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AN-1026 ᆌᆩԴऻ
AN-1026 ᆌᆩԴऻ One Technology Way t P.O. Box 9106 t Norwood, MA 02062-9106, U.S.A. t Tel: 781.329.4700 t Fax: 781.461.3113 t www.analog.com ߛֶݴADCൻۯഗยऺ୯ ፕኁǖJohn Ardizzoni ० ܠຕ၄ߛپႠీADCۼ૧ᆩֶݴઠᅞࠌఇሯำत߅ ඡLjॽۯༀߛ༵ྷݔ2ԠLjժཚࡗೝ࢚႑ࡽ༵ߛጺ༹Ⴀ ీă࠶ݴֶټڦADCᅜথ܋ڇ႑ࡽLjڍሞ ֶݴ႑ࡽ้LjADCڦႠీ֍ీڟٳፌॅጒༀăADCൻ ۯഗ—ཚยऺᆩᇀ༵ࠃُૌ႑ࡽۉڦୟ—ኴႜܠዖዘᄲ ࠀీLjԈઔ܈ޗݣĂ܋ڇ-ֶݴገ࣑Ă࣐؋Ăࠌఇ฿ۙۙ ኝĂ୳հڪăጲAD8138ླྀᅜઠLjֶݴADCൻۯഗᅙׯ ྺຕ֑णဣཥዐՂփณڦ႑ࡽۙᇮॲă RF1 VIN, dm VA RG2 VOUT, dm VA ֶఇۉუ VIN, dmᅜतࠌఇۉუ VIN, cmݴ՚ᆯڪ๕1 ࢅڪ๕2ۨᅭă VIN, dm = VIP – VIN (1) VIP + VIN 2 (2) VON – VOCM – VIN ᇀူ࿔༪ஃႴᄲLjሞُံඓᅃၵۨᅭăසࡕೝ࢚ ႑ࡽLjV IPࢅV INᅜࠌཞएጚۉუྺ֖ቷLjഄఁᅭ܈ޗ၎ ڪĂ၎࿋၎ݒăړ܋ڇ႑ࡽ้Ljᅃ߲ۉ܋უࠦ ۨLjଷᅃ܋ሶᅺഄܸՎࣅăଇዖ൧ူLj႑ࡽ ۨᅭྺVIP – VINă VIN, cm = VOP + RF2 08263-001 + VIP RG1 Jonathan Pearson 1. ֶٷݣݴഗ 1๖ྺᅃዖएԨڦඇֶۉݴუݒઍADCൻۯഗă ९Ljഄᇑدཥڦሏ໙ٷݣഗݒઍۉୟ٪ሞଇֶۅᅴăֶݴ ADCൻۯഗܠᅃ߲ᆅগ(VON)ࢅᆅগ(VOCM)ăॽ႑ ࡽথݴֶټڦ܋ADC้Ljኄၵᆅগټઠटڦٷଳ ऄႠă ֶݴADCൻۯഗׂิڦփ܋ڇ႑ࡽLjܸሞVOPࢅ VONኮक़ᅜVOCMྺׂ֖ิೝֶ࢚ݴ႑ࡽă(P๖ኟ टLjN๖टă)܋VOCMᆩᇀ੦ࠌఇۉუăኻ ᄲᇑتᇀ߳ጲ၌܈ኮాLjࠌఇۉუᅃۨڪᇀ ᆌᆩᇀVOCMۉڦ܋უăݒઍࢅߛਸ࣍ሺᅮࣷ๑VA+ ࢅVA–ଇ߲ٷݣഗᆅগۉڦتუํाฉ၎ڪă ܔᇀೝ࢚႑ࡽLjࠌఇۨᅭᅃణକLj܋ڇܔڍ ႑ࡽཞᄣᆶၳă ۉუཞᄣᆶֶఇࢅࠌఇଇዖLjݴ՚ᆯڪ๕3ࢅڪ๕4ۨ ᅭă VOUT, dm = VOP – VON VOUT, cm = VOP + VON 2 (3) (4) ൩ጀᅪํाࠌఇۉუVOUT, cmᇑVOCMᆅগኮֶLjࢫ ኁᆩᇀඓۨࠌఇۉೝă ݴဆֶݴADCൻۯഗԲݴဆدཥሏ໙ٷݣഗᄲްሗܠڥă ྺକ०ࣅپຕ๕Ljփۨݟᅭଇ߲ݒઍᅺጱβ1ࢅβ2Ljසڪ๕ 5ࢅڪ๕6๖ă β1 = RG 1 RF 1 + RG 1 (5) β2 = RG 2 RF 2 + RG 2 (6) Rev. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2009 Analog Devices, Inc. All rights reserved. www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ ణ ० .................................................................................................... 1 ሯำ .................................................................................................... 7 Ⴊ۩૦๏ ........................................................................................... 2 ۉᇸۉუ!.......................................................................................... 9 ! ॽᆅগ܋থADCൻۯഗ ........................................... 3 ၿհ฿ኈ ......................................................................................... 10 ! ࠌఇۉუ(ྷݔICMVR) ................................................ 5 ࢅټუӦ୲ ................................................................................ 11 ! ࢅ᳘ࢇǖୁईୁ ........................................... 6 ࿘ۨႠ ............................................................................................. 11 ! Ӧ ޗ................................................................................... 7 PCBۉୟӱքਆ! ........................................................................... 12 Ⴊ۩૦๏ 200911ሆ——ӲԨ0ǖ؛๔Ӳ Rev. 0 | Page 2 of 16 www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ! ሞܠຕADCൻۯᆌᆩዐLjβ1 = β2LjڍᅜVIPĂVINĂVOCMĂβ1 ࢅβ2ྺᅺጱLjVOUT, dmڦᅃӯԿ࣍ڪ๕ᆩᇀକβ฿ದස ࢆᆖၚႠీڦăڪ๕7๖VOUT, dmڪ๕Ԉઔٷݣഗᆶ၌ೕ୲ ᅈડႠLjਸ࣍ۉუሺᅮA(s)ă [ VOCM ( β1-β2 )+VIP (1-β1 ) - VIN (1-β2 ) 2 2 β1+β2 1+ 1 2 A(s)(β +β ) ] (7) ړβ1 ≠ β2้LjֶݴۉუൽਦᇀVOCMLjኄዖࡕժփ ၙLjᅺྺࣷሞֶݴዐׂิ฿ۙࢅࡗଉሯำăۉუݒ ઍࠓڦሺᅮټओྺຕăᆶڦLjሺᅮټओዐڦ ሺᅮྺଇ߲ݒઍᅺጱೝኵڛڦຕă ړβ1 = β2 ≡ β้Ljڪ๕7०ࣅྺ8ă [ ] RF 1 1+ (8) 1 A(s)(β ) RG RIN, dm ኄ߲ڪ๕߸ྺᄅຄǗړA(s) → ∞้LjၙԿ࣍ሺᅮ०ࣅྺ RF/RGăሺᅮټओཞᄣᄅຄLjሯำሺᅮڪᇀ1/βLjᇑدཥ ሏ໙ٷݣഗᅃᄣă ದݒઍᅺጱֶݴADCൻۯഗڦၙԿ࣍ሺᅮසڪ๕9 ๖ă Av = ADCൻۯഗڦۉፆLjஃຌᇀֶ࣏ݴ܋ڇႠዊLjۼ ՂႷٷᇀईڪᇀణՔۉ܋ፆLjᅜՍཁेᅃ߲ۉ܋ፆRTᇑݣ ٷഗ܋ժLjᅜइڥႴۉፆăሞُت୯߳ڦ๖૩ ዐLjᆶADCൻۯഗ֑ᆩೝ࢚ݒઍԲยऺLjස2 ๖ă VOUT,dm RF = VIN,dm RG (9) RG ೝ࢚ဃֶ=20log 10 [ ΔV out,dm ] RF 2. ֶٷݣݴഗፆੇ ᆯᇀݒઍ๑ٷݣഗଇ߲܋ኮक़ۉڦუՎׯଭLjᅺ ُLjଇ߲ྺ܋ႵথLjֶݴۉፆRINৈྺ2 × RGă ྺକದد၍ۉፆRLLjॽۉፆRT)ཚࡗڪ๕11ऺ໙*ڥ ዃᇀֶݴฉă3๖ྺۆ႙ۉፆRF = RG = 200 ΩLjణ ՔRL, dm = 100 Ω RT = 133 Ωă ፕྺֶݴADCൻۯഗڦዘᄲႠీኸՔኮᅃڦೝ࢚Ԉઔ ଇ߲ևݴǖ܈ޗೝ࢚ࢅ၎࿋ೝ࢚ă܈ޗೝ࢚࢚ଉଇ߲ ሞ܈ޗฉڦದڦ܈ײᅃၜኸՔǗሞၙٷݣഗዐLjܾ ኁඓದă၎࿋ೝ࢚ኄၜኸՔኼሞ࢚ଉଇ߲ڦ ၎࿋ֶ180°ڦਐă܈ޗई၎࿋ැ٪ሞ฿࢚Lj ࡕࣷሞዐׂิփଆࠌఇݴׯăೝ࢚ဃֶ)ڪ๕ 10*ྺֶݴ႑ࡽׂิڦࠌఇۉუᇑཞᅃ႑ࡽׂ ิڦֶఇۉუኮܔຕԲLjڇ࿋ྺݴԞă ΔVOUT,cm VOCM RT = 1 1 1 R L R IN (10) 200 200 RL, dm = 100 RT 200 (10) ాևࠌఇݒઍ࣍ୟ೨๑VOUT, cmڪᇀᆌᆩᇀVOCMۉڦუLj ࡕׂิଆࡻڦೝ࢚ă Rev. 0 | Page 3 of 16 VOCM RT = 200 1 1 100− − 1 400− 3. ದ 100 Ω ၍ୟ www.BDTIC.com/ADI = 133− 08263-003 [ ] VOUT,dm R = F VIN,dm RG ADCൻۯഗཚᆩሞتߛ႑ࡽڦဣཥዐăਐࡗג႑ ࡽհᅃၭևڦݴഗॲՂႷཚࡗፆੇ੦ۉڦഘد၍၎ Ljᅜݞኹ฿႑ࡽྜኝႠăدړ၍ଇ܋ᅜഄ༬Ⴀፆ ੇ܋থ้LjइڥፌॅႠీăൻۯഗᅃӯዃᇀADCৎLj ᅺُଇኁዐक़փႴᄲ੦ፆੇথǗܸLj६ᇀADCൻ ۯഗڦ܋႑ࡽথডLjՂႷ๑ᆩᅃ߲੦ፆੇ থLjժӀۉړፆႜ܋থă 08263-002 [ ] VOUT,dm= ॽᆅগ܋থADCൻۯഗ AN-1026 ᆌᆩԴऻ ܋থ܋ڇᄲݑႹܠă4ቛ๖କADCൻۯഗሞ܋ڇ तֶݴ߾ڦူፕݛ๕ă ૧ᆩڪ๕12໙܋ڇۉፆ267 Ωăߵڪ๕13ኪLj ᄲ๑267 Ωڦۉፆই50 ΩLjժۉፆRTᆌྺ61.5 Ωă 3.5V RT = 2.5V 1.5V RG 500 VOCM RG 500 RF 500 1.75V 1.25V 0.75V 200 3.5V 50 08263-004 2.5V 1.5V 200 RT 61.5 2V p-p ૧ᆩڪ๕3ࢅڪ๕4Lj ڥVOP = VOCM + VIN/2Lj±1 Vཞ၎Ӧ ۯሀ2.5 VăVON = VOCM – VIN/2Lj±1 Vݒ၎Ӧۯሀ2.5 Văᅺ ُLjVA+ࢅVA−ሞ±0.5 VူሀӦۯ1.25 VăՂႷᆯVIN༵ࠃۉڦ ୁڦୁ(ྺݴׯ2 V – 0.5 V)/500 Ω = 3 mALjᅺُLjՂႷ ದڦথۉںፆ)ٗVINੂࡗඁ*ྺ667 Ωă ( RG RF 12 × ( RG + RF ) ) (12) 200 ۉୟߴටڼڦᅃᆇၡྜኝLjڍৈฉ࿋ۉፆRG৽ཁेକ ᅃ߲61.5 Ωڦ࿄ದۉፆLjᇑ50 Ωۉፆժăኄࣷ߀Վሺᅮ त܋ڇۉፆLjժ๑ݒઍᅺጱ฿ඁದăܔᇀၭሺᅮLj ۉፆڦՎࣅডၭLjሡ้ࢮփऺLjݒڍઍᅺጱධ ՂႷڟڥದăፌ०݆ݛڦڇߴگ࿋ۉፆRGሺेۉፆă 7๖ྺᅃዖྼٻౢڪၳۉୟLjഄዐLjമຎժፇࢇ؊ ړᇸۉፆă RTH 27.6 VTH 1.1V p-p 7. ྼٻౢڪၳᇸ ሞ༺ۉپୟዐLjၠگ࿋࣍ୟሺेକᅃ߲27.6 ΩۉፆRTSLjᅜ . Սದ࣍ୟݒઍᅺጱLjස8๖ă ኄऺ໙ۉ܋ፆڼڦᅃօăܸLjႴᄲጀᅪڦLj߳ٷݣ ഗሺᅮڪ๕एᇀፆੇᇸྺଭ्ڦยăړ٪ሞᆯ܋ڇ ڞዂڦ฿้࢚LjՂႷ၎ದڦᆶၳᇸፆੇኻࣷߴฉ࿋ ۉፆRGሺेۉፆăྺԍೝ࢚LjՂႷߴگ࿋ۉፆRGሺेۉ ፆLjڍኄᆼࣷᆖၚሺᅮă ሞ܋থ܋ڇ႑ࡽ้֑ᆩԿ๕Ljྺ߸݆پ۞ڍ ᆩăሞᅜူ๖૩ዐLj۞ڦ݆پፕᆩ߸े၂ă RF 200 RTH 27.6 VTH 1.1V p-p RG 200 2.5V RTS 27.6 RF 200 8. ೝ࢚܋܋ڇटۉୟ 2.5V 200 VON – VOUT, dm + VOP VOCM 200 08263-005 200 200 5. ܋ڇፆੇ Rev. 0 | Page 4 of 16 VOCM RG 200 5ዐLjྺԍگሯ܈LjႴᄲᅃ߲ኵྺ1܋ڇڦገֶݴሺ ᅮLjᅃ߲50 Ωڦᆅগᅜतኵথৎ200 Ωڦැ߅ݒઍۉፆ ࢅሺᅮۉፆă 267 VON – VOUT, dm + VOP 6. ټᇸۉፆࢅۉ܋ፆۉ܋ڇڦୟ ሞ߳࣍ୟݒઍᅺጱ၎ದ้Ljඓۨ܋ڇۉፆڦཚᆩࠅ ๕ྺڪ๕12LjഄዐLjRIN, seྺ܋ڇۉፆă RIN ,se = VOCM 200 4. ADCൻۯഗ܋ڇڦ๖૩ ྺ܋ڇႠዊLjڍVIN, dmධڪᇀVINăᆯᇀۉፆRFࢅRG ၎ڪೝ࢚Ljࠤྺڇ࿋ሺᅮLjֶݴVOP − VONڪᇀ Ljन4 V p-păVOUT, cmڪᇀVOCM = 2.5 VǗઠጲݒگઍۉୟ ڦଇ߲ۉუVA+ࢅVA−ڪᇀ VOP/2ă 2.5V 08263-006 –2V www.BDTIC.com/ADI VON – VOUT, dm + VOP 08263-008 2.5V 6๖ۉୟߴକᇸۉፆࢅۉ܋ፆăړᇸۉፆኵྺ50 Ω้Lj ᇸۉፆڦਸୟۉუྺ2 V p-păړᇸۉፆ܋থᇀ50 Ω้Lj ۉუইྺ1 V p-pLjኵཞ้ྺڇ࿋ሺᅮൻۯഗݴֶڦۉ უă VON – VOUT, dm + VOP VIN 0V (13) 08263-007 RF 500 2V 1 = 61.5 1 1 − 50 Ω 267 Ω AN-1026 ᆌᆩԴऻ! ጀᅪLj1.1 V p-pྼٻڦౢۉუٷᇀ1 V p-pڦኟඓ܋থۉუLj ߲߳ሺᅮۉፆڦኵሺे27.6 ΩLjࡕইگକԿ࣍ሺᅮăሞ ۉٷፆ(>1 kΩ)ࢅၭሺᅮ)1ई2*ڦ൧ူLjኄዖݒၠፕᆩ၎ ࢻڸၩLjڍሞၭۉፆईߛሺᅮ൧ူLjժփీྜඇڸၩă ړԿ࣍ሺᅮྺ1ई2้Ljُتຎپ۞݆ݛᅃْनăܔᇀ ߸ߛሺᅮLjRTSڦኵথৎRGLjߵڪ๕18໙ڦRIN, seኵᇑߵ ڪ๕12൱ڦڥኵኮֶॽՎٷăኄૌ൧Ⴔᄲႜ۞ْܠ پă ၄ሞLj்ᅜൟݴںဆ8๖ۉୟLjഄֶݴۉ უ૧ᆩڪ๕14ऺ໙ă ኄ߲ඪခփ໙ड़ǖፌৎ݀քٷݣݴֶڦഗऺ໙ഗ߾ਏ ADIsimDiffAmp™तADI Diff Amp Calculator™ᅜڅᆶ ݏዘહۯLjৈႴຕ௱नྜׯᅜฉऺ໙ăᆶ࠲߸ܠ႑တLj ൩֖ੂwww.analog.comă ( VOUT ,dm = 1.1Vp - p ) 200 Ω = 0.97Vp - p 227.6 Ω (14) ֶݴۉუժ࿄ྜඇتᇀ1 V p-pڦၙೝLjڍཚࡗႪ ߀ݒઍۉፆઠ܀૬ܔሺᅮႜፌዕۙኝLjසڪ๕15๖ă 227.6 Ω ( ( ) Desired VOUT,d = 1.1Vp - p (15) 1.0Vp - p = 206.9 Ω 1.1Vp - p ) 9ቛ๖ڦྜኝۉୟLj֑ᆩՔጚ1%ۉፆኵă RF 205 RIN, se RS 50 Vacm V A± = RG 200 RT 61.9 RTS 28 VOCM 2.5V RG 200 RF 205 VON – VOUT, dm + VOP 9. ྜኝ܋܋ڇटۉୟ ֖ቷ9LjᅺRFࢅRGଇ߲ۉፆ݀ิՎࣅLjൻۯഗ܋ڇڦ ۉፆRIN, seᄺໜኮՎࣅăൻۯഗڦሺᅮۉፆሞฉ࿋࣍ୟዐྺ 200 ΩLjူ࿋࣍ୟዐྺ200 Ω + 28 Ω = 228 Ωăሞփཞڦሺᅮ ۉፆኵူLjऺ໙RIN, seံႴᄲऺ໙ଇ߲βኵLjݴ՚සڪ๕ 16ࢅڪ๕17๖ă RG 200Ω β1 = = = 0.494 RF + RG 405Ω β2 = RG + RTS 228Ω = = 0.527 RF + RG + RTS 433Ω RG ( β1 + β2 ) = 271Ω β1 ( β2 + 1) A Q2 Q1 (16) ഄࡕᇑፌ؛໙ڦ267 Ωֶ՚փٷLjܔRTփׂࣷิڦٷᆖ ၚLjᅺྺRIN, seᇑRTຌᇀժ࠲ဣă සࡕႴᄲ߸ेඓڦጺሺᅮLj๑ᆩ߸ߛۉڦ܈ፆࢅز ۙኝۉፆă Q3 Q4 +IN 10. ०ࣅӲֶٷݣݴഗ(ೋᅎ႙ICMVR) (17) (18) (20) ጀᅪLjVA๔ዕ႑ࡽڦၭӲԨ(ස4๖)ăࠌ ఇۉუྷݔᅺٷݣഗڦૌ՚ܸᅴăADIߛֶݴADCൻۯ ഗᆶଇዖपದዃLjݴ՚ྺዐ႐႙ࢅೋᅎ႙ăዐ႐႙ ADCൻۯഗڦ߲ࠃۼࡆۉᆶሀ1 Vڦᇧଉ(ᅺܸྺዐ႐ ႙)ăೋᅎ႙पሺेକଇ߲ৗ༹࠶LjᅜሎႹ܋ଉ ੍ৎ–VSࡆӦۯă10๖ྺᅃዖۆ႙ٷݣݴֶڦഗڦ० ࣅ๖ᅪ(Q2ࢅQ3)ă –IN ۉፆRIN, seऺڦ໙݆ݛසڪ๕18๖ă RIN，N，= 2 β 1 β 2VOCM + VIP β 1 (1 - β 1 ) + VIN β 1 (1 - β 2 ) (19) β1 + β 2 Vacm V A± = V IN ,CM + β (VOCM - V ICM ) 08263-009 2V p-p ICMVRࡀۨᆌᆩᇀֶٷݣݴഗܸ܋փᆖၚኟሏႜ ۉڦუྷݔăኄၵ܋၄ۉڦუྺICMVĂVacm ईVA±ăڍኄᅃࡀ߭ঢ়ԥဃăፌ९ڦઓవඓֶۨ ٷݣݴഗํڦ܋ाۉუLjᆮഄ၎ܔᇀۉუܸ ჾăሞᅙኪVIN, cmĂβࢅVOCMෙ߲Վଉڦ൧ူLj໙ݣ ٷഗۉუ(VA±)Lj߳βփ้ڪ๑ᆩཚᆩڪ๕19Lj߳β၎ڪ ้๑ᆩ०ࣅڪ๕20ă 08263-010 RF = 227.6 Ω ࠌఇۉუ(ྷݔICMVR) ೋᅎ႙ࠓሎႹֶٷݣݴഗتມटႠ႑ࡽLjन ๑ٷݣഗᆯۉڇᇸൻۯᄺසُLj༬՚ࢇ֑ᆩۉںუई ۉںუᅜူۉڇڦᇸᆌᆩă܋ሺेڦPNPৗ༹࠶ (Q1ࢅQ4)ॽၠֶܔݴೋᅎᅃ߲ৗ༹࠶Vbeă૩සLjැ –INᆌᆩۉუྺ–0.3 VLjሶAྺۅ0.7 VLj๑ֶܔݴᅜኟሏ ႜăැPNP(ዐ႐႙प)LjA–ۅ0.3 Vۉڦუࣷ๑NPNֶ ݒิ݀ܔݴၠೋዃLjժዐኟሏႜă Rev. 0 | Page 5 of 16 www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ 1. ߛADCൻۯഗࡀ߭ ۉᇸۉუ(V) ADCൻۯഗ ICMVR VOCM ׂ႙ࡽ AD8132 AD8137 ټ (MHz) 350 76 უӦ୲ (V/μs) 1200 450 ሯำ (nV) 8 8.25 ±5 V –4.7+3 –4+4 +5 V 0.33 1 to 4 +3.3 V 0.31.3 12.3 +3 V 0.31 12 ±5 V ±3.6 ±4 +5 V 13.7 14 +3.3 V N/A 12.3 +3 V 0.31 12 ೋࠃ ڦࡆۉ Ӧޗ (V) ±1 ࡆࡆڟ AD8138 AD8139 320 410 1150 800 5 2.25 –4.7+3.4 –4+4 0.33.2 14 N/A N/A N/A N/A ±3.8 ±3.8 13.8 13.8 N/A N/A N/A N/A ±1.4 ࡆࡆڟ 20 25 ADA4927-1/ ADA4927-2 ADA4932-1/ ADA4932-2 ADA4937-1/ ADA4937-2 ADA4938-1/ ADA4938-2 ADA4939-1/ ADA4939-2 2300 5000 1.4 –3.5+3.5 1.33.7 N/A N/A ±3.5 1.53.5 N/A N/A ±1.2 20 1000 2800 3.6 –4.8+3.2 0.23.2 N/A N/A ±3.8 1.23.2 N/A N/A ±1 9 1900 6000 2.2 N/A 0.33 0.31.2 N/A N/A 1.23.8 1.22.1 N/A ±0.9 40 1000 4700 2.6 –4.7+3.4 0.33.4 N/A N/A ±3.7 1.33.7 N/A N/A ±1.2 37 1400 6800 2.3 N/A 1.13.9 0.92.4 N/A N/A 1.33.5 1.31.9 N/A ±0.8 37 ࢅ᳘ࢇǖୁईୁ Ⴔᄲୁ᳘ࢇ࣏ୁ᳘ࢇీݴֶܔADCൻۯഗڦስ ഐጣዘᄲڦᆖၚă᳘ࢇࢅ᳘ࢇଇዖ൧ᆶփཞڦ ୯ă ୁ᳘ࢇपස11๖ă RF CIN RG CIN RG 08263-011 VOCM RF 11. ୁ᳘ࢇADCൻۯഗ ܔᇀټୁ᳘ࢇݴֶڦ܋ገֶݴᆌᆩLj၄ሞٷݣഗ ᆅগڦتୁࠌఇۉუڪᇀୁࠌఇۉუLjᅺྺ ۉඹፆକୁݒઍୁۉăཞ้Ljୁူݒڦઍᅺጱ ၎ࢻದྜඇᇑڇ࿋ኵ၎ڪăVOCMतୁࠌఇۉუ ཚยዃሞۉᇸۉუᅃӷৎă֑ᆩዐ႐႙ࠌఇྷݔ ڦADCൻۯഗሞኄૌᆌᆩዐ߾ፕଆࡻLjഄࠌఇۉუথ ৎՔۨڦྷݔዐ႐ă ୁ᳘ࢇ܋ڇገֶݴᆌᆩᇑֶݴᆌᆩ၎ຼLjڍሞٷݣ ഗᆅগتᆶࠌఇ࿖հLjྺ႑ࡽڦၭݴଉă֑ᆩ ዐ႐႙ࠌఇڦྷݔADCൻۯഗॽࠌఇۉუዃᇀՔ ۨྷݔዐ႐ৎLjྺܠຕᆌᆩዐڦ࿖հ༵ࠃକ؊ፁڦᇧ ଉă ړ᳘ࢇ้LjኵڥጀᅪڦLjټୁ᳘ࢇڦ ADCൻۯഗگࡼࠀڦᇀټୁ᳘ࢇڦૌຼൻۯഗLjᅺ ྺଇ߲ݒઍ࣍ୟዐۼփ٪ሞୁࠌఇୁۉă ୁ᳘ࢇLjړADCᄲ൱ࠌఇۉუᇑൻۯഗڦ܋ ᆩۉუ၎ֶ้ٷLjܔADCൻۯഗڦ܋ႜୁ᳘ ࢇăړVOCMยྺۉᇸۉუᅃӷৎ้LjൻۯഗڦӦޗ ፌٷǗሞൻۯᄲ൱टگࠌఇۉუۉگڦუADC้Ljኄ ࣷټઠᅃ߲࿚༶ăᅃዖ०ڦڇਦӸ݆ॽൻۯഗ܋ ᇑADC܋ኮक़ڦথୁ᳘ࢇഐઠ(ස12๖)Ljᅜ ၩأADCൻۯഗڦ܋ୁࠌఇۉუLjժሎႹၠADC ୁ᳘ࢇᅃ֨ጀࢇࠌڦఇۉೝă૩සLjൻۯഗీ֑ᆩ 5 VۉڇڦᇸLjഄዐVOCM = 2.5 VLjADCీ֑ᆩ1.8 Vڇڦ ۉᇸLjᆌᆩᇀADC CMVڦᄲ൱ࠌఇۉუྺ0.9 Vă RF COUT RG ROUT ADC CMV VOCM ROUT RG RF COUT 12. ټୁ᳘ࢇڦୁ᳘ࢇ Rev. 0 | Page 6 of 16 www.BDTIC.com/ADI TO ADC 08263-012 1ྺADI ADCൻۯഗܠڦዖࡀ֖߭ຕ༵ࠃକ֖LjԈ ઔనၵൻۯഗ֑ᆩକೋᅎ႙ICMVRದዃLjనၵ࿄֑ᆩă ISUPPLY (mA) 12 3.2 AN-1026 ᆌᆩԴऻ! 2ጺକ߳ዖ᳘ࢇतۉᇸፇࢇཉॲူፌ९ڦADC ൻۯഗपૌ႙ăܸLjُૌስփᅃۨፌॅስLj ߲ဣཥۼᆌႜਏ༹ݴဆă VOUT = 2V p-p ႑ࡽ ඪᅪ ܋ڇ ܋ڇ ֶݴ ֶݴ HD2 @ 10MHz HD3 @ 10MHz HD2 @ 30MHz HD3 @ 30MHz –50 –60 –70 –80 –90 –100 –110 –120 1.4 2. ᳘ࢇतपၜ ᳘ࢇ ඪᅪ ୁ ୁ! ୁ ୁ –40 1.6 1.8 2.0 2.2 2.4 2.6 VOCM (V) ۉᇸ ມۉᇸ ۉڇᇸ ۉڇᇸ ۉڇᇸ ۉڇᇸ ૌ႙ ඪᅃ ዐ႐႙ ೋᅎ႙ ዐ႐႙ ዐ႐႙ Ӧޗ ྺକํ၄ADCۯༀڦྷݔፌࣅٷLj႑ࡽႴᄲڟٳADC ڦ܈ޗྷݔăܸLjൻۯADCᆌัྺฉăසࡕ ADCൻܠࡗۯLjీ࣋܋ǗසࡕൻۯփፁLjᆼࣷ ฿ݴՐ୲ăܔADCႜ܈ޗྷݔൻۯժփ๖ٷݣ ഗ܋ՂႷඇྷݔӦۯăֶݴڦዘٷᆫኮᅃሞ ᇀLj߳܋ৈႴӦدۯཥ܋ڇڦ܋ᅃӷăൻۯഗ ܋ᅜᇺࠃࡆۉLjࡕ३ณ฿ኈăڍLj܋ڇൻۯ ഗժݥසُăൻۯഗڦۉუሁথৎࠃࡆۉLjٷݣഗڦ ၍Ⴀ܈ሁֶLj฿ኈሁ၂ă ܔᇀᄲ൱ࡹޚۉუڦᆌᆩLj൩֖९1ዐࡆڟࡆټ ڦ܋ADCൻۯഗLjഄᇧଉٗຕࡹڟޚຕӥࡹޚփڪLjਏ ༹ൽਦᇀሜă 2.8 3.0 3.2 3.4 08263-013 ֑ᆩ܋ڇईֶݴࢅୁ᳘ࢇईୁ᳘ࢇڦມۉᇸဣ ཥLjᅺᇧଉሺेLjሞଇૌपዐۼइڥᆫᅴڦႠీă –20 –30 HARMONIC DISTORTION (dBc) ֑ᆩೋᅎ႙ࠌఇڦྷݔൻۯഗᅃӯሞ֑ᆩۉڇᇸڦ ୁ᳘ࢇဣཥዐࣩ݀ፌٷᆫăഄᇱᅺሞᇀLjࠌఇ ۉუཚࡗݒઍ࣍ୟݴუLjഄՎݴׯీথৎᇀথۉںუ ()ࡆۉăሞ܋ڇ൧ူLj၎࠲࿖հᆖၚLj ࠌఇۉუฯ߸থৎࡆۉă 13. ADA4932ሞփཞೕ୲ူڦၿհ฿ኈᇑ VOCM (ۉᇸۉუǖ5V) 13ቛ๖ڦADA4932ሞփཞೕ୲ူڦၿհ฿ኈᇑVOCMLj ഄۆ႙Ӧྺޗ1.2 V/ࡆăӦྺޗVOCMᇑ႑ࡽVPEAKኮ ࢅ(1 V)ăጀᅪLjۉუࡗג2.8 V้Lj฿ኈࣷथਗሺे(3.8 VPEAK ईԲ5 Vࠃگࡆۉ1.2)ă้܋گLj฿ኈሞ2.2 V(–1 VPEAK)้Lj ධگăࢅټუӦ୲ڦ༪ஃዐ༵ࣷڟૌຼ၄ă ሯำ ADCڦඍ။ԈઔଉࣅሯำĂۉሯำईໜऐሯำᅜतၿհ฿ ኈăፕྺܠຕᆌᆩዐڦዘᄲᅺ໎Ljሯำཚټဣཥዐ ፌዘᄲڦႠీኸՔă ᆶADCᇑิਓઠۼ٪ሞଉࣅሯำLjਏ༹࿋ຕܸۨ(n)Ǘ ཚࡗሺे࿋ຕ(n)Lj३ณଉࣅሯำăन๑ၙڦገ࣑ഗ ᄺׂࣷิଉࣅሯำLjᅺُLjට்ӝଉࣅሯำړፕ࢚ଉໜऐ ሯำࢅၿհ฿ኈڦᅃዖएጚăADCൻۯഗׂิڦሯำ ᆌ၎ړᇀईگᇀADCڦໜऐሯำࢅ฿ኈăথူઠLj் ံִADCሯำत฿ኈڦ༬ۅLjࢫ༑༪සࢆएᇀႠీઠ ࢚ଉADCൻۯഗڦሯำă ଉࣅሯำׂิڦᇱᅺሞᇀLjADCॽݴՐ୲၌ڦఇె႑ࡽ ଉࣅׯຕଉᆶ၌ڦොຕăᅃ߲n࿋ADCᆛᆶ2n߲ܾ पă߳पኮֶپጣᅜဆڦፌၭֶLjྺଉࣅपڦ ፌگᆶၳ࿋(LSB)Lj०qăᅺُLjᅃ߲ଉࣅपྺገ࣑ഗݔ ྷڦ1/2năසࡕՎۉუᆯྜெڦn࿋ADCገ࣑LjࢫՎ࣑ ࣮ఇె႑ࡽLjምٗADCڦ႑ࡽዐ३أLjഄᇆֶሶ၄ ྺሯำăഄߵݛኵྺ ߵݛଉࣅሯำ= Rev. 0 | Page 7 of 16 www.BDTIC.com/ADI q 12 = 1 2 12 n (21) AN-1026 ᆌᆩԴऻ ߵڪ๕Ljᅜླྀڞn࿋ADCሞഄలઊຯڦူټ႑ ࡽ-ଉࣅሯำԲܔຕ(dB)ࠅ๕(ڪ๕22)Ǘኄn࿋ገ࣑ഗ इڦڥፌॅ႑ሯԲă ႑ࡽ-ଉࣅሯำԲ(dB) = 6.02n + 1.76 dB (22) ADCዐڦໜऐሯำᆯඤሯำĂො૭ሯำࢅຮሯำࠓׯLj ᅃӯԲଉࣅሯำٷăၿհ฿ኈADCዐݥڦ၍Ⴀڞ܈ዂ ڦLjࣷሞዐׂิሞၿհฉᇑ႑ࡽ၎࠲ڦփଆ႑ ࡽăጺၿհ฿ኈࢅሯำ(THD + N)ADCڦᅃၜዘᄲႠీኸ ՔLjᆩᇀॽۉሯำࢅၿհ฿ኈᇑথৎADCଉײྷݔ ڦఇెႜԲডăۉሯำሞ༬ۨాྷݔټओݴLj ྷݔټԈઔႴᄲ୯ฉْၿհڦೕ୲ăሞڪ๕23ዐLjጺ ၿհ฿ኈTHDԈઔമ߲ၿհ฿ኈݴׯLjᇑሯำᅃഐൽ ߵݛኵă [ 1 THD+N ] (24) ැᅜ႑ࡽ-ଉࣅሯำԲ(ڪ๕22)༺پSINADLjሶۨᅭገ࣑ ഗሞ႑ࡽ-ଉࣅሯำԲڪᇀഄSINAD(ڪ๕25)ڦ൧ူڦᆶ ၳ࿋ຕ(ENOB)ă SINAD(dB) = 6.02(ENOB) + 1.76 dB (25) ENOBᄺᅜSINADྺᅺጱLjසڪ๕26๖ă ENOB = SINAD(dB) - 1.76 dB 6.02 (26) ENOBᆩܔADCൻۯഗڦሯำႠీᇑADCڦሯำႠీ ႜܔԲLjᅜඓۨഄޏࢇൻۯADCă14๖ྺᅃዖ ֶݴADCሯำఇ႙ă THD+ሯำ= VnRG1 [ν 2 (rms)]2 + [ν 3 (rms)]2 + [ν 4 (rms)]2 + [ν 5 (rms)]2 + [ν 6 (rms)]2 + ν n 2 RG1 VnRF1 RF1 inIN+ [ν 1 (rms)]2 + (23) inIN– VnIN ႑ࡽྺv1Ljമ߲ၿհ฿ኈኮओྺv2v6LjADCۉሯ ำྺvnă Vno, dm VOCM VnRG2 THD +ሯำڛڦຕLjन႑ሯ฿ኈԲ(SINAD)ཚ๖ྺݴԞ (ڪ๕24)ă RG2 RF2 VnCM VnRF2 08263-014 ! SINAD( dB ) = 20 log10 14. ֶݴADCൻۯഗڦሯำఇ႙ ᅃӯ൧ူβ1 = β2 ≡ β้Ljӗ߲ᇸܔጺሯำ߳ڦ܈ ጲࠋ၅ݴ՚ස27ዐ၎ᆌڪ๕๖ă v no ,dmᅺ v nIN = 2v nIN v nIN = ，β1 = β 2 = β β1 + β 2 β v no ,dm ᅺ v nCM = 2v nCM ( β1 - β 2 ) = 0 ，β 1 = β 2 = β β1 + β 2 v no ,dm ᅺ i nIN + = 2i nIN + (1- β1 ) RG1 = (i nIN+ ) ( R F 1 ) ，β1 = β 2 = β β1 + β 2 vno ,dmᅺ inIN- = 2inIN- (1- β1 ) RG 2 = (inIN - ) ( RF 2 ) ，β1 = β2 = β β1 + β2 vno ,dmᅺ vnRG1 = vno ,dmᅺ vnRG2 = vno ,dmᅺ vnRF1 = vno ,dmᅺ vnRF2 = (2 4kTRG1 )(1 - β1 ) β1 + β2 (2 4kTRG 2 )(1 - β2 ) β1 + β2 (2 β1 4kTRF 1 ) β1 + β2 (2 β1 4kTRF 2 ) β1 + β2 = 4kTRG1 ( RF 1 ) ，β1 = β2 = β RG1 = 4kTRG 2 ( RF 2 ) ，β1 = β2 = β RG 2 = 4kTRF 1 ，β1 = β2 = β = 4kTRF 2 ，β1 = β2 = β (27) Rev. 0 | Page 8 of 16 www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ ጺሯำۉუ܈vno, dmཚࡗऺ໙ኄၵڦݴׯڥߵݛă ॽኄၵڪ๕ۉጱ߭ऺ໙ጺሯำۉუڦ܈ፌ ॅݛ๕ăADI Diff Amp Calculator໙ሯำĂሺᅮत ֶݴADCൻۯഗڦഄᆶᆩ႑တLjٗwww.analog.comူ ሜă ၄ሞLjᅜॽADCൻۯഗڦሯำႠీᇑADCڦENOBႜ ԲডăԲසLjሺᅮྺ2ڦAD9445 ADCֶݴൻۯഗLj֑ᆩ5 V ۉᇸࢅ2 VଉײǗൻۯഗتথ᳘ࢇټ႑ࡽLj ᆩ50 MHz (−3 dB)ټڦLjᅜڇट୳հഗႜ၌ăߵ ࠲ᇀ߳ዖཉॲူENOBࡀ߭ڦຕLjሞలઊຯ༬ྺټ 50 MHzڦ൧ူLjENOB = 12࿋ă ADA4939ᅃዖߛႠీݴֶټڦADCൻۯഗLjኧথ ᳘ࢇă৽ሯำܸჾLjൻۯAD9445ڦฉࡻስăຕ ླྀ४RF = 402 ΩRG = 200 ΩLjֶݴሺᅮሀྺ2ăኄዖದዃڦ ጺۉუሯำྺ܈9.7 nV√Hză ံLjऺ໙ဣཥڦሯำټBNLjኸڦሯำࠀࡼᇑํ ा୳հഗ၎ڪڦڪၳਈႚگཚ୳հഗټڦLjํा୳հഗ ඓۨᅙኪຕሯำࠀ୲ೕڦ܈ဣཥټăܔᇀڇ ट୳ۅհഗLjBNڪᇀπ/2ױᅜ3 dBټױڥओLjසڪ๕28 ๖ă π BN = 50 MHz = 78.5 MHz (28) 2 থူઠLjऺ໙ሯำ܈ሞဣཥټڦူߵݛओݴLjᅜ൱ ߵݛሯำ(ڪ๕29)ă ۉᇸۉუ ୯ۉᇸۉუࢅୁۉၭADCൻۯഗስڦྷݔ०Սݛ ๕ă1०ᄲጺକADCൻۯഗሞ߳ዖۉᇸۉუူڦႠ ీLjࠃ֖ăۉᇸۉუࣷᆖၚټĂ႑ࡽӦޗत