采样数据系统基本原理

Rev. A | Page 1 of 21 AN-282 ᆌᆩԴऻ 0/&�5&$)/0-0(:�8":�t�1�0��#09������t�/03800% �."44"$)64&554������������t������������� ֑ᄣຕ਍ဣཥएԨᇱ૙ ཮3.1 ۆ႙%41֑ᄣຕ਍ဣཥ ۆ႙֑ᄣຕ਍DSPဣཥ઀཮ස཮3.1໯๖ăሞํाኴႜఇຕ ገ࣑ኮമLjఇె႑ࡽཚ׉ࣷཚࡗగዖ႑ࡽۙ૙ۉୟLjኴႜ ݣٷĂປ३ई୳հڪࠀీăසࡕఇె႑ࡽڦઠᇸ๟࿒܈Ă უ૰Ăୁ໏ई૰LjሶႴᄲ๑ᆩ๢ړڦدߌഗLj๯ံॽ࿿૙ ଉገࣅྺۉუईۉୁă ֑ᄣຕ਍ဣཥڦዷᄲᇮॲ ํाڦఇຕገ࣑ࡗײภतڟଇ߲࠲॰߁౒ǖ૗ො้क़֑ᄣ ࢅଉࣅ໯ዂᆶ၌ናޗݴՐ୲ăକ঴ኄၵ߁౒ܔᇀDSPᆌᆩ ዁࠲ዘᄲă ᆌᆩԴऻ Rev. A | Page 2 of 21 AN-282 ఇె႑ࡽڦ૗ො้क़֑ᄣ ఇె႑ࡽڦ૗ො้क़ࢅናޗ֑ᄣڦ߁౒ස཮3.2໯๖ă૶Ⴤ ఇెຕ਍ՂႷᅜ૗ොڦ้क़क़߰ts֑ᄣLj޿้क़क़߰ՂႷ ৛႐჋ስLjඓԍ֑ᄣຕ਍ీ৛ඓ௮ຎᇱ๔ఇె႑ࡽă࢔၂ ඗Lj֑ᄣሁܠ)֑ᄣ໏୲ሁ੺*Ljఇె႑ࡽڦຕጴ՗๖৽ሁ ৛ඓăසࡕ֑ᄣডณ)֑ᄣ໏୲ড஥*Ljሶณڟగᅃۅ้Lj ఇె႑ࡽڦ࠲॰႑တॽᅺڥփڟ֑ᄣܸ۪฿ăኄ๑࿢்੗ ᅜڥ؜࠲ᇀలઊຯ༬ጚሶڦרຎLjස཮3.3໯๖ă ఇె႑ࡽڦ૗ො֑ᄣ ྺକ૙঴ं۠ܔ้ᇘࢅೕᇘڦᆖၚLj๯ံ൩੊୯཮3.4໯๖ ڦᅃ߲֑ᄣኟ၀հ႑ࡽڦ้ᇘ՗๖ڦ຺ዖ൧઄ăڼᅃዖ൧ ઄ዐڦ֑ᄣຕଉ၂඗๟؊ፁڦLj੗ᅜԍା޿ኟ၀հڦ႑ တăڼܾዖ൧઄ዐLj௅߲ዜ೺ኻ֑णକ຺߲ᄣԨLjධ඗ፁ ᅜԍା޿ኟ၀հڦ႑တăڼෙዖ൧઄՗๖fs=2faኄዖఇࢵڦ ट၌ཉॲăසࡕ֑ᄣۅᇑኟ၀հኮक़ڦ࠲ဣၹۙփړLjڞ ዂߑࡻሞଭ঍ሁتܔኟ၀հ৊ႜ֑ᄣ(ܸփ๟཮ዐ໯๖ڦރ ኵت)Ljሶ۪ࣷ฿࠲ᇀ޿ኟ၀հڦ໯ᆶ႑တăڼ຺ዖ൧઄ ՗๖fs<2faኄዖ൧઄LjٗᄣԨइڥڦ႑တ၂๖ኟ၀հڦೕ ୲گᇀfs/2Ljनټྔ႑ࡽं۠ڟDCᇑfs/2ኮक़ڦలઊ లઊຯ༬ጚሶ ■ ྺՆ௨႑တ۪฿Ljټ੻ྺfaڦఇె႑ࡽՂႷᅜ fs>2faڦ֑ᄣ໏୲৊ႜ֑ᄣă ■ ැfs<2faLjሶఇె႑ࡽټ੻ዐॽ݀ิं۠၄ၡă ຯ༬ټ੻ዐăໜጣ֑ᄣ໏୲৊ᅃօইگLjժ൐ఇె๼෇ೕ ୲fa൵ৎᇀ֑ᄣೕ୲fsLjं۠႑ࡽሞೕ೷ዐॽ൵ৎᇀDCă ं۠ڦ้ᇘၳᆌ ฉຎ൧઄ڦܔᆌೕᇘ՗๖ස཮3.5໯๖ă൩ጀᅪLjᅜ֑ᄣ໏ ୲fsܔఇె႑ࡽfa৊ႜ֑ᄣ้Ljํाฉׂࣷิଇዖं۠ೕ୲ ׯݴǖfs+faࢅfs-faăฉं۠(fs+fa)࢔ณࠓׯ࿚༶Ljᅺྺ໲࿋ ᇀలઊຯ༬ټ੻ኮྔăူं۠ׯݴ(fs-fa)ሶփ඗Ljړ๼෇႑ ࡽגࡗలઊຯ༬ټ੻fs/2้Lj໲৽ࣷᆅ݀࿚༶ă ं۠ڦೕᇘၳᆌ ཮3.2 ཮3.3 ཮3.5 ཮3.4 Rev. A | Page 3 of 21 AN-282 ᆯᅜฉڦ༪ஃ੗ኪLjADCኮമՂႷݣዃੇं۠୳հഗLj໲ ሞfs/2तᅜฉೕ୲ՂႷᆶፁࠕڦፆټປ३LjᅜݞኹփႴᄲڦ ټాं۠ăं۠ᄺ੗ీᇸጲփሞలઊຯ༬ټ੻ݔྷኮాڦ एԨ႑ࡽڦၿհLjईኁᇸጲADC๼෇܋ڦ࿄୳հ੻ټሯ ำă ं۠ܔ֑ᄣຕ਍ဣཥۯༀݔྷڦᆖၚස཮3.6໯๖ăฉ཮၂ ๖లઊຯ༬ೕ୲ۅڦ໯ႴጒༀLjഄዐं۠ׯݴᇑ๼෇႑ࡽ ၎঍ᇀ໯Ⴔۯༀݔྷᅜူڦᅃۅăူ཮၂๖ডߛೕ୲ۯༀ ݔྷ๴ڟं۠ׯݴ၌዆ڦጒ઄ăኄዖጒ઄ॽڞዂডߛೕ୲ ้ڦኝ༹႑ሯԲইگLjܸ൐ं۠ټྔ႑ࡽᅼईၿհ੗ీࣷ ᆅഐ฿ኈLjස཮3.7໯๖ă ं۠ܔۯༀݔྷڦೕᇘၳᆌ ੇं۠୳հഗڦ჋ስ ၄ሞ࿢்ᆌ޿ൣؤLjܔᇀߴۨఇె๼෇ټ੻faLjੇं۠୳ հഗڦᄲ൱փৈᇑ֑ᄣ໏୲fs၎࠲Ljܸ൐ᇑ໯Ⴔڦဣཥۯ ༀݔྷ၎࠲ă໯࿍ۯༀݔྷLj०ჾኮ๟ኸᇨ೺ፌٷ႑ࡽᇑ ՂႷ঴ဆڦፌၭ႑ࡽڦԲኵLjཚ׉ᆩdB՗๖ă࿢்ړമ࠲ ႐ڦ๟ं۠ܔۯༀݔྷڦ၌዆ăADCଉࣅሯำतഄ໲ݥ၍ Ⴀᅺ໎ڦ၌዆ၳᆌॽሞฎࢫ༪ஃăူ௬ڦঢ়ᄓ݆ሶܔᇀ୳ հഗڦ჋ስ੗ీࡗᇀჹ߭Ljڍഄᇱ૙๟ᆶၳڦLjժ൐੗ۙ ኝᅜ๢ࢇํाڦဣཥᄲ൱ă ੇं۠୳հഗڦᄲ൱ ๯ံLjยዃੇं۠୳հഗڦገችೕ୲ڪᇀ໯Ⴔڦఇె๼෇ ټ੻faLjኄ৽ۨᅭକ୳հഗڦཚټfpass=faăۨᅭ୳հഗፆټ ڦഐ๔ೕ୲fstop=fs/2ăସ୳հഗፆټປ३ڪᇀ໯Ⴔڦডߛೕ ୲ۯༀݔྷDRLjᆩdB՗๖ăኄၵ֖ຕۨᅭ୳հഗڦࡗ܉ ټ༬ኙLjन໲ՂႷሞlog2(fstop/fpass)Ԡೕײฉํ၄ᇑۯༀݔྷ ၎ڪڦፆټປ३ă඗ࢫՍ੗ඓۨྺํ၄޿ࡗ܉ټၽ୲໯Ⴔ ڦ୳հഗৎຼ঩ຕM(टۅຕ)Ljᅺྺ୳հഗࡐইሀྺ௅Ԡ ೕײ6M dBă཮3.9၂๖କᅃ߲०ڇڦऺ໙๖૩Ljഄዐ႑ࡽ ټ੻faྺ3 kHzLj֑ᄣ໏୲fsྺ12 kHzLjᄲ൱60 dBڦۯༀݔ ྷăऺ໙՗௽LjႴᄲᅃ߲10टۅ୳հഗă൩ጀᅪLjሞํ७ ዐLjยऺ8टۅᅜฉڦఇె୳հഗݥ׉ઓవLjยऺ12टۅ ᅜฉڦ୳հഗሶबࢭփ੗ీׯࠀLjأݥ๟ঢ়ᄓݿ޷ڦ୳հ ഗยऺටᇵăڟణമྺኹLjช࿄੊୯୳հഗڦ၎࿋༬ኙᅜ तټాࢅټྔ࿖հᄲ൱ăසࡕेฉኄၵ֖ຕLjੇं۠୳հ ഗڦยऺ߾ፕॽସටྭܸิ࿇ă ं۠ᆅഐڦ߅ඡ႑ࡽᅼ ཮3.6 ཮3.7 ཮3.8 ᆌᆩԴऻ AN-282 ฉຎᆩᇀඓۨੇं۠୳հഗްሗ܈ڦঢ়ᄓ݆ሶ्ย஢ଉײ ႑ࡽ੗ᅜ؜၄ሞలઊຯ༬ೕ୲ᅜฉڦ໯ᆶ๼෇ೕ୲ăํा ൧઄ཚ׉ժݥසُLjܸ൐ሞ๼෇ೕ୲ডߛ้Lj໯ت૙ڦ႑ ࡽࣷᆶᅃၵጲ඗ປ३ă૩සLjሞฉ૩ዐLjසࡕలઊຯ༬ೕ ୲तᅜฉೕ୲ڦ႑ࡽᅙঢ়ປ३କ12 dBLjሶሞ6 kHzڦలઊ ຯ༬ೕ୲้ৈႴᄲ48 dBڦ୳հഗፆټປ३ăኄຫ௽LjৈႴ ᄲᅃ߲8टۅ୳հഗă཮3.10၂๖କኄᅃ൧઄ă ټྔປ३ܔੇं۠୳հഗڦᆖၚ ᆯᅜฉ༪ஃ੗ኪLjཚࡗ༵ߛ֑ᄣ໏୲(׬ྺ“ࡗ֑ᄣ”)Lj੗ ᅜইگܔੇं۠୳հഗڦᄲ൱ăሞࢫ௬ڦჺ༪ࣷዐ࿢்ॽ ੂڟLjᆶᅃૌ༬๺ڦADCࢅDACLj׬ྺΣ-Δ႙ገ࣑ഗLj໲ ்Ԩว৽๟ࡗ֑ᄣገ࣑ഗLj੗ᅜटٷںইگੇं۠୳հഗ ڦްሗ܈ă ࡗ֑ᄣᇑ؏ൽ ኟසമ௬໯༪ஃڦLjܔ๼෇႑ࡽ৊ႜࡗ֑ᄣڦዷᄲࡻت๟ ੗ᅜ०ࣅੇं۠୳հഗڦᄲ൱ăړ඗Ljࡗ֑ᄣᄺᆶփ૧ڦ ᅃ௬Ljन໲༵ࣷߛADC๼؜ຕ਍໏୲LjDSPՂႷీࠕ߶ฉ ޿໏୲LjᅜՍྼ׼ํ้֡ፕăසࡕຕ਍Ⴗᅜزႜႚ๕د ๼Ljሶ໲ॽ቞ᆩ߸ܠೕ೷ጨᇸăᅃዖᆶဌᆅ૰ڦ༺پݛӄ ๟ཞ้ሏᆩఇె୳հࢅຕጴ୳հरຍĂࡗ֑ᄣᅜतᅃዖ׬ ྺ“؏ൽ”ڦت૙ࡗײă཮3.11໯๖ྺدཥ൧ႚLjഄዐ໯ᆶ ੇं۠߾ፕۼᆯADCኮമڦఇె๼෇୳հഗ׶څă཮3.12 ሶփཞLjࡗ֑ᄣԲK)Kྺኝຕ*ॽలઊຯ༬ೕ୲༵ߛ዁ Kfs/2Ljܸٗ੗ইگ๼෇ఇె୳հഗڦࡐইᄲ൱ăADCኮࢫ ڦຕጴ୳հഗ)ڼ7বॽၘဦ༪ஃຕጴ୳հ*ߵ਍fsํႜੇं ۠ࠀీLjժ൐ሞfs/2้ᆶፁࠕڦፆټປ३Lj੗ᅜํ၄໯Ⴔڦ ۯༀݔྷăሞࢫ௬ڦჺ༪ࣷዐ࿢்ॽକ঴ڟLjਏᆶ෍পኹ ༬ኙࢅଆࡻ၎࿋ၚᆌڦຕጴ୳հഗᇺԲ၎ᆌڦఇె୳հഗ ඹᅟํ၄)्ยDSP໏܈ፁࠕ੺*ăᆶ၌ஞ؋ၚᆌ(FIR)୳հ ഗ੗ᅜยऺׯਏᆶ၍Ⴀ၎࿋༬ኙăᆯᇀຕጴੇं۠୳հഗ ᅙॽټ੻ই዁fs/2Ljᅺُຕጴ୳հഗ༵ࠃڦຕ਍ํाฉࡤᆶ රᇆ႑တLjுᆶՂᄲֱੂ௅߲ᄣԨă๚ํฉLj௅K߲ᄣԨ ኻႴᄲֱੂᅃ߲ᄣԨăኄᅃࡗײ׬ྺ“؏ൽ”Ljॽሞ࠲ᇀ Σ-Δ႙ገ࣑ഗڦჺ༪ࣷևݴ)ڼ6ব*ዐᇎᅜၘဦ༪ஃăُ ྔLjํाڦ؏ൽ߾ፕ੗ᅜᆯFIR୳հഗԨวཚࡗऺ໙௅K߲ ๼෇ᄣԨڦᅃ߲๼؜ᄣԨઠኴႜăኄዖࡗ֑ᄣᇑ؏ൽᇱ૙ ๟ํाDSPڦፌዘᄲᇱ૙ኮᅃă ֑ᆩఇెگཚ୳հഗ৊ႜలઊຯ༬֑ᄣ ੇं۠୳հഗ๖૩ ཮3.9 ཮3.10 ཮3.11 Rev. A | Page 4 of 21 ᆌᆩԴऻ AN-282 വ֑ᄣतഄᆌᆩ ሞԨবዐ࿢்ॽକ঴ڟLjᆶၵDSPᆌᆩྜඇ੗ᅜথ๴ं ۠Ljժీᆶၳںेᅜ૧ᆩăړᆯADC৊ႜຕጴࣅت૙ڦఇ ె႑ࡽגࡗfs/2้Ljኄዖጒ઄׉ԥ׬ྺ“גలઊຯ༬ೕ୲”ई “വ֑ᄣ”ăలઊຯ༬ጚሶ՗௽Ljྺԍା႑တLj৊ႜຕጴࣅ ت૙ڦ႑ࡽڦټ੻)ݥํाೕ୲*փᆌגࡗfs/2ăਉ૩ઠຫLj ੊୯ᅃዖۉ႑د๼ܠୟްᆩഗᆌᆩLjഄዐೕݴܠୟްᆩ (FDM)ຕ਍቞ᆩ60 kHz዁108 kHzڦټ੻Ljᅜ112 kHzڦೕ୲ ܔഄ৊ႜ֑ᄣă཮3.13၂๖କ޿႑ࡽڦೕ೷ᅜतं۠ׯݴ ڦ࿋ዃăሞဣཥڦথ๭܋LjዘࠓDACኮࢫڦ୳հഗྺټཚ ୳հഗLjܸփ๟گཚ୳հഗLjՂႷ୳أ4 kHz዁52 kHzݔྷ ᅜాڦं۠ׯݴLjᅜत࿋ᇀ֑ᄣೕ୲112 kHzڦׯݴă גలઊຯ༬ೕ୲֡ፕڦଷᅃዖᆌᆩ๟ዐೕ႑ࡽ዁एټڦ኱ থገ࣑ăሞ֑ᆩADCࢅDSPڦٷܠຕدཥཚ႑ࢅૃٳথ๭ ऐ໯ᆩڦဣཥዐLjઠጲথ๭ऐമ܋ڦዐೕ(IF)႑ࡽᆯंೕ ഗࢅگཚ୳հഗူՎೕई঴ۙྺएټ႑ࡽLjස཮3.14໯ ๖ăፌዕዐೕप๑ᆩᅃ߲ᇑ႑ࡽሜհೕ୲၎࿋ᅃዂڦԨ ናăंೕഗ๼؜Ԉࡤᅃ߲एټ႑ࡽLj໲ᇑଇୟ๼෇ኮक़ڦ ၎࿋ֶׯԲ૩ăंೕഗኮࢫ๟گཚ୳հഗĂݣٷഗࢅ ADCăۆ႙ंೕഗڦገ࣑໦ࡼሞ4 dB዁6 dBኮक़ăړ႑ሯ Բ๴၌ᇀമ܋้Ljඁأंೕഗॽ੗ᅜ߀฀থ๭ऐڦኝ༹ሯ ำဣຕă ఇెူՎೕई঴ۙ සࡕᅜᇑԨናೕ୲၎ڪڦ໏୲ܔዐೕ႑ࡽ৊ႜ֑ᄣLjሶ੗ ᅜඁأंೕഗ(ස཮3.15໯๖)ă၄ሞLjADCഐڟ঴ۙഗڦ ፕᆩăසࡕADCڦ֑ᄣೕ୲ᇑఇె႑ࡽڦೕ୲၎ཞLjຕጴ ࣅ๼؜ॽྺᅃ߲DCኵăఇె႑ࡽᇑ֑ᄣೕ୲ڦඪࢆೋֶ ੂഐઠۼၟ๟ಆೕDfLjᆯُՍ੗ྜׯ঴ۙࡗײă ֑ᆩఇెࢅຕጴ୳հ৊ႜࡗ֑ᄣ FDM႑ࡽڦגలઊຯ༬ೕ୲֑ᄣ ཮3.12 ཮3.14 ཮3.13 Rev. A | Page 5 of 21 ᆌᆩԴऻ AN-282 ઠጲADCڦຕ਍ՂႷᆯDSP๑ᆩFFTت૙Ljऺ໙ຕጴࣅ႑ ࡽڦํևࢅႵևăྺକԍା঴ۙ႑ࡽዐԈࡤڦ၎࿋႑တLj ኄዖت૙๟Ղᄲڦă ၂ܸᅟ९LjړADCሞגలઊຯ༬ೕ୲࣍ৣዐ߾ፕ้LjՂႷ ኪڢገ࣑ഗኍܔలઊຯ༬ೕ୲ᅜฉڦ๼෇ೕ୲ڦۯༀႠ ీă๼෇ೕ୲ডߛ้LjADCڦ႑ሯԲࢅၿհ฿ኈႠీཚ׉ ࣷইگLjᅺُኍܔ໯Ⴔ๼෇ೕ୲ڦ঍ୁႠీՂႷፁᅜ஢ፁ ဣཥႴ൱ăגలઊຯ༬ೕ୲֡ፕཚ׉ᄲ൱ܔߛೕ๼෇႑ࡽ ߸ྺ୛ԀڦADCLjܸփ๟ኻీᆩᇀگᇀలઊຯ༬ೕ୲ڦᆌ ᆩڦADCă ଉࣅ໯ዂᆶ၌ናޗݴՐ୲ڦᆖၚ ֑ᄣຕ਍ဣཥႴᄲ੊୯ڦڼܾዖዷᄲᆖၚ๟ఇຕईຕఇገ ࣑ࡗײڞዂڦᆶ၌ናޗݴՐ୲ڦᆖၚă༪ஃዐLj࿢்ॽ׬ ADC)ईDAC*ڦ࿋ຕྺገ࣑ഗڦݴՐ୲NăܔᇀADCLj๼ ෇ݔྷݴྺ2N߲૗ොपLj߳पᆯᅃ߲N࿋ܾ৊዆ጴ՗๖ă ܔᇀDACLj๼෇ᆯN࿋ܾ৊዆ጴፇׯLj๼؜ᆶ2N߲੗ీڦ ૗ොपă཮3.16၂๖࿋ຕNĂܔᆌڦपຕ2Nᅜतፌگᆶၳ࿋ (LSB)ڦ඄ዘLj඄ዘᆩଇዖݛ๕՗๖ǖᅃྺӥݴԲLjᅃྺᆩ dB [20 log10(2N)]ई6.02N dB՗๖ڦԲ୲ăُԲኵ)՗๖ྺӥ ݴԲईdB*پ՗ገ࣑ഗڦۯༀݔྷLjनፌٷ੗঴ဆ႑ࡽᇑ ፌၭ੗঴ဆ႑ࡽڦԲኵăኄ૛ՂႷኸ؜Lj཮3.16ዐڦۯༀ ݔྷኵ՗๖૙ၙADCࢅDACڦۯༀݔྷኵLjܸுᆶ੊୯ၿ հࢅ঍ۙ฿ኈڪ঍ୁႠీ၌዆ăኄၵኵᄺփپ՗႑ࡽᇑଉ ࣅሯำڦ૙ஃԲኵăᆶ࠲ኄၵࣆ༶Lj࿢்ॽሞฎࢫምፕ༪ ஃă ଉࣅ૙ஃĂ႑ሯԲतᆶၳ࿋ ADCࢅDACڦᆶ၌ݴՐ୲ڞዂ႑ሯԲ(SNR)ᆶᅃ߲૙ஃ၌ ኵLj໲๟࿋ຕNڦࡧຕăྺକ৊ႜᆶᅪᅭڦ֪ଉLjᆩฎگ ᇀገ࣑ഗ၌ޗݔྷڦ஢ଉײኟ၀հ๼෇घ૤ADCăኄࣷڞ ዂᄣԨᇑᄣԨक़ڦဃֶLjׂܸٗิଉࣅሯำăኄ੗ᅜᆩຕ ბݛ݆ຫ௽ǖሞలઊຯ༬ټ੻ݔྷా֪ڥڦଉࣅ໯ዂ਩ݛ ߵሯำۉუ੗ᅜᆩ࿢்ຄဒڦࠅ๕q/√12՗๖Ljഄዐqྺገ ࣑ഗፌگᆶၳ࿋(LSB)ڦ඄ዘăLSBڦኵqڦऺ໙ݛ݆๟ॽ ADCईDACڦ஢ଉײݔྷأᅜ2Năሞுᆶဃֶᇸڦ૙ၙገ ࣑ഗዐLj૙ஃฉڦ਩ݛߵଉࣅሯำۉუᄺᇑ๼෇႑ࡽናޗ ࢅೕ୲࿮࠲ă࠲ᇀኄᅃ०ڇࠅ๕ڦླྀڞࡗײLj൩֖੊ᅜူ ࿔၅ǖ W.R. Bennett, Spectra of Quantized Signals, BSTJ 27, pp. 446-472, July 1948 ܔᇀ஢ଉײኟ၀հ๼෇Lj੗ᅜ৊ᅃօڥኪLj૙ஃฉڦ਩ݛ ߵ႑ࡽᇑଉࣅሯำԲڦऺ໙ࠅ๕ྺǖ SNR = 6.02N + 1.76dB. ኱থዐೕገຕጴူՎೕई঴ۙ ADCࢅDACڦݴՐ୲तۯༀݔྷ ཮3.15 ཮3.16 ࿋ຕN पຕ2N %, 100/2N dB, 6N 8 256 0.4 48 10 1024 0.1 60 12 4096 0.025 72 14 16384 0.006 84 16 65536 0.0015 96 18 262144 0.0004 108 20 1048576 0.0001 120 22 4194304 0.000025 132 24 16777216 0.000006 144 Rev. A | Page 6 of 21 ᆌᆩԴऻ AN-282 ᆌጀᅪLj਩ݛߵଉࣅሯำᅃӯৎຼڪᇀలઊຯ༬ټ੻ݔྷ ాڦ੻ټሯำăڍ๟Ljኄᅃࡀሶሞగၵཉॲူփׯ૬ăස ࡕଉࣅဃֶ႑ࡽᇑ৊ႜຕጴࣅت૙ڦ႑ࡽኮक़٪ሞ၎࠲࠲ ဣLjሶଉࣅሯำ੗ీणዐሞ๼෇႑ࡽڦၿհฉLjܸփ๟਩ ሌݴොᇀኝ߲ټ੻ݔྷాăړ๼෇႑ࡽྺኟ၀հ൐ྺ֑ᄣ ೕ୲ڦݴೕၿհ้Ljटᆶ੗ీ݀ิฉຎ൧઄ă ֪๬ADC้Ljཚ׉ॽᅃ߲كኟ၀հ႑ࡽแेᇀADCڦ๼෇ ܋Ljժ૧ᆩDSPरຍऺ໙SNRLjස཮3.18໯๖ă੺໏ޱ૛ᄾ Վ࣑(FFT)ت૙ᆶ၌ຕଉڦ้क़ᄣԨLjժॽഄገ࣑ڟೕ೷ ዐLj૩ස཮3.19ኍܔ12࿋200 kSPS֑ᄣADC AD678໯๖ڦ ೕ೷ă඗ࢫLjᆩೕ೷ऺ໙SNRࢅएԨ๼෇႑ࡽڦၿհLjኄ ᇑఇెೕ೷ݴဆᅏݥ׉၎ຼă๯ံऺ໙႑ࡽڦ਩ݛߵኵLj ඗ࢫऺ໙లઊຯ༬ټ੻ݔྷా໯ᆶഄ໲ೕ୲ׯݴ)ኄփৈԈ ࡤሯำLjܸ൐Ԉࡤ฿ኈׂ࿿*ڦ਩ݛߵኵăኄଇ߲ଉڦԲኵ ᆩdB՗๖नྺ႑ሯԲ(SNR)ăADCڦ߳ዖሯำᇸLjԈઔओ ݴࢅྲݴݥ၍ႠĂ฿ஓᅜतADCాևሯำᇸLjڞዂ֪ڥڦ SNRگᇀ૙ஃኵ6.02N+1.67dBăُྔLjኄၵဃֶཚ׉๟๼ ෇უӦ୲ڦࡧຕLjᅺُࣷໜጣ๼෇ೕ୲ڦ༵ߛܸሺٷăऺ ໙ሯำڦ਩ݛߵኵ้Ljသ࠹ฉᄲԈઔएԨ႑ࡽڦၿհăᆶ ้ࢪॽኄᅃ֖ຕ׬ྺ႑ࡽᇑሯำे฿ኈԲS/(N+D)Ljڍཚ ׉๟०ڇں׬ྺ႑ሯԲ SNRă֑ᄣADC) 12࿋Ă 200 kSPS*AD678ڦS/(N+D)ڦۆ႙൸၍ස཮3.20໯๖ă ଉࣅሯำएԨኪ๎ లઊຯ༬ټ੻fs/2ݔྷాڦ਩ݛߵଉࣅሯำǖ లઊຯ༬ټ੻ݔྷాڦ஢ଉײኟ၀հ਩ݛߵ႑ࡽ ᇑ਩ݛߵሯำԲǖ ᆶၳ࿋ຕ(ENOB)ǖ ঴๥SNRڦଷᅃዖݛ݆๟๑ᆩᆶၳ࿋ຕईENOBăᆶၳ࿋ ऺ໙ݛ݆๟૧ᆩ֪ڥڦSNRኵLj൱঴SNRࠅ๕ዐڦN)֖९ ཮3.17*ă૩සLj૙ၙڦ12࿋ADCਏᆶ74 dBڦ૙ஃSNRኵLj ܔᆌᇀ12߲ᆶၳ࿋ăසࡕ֪ڥڦSNRྺ68 dBLjሶ໲ܔᆌᇀ 11߲ᆶၳ࿋ăኄຫ௽Ljํाڦ12࿋ADCڦႠీᇑ૙ၙڦ11 ࿋ADCڦႠీ၎ړă཮3.20ᄺሞSNR൸၍ฉ၂๖କAD678 ڦENOBႠీă൩ጀᅪLjሞگೕ้LjAD678ڦᆶၳ࿋ຕג ࡗ11.4ă ᄺ੗ᅜ૧ᆩኟ၀հ൸၍ెࢇݛ݆ऺ໙ᆶၳ࿋ຕă֑ᆩኄዖ ݛ้݆LjႴॽᅃ߲ኟ၀հแेᇀADCLjժ֑णැ߅ᄣԨă ADCۯༀ֪๬ 12࿋Ă200 kSPS ADC AD678ڦ2048ۅFFT๼؜ ཮3.17 ཮3.18 ཮3.19 Rev. A | Page 7 of 21 ᆌᆩԴऻ AN-282 ኄዖݛ݆փ๟ܔ้क़ᄣԨኴႜFFTLjܸ๟ऺ໙ຕ਍ۅڦፌ ॅెࢇኟ၀հă჋ስኟ၀հናޗĂೋᅎĂೕ୲ࢅ၎࿋ڦᇱ ሶ๟ᄲ๑ํाኟ၀հຕ਍ۅᇑ૙ஃኟ၀հኮक़ڦ਩ݛߵဃ ֶፌၭăཞᄣLj૙ၙADCڦ૙ஃ਩ݛߵဃֶྺq/ ă૧ᆩ཮ 3.21໯๖ࠅ๕Ljऺ໙ํाኟ၀հᇑ૙ஃኟ၀հኮक़ڦ਩ݛ ߵဃֶᅜतᆶၳ࿋ຕă๑ᆩኟ၀հ൸၍ెࢇݛ݆֪ڥڦ ENOBᇑ๑ᆩSNRरຍइڥڦENOBኮक़ਏᆶଆࡻڦ၎࠲ ႠăසࡕSNRऺ໙໯ᆩڦ႑ࡽၭᇀ஢ଉײLjሶྺ๑ኄଇዖ ݛ݆၎࠲LjՂႷሺेᅃ߲ၯኟဣຕLjසူ཮໯๖ă ๑ᆩኟ၀հ൸၍ెࢇݛ݆ऺ໙ENOB QA = ᆯెࢇኟ၀հڥڟڦํा਩ݛߵဃֶ QT = ᆯፌॅెࢇኟ၀հڥڟڦ૙ஃN࿋਩ݛߵ ဃֶ= ᇑSNR၎࠲ǖ SNRํा-1.76DB+گഥ஢ଉײڦ႑ࡽ຤ೝ SNR = 6.02 ཮3.22၂๖କႹܠ๢ࢇDSPت૙ڦᆌᆩLjժߴ؜କܔᆌ႑ ࡽڦৎຼټ੻ࢅۯༀݔྷăۯༀݔྷํाฉᆶଇݛ௬ǖ኱ ୁࢅ঍ୁă኱ୁۯༀݔྷܔᆌᇀ཮3.22ዐ༵ࠃڦኵ)ࢮ୼ ADCৢༀဃֶ*ă঍ୁۯༀݔྷሶᇑADCڦၿհ฿ኈႠీ ၎࠲ă૩සLjሞຕጴೕ೷ݴဆᆌᆩዐLj஢ଉײኟ၀հ๼෇ ႑ࡽڦၿհࣷ၌዆ဣཥሞٷ႑ࡽ٪ሞڦ൧઄ူ঴ဆၭ႑ࡽ ڦీ૰ă঍ୁ၍Ⴀཚ׉ᆩၿհ฿ኈईጺၿհ฿ኈ(THD)՗ ๖ăܔᇀํाڦADCLj࿋ຕ੗ీժփీ࢔ࡻںኸ๖ገ࣑ഗ ڦၿհ฿ኈႠీă঍ୁۯༀݔྷگᇀSNRࠅ๕໯ᇨ֪ڦۯ ༀݔྷ6.02N + 1.76dBăᆯᇀኄၵᇱᅺLjຕ਍๮֩ՂႷԈࡤ ኱ୁࢅ঍ୁ༬ႠLjᅜՍᆩࢽߵ਍ᆌᆩፔ؜௽዇ڦ჋ስă ߵ਍႑ࡽۯༀݔྷ჋ስADCݴՐ୲ ኍܔߴۨᆌᆩ჋ስ๢ړڦADCᇺփኹ๟ഡภڟඓۨ໯Ⴔ࿋ ຕࢅ֑ᄣ໏୲Lj࣏ՂႷߵ਍໯ت૙ڦఇె႑ࡽ੊ִADCڦ ኱ୁࢅ঍ୁ༬ႠLjቴڟ๢ړڦ೅ದă၂඗Ljኄᅃࡗײփ੗ Ն௨ںࣷภतڟႠీᇑׯԨڦ඄࢚ă DSPᆌᆩࢅۯༀݔྷᄲ൱ 12࿋Ă200 kSPS ADC AD678ڦS/(N+D)ࢅᆶၳ࿋ຕ ཮3.20 ཮3.22 ཮3.21 Rev. A | Page 8 of 21 ᆌᆩԴऻ AN-282 ሞᅃ߲3࿋ADCڦ૙ၙدڿࡧຕዐ)཮3.24*Ljఇె๼෇႑ࡽ ࿋ᇀ຤ೝዡLjຕጴ๼؜࿋ᇀؽ኱ዡăADCڦຕጴ๼؜ሞᅃ ۨڦ๼෇႑ࡽݔྷాᆶၳăܔᇀߴۨ๼؜ஓLj๼෇ڦଉ׬ ྺஓڦ੻܈ă૙ၙ੻܈ྺ1 LSB)ፌگᆶၳ࿋*LjڍํाฉLj ௅߲ஓڦ੻܈਩ᇑഄ၎ତஓփཞăஓ੻܈ᇑ૙ၙڦ1 LSBኵ ڦೋֶ׬ྺྲݴݥ၍ႠईDNLăᅃ߲ਏᆶܠዖփཞဃֶڦ 3࿋ADCڦدڿࡧຕස཮3.25໯๖ă൩ጀᅪLjஓ100ᅺྺ၎ ତஓڦDNLဃֶডٷܸ۪฿ăሞԿ࣍ဣཥዐLj฿ஓ੗ీࣷ ׂิናږࢅӦۯLjᅺُ޿֖ຕܔᇀኄዖᆌᆩዐڦADC჋ስ ݥ׉ዘᄲă ओݴݥ၍ႠईINLཚ׉๟၎ܔᇀஓዐ႐ઠ֪ଉăཚࡗ܋ۅ ࣃᅃཉ኱၍Ljஓዐ႐ᇑ޿૙ၙ኱၍ڦፌٷೋֶनྺINLLj ස཮3.25໯๖ăᅃၵ൧઄ူLjओݴݥ၍Ⴀ၎ܔᇀፌॅెࢇ ኱၍ઠۨᅭLj޿኱၍ཚ׉૧ᆩፌၭܾױ݆ઠऺ໙ă ሺᅮࢅೋᅎဃֶ਩ڪںᆖၚ໯ᆶஓLjཚ׉ᆩԲডدཥڦर ຍٗဣཥዐᇎᅜၩأă ૙ၙ3࿋ADCڦدڿࡧຕ ADCৢༀدڿ༬Ⴀ ௮ຎADCৢༀႠీڦएԨ༬Ⴀස཮3.23໯๖ă ADCৢༀ༬Ⴀ Ŗ ྲݴݥ၍Ⴀ(DNL) Ŗ ओݴݥ၍Ⴀ(INL) Ŗ ฿ஓ Ŗ ሺᅮဃֶ Ŗ ೋᅎဃֶ ᅃ߲૙ၙ3࿋DACڦৢༀدڿࡧຕස཮3.27໯๖ăຕጴ๼෇ ኵ࿋ᇀ຤ೝዡฉLjܔᆌڦఇె๼؜ኵ࿋ᇀؽ኱ዡฉăᇑ ADCփཞLjDACփࣷᆶ฿ஓăኍܔ௅߲ຕጴ๼෇ஓLjۼࣷ ׂิᅃ߲૗ොڦఇె๼؜ۉუăྲݴݥ၍Ⴀۨᅭྺ၎ତఇ ె๼؜ኵኮक़ڦक़߰ᇑ૙ၙڦ1 LSBኵڦೋֶăࡗٷڦDNL ဃֶ੗ీڞዂݥڇۙႠጒ઄Ljස཮3.28໯๖ăසࡕຕጴஓ ๼෇ڦ༵ߛᆅഐఇె๼؜ኵڦইگLjሶණྺDACྺݥڇۙ Ⴀă၎ݒLjසࡕDACدڿ༬Ⴀڦၽ୲ሞኝ߲ݔྷాਏᆶ၎ ཞڦޙࡽLjሶණྺDACྺڇۙႠăሞԿ࣍ဣཥዐLjݥڇۙ Ⴀጒ઄ׂࣷิናږLjᅺُኄᅃ༬ႠܔᇀኄዖᆌᆩዐڦDAC ჋ስݥ׉ዘᄲă ݥ૙ၙ3࿋ADCڦدڿࡧຕ ཮3.23 ཮3.18 ཮3.26 ཮3.25 ཮3.24 DACৢༀدڿ༬Ⴀ ௮ຎDACৢༀدڿ༬ႠڦएԨ༬Ⴀස཮3.26໯๖ă DACৢༀ༬Ⴀ Ŗ ྲݴݥ၍Ⴀ(DNL) Ŗ ओݴݥ၍Ⴀ(INL) Ŗ ݥڇۙႠ Ŗ ሺᅮဃֶ Ŗ ೋᅎဃֶ Rev. A | Page 9 of 21 ᆌᆩԴऻ AN-282 ओݴݥ၍Ⴀۨᅭྺఇె๼؜ኵ၎ܔᇀཚࡗ܋ۅ໯ࣃڦ૙ၙ ኱၍ڦፌٷೋֶăᇑADCᅃᄣLjINLᄺ੗ᅜ၎ܔᇀፌॅె ࢇ኱၍ઠۨᅭă ฎࢫ࿢்ॽੂڟLjᆶႹܠॐࠓ๢ࢇDSP ADCยऺLjٷևݴ ॐࠓۼᄲ൱ሞገ࣑ഗኮമݣዃᅃ߲֑ᄣԍ׼ݣٷഗ (SHA)Ljස཮3.30໯๖ăኵڥጀᅪڦ૩ྔ๟Flash႙ገ࣑ഗࢅ Σ-Δ႙ገ࣑ഗLjࢫኁᆮྺዘᄲăྺइڥSHA-ADCܔڦྜኝ ۯༀႠీLjՂႷॽܾኁणׯሞཞᅃႊೌฉLjईኁ዁ณፕྺ ᅃ߲ྜኝڦࠀీڇᇮ༵ࠃăޏሶLjᆯڇ߲ഗॲڦ༬Ⴀඓۨ SHA-ADCፇࢇڦኝ༹ۯༀႠీबࢭ๟փ੗ీڦăܔADC ڦྜኝ኱ୁࢅ঍ୁ༬Ⴀڦᄲ൱٣ิକాዃೌฉSHAڦ֑ᄣ ADCăኄၵገ࣑ഗփ٪ሞSHAᇑADCথ੨ڦ࿚༶Ljժྺᆩ ࢽ༵ࠃକྜኝڦ኱ୁࢅ঍ୁ༬Ⴀă ૙ၙ3࿋DACڦدڿࡧຕ ݥ૙ၙ3࿋DACڦدڿࡧຕ ཮3.27 ཮3.29 ཮3.28 ሺᅮࢅೋᅎڦۨᅭᇑADC၎ຼLjժ൐਩ڪںᆖၚ໯ᆶఇె ๼؜ኵă ADCۯༀႠీ ྺକీᆩᇀٷܠຕDSPᆌᆩLjADCՂႷਏᆶ੗থ๴ڦ኱ୁ ࢅ঍ୁ༬ႠăADCڦፌዘᄲۯༀ༬Ⴀଚ՗ස཮3.29໯๖ă ADCۯༀ༬Ⴀ !!!!!Ŗ! ႑ࡽᇑሯำे฿ኈԲ(S/N + D)तᆶၳ࿋ຕ !!!!!Ŗ ރኵሗොĂރኵၿհׯݴत࿮ሗොۯༀݔྷ(SFDR) !!!!!Ŗ ጺၿհ฿ኈ(THD) !!!!!Ŗ ඇࠀ୲ټ੻(FPBW) !!!!!Ŗ ඇ၍Ⴀټ੻ !!!!!Ŗ ঍ۙ฿ኈ(IMD) !!!!!Ŗ ੥০ჽ׿้क़ࢅ੥০۶ۯ !!!!!Ŗ ຨༀၚᆌ !!!!!Ŗ ࡗუ࣬ް Rev. A | Page 10 of 21 ᆌᆩԴऻ AN-282 ႑ሯԲࢅᆶၳ࿋ຕ ኟසኮമ໯༪ஃڦLj႑ሯԲ༬Ⴀٷ߁๟ړৃᄽহ໯ᆩڦా ࡥፌݿ޷ڦ঍ୁ༬Ⴀăॽၿհ฿ኈڦᆖၚԈࡤሞኄᅃ༬Ⴀ ዐ๟׉ࡀፔ݆Ljᅺُ(S/N+D)ۨᅭྺ֪ڥڦ๼෇႑ࡽڦ਩ ݛߵኵᇑలઊຯ༬ೕ୲ᅜူڦ໯ᆶഄ໲ೕ೷ׯݴ)Ԉઔၿ հLjڍփԈઔDC*ڦ਩ݛߵࢅڦԲኵă཮3.31၂๖କෙዖ ߛ໏Flash႙ADCڦ(S/N+D)ۆ႙൸၍཮ă཮ዐཞ้၂๖କ ۉୁݒઍ႙ሏ໙ݣٷഗAD9617ڦၿհ฿ኈႠీLjᅜࠃԲ ডăSNR֪ଉ঳ࡕᄺ੗ᅜᆩᆶၳ࿋ຕईENOB՗๖Lj཮3.31 ᄺ၂๖କኄᅃۅă FLASH႙ADCतሏ໙ݣٷഗڦۯༀႠీ ጺၿհ฿ኈ(THD) ጺၿհ฿ኈ(THD)ኸമୃ߲ၿհׯݴڦ਩ݛߵࢅᇑ஢ଉײ ๼෇႑ࡽڦ਩ݛߵኵኮԲLjᆩӥݴԲईdB՗๖ăܔᇀߛᇀ లઊຯ༬ೕ୲ڦ๼෇႑ࡽईၿհLjᆩഄं۠ׯݴऺ໙ă཮ 3.33၂๖କAD678ڦۆ႙THDႠీă AD678ڦጺၿհ฿ኈĂඇࠀ୲ټ੻ࢅඇ၍Ⴀټ੻ ాዃ֑ᄣԍ׼ࠀీڦADC ཮3.30 ཮3.32 ཮3.31 ཮3.33 ރኵሗොĂރኵၿհׯݴत࿮ሗොۯༀݔྷ (SFDR) ރኵሗොईރኵၿհׯݴ๟๼෇႑ࡽࢅDCኮྔፌٷڦೕ ೷ׯݴă޿ኵ՗๖ྺ၎ܔᇀ஢ଉײ๼෇႑ࡽڦ਩ݛߵኵڦ dBኵăރኵሗො༬Ⴀᆶ้ᄺ׬ྺ࿮ሗොۯༀݔྷ(SFDR)ă ཮3.32၂๖କAD678ڦރኵሗොႠీۆ႙൸၍ă AD678ڦރኵሗොၚᆌ(200 kSPSĂݥೝ਩2048 ۅFFT) FLASH႙ADC ݴՐ୲ ֑ᄣ໏୲ AD9020 10 BITS 40 MSPS AD9060 10 BITS 60 MSPS AD9028/9038 8 BITS 250 MSPS AD9006/9016 6 BITS 400 MSPS Rev. A | Page 11 of 21 ᆌᆩԴऻ AN-282 ඇࠀ୲ټ੻ ADCڦ஢ࠀ୲ټ੻(FPBW)๟ኸኍܔ஢ଉײ๼෇Ljዘࠓ)๑ ᆩFFT*एԨೕ୲ڦናޗԲ஢ଉײگ3 dB้ڦ๼෇ೕ୲ăٗ ཮3.33੗ᅜੂ؜LjAD678ڦ஢ࠀ୲ټ੻ሀྺ1 MHză඗ܸLj ྺ๑޿༬ႠᆶᅪᅭLjՂႷॽ໲ᇑSNRĂENOBࢅၿհ฿ኈ ঳ࢇഐઠ੊ִLjܸٗඓۨADCሞFPBWೕ୲ڦኈኟۯༀݔ ྷă ඇ၍Ⴀټ੻ ADCڦඇ၍Ⴀټ੻๟ኸٳڟ๼෇֑ᄣԍ׼(SHA)ڦუӦ୲ ้ڦ๼෇ೕ୲ăُ้Ljዘࠓኟ၀հڦናޗইگփڟ-0.1 dBăᅃڋגࡗُೕ୲Lj֑ᄣ๼෇႑ࡽڦ฿ኈॽ၂ዸሺٷă AD678 ADCᅙኍܔ๼෇ټ੻৊ႜᆫࣅLj੗ᅜܔ၂ዸߛᇀገ ࣑ഗలઊຯ༬ೕ୲ڦ๼෇႑ࡽ৊ႜവ֑ᄣăAD678ڦඇ၍ Ⴀټ੻ྺ500 kHzLj཮3.33ᄺ၂๖କኄᅃۅă ঍ۙ฿ኈ(IMD) ړ๼෇ᆯଇዖೕ୲)F1ࢅF2*ڦኟ၀հፇׯ้LjՍࣷ݀ิ঍ ۙ฿ኈ(IMD)ăඪࢆਏᆶݥ၍Ⴀڦഗॲۼࣷሞࢅೕ୲ࢅֶೕ ୲mF1± nF2ׂ้ิ(m+n)঩฿ኈओLjഄዐmĂn = 0,1,2,3...ă ঍ۙၜኸmईnփڪᇀ0ڦఫၵၜă૩සLjܾ঩ၜྺ(F1 + F2) ࢅ(F1 - F2)Ljෙ঩ၜྺ(2F1 + F2)Ă(2F1 - F2)Ă(F1 + 2F2)ࢅ (F1 - 2F2)DŽ֖९཮3.34DžăIMDओ՗๖ྺ֪ڥڦ๼෇႑ࡽ ڦ਩ݛߵࢅᇑ฿ኈၜڦ਩ݛߵࢅኮdBԲăแेᇀADCڦଇ ߲႑ࡽਏᆶ၎ཞڦናޗLjഄࢅڦރኵᇑ஢ଉײ၎ֶ-0.5 dBăIMDओࡃᅃࣅྺ0 dB๼෇႑ࡽă཮3.35၂๖କAD678ڦ ۆ႙IMD FFT൸၍ă ঍ۙओ ᆩ኱ݛ཮ݛ݆इڥ঍ୁ၍Ⴀ൸၍ ܔᇀኄዖ֪ଉLjႴॽᅃ߲஢ଉײኟ၀հแेᇀADCLjժ֑ णٷଉᄣԨă௅߲ஓڦ؜၄ْຕऻ୤ሞ኱ݛ཮ฉLjස཮ 3.36ፑฉݛ൸၍໯๖ăܔᇀ12࿋ገ࣑ഗLjྺକइڥᆶཥऺ ᅪᅭڦ঳ࡕLjႴᄲ֑णຕӥྤᄣԨă኱ݛ཮ᆌޙࢇኟ၀հ ڦ૙ၙ߁୲௢܈ݴքLjස཮3.36ᆸฉݛ൸၍໯๖ă඗ࢫLj ૧ᆩኟ၀հ߁୲௢܈ࡧຕࡃᅃࣅ኱ݛ཮ຕ਍Ljᅜइڥ཮ዐ ူݛ൸၍໯๖ڦDNL཮ăओݴݥ၍Ⴀ੗ᅜཚࡗՊ዆ેओ኱ ݛ཮ઠඓۨăેओ኱ݛዹ੻܈ྺدڿ຤ೝă཮3.37໯๖ྺ 12࿋Ă100kSPS ADC AD7870ᅜ100 kSPS໏୲ܔᅃ߲25 kHz ๼෇႑ࡽ৊ႜຕጴࣅت૙้Lj૧ᆩ኱ݛ཮ݛ݆इڥڦ঍ୁ ၍Ⴀ൸၍ă཮ዐுᆶ؜၄ডٷڦॖރLj՗௽ਏᆶଆࡻڦֶ ݴ၍Ⴀ܈ăᆶ࠲ຕბऺ໙ڦၘဦ႑တLj൩֖੊AD7870ຕ਍ ๮֩ă ཮3.35 ཮3.34 AD678ڦIMD൸၍DŽF1 = 9.08 kHZLjF2 = 9.58 kHzLj fs = 200 kSPSDž Rev. A | Page 12 of 21 ᆌᆩԴऻ AN-282 ੥০ჽ׿้क़(ईᆶၳ੥০ჽ׿้क़) ੥০ჽ׿้क़)ᆶ้ᄺ׬ྺ੥০้क़*ኸ֑ٗᄣ้ዓڦമᄂ ڟADCํा֑ᄣڦ้क़ଉ)֖९཮3.38*ăኄᅃ༬Ⴀኮ໯ᅜ ዘᄲLj๟ᅺྺ໲ᆶዺᇀᆩࢽኪڢ၎ܔᇀ๼෇႑ࡽ้ႾLjࢆ ้ᆌᆩ֑ᄣ้ዓăሞܠ߲ADCت૙ۯༀ႑ࡽ้Ⴔᄲཞօ֑ ᄣईႴᄲԵُ߶ጷڦഄ໲ᆌᆩዐLjՂႷኪڢ߳ഗॲኮक़࠲ ᇀ޿֖ຕڦֶᅴईඹֶă ੥০۶ۯ ੥০۶ۯኸᄣԨᇑᄣԨኮक़ሞํा֑ᄣڦᆶၳ้क़ۅฉڦ ֶᅴLjස཮3.39໯๖ăኄၵဃֶڦׂิᇱᅺᅃӯᆶܠዖă ሞํाڦADCዐLjঢ়׉ࣷᆶ߅ඡᇸܔ֑ᄣ้ዓ৊ႜ၎࿋ۙ ዆ǗփଆքਆĂಖୟࢅথںरຍᆅഐڦ੻ټໜऐሯำĂۉ ᇸ၍ሯำईຕጴሯำۼ੗ీׯྺ߅ඡᇸăᆯُሰׯڦဃֶ ੗ᅜᆩ਩ݛߵ้क़۶ۯઠ՗๖ă਩ݛߵ੥০۶ۯᆅഐڦ၎ ᆌ਩ݛߵۉუဃֶࣷইگADCڦኝ༹႑ሯԲă๼෇ኟ၀հ ฉڦ၎࿋۶ۯ੗ᅜׂิᇑ֑ᄣ้ዓฉڦ۶ۯ၎ཞڦᆖၚă ੥০۶ۯڦᆖၚ ᆩ኱ݛ཮ऺ໙঍ୁ၍Ⴀ ᆶၳ੥০ჽ׿้क़ڦ֪ଉ AD7870ڦ঍ୁ၍Ⴀ12࿋Ă100 kSPS ADCLj25 kHz๼෇ ཮3.36 ཮3.37 ཮3.38 ཮3.39 Rev. A | Page 13 of 21 ᆌᆩԴऻ AN-282 ཮3.40၂๖କփཞ੥০۶ۯኵ้੥০۶ۯኄᅃڇ߲ᅺ໎ܔ SNRׂิڦᆖၚLj໲๟஢ଉײኟ၀հ๼෇ೕ୲ڦࡧຕă࠲ ᇀSNRᇑ੥০۶ۯڦ࠲ဣݛײ๕ڦླྀڞࡗײLj൩֖੊࿔၅1ă ੥০۶ۯܔSNRڦᆖၚ ຨༀၚᆌईॺ૬้क़ ADCڦຨༀၚᆌ)ईॺ૬้क़*๟ኸሞแे஢ଉײ঩ሂ๼෇ ࢫLjADCॺ૬዁ܮۨ৛܈໯Ⴔڦ้क़)֖९཮3.41*ăሞ ADC֑ᆩఇెܠୟްᆩഗൻۯڦᆌᆩዐLjස཮3.42໯๖Lj ኄᅃ༬Ⴀ዁࠲ዘᄲăܠୟްᆩഗ๼؜੗ᅜ๑ADCڦ๼෇݀ ิ஢ଉײޗ܈ڦཌՎăසࡕܠୟްᆩഗࢅADC਩࿄؊ݴॺ ૬዁໯Ⴔ৛܈Ljሶॽᆅഐ኱ୁཚڢᇑཚڢक़زඡă ADCຨༀၚᆌ ࡗუ࣬ް้क़ ࡗუ࣬ް้क़ۨᅭྺٗࡗუ႑ࡽዘႎ৊෇ገ࣑ഗݔྷ้ਸ ๔ڟADCٳڟࡀۨ৛܈໯Ⴔڦ้क़ଉLjස཮3.43໯๖ăኄ ᅃ༬Ⴀཚ׉๟ኍܔג؜ADC๼෇ݔྷ50%ڦ႑ࡽܸჾă࿮ Ⴔ጖ჾLjADCܔᇀגଉײ႑ࡽᆌഐڟ૙ၙ၌ޗഗڦፕᆩǗ ሞࡗუጒ઄ူLjADCᆌׂิኟ஢ଉײஓई޶஢ଉײஓăᅃ ၵገ࣑ഗ༵ࣷࠃגଉײࢅവଉײՔኾLjᅜՍघऄሺᅮۙኝ ۉୟă ADCࡗუ࣬ް้क़ ཮3.42 ཮3.43 ཮3.40 ཮3.41 ๑ᆩఇెܠୟްᆩഗڦدཥຕ਍֑णဣཥ Rev. A | Page 14 of 21 ᆌᆩԴऻ AN-282 DACۯༀႠీ ٷܠຕDSPᆌᆩፌዕۼᄲዘࠓۯༀఇె႑ࡽLjᅺُDACڦ ঍ୁႠీᇑADCႠీᅃᄣዘᄲăDACڦዷᄲ঍ୁ༬Ⴀස཮ 3.45໯๖ă DACۯༀ༬Ⴀ ■ ॺ૬้क़ ■ றِஞ؋௬ओ ■ ၿհ฿ኈ ■ ႑ሯԲ ■ ᅼೕጆᆩ༬Ⴀ ॺ૬้क़ DACڦॺ૬้क़دཥฉۨᅭྺٗຕጴ๼෇ገ࣑(ཚ׉ٗ50% ۅਸ๔֪ଉ )ڟDAC๼؜ॺ૬዁గᅃဃֶټ (ཚ׉ྺ1/2 LSBLjᅜፌዕኵྺዐ႐)ᅜాڦ้क़ăස཮3.45໯๖Ljॺ૬ ้क़ڦᅃևݴ੗ీᄲࡃᅺᇀਸ࠲ڦࠦۨد๼ჽ׿ăසࡕ DACᆶᅃፇ๼෇໮٪ഗईस٪ഗLjሶॺ૬้क़ᆌٗ໮٪ഗ ჋ཚஞ؋ईस٪ഗ้ዓஞ؋ڦ50%ۅਸ๔֪ଉăDAC஢ଉ ײॺ૬้क़๟၎ܔᇀٗ000...0዁111...1ڦຕጴ๼෇ገ࣑ܸ ჾăDACዐଉײॺ૬้क़๟၎ܔᇀٗ011...1ڟ100...0ईٗ 100...0ڟ011...1ڦຕጴ๼෇ገ࣑ܸჾă ৈৈ၎ܔᇀ๼؜LjۨᅭDACॺ૬้क़ᄺ๟ྜඇኟඓڦLjස ཮3.46໯๖ăُ้Ljॺ૬้क़๟ኸٗ๼؜૗ਸᅜ؛๔ኵྺ ዐ႐ڦ±1/2 LSBဃֶټڟ๼؜ཕାሞᅜፌዕኵྺዐ႐ڦ±1/2 LSBဃֶټᅜాڦ้क़ଉăኄᄣLj±1/2 LSB஢ଉײॺ૬้क़ ܔᆌڦፌٷඹႹDAC߸ႎ໏୲नྺfmax = 1/tsăසࡕDAC๼෇ ڦᄣԨᇑᄣԨक़Վࣅኵ๔ዕگᇀ஢ଉײLjሶ੗ᅜ๑ᆩ߸੺ ڦ߸ႎ໏୲ă றِஞ؋௬ओ ૙঴றِஞ؋௬ओڦፌॅݛ݆๟੊ִ཮3.47໯๖ڦհႚă DAC཭հڦׂิᇱᅺ๟ຕጴ๼෇இडೋၽࢅDACਸ࠲ڦد ๼ჽ׿փᅃዂ)ڍΣ-Δ႙DACॐࠓ๟ᅃ߲ኵڥ࠲ጀڦ૩ྔLj ࢫ௬ڦჺ༪ࣷॽᇎᅜ༪ஃ*ăறِཚ׉ሞዐଉײገ้࣑ፌ ٷLjᅺྺُ้DACዐڦ໯ᆶ࿋ۼᄲ߀Վă011...1ڟ100...0ገ ࣑໯ׂิڦறِཚ׉ᇑ100...0ڟ011...1ገ࣑໯ׂิڦறِփ ཞLjᅺُՂႷڇ܀ݴဆ௅ዖ൧઄ăறِஞ؋௬ओ৽๟༬ۨ றِڦ௬ओLjཚ׉ᅜpV-sྺڇ࿋ઠ՗๖ǗᅺُLjྺ๑փཞ DACኮक़ڦԲডᆶᅪᅭLjՂႷኪڢDACڦ஢ଉײ๼؜ۉ უă๑ᆩ“றِీଉ”ኄᅃຍᇕ๟փኟඓڦLjᅺྺڇ࿋pV-s ժփ๟ీଉڦ܈ଉՔጚă ٗ཮3.47੗ᅜੂ؜Ljᆶ6߲੗ీڦறِஞ؋௬ओႴᄲت૙ă DACॺ૬้क़հႚ ၎ܔᇀDAC๼؜ۨᅭڦॺ૬้क़ ཮3.44 ཮3.45 ཮3.46 Rev. A | Page 15 of 21 ᆌᆩԴऻ AN-282 ௅ْገ࣑ᆶଇ߲၎࠲ڦறِஞ؋Ljॽഄ௬ओݴ՚׬ྺ1Ă 2Ă3Ă4ăُྔLj੊୯ᇑْ߳ገ࣑၎࠲ڦ“৫றِஞ؋”ᄺ࢔ ᆶᆩă৫றِஞ؋௬ओݴ՚ྺAREA 1 - AREA 2ࢅAREA 3 - AREA 4ăᅺُLjړֱੂDACຕ਍๮ ֩ฉڦறِஞ؋௬ओ༬Ⴀ้Ljසࡕ዆ሰฆຫ௽ڥփࠕൣ ؤLjሶ࢔੗ీࣷሰׯंၫă ࿮ஃ୳հᇑޏLjறِஞ؋௬ओԍ׼փՎă੺໏ॺ૬้क़ժ փጺ๟ᅪ࿆ጣறِஞ؋௬ओၭăԲড૙ၙڦጒ઄๟Ljܔᇀ ௅ْገ࣑LjDACڦ৫றِஞ؋௬ओྺ0LjनAREA 1 - AREA 2 = AREA 3 - AREA 4 = 0ăړ඗Ljሞ૙ၙጒ઄ူLj໯ᆶ຺߲ ௬ओ਩ྺ0ă ၿհ฿ኈ ৫றِஞ؋௬ओᇑஓ၎࠲LjᅺُړDACዘࠓኟ၀հ้Lj໲ ׂࣷิၿհăሞዘࠓኟ၀հڦᅃ߲ዜ೺ాLj৫ዐଉײறِ ࣷ؜၄ଇْ)ሞ௅߲ଭ঍ሁฉ*Ljᅺׂܸࣷิኟ၀հڦڼܾ ߲ၿհLjස཮3.48໯๖ă൩ጀᅪLjዘႎं۠ڟలઊຯ༬ټ ੻ాڦኟ၀հڦডߛ঩ၿհ࿮݆୳հă࢔వᇨ֪༬ۨ৫ற ِஞ؋௬ओᆅഐڦၿհ฿ኈLjᅺُLjྺକ؊ݴೠࠚዘࠓ DACڦۯༀႠీLjኄଇ߲༬Ⴀ਩Ⴔᄲ੊୯ă ጺၿհ฿ኈ(THD)੗ᅜᆩDSPरຍઠ֪ଉLjස཮3.49໯ ๖Ljഄዐܔ18࿋ᅼೕDAC AD1860৊ႜକ֪๬ă޿DAC֑ ᆩೕ୲ྺ990.5 Hzڦ18࿋ຕጴኟ၀հઠൻۯLjDAC߸ႎ໏ ୲ྺ176.4 kHzăDSPܔ๼؜֪๬հႚڦ4096߲ᄣԨ৊ႜຕ ጴࣅت૙LjԈࡤ޿ኟ၀հڦ23߲ྜኝዜ೺ăܔ֪๬঳ࡕኴ ႜ4096ۅ੺໏ޱ૛ᄾՎ࣑(FFT)ă඗ࢫLjߵ਍FFT঳ࡕऺ໙ ጺၿհ฿ኈࢅSNRă။հ୳հഗ੗ݞኹ990.5 Hzڦٷናޗए հׯݴ৊෇ຕጴገ࣑ഗLjᅺُຕጴገ࣑ഗڦඇևݔྷ਩੗ ጆோᆩᇀت૙ሯำࢅၿհׯݴă཮3.50၂๖କ஢ଉײ๼෇ ࢅ-20 dB๼෇ଇዖ൧઄ڦۆ႙THDेሯำ཮ăᆌጀᅪLjኄ ၵ֪ଉዐժ࿄๑ᆩඁறِഗࢅMSBۙኝरຍă ཮3.48 ཮3.47 ཮3.49 ཭հஞ؋հႚ 18࿋ᅼೕDAC AD1860ڦFFT֪๬ Rev. A | Page 16 of 21 ᆌᆩԴऻ AN-282 ᆩSHAඁأDACڦறِ ᆩSHA੗ᅜඁأDACڦறِLjස཮3.51໯๖ă৽ሞᄲॽႎ ຕ਍໮٪዁DACኮമLjॽSHAዃᇀԍ׼ఇ๕LjܸٗॽDAC ਸ࠲཭հᇑ๼؜߰૗ăSHA໯ׂิڦਸ࠲ຨՎᇑஓ࿮࠲Lj ժ൐ᅜ߸ႎೕ୲؜၄Ljᅺُ࢔ඹᅟᇎᅜ୳أă SHAᆩፕඁ཭հഗ Sin(x)/xೕ୲ࡐইၳᆌ ዘࠓDACڦ๼؜੗ᅜႚၡں՗๖ྺᅃဣଚਈႚஞ؋Ljഄ੻ ܈ڪᇀ߸ႎ໏୲ڦڛຕLjස཮3.52໯๖ă൩ጀᅪLj၎ܔᇀ گೕኵLjዘࠓ႑ࡽሞలઊຯ༬ೕ୲ट၌้گ3.92 dBăᆶ้ ሞDACኮࢫݣዃᅃ߲ݒၠsin(x)/x୳հഗLjᅜၯኟُၳᆌă SIN X/Xࡐই ૧ᆩFFTݛ݆֪ڥڦ18࿋ᅼೕDAC AD1860ڦጺၿ հ฿ኈ ཮3.50 ཮3.52 ཮3.51 Rev. A | Page 17 of 21 ᆌᆩԴऻ AN-282 ਸ࠲ۉඹ୳հഗ ႑ࡽ୳հᅃ܈ྜඇ๟ሞ૶Ⴤఇెᇘዐᆯ࿮ᇸഗॲ(ཚ׉๟ۉ ߌĂۉፆࢅۉඹ)ڦದዃઠኴႜăࢫઠLjཚࡗ࣐؋ࢅሺᅮڦ ሏݣࠓॺڦᆶᇸ୳հഗྺ୳հഗยऺටᇵ༵ࠃକ߸ٷڦଳ ऄႠࢅ߸ߛڦႠీLjڍධ඗๟ሞఇె႑ࡽฉ૶Ⴤ߾ፕă DSPरຍ٣ิକ࿘ܸۨଳऄڦ૗ො้क़ຕጴ୳հഗLj֑ᄣ ఇె႑ࡽྜඇᆯຕኵऺ໙ઠت૙Ljഄዐ໯ᆩڦᅃၵ୳հ໙ ݆࿮݆ᆯ૶Ⴤ้क़ఇె୳հഗઠํ၄ă ਸ࠲ۉඹ୳հഗ(SCF)๟ᅃዖዐक़ૌ႙ڦഗॲLjጹࢇକ૶Ⴤ ้क़ࢅ૗ො้क़ଇݛ௬༬ኙăኄዖ୳հഗཚ׉૧ᆩCMOS ਸ࠲ࢅۉඹํ၄LjᅜఇెۉፆڦႜྺăᅺُLjႹܠ୳հഗ ॐࠓۼ੗ᅜྜඇᆯڇႊೌഗॲઠํ၄Ljܸ࿮Ⴔྔևഗॲă ਸ࠲ۉඹ୳հഗᇑDSPरຍᅃഐLjሞᇕᅼࢅᅼೕټ੻႑ࡽ ᆌᆩዐ༬՚ᆶᆩăᆯᇀਸ࠲ۉඹ୳հഗ๟֑ᄣഗॲLjᅺُ ࠲ᇀ૗ො้क़֑ᄣڦ໯ᆶ߁౒਩๢ᆩᇀኄዖഗॲǖలઊຯ ༬ۨ૙Ăं۠ڪڪă ୳հरຍ ■ ৗናĂSAW୳հഗ ■ ࿮ᇸഗॲ)ۉፆĂۉߌࢅۉඹ* ■ ᆶᇸ୳հഗ)ۉፆĂۉඹࢅሏݣ* ■ ਸ࠲ۉඹ୳հഗ)ᆩCMOSਸ࠲ࢅۉඹൽپۉፆ* ■ ຕጴ୳հഗ)૧ᆩຕኵऺ໙ํ၄Lj੗ీுᆶܔᆌڦ! ! ఇెഗॲ* ሞणׯۉୟዐLjڇژມዀਸ࠲૧ᆩCMOSਸ࠲ํ၄Ljᆯݥ ዘ۠ڦມ၎้ዓൻۯLjස཮3.55ăྺ๑ኄዖरຍᆶၳLjਸ ࠲ՂႷਏᆶݥ׉گڦڞཚۉፆࢅݥ׉ߛڦ࠲܏ۉፆLjܸ CMOSरຍኟࡻీ༵ࠃኄᄣڦਸ࠲ă ਸ࠲ۉඹڦCMOSํ၄ݛ݆ ૧ᆩኄዖڪၳڦਸ࠲ۉඹۉፆLj੗ᅜํ၄Ⴙܠدཥڦ࿮ᇸ ࢅᆶᇸ୳հഗದዃă཮3.56၂๖କᅃ߲ڇटۅ࿮ᇸRC୳ հഗतഄڪၳڦਸ࠲ۉඹ୳հഗăRC୳հഗڦ-3 dBೕ୲ ྺ1/(2πR1C1)ăܔᇀਸ࠲ۉඹ୳հഗLj f3dB = fsC1/(2πC2) ࿮ᇸRCྪஏڦڪၳਸ࠲ۉඹ ૧ᆩ཮3.54໯๖ڦۉࢁገᅎ߁౒Lj੗ᅜๆݴൣؤںକ঴ਸ࠲ ۉඹ؊ړۉፆڦएԨ߁౒ăසࡕۉඹٗV1ൎ࣑዁V2Ljሶॽ݀ ิຨ้ۉࢁገᅎLjΔQ = C(V1 - V2)Ljۉࢁୁ෇ईୁ؜V2ăഄ ዐԈࡤڦ्ยཉॲ๟Cுᆶز૴ۉፆLjܸ൐V1ࢅV2ྺ૙ၙۉ უᇸăසࡕ޿ਸ࠲ᅜగᅃ้ዓೕ୲fs)ዜ೺ྺT*ઠ࣮ਸࢇLjሶ V1ᇑV2ኮक़ॽᆶᅃ߲ೝ਩ۉୁiୁࡗLji =ΔQ/T = CAV/Tă༵ ࠃཞᄣٷၭೝ਩ۉୁڦڪၳۉፆ“R”ྺǖ “R” =ΔV/i = T/C = l/(Cfs) ཮3.55཮3.53 ཮3.54 ཮3.56 ਸ࠲ۉඹĐۉፆđ Rev. A | Page 18 of 21 ᆌᆩԴऻ AN-282 ൩ጀᅪLjܔᇀਸ࠲ۉඹ୳հഗLjټ੻ൽਦᇀ֑ᄣ໏୲ࢅۉ ඹኵኮԲăྺ๑้क़֑ᄣࢅۉࢁࠌၛڦᆖၚፌၭLjՂႷፔ ؜ᅃ߲ዘᄲ्ยLjनfs>>f3dB)ཚ׉ᄲ൱50ڟ100Ԡ*ăᅺُLj ړ๑ᆩਸ࠲ۉඹ୳հഗ߁౒้Ljଣহೕ୲ᆯۉඹԲࢅ֑ᄣ ้ዓೕ୲ਦۨLjܾኁ਩੗ᅜݥ׉৛ඓ൐࿮೏ᅎă ֑ᆩਸ࠲ۉඹ୳հഗ৊ႜᅼೕࢅᇕᅼ୳հLj੗ᅜٷٷ३ၭ ࿮ᇸഗॲڦ࿿૙؅٫ăࠓॺᅼೕ୳հഗ้Ljැᄲ๑ᆩࢇ૙ ٷၭڦڇႊೌۉඹ)ሀ10 pF*Ljሶᄲ൱ۉፆሞ10 MΩຕଉपă ᅜ100 kHz໏୲ൎ࣑ᅃ߲1 pFۉඹ੗ᅜൟ຿ํ၄޿ۉፆኵLj ໯Ⴔࡂ௬ओሀྺ0.01 mm2ăසࡕ๑ᆩܠৗࡂईકොरຍઠ ํ၄10 MΩۉፆLjሶ໯Ⴔ௬ओ዁ณᄲٷ100Ԡă ਸ࠲ۉඹ୳հഗڦᆫ๞ ■ ୳հഗټ੻ᇑۉඹԲׯԲ૩Ljܸփ๟ᇑਨܔኵׯ! ! Բ૩ ■ ୳հഗټ੻ໜ้ዓೕ୲ܸՎࣅ ■ ၟঢ়ۆఇె୳հഗᅃᄣۨᅭ ■ ᅼೕೕ୲ᄲ൱گኵۉඹǖᅜ100 kSPSൎ࣑ 1 pFۉඹڪၳᇀ10 MΩۉፆ ■ ݥ׉๢ࢇDSP CMOS߾ᅝ ਸ࠲ۉඹۉፆᇑഄ໲ۉඹࢅሏݣᅃഐ๑ᆩLj੗ᅜํ၄دཥ RCᆶᇸ୳հഗዐ๑ᆩڦႹܠۉୟದዃăᇑຕጴ୳հഗփ ཞLjਸ࠲ۉඹ୳հഗྜඇ੗ᅜၟఇె୳հഗᅃᄣۨᅭă཮ 3.58၂๖କᅃ߲ᅃ঩૶Ⴤ้क़ᆶᇸگཚRC୳հഗतഄܔᆌ ڦਸ࠲ۉඹ୳հഗă ਸ࠲ۉඹ୳հഗܔఇె႑ࡽ৊ႜ֑ᄣLjᅺُཚ׉ՂႷമዃ ૶Ⴤ้क़ੇं۠୳հഗLjᅜၩأలઊຯ༬ೕ୲ᅜฉڦೕ೷ ׯݴăᆯᇀਸ࠲ۉඹ୳հഗڦ֑ᄣ໏୲ཚ׉ᇺߛᇀഄཚ ټLjᅺُᅃ߲ڇटۅईມटۅRC୳հഗཚ׉৽ీٳڟฉຎ ణڦă ྺକܔۉᇸ၍ሯำڪ߅ඡ႑ࡽํႜ؊ݴڦࠌఇᅞ዆Ljఇె ۉୟঢ়׉๑ᆩֶݴݣٷഗăਸ࠲ۉඹ୳հഗڦยऺᄺ੗ᅜ ๑ᆩኄၵᇱሶă཮3.59၂๖କᅃ߲ᆶᇸֶݴओݴഗतഄڪ ၳڦਸ࠲ۉඹăأକీ༵ࠃܔሯำڦଆࡻࠌఇᅞ዆Բ (CMRR)ኮྔLjֶݴದዃ࣏ీܔਸ࠲֡ፕᆅഐڦຨՎํႜ ࠌఇᅞ዆ăਸ࠲ۉඹओݴഗঢ়׉ᆩᇀΣ-Δ႙ADCڦۙ዆ഗ ۉୟዐLjኄॽሞࢫ௬ڦჺ༪ࣷᇎᅜ༪ஃă ᆶᇸֶݴओݴഗतഄڪၳਸ࠲ۉඹ୳հഗ Sin(x)/xೕ୲ࡐইၳᆌ ዘࠓDACڦ๼؜੗ᅜႚၡں՗๖ྺᅃဣଚਈႚஞ؋Ljഄ੻ ܈ڪᇀ߸ႎ໏୲ڦڛຕLjස཮3.52໯๖ă൩ጀᅪLj၎ܔᇀ گೕኵLjዘࠓ႑ࡽሞలઊຯ༬ೕ୲ट၌้گ3.92 dBăᆶ้ ሞDACኮࢫݣዃᅃ߲ݒၠsin(x)/x୳հഗLjᅜၯኟُၳᆌă SIN X/Xࡐই ཮3.59 ཮3.58 ཮3.57 Rev. A | Page 19 of 21 ᆌᆩԴऻ AN-282 ਸ࠲ۉඹ୳հഗᄺᆶܠዖਆ၌Ⴀࢅဃֶᇸă໲ኻీሞᅼೕ ټ੻ా๑ᆩLjᅺྺ૧ᆩణമڦCMOSरຍ࣏փీൟ຿ںํ ၄ຕӥkHzᅜฉڦ֑ᄣ໏୲ăਸ࠲ۉඹࢅሏݣࣷᆅ෇ໜऐ ሯำLjႅ୑ۉୁሶ੗ీׂࣷิ฿ۙဃֶăઠጲਸ࠲Ԩวڦ ้ዓઍཚ੗ీׂࣷิཞօဃֶăፌࢫLjᆯᇀਸ࠲ۉඹ୳հ ഗ๟֑ᄣഗॲLjᅺُྺକݞኹं۠ᆅഐဃֶLjཚ׉ᄲ൱ড ٷڦࡗ֑ᄣԲă ֖੊࿔၅ 1. Frederic J. Harris, "On the Use of Windows for Harmonic Analysis with the Discrete Fourier Transform", IEEE Proceedings, Vol. 66, No. 1, Jan. 1978, pp. 51-83. 2. Joey Doernberg, Hae-Seung Lee, David A. Hodges, "Full Speed Testing of A/D Converters", IEEE Journal of Solid State Circuits, Vol. SC-19, No. 6, Dec. 1984, pp. 820-827. 3. James R. Andrews, Barry A. Bell, Norris S. Nahman, and Eugene E. Baldwin, "Reference Waveform Flat Pulse Generator", IEEE Transactions on Instrumentation and Measurement, Vol. IM-32, No. 1, March 1983, pp. 27-32. 4. Brendan Coleman, Pat Meehan, John Reidy and Pat Weeks, "Coherent Sampling Helps When Specifying DSP A/D Converters", EDN, October 15, 1987, pp. 145-152. 5. Howard K Schoenwetter, "A Programmable Voltage Step Generator for Testing Waveform Recorders", IEEE Transactions on Instrumentation and Measurement, Vol. IM-33, No. 3, Sept. 1984, pp. 196-200. 6. Robert W. Ramirez, The FFT: Fundamental and Concepts, Prentice-Hall, 1985. 7. R.B. Blackman and J.W. Tukey, The Measurement of Power Spectra, Dover Publications, New York, 1958. 8. James J. Colotti, "Digital Dynamic Analysis of A/D Conversion Systems Through Evaluation Software Based on FFT/DFT Analy sis", RF Expo East 1987 Proceedings, Cardiff Publishing Co., pp. 245-272. 9. Sid Kaufman, "Multistage Error Correcting A/D Converters", Electronic Products, April 18, 1983, pp. 103-110. 10. HP Journal, Nov. 1982, Vol. 33, No. 11 11. HP Product Note 5180A-2. 12. HP Journal, April 1988, Vol. 39, No. 2. 13. HP Journal, June 1988, Vol. 39, No. 3. 14. Dan Sheingold, Editor, Analog-to-Digital Conversion Handbook, Third Edition, Prentice-Hall, 1986. ਸ࠲ۉඹ୳հഗڦਆ၌Ⴀࢅဃֶᇸ ■ ਆ၌ᇀডگೕ୲ ■ ሯำĂ฿ۙĂ฿ኈ ■ ՂႷፏٗలઊຯ༬֑ᄣ݆ሶ ■ ਸ࠲Ԩวࣷڞዂ้ዓઍཚ)ᄲ൱ੇं۠୳հഗDž ཮3.60 Rev. A | Page 20 of 21 ᆌᆩԴऻ AN-282 15. W.R. Bennett, "Spectra of Quantized Signals", Bell System Technical Journal, No. 27, July 1948, pp. 446-472. 16. G.A. Gray and G.W. Zeoli, "Quantization and Saturation Noise Due to Analog-Digital Conversion", IEEE Transactions on Aerospace and Electronic Systems, Jan. 1971, pp. 222-223. 17. M.J. Tant, The White Noise Book, Marconi Instruments, July 1974. 18. W.A. Kester, "PCM Signal Codecs for Video Applications", SMPTE Journal, No. 88, November 1979, pp. 770-778. 19. Lawrence Rabiner and Bernard Gold, Theory and Application of Digital Signal Processing, Prentice-Hall, 1975. 20. Matthew Mahoney, DSP -Based Testing of Analog and Mixed-Signal Circuits, IEEE Computer Society Press, Washington, D.C., 1987. 21. IEEE Trial-Use Standard for Digitizing Waveform Recorders, No. 1057-1988. 22. Richard J. Higgins, Digital Signal Processing in VSLI, Prentice-Hall, 1990. 23. High Speed Design Seminar, Analog Devices, 1990. 24. M. S. Ghausi and K R. Laker, Modern Filter Design: Active