilima kakhulu.

Le ndlela yokubala jikelele inani comparators na ngolu hlobo lulandelayo: 2 ^ N. Phantsi N kuyimfuneko ukubeka inani lamasuntswana. Kujongwa umzekelo yangaphambili zingasetyenziswa kwakhona: 2 ^ 3 = 8. Losuku ekubhobhozeni lesithathu kufuneka comparators-8. Lo ngumthetho-siseko le ADC, ayayilwa kuqala. Not elula kakhulu, ngoko kamva kwakukho nezinye izakhiwo.

Analog-to-digital converters, isilinganiselo ngokulandelana

algorithm "weighting" lisetyenziswa apha. Kukunciphisa izixhobo osebenza kuloo nkqubo, kuthiwa ADC amatyala ezilandelelanayo. Umgaqo tyando ngolu hlobo lulandelayo: ifowuni kulinganiswa umqondiso igalelo, yaye ngoko ke kuthelekiswa amanani, apho uzikise ngokuhambelana nenkqubo ethile:

1. Iiseti yesiqingatha kunokwenzeka ombane reference.
2. Ukuba umda uphawu ubukhulu boyise uhambo №1, oko kuthelekiswa nenani edulusele tiko phakathi ixabiso eseleyo. Ngoko ke, kwimeko yethu uya kuba ¾ le reference ombane. Ukuba uphawu reference iyasilela ukufikelela oku mzobo, isifaniso ziya kuqhutywa kunye nenye inxalenye lekhefu yi-siseko efanayo. Kulo mzekelo, ¼ le reference ombane.
3. Inyathelo 2 kufuneka uphindaphindwe amaxesha n, nto leyo eya kusinika N wayemana isiphumo. Oku kungenxa nokuziphatha N inani uthelekiso.

Lo mgaqo we izixhobo ivumela ukufumana kunye lokuguqulwa isalamane eziphakamileyo, ezo ADCs isilinganiselo ezilandelelanayo. Umgaqo yokusebenza, njengokuba ubona, ilula, yaye ezi zixhobo ilungele ezahlukahlukeneyo izihlandlo.

Okunxuseneyo analog-to-digital converters

Basebenza ngathi isixhobo serial. Calculation ifomula - (2 ^ n) -1. Kuba xa kuqwalaselwa ngaphambili, kufuneka (2 ^ 3) -1 comparators. Kuba ukusebenza ngokusebenzisa uluhlu oluthile zezi zixhobo, nganye ukuze uthelekise igalelo kunye ombane ngamnye reference. converters Parallel analog-to-digital zizixhobo noko ukuzila. Kodwa ke umgaqo zokwakha ezi zixhobo kukuba ukuxhasa ukusebenza zabo kufuna ngamandla ebalulekileyo. Ngoko ke, ukusetyenziswa kwabo ibhetri-anikwe engafanelekanga.

Analog-to-digital Converter nge balancing ezilandelelanayo

Oku kusebenza kakuhle ngendlela efanayo njengoko isixhobo elidlulileyo. Ngoko ke, ukuze ukuchaza ukusebenza zilandelelana zokulinganisa ADC, umgaqo yokusebenza kwabasaqalayo ziya kuqwalaselwa ngokoqobo phezu iminwe. Kwezi zixhobo ezisekelwe isenzeko le dichotomy. Ngamanye amazwi, le uthelekiso serial yenziwa ixabiso ilinganiswa inxalenye ethile kwexabiso eliphezulu. Unako ukuthatha imilinganiselo ½, 1/8, 1/16 njalo njalo. Ngoko ke, analog-to-yedijithali converter unokwenza inkqubo ye N bophindo (amanyathelo alandelelanayo). Uthe ngoko N lilingana ADC bit (khangela kwi iifomyula ngaphambili ngasentla). Ngoko ke, siya kuba inzuzo enkulu ngexesha, ukuba ubuchule kubaluleke ngokukhethekileyo yokusebenza. Nangona isantya enkulu, aba izixhobo linophawu impazamo phantsi ndawonye.

Analog-to-digital converters kunye isigxina balancing (ogudle-kelly)

Yeyona hlobo umdla yesixhobo, kungekhona ngenxa komncinane Umgaqo esisetyenziswa ngayo. It sikuko ukuba yombane igalelo zithelekiswa ukwenzela ukuba integrator wayiqokelela. Ngaba pulses input kunye wokwephuka thabatha, okanye dibanisa (kuxhomekeke ngesiphumo msebenzi odlulileyo). Ngenxa yoko, sinokuthi onjalo analog-to-digital converter indlela yophawulo elula. Kodwa le ngumzekelo nje i sothelekiso, ukuze uqonde ukuba yintoni na ogudle-kelly ADC. Umgaqo inkqubo yokusebenza, kodwa ngokusebenza ngempumelelo analog-to-digital converter akwanelanga. Isiphelo Isiphumo uthotho abo kunye Amaqanda, nto leyo ucanda lokucoca esezantsi-yokupasa yedijithali. Bakha ulandelelwano ethile bit. Ukwahlula converters ADC yomyalelo yokuqala neyesibini.

Ukuhlanganiswa analog-to-digital lokuguqulela

Oku ityala eyodwa yokugqibela, nto leyo iya kuqwalaselwa njengenxalenye inqaku. Okulandelayo, siza ukuchaza ukusebenza ezi zixhobo, kodwa kwinqanaba jikelele. Le ADC is analog-to-digital Converter nge nokuhlanganiswa push-ezotyhalo. Ukuhlangabezana isixhobo onjalo kunokuba ibe multimeter yedijithali. Kwaye oku akumangalisi, kuba zinika ukuchana eliphezulu kwaye ngexesha elinye abayithintelayo kakuhle kokuphazanyiswa.

Ngoku makhe siqwalasele siseko walo wokusebenza. Ihlala isibakala sokuba capacitor igalelo eso abekwa ityala ngenxa ixesha elimisiweyo. Ngokuqhelekileyo, eli xesha yenye-mbane rhoqo apho amagunya isixhobo (50 Hz okanye 60 Hz). Kwakhona iphindaphindeke. Ngenxa yoko, aphezulu-rhoqo umsindo livunyelwe. Kwangaxeshanye angabekwa impembelelo ezingazinzanga umthombo wamandla ombane wombane ukuchaneka isiphumo.

Xa ixesha isigxina iphela analog-digital lokuguqulela, lo capacitor uqalisa ukwenza enesantya elithile elimisiweyo. isixhobo yangaphakathi counter sibala inani pulses iwotshi leyo eyenziwe ngeli xesha lale nkqubo. Ngoko ke, lo elide ixesha lekhefu, kokukhona ukusebenza.

ADC twostroke ukuhlanganiswa babe ukuchana eliphezulu kunye nokusonjululwa. Ngenxa oku, kwakunye nokwakhiwa isakhiwo elula, baye kubulawa njenge chip. Eyona ethile ye umgaqo enjalo lomsebenzi - ngokuxhomekeke network yokusebenza. Khumbula ukuba izakhono zalo ebotshelelwe lonke ixesha qho umbane.

Nantsi indlela ADC uhlanganiso kabini. Umgaqo esebenza ngayo ifowuni nangona sinzima kakhulu, kodwa inika iziphumo nomgangatho. Kwezinye iimeko, oku nje ufunwayo.

Khetha APC us nomgaqo eyimfuneko

Makhe sithi, thina senze umsebenzi othile. Yeyiphi ukukhetha ifowuni ukuze ikwazi ukuhlangabezana nazo zonke iimfuno zethu? Okokuqala, makhe sithethe sigqibo nokuchaneka. Amaxesha amaninzi ke bedidekile, nangona practice ukuba ixhomekeke okwanamhlanje lowo wesibini. Qaphela ukuba 12 bit-analog-to-digital converter kusenokuba echanileyo ngaphantsi kwe-bit 8. Kulo mzekelo, sigqibo - ngumlinganiselo kobungakanani uziziqwempu nga zabelwe elilinganisiweyo uluhlu uphawu igalelo. Ngenxa yoko, 8-bit ADC ilifa Agasti ² = 256 ezinjalo iiyunithi.

Ukuchaneka - sisiphumo iyonke ukuguquka wafumana ukutenxa amaxabiso efanelekileyo, leyo kufuneka ibe ombane kunikwa. Oko kukuthi, eyokuqala i parameter ubonakalise enokubakho unalo ADC, yaye owesibini ubonisa oko esinazo practice. Ngoko ke, siya angangenelela phezulu kunye uhlobo elula ngakumbi (umzekelo, analog-to-digital converters ngqo), nto leyo eya kuhlangabezana neemfuno ngenxa ukuchana yalo phezulu.

Ukuze sinengcamango yokuba yonke into efunekayo ukuze uqale ukubala physical nomgaqo ukwakha buboniswe yentsebenziswano. Kubalulekile ukuba iimpazamo ezimile kunye neguquguqukayo, kuba xa usebenzisa izakhi kunye nemigaqo zolwakhiwo isixhobo ezahlukeneyo baya kuba nefuthe eyahlukileyo ngenkqubo yaso. Okunye inkcazelo ethe vetshe zifumaneka amaxwebhu zobugcisa ezinikezelwa yi kumenzi wesixhobo nganye ethile.

umzekelo

Makhe sijonge SC9711 ADC. Lo mgaqo uyasebenza kule divaysi intsonkothile ngenxa yobukhulu balo kunye nesikhundla. Ethetha kule yokugqibela, kufanele kuphawulwe ukuba zahlukahlukene ngokwenene. Ngoko ke, umzekelo, umsebenzi kunokwenzeka rhoqo yahluka ukusuka 10 Hz ukuya 10 MHz. Ngamanye amazwi, oko kunokwenza iisampulu million 10 ngomzuzwana! Kwaye ke isixhobo ngokwalo ayikho into eqinileyo, kwaye nokwakhiwa zeemodyuli eso sakhiwo. Kodwa lidla ezisetyenziswa kwizicelo entsonkothileyo apho kufuneka basebenze inani elikhulu signal.

isiphelo

Njengoko ubona, ADCs akuboni ukuba imigaqo eyahlukileyo yokusebenza. Oku kukuvumela ukuba ukukhetha ifowuni ukuba uya kuzanelisa iimfuno evela kunye nokuvumela ukusetyenziswa olufanelekileyo kwezibonelelo ezikhoyo.