ICMVRăስֶٷݣݴഗ้LjႴᄲ࢚ଉ߳ၜ֖ຕࢅችዔ๚ ၜLjኄݥዘᄲڦă ଷᅃၜዘᄲࡀ֖߭ຕۉᇸᅞ(PSR)ăۉᇸᆅগሞፕྺݣ ٷഗݛ܋௬ഐڦፕᆩྫྫԥࢮăۉᇸ၍٪ሞڦඪ ࢆሯำईኁ᳘ࢇۉڟᇸ၍ዐڦሯำۼీ೦࣋႑ࡽă ૩සLjሞADA4937-1ฉेฉ50 mV p-pĂ50 MHzሯำۉڦᇸă ഄ50 MHzۉᇸᅞྺ−70 dBăኄ৽ᅪ࿆ጣLjሞٷݣഗ ܋Ljۉᇸ၍ฉڦሯำॽই16 μVፑᆸăሞټ1 Vଉײ ڦ16࿋ဣཥዐLj1 LSBྺ15.3 μVǗᅺُLjઠጲۉᇸ၍ڦሯำ ࣷޮ߃1߲LSBă ྺକ߀ኄዖ൧LjሺेزSMTཎᄟ༹ىዩL1ࢅL2Lj ᅜतୁݴಖୟۉඹC1ࢅC2(९15)ă V+ L1 U1 AD8138AR () 3 8 C1 10nF 5 –OUT 4 +OUT 2 V OCM 1 6 = 86 μV rms ߵ्ยLjሯำ܈ޗᆌߛװຯݴքǗᅺᆅLj૧ᆩރރኵሯ ำ)ٷሀሞ99.7%้ڦक़ዐLjሯำۉუࣷሞኄၵ၌ኵኮक़Ӧ ڦ*ۯ९±3σ၌ኵLjރރኵሯำऺ໙݆ݛසူ๖ǖ vno, dm (p-p) ≈ 6(86 μV rms) = 516 μV p-p (30) ၄ሞLj்ઠԲডᅃူൻۯഗރރڦኵሯำᇑ AD9445 LSBڦ1 LSBLjԲডڦएإENOBྺ12࿋Ljଉ ײྺྷݔ2VLjසڪ๕31๖ă ! ڇLSB = 2 V/212 = 488 μV L2 (29) (31) ሞ12࿋ENOBူLjൻۯഗׂิރރڦኵሯำૌຼᇀ ADCڦLSBǗᅺُLjٗሯำঙ܈ઠੂLjൻۯഗԨᆌᆩ ڦፌॅስăፌዕਦ֧ՂႷएᇀܔൻۯഗतADCፇࢇࠓڦ ॺࢅ֪ă C2 10nF V– 08263-015 vno, dm (rms) = (9.7 nV/√Hz)(√78.5 MHz) 15. ۉᇸಖୟ 50 MHzူLjཎᄟ༹ىዩڦፆੇྺ60 ΩLj10 nF (0.01 μF)ۉඹ ڦፆੇྺ0.32 Ωăኄଇ߲ᇮॲࠓڦׯປ३ഗ༵ࠃ45.5 dBڦ ປ३)९ڪ๕32*ă ݆أഗປ३ = 20log ( 0.32 ) = −45.5 dB 0.32 + 60 (32) ݆أഗປ३ᇑ–70 dBۉڦᇸᅞᅃഐׂิሀ115 dBڦᅞ Ⴀీăࡕ๑ሯำইሀ90 nV p-pLjᇺᇺگᇀ1 LSBă Rev. 0 | Page 9 of 16 www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ ၿհ฿ኈ ೕᇘฉڦگၿհ฿ኈܔټࢅټဣཥݥۼዘᄲăൻۯ ഗዐݥڦ၍Ⴀࣷ܈ሞٷݣഗڇิׂ܋ೕၿհ฿ኈतܠ ೕۙ฿ኈׂă ݴဆሯำᅃ૩ዐᆩ݆ݛڦڟᅜᆩઠݴဆၿհ฿ኈLjԲড ADA4939ڦၿհ฿ኈᇑAD9445 12࿋ENOBሞ2Vଉײ ူڦ1߲LSBăሯำݴဆዐLjᅃ߲ENOB LSBྺ488 μVă ADA4939֖ຕዐڦ฿ኈຕሺᅮྺ2้Ljሞփཞೕ୲ ူԲড2ْࢅ3ْၿհڦڥࡕă3๖ྺሞሺᅮྺ2 ֶݴӦྺޗ2 V p-p้ڦၿհ฿ኈຕă 3. ADA4939ْܾڦतෙْၿհ฿ኈ ֖ຕ HD2 @ 10 MHz HD2 @ 70 MHz HD2 @ 100 MHz HD3 @ 10 MHz HD3 @ 70 MHz HD3 @ 100 MHz ၿհ฿ኈ(dBc) −102 −83 −77 −101 −97 −91 ຕ၂๖Ljၿհ฿ኈໜೕ୲ܸሺेLjሞణՔ(ټ50 MHz)ူLjHD2၄ԲHD3ֶăၿհ฿ኈׂڦೕ୲ߛᇀ ణՔೕ୲LjᅺُLjཚࡗ၌ဣཥೕټઠইگഄ܈ޗăස ࡕဣཥሞ50 MHzူ֑ᆩ“ጇ഻๕”୳հഗLjሶኻႴ୯ߛᇀ 25 MHzڦೕ୲Ljᅺྺ୳հഗၩأକೕ୲߸ߛڦඇևၿհă ܸLjဣཥڦፌߛټยྺ50 MHzLjᅺྺᆩ୳հഗీ ݆؊ݴᅞၿհLj฿ኈׂీᅜሗො႑ࡽ႑ࡽټ ă16ቛ๖କړྺ2 V p-p้LjADA4939ሞփཞۉᇸۉ უူڦၿհ฿ኈᇑೕ୲࠲ڦဣă VOUT, dm = 2V p-p –75 VS (SPLIT VS (SPLIT VS (SPLIT VS (SPLIT SUPPLY) = ±2.5V SUPPLY) = ±2.5V SUPPLY) = ±1.65V SUPPLY) = ±1.65V –80 –85 HD2 –88dBc @ 50MHz –90 ᆯᇀADCൻۯഗຌᇀݒઍٷݣഗLjഄ฿ኈൽਦᇀݣ ٷഗۉୟዐ࣍ڦୟሺᅮଉăݒઍٷݣഗాڦևਸ࣍฿ኈ ူই1/(1 + LG)LjഄዐLjLG๖ᆩ࣍ୟሺᅮă ٷݣഗڦ(ဃֶۉუ)ױᅜᅃডٷኟၠۉუሺᅮA(s)Lj ࢫཚࡗݒઍᅺጱβLjݒઍڟ܋Ljሞُۙኝᅜ३ ณဃֶăᅺُLjኄૌٷݣഗ࣍ڦୟሺᅮྺA(s) × βǗໜጣ࣍ ୟሺᅮ(A(s)ĂβLjईኁଇኁग़ܸᆶኮ)ڦ३ณLjၿհ฿ኈࣷ ሺेăओݴഗኮૌۉڦუݒઍٷݣഗยऺᆩᇀሞୁतگ ೕူׂิٷA(s)Ljࢫሞኸۨߛೕוتጣڇ࿋1װ1/fࡐইă ໜጣA(s)ࡐڦইLj࣍ୟሺᅮࣷ३ၭLj฿ኈࣷሺेă९Lj ၿհ฿ኈྺA(s)ڛڦຕă ݒୁۉઍٷݣഗॽဃֶୁۉᆩፕݒઍ႑ࡽăဃֶୁۉ ױᅜᅃডٷኟၠੵፆT(s)Ljॽୁۉገ࣑ׯۉუLjࢫ ཚࡗݒઍᅺጱ1/RFLjॽۉუገ࣑ݒׯઍୁۉLjᅜ३ ณဃֶୁۉăᅺُLjၙݒୁۉઍٷݣഗ࣍ڦୟሺᅮ ྺT(s) × (1/RF) = T(s)/RFăᇑA(s)ૌຼLjT(s)ਏᆶডڦٷୁ ኵLjࣷໜጣೕ୲ሺेࡐইLjࡕ३ณ࣍ୟሺᅮĂሺेၿհ ฿ኈă –95 –100 –105 –110 1 10 100 FREQUENCY (MHz) (33) ฿ኈׂৈྺ80 μV p-pLj၎ړᇀ1 ENOB LSBڦ16%ăᅺُLj ٗ฿ኈঙ܈ઠੂLjADA4939AD9445 ADCൻۯഗڦଆࡻ ስă 08263-016 HARMONIC DISTORTION (dBc) HD2, HD3, HD2, HD3, –70 -88 HD2=(2Vp - p)(10 20 ) ≈ 80 μV p - p ࣍ୟሺᅮཞ้ᇑݒઍᅺጱ1/RFᆶথ࠲ဣăၙݒୁۉઍ ٷݣഗ࣍ڦୟሺᅮժփൽਦᇀԿ࣍ۉუሺᅮLjᅺُLjၿհ ฿ኈႠీփࣷໜጣԿ࣍ሺᅮڦሺेܸူইăሞ၄ํݒୁۉ ઍٷݣഗዐLj࣍ୟሺᅮሞᅃۨ܈ײฉൽਦᇀԿ࣍ሺᅮLjڍ ᅈડ܈ײᇺگᇀۉუݒઍٷݣഗăኄᄣLjܔᇀᄲ൱ߛԿ࣍ ሺᅮࢅگ฿ኈڦᆌᆩઠຫLjݒୁۉઍٷݣഗ(සADA4927) ᆫᇀۉუݒઍٷݣഗă –60 –65 ၎ܔᇀ2 V p-pڦ႑ࡽLj50 MHzူڦHD2ሀྺ−88 dBcă ྺକԲডၿհ฿ኈᇑ1 ENOB LSBLjՂႷॽۉೝገ࣑ۉׯ უLjසڪ๕33๖ă 16. ၿհ฿ኈᇑೕ୲࠲ڦဣ Rev. 0 | Page 10 of 16 www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ 17ቛ๖କሞԿ࣍ሺᅮሺे้LjADA4927฿ኈႠీڦ൧ ă VOUT, dm = 2V p-p –50 VO = VP sin 2πft (34) –60 ଭሁူLjڪ๕34ڞڦຕ)Վࣅ୲*नፌٷՎࣅ୲ྺ –70 dv = 2πfv p dt max –80 –90 –110 G=1 G = 10 G = 20 –120 –130 1 10 100 FREQUENCY (MHz) 1k FPBW = 17. ฿ኈᇑೕ୲ࢅሺᅮ࠲ڦဣ ࢅټუӦ୲ ࢅټუӦ୲ሞADCൻۯഗᆌᆩዐ၂ڥᆮഄዘᄲăᅃӯ ںLjၭ႑ࡽྺټഗॲټڦLjܸუӦ୲ሶኼሞ࢚ଉٷݣ ഗ܋ሞٷ႑ࡽӦڦူޗፌٷՎࣅ୲ă ᇑENOBૌຼLjᆶၳᆩ(ټEUBW)௮ຎڦټăႹܠ ADCൻۯഗࢅሏ໙ٷݣഗۼำਏᆶټڦLjڍժݥ ඇևీۼټಋฉᆩׇă૩සLj−3 dBټ࢚ټڦࡀ ଉݛ๕Ljڍժփ๖ඇև−3 dBۼټᆩڦă−3 dBټ ࢅ܈ޗڦ၎࿋ဃֶᅜԲํाڦপኹೕ୲༵മๆԠ၄ă ඓۨᆩڦټᅃ߲ࡻӸֱ݆ለຕ֩ዐڦ฿ኈă 18၂๖Ljྺକ๑ْܾࢅෙْၿհྼሞٷᇀ−80 dBcڦ ೝLjሶփీሞߛᇀ60 MHzڦೕ୲ူ๑ᆩADCൻۯഗăᆯᇀ ᆌᆩ߳փ၎ཞLjᆌߵဣཥᄲ൱ઠስټ؊ፁĂ฿ኈႠ ీଆࡻڦൻۯഗă –50 HD2, HD3, HD2, HD3, –60 G G G G = 1, = 1, = 2, = 2, (35) ഄዐǖ dv/dt maxྺუӦ୲ă VPྺރኵۉუă fྺඇࠀ୲(ټFPBW)ă൱FPBWǖ –100 08263-017 SPURIOUS-FREE DYNAMIC RANGE (dBc) –40 უӦ୲(ᅃዖٷ႑ࡽ֖ຕ)ኸሞփ၄ࡗଉ฿ኈڦ൧ူLj ٷݣഗ܋ᅜܔ܋ႜ߶ጷڦፌٷՎࣅ୲ă୯ უӦ୲ူڦኟ၀հă უӦ୲ 2πVp (36) ९LjሞስADCൻۯഗ้LjՂႷ୯ሺᅮĂࢅټუӦ ୲(FPBW)LjᅜඓۨٷݣഗీޏፁᆌᆩႴᄲă ࿘ۨႠ ֶݴADCൻۯഗ࿘ۨႠ୯ᇑሏ໙ٷݣഗ၎ཞă࠲॰֖ຕ ၎࿋ᇧଉă༬ۨٷݣഗದዃڦ၎࿋ᇧଉߵຕ֩ ڟڥLjܸLjሞ၄ํဣཥዐLjPCBۉୟӱքਆ٪ሞڦसิ ၳᆌీޗٷইگ၎࿋ᇧଉă ۉუݒઍٷݣഗڦ࿘ۨႠൽਦᇀഄ࣍ୟሺᅮ(नA(s) × β) ڦଉࢅࡽޙăֶݴADCൻۯഗᆛᆶଇ߲ݒઍᅺጱLjᅺܸԲ ۆ႙ڦሏ໙ٷݣഗۉୟᄲްሗᅃၵă࣍ୟሺᅮ၄ሞڪ๕ 7ࢅڪ๕8ݴڦజዐăڪ๕37௮ຎڦ࿄ದݒઍᅺጱူڦ ࣍ୟሺᅮ(β1 ≠ β2)ă ࣍ୟሺᅮ = A(s)( β1 + β 2 ) 2 (37) ݒړઍᅺጱփದ้Ljᆶၳݒઍᅺጱྺଇ߲ݒઍᅺጱڦ ೝኵăܾړኁ၎ದۨᅭྺβ้Lj࣍ୟሺᅮ०ࣅྺ A(s) × βă RF = 200 RF = 200 RF = 402 RF = 402 –80 –90 –100 –110 –120 1 10 100 FREQUENCY (MHz) 18. ADA4937 ݒୁۉઍADCൻۯഗڦ฿ኈ൸၍ 08263-018 DISTORTION (dBc) –70 ྺକ๑ݒઍٷݣഗԍ࿘ۨLjഄ࣍ୟሺᅮփڪڥᇀ−1ई ഄڪၳኵLjन၎ᅎ−180°้ྺ܈ޗ+1ăܔᇀۉუݒઍٷݣ ഗܸჾLjሞഄਸ࣍ሺᅮೕ୲ፖՔฉLj࣍ୟሺᅮڪᇀ1 (न0 dB)ۅڦኟࡻA(s)ڦଉڪᇀݒઍᅺጱڛຕۅڦăܔᇀ एԨٷݣڦഗᆌᆩLjݒઍك٦ྺۉፆ๕Ljփࣷሞݒઍ࣍ୟ ዐׂิ၎ᅎăݒړઍᅺጱ၎ದ้Lj܀૬ᇀݒઍᅺጱڛຕ1 + RF/RGڦೕ୲ཚྺሯำሺᅮăසࡕॽᅜݴԞྺڇ࿋ڦ փՎሯำሺᅮࣃሞᇑਸ࣍ሺᅮA(s)၎ཞڦፖՔฉLjሶଇ ཉ൸၍၎ڦتೕ୲ྺ࣍ୟሺᅮྺ1ई0 dBኮتăA(s)ሞ ೕ୲ူڦ၎࿋ᇑ−180°ኮֶԥۨᅭྺ၎࿋ᇧଉLjྺକሏႜ ࿘ۨLjഄኵՂႷٷᇀईڪᇀ45°ă Rev. 0 | Page 11 of 16 www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ 19ቛ๖କADA4932ሞRF/RG = 1(ሯำሺᅮ= 2)้ڇڦ࿋࣍ ୟሺᅮࢅۅ၎࿋ᇧଉă 45 ࣍ୟሺᅮྺ0 dBLj300 Ωݒઍۉፆೝ၍ᇑੵፆଉ൸၍၎ ᇀُăሞُೕ୲ူLjT(s)ڦ၎࿋ሀྺ−135°Ljࡕڟڥ+45° ڦ၎࿋ᇧଉă၎࿋ᇧଉࢅ࿘ۨႠᇑRFཞၠืইăݒୁۉઍ ٷݣഗᆌ๔ዕ֑ᆩ၎࿋ᇧଉ؊ᇧۉكڦፆ๕ݒઍă 0 PCBۉୟӱքਆ 90 80 GAIN RF 1+ =2 RG 60 (6dB) PHASE LOOP GAIN = 0dB –45 6 0 –90 –20 PHASE MARGIN –135 70° –40 –180 –60 –225 –80 1k 10k 100k 1M 10M 100M –270 10G 1G ሞยऺ࿘ۨڦADCൻۯഗ้LjኄዖາၙՂႷሞPCBۉୟӱ ฉํ၄ăۉୟӱዐڦसิᇮॲࣷڞዂևݴ၎࿋ᇧଉ฿Lj ᅺُՂႷॽُૌᇮॲ३ፌณăႴᄲ༬՚ጀᅪڦሜۉ ඹĂݒઍ࣍ୟࢅߌۉ൱ࢅবۉۅඹăُ߲߳ૌसิۼੇۉ ࣷሺेݒઍ࣍ୟዐڦውࢫ၎ᅎLjᆯُڞዂ၎࿋ᇧଉ३ณă සࡕPCBۉୟӱքਆփړLjยऺԨวन฿20°ईᅜฉڦ ၎࿋ᇧଉă 08263-019 GAIN (dB) 20 PHASE (Degrees) 40 FREQUENCY (Hz) ሞۉუݒઍٷݣഗڦ൧ူLjፌࡻ֑ᆩၭڦRFLjᅜ३ณᅺ RFᇑ൱ࢅবۉۅඹႚڦׯटڞۅዂڦ၎ᅎăසࡕႴᄲ֑ᆩ ٷRFLjሞ߳ݒઍۉፆฉ૧ᆩၭۉඹCFઠցۉඹLjၭ ۉඹڦኵᆌ๑RFCFڪᇀRGᇑ൱ࢅবۉۅඹኮओă 19. ADA4932ਸ࣍ሺᅮଉࢅ၎࿋ᇑೕ୲࠲ڦဣ ጮဦִ19ᅜ݀၄Ljړሯำሺᅮྺ1(߳࣍ୟݒઍ100%) ้LjADA4932ڦ၎࿋ᇧଉሀྺ50°ă๑ADCൻۯഗሏ ႜᇀଭሺᅮူփൎํाڦLjִ࠵ڍLj ADA4932ሞ ၭຕֶݴሺᅮ(૩සLjRF/RG = 0.25Ljሯำሺᅮ= 1.25)ူ࿘ۨ ሏႜăڍժݥᆶֶݴADCൻۯഗদසُăሞᆶADC ൻۯഗڦຕ֩ዐLjᅜੂڟፌၭ࿘ۨሺᅮă PCBۉୟӱքਆํाฉยऺୁڦײፌࢫօየኮᅃăփ႞ ڦLj࠶ߛۉୟڦႠీߛ܈ᅈડᇀքਆLjኄཞ้ᄺ ยऺࡗײዐፌᅟԥࢮڦօየኮᅃăยऺփڦړքਆీ ๑Ⴀీٶٷች੩Ljฯ๑ഄ฿ඁၳᆩăُتփీࡥ ߃ߛPCBۉୟӱยऺݛ߲߳ڦ௬Ljڍ்ॽ༪ஃब߲࠲ ॰ࣆ༶ă ݒୁۉઍADCൻۯഗڦ၎࿋ᇧଉᄺߵਸ࣍ၚᆌઠඓ ۨăݒୁۉઍٷݣഗ֑ᆩڦփኟၠሺᅮA(s)Ljܸኟၠ ੵፆT(s)Ljᅜဃֶୁۉፕྺݒઍ႑ࡽăټದݒઍۉፆڦ ݒୁۉઍൻۯഗ࣍ڦୟሺᅮྺT(s)/RFǗᅺُLjړT(s) = RF ้Ljݒୁۉઍٷݣഗ࣍ୟሺᅮଉڪᇀ1(न0 dB)ۅሞਸ࣍ ੵፆᇑ၎࿋࠲ဣፖՔฉൟቴڟLjഄ݆ݛᇑۉუݒઍݣ ٷഗ၎ཞăۉܔፆᇑ1 kΩኮԲፕLjሞܔຕፖՔฉ๖ ۉፆă20ቛ๖କADA4927ݒୁۉઍֶݴADCൻۯഗሞRF = 300 Ω้ڇڦ࿋࣍ୟሺᅮࢅۅ၎࿋ᇧଉă 1k सิᇮॲࣷဎึߛۉୟڦႠీăसิۉඹᆯᇮॲࡰಎࢅ ք၍ᇑথ֫ںईۉᇸ֫ႚׯăথڦ֫ںք၍ࣷႚׯस ิߌۉLjీሞຨༀၚᆌዐڞዂናଯናږईഄփ࿘ۨႜ ྺăसิۉඹሞٷݣഗڦ൱ࢅবتۅᆮഄླ၃Ljᅺྺኄዖ ۉඹࣷሞݒઍၚᆌዐׂิटۅLjڞዂࢅࣅރփ࿘ۨăᅃዖ ਦӸ݆ඓԍሞۉୟӱ߳֫ዐLjADCൻۯഗኧॐतݒઍ ᇮॲࡰಎူݛփ٪ሞথۉࢅ֫ںᇸ֫ă ྺକ३ณփଆसิੇۉLjᆌଉ܌ᆶք၍ڦਐă FR-4ฉ֫ྔڦ50 Ω PCBۉୟӱք၍ࣷࠋ၅ٷሀ2.8 pF/ᆈ٫ ࢅ7 nH/ᆈ٫ڦसิߌۉăܸా֫50 Ωք၍ሶࣷ๑ُૌसิ ੇۉሺेሀ30%ăଷႴඓԍڦጽ၍ူݛᆶথ֫ںLjᅜ३ ณք၍ߌۉăଉ܌ք၍ਐĂ३ၭഄٷၭᆶዺᇀইگ सิۉඹࢅߌۉLjᆶ૧ᇀྼยऺྜڦኝႠă 50 100 0 PHASE –50 10 –100 1 –135 –150 IMPEDANCE PHASE (Degrees) PHASE MARGIN 0.3 45° –180 0.1 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 100M 1G –200 10G 08263-020 IMPEDANCE MAGNITUDE (k ) MAGNITUDE 20. ADA4927ਸ࣍ሺᅮଉࢅ၎࿋ᇑೕ୲࠲ڦဣ Rev. 0 | Page 12 of 16 www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ ୁۉಖୟۉୟӱքਆዐڦଷᅃ߲࠲॰ǗခՂඓԍۉᇸಖ ୟۉඹᅜतVOCMಖୟۉඹ࿋ᇀଉথৎٷݣഗᆅগኮتă ଷྔLjሞۉᇸ֑֫ᆩ߲ܠಖୟۉඹᆶዺᇀඓԍྺټሯำ ༵ࠃᅃ߲گፆੇୟ০ă21๖ྺᅃዖۆ႙ٷݣݴֶڦഗ ๖ᅪLjഄዐࡤᆶۉᇸಖୟLjټ܋ᅃگཚ୳հഗă گཚ୳հഗᆩᇀ၌ADCࢅټڦሯำăၙ൧ ူLjۉᇸಖୟۉඹ࣮ୟᆌ੍ৎሜ࣮ୟǗኄᄣᆶዺᇀ३ณ থ֫ںዐڦთ࣍ୁۉժ༵ߛADCൻۯഗڦႠీ(֖९ 22)ă থ֫ںᅜत࠽ᅭথں߲ాඹްڦݿሗࣆ༶LjגକԨ ᆌᆩԴऻྷݔڦăڍ୯ᅜူ࠲॰(ۅ९22)ǖ t ኻሞᅃ߲ۅฉথఇెࢅںຕጴںăኄᄣ३ณఇె ࢅୁۉຕጴୁۉሞথ֫ںዐڦࢻፕᆩLjՆ௨ഄሞဣ ཥዐׂิሯำă ॽఇెۉᇸথఇెۉᇸ֫Ljॽຕጴۉᇸথຕጴۉ ᇸ֫ă ܔᇀंࢇ႑ࡽICLjॽఇె࣮ںୟথఇెথ֫ںLjॽ ຕጴ࣮ںୟথຕጴথ֫ںLjժৈᆩᅃၭথॽଇ߲ থ֫ں၎Ljᅜ३ณຕጴୁۉᇑఇె(ࢇंڦୁۉ९ 23)ă t t R4 +VS C2 ᆶ࠲ߛᆇຘۉୟӱ(PCB)քਆၘڦ൧Lj൩֖ለĖߛᆇ ຘۉୟӱքਆํᆩኸళėLjྪǖwww.analog.comă C3 R2 RS RT C6 U1 C1 R1 ԨᆌᆩԴऻࡤ႑တኼሞӻዺॆٷາሞยऺADCൻۯഗ ้ՂႷ୯߳ڦዖᅺ໎ăศକֶٷݣݴഗժٗยऺኮ ؛नጀᅪADCൻۯഗยऺဦবLjᆶ૧ᇀ३ณॽઠڦ࿚༶Lj ইޅگ၃LjඓԍยऺڦԀႠă R6 VOCM R7 TO ADC C7 R3 C4 C5 08263-021 –VS R5 21. ۉټᇸಖୟࢅگཚ୳հഗڦADCൻۯഗ R2 R4 C2 R6 RT C3 U1 C6 C4 C7 R7 C1 C5 R5 (a) 08263-022 R3 (b) 22. ᇮॲ֨௬ (a)Ăۉୟ֨௬ (b) VA ANALOG CIRCUITS SYSTEM STAR GROUND A ANALOG CIRCUITS VD VD MIXED SIGNALS AGND DGND VA A D A D ANALOG SUPPLY DIGITAL CIRCUITS D DIGITAL CIRCUITS DIGITAL SUPPLY 08263-023 R1 23. ंࢇ႑ࡽথں Rev. 0 | Page 13 of 16 www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ ጀ Rev. 0 | Page 14 of 16 www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ! ጀ Rev. 0 | Page 15 of 16 www.BDTIC.com/ADI AN-1026 ᆌᆩԴऻ ጀ ©2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. AN08263-0-11/09(0) Rev. 0 | Page 16 of 16 www.BDTIC.com/ADI