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DS90CR288A Datasheet, PDF (16/20 Pages) National Semiconductor (TI) – 28-Bit Channel Link-85MHz
ΞϓϦέʔγϣϯ৘ใ
DS90CR287 ͱ DS90CR288A ͷ TSSOP ൛͸طଘͷ 5V νϟω
ϧɾϦϯΫɾτϥϯεϛολ/ϨγʔόɾϖΞ(DS90CR283ͱDS90CR284)
׵ޓͱੑ͕͋Γ·͢ɻ5V ͔Β 3.3V γεςϜ΁Ҡߦ͢Δࡍʹ͸ɺ
࣍ͷ఺ʹ஫ҙ͍ͯͩ͘͠͞ɻ
ݯిΛ 5V ͔Β 3.3V ΁มߋ͠ɺτϥϯεϛολͱϨγʔόͷશిݯ
ϐϯ (VCCɺLVDS VCCɺPLL VCC) ͍ͩͯ͘͞͠څڙʹɻ
9. τϥϯεϛολͷೖྗϐϯͱ੍ޚೖྗϐϯʹ͸3.3V TTL/CMOS
৴߸Λೖྗ͍ͯͩ͘͠͞ɻ5V ৴߸ೖྗ଱ѹ͸͋Γ·ͤΜɻ
10. Ϩγʔό͸ύϫʔμ΢ϯ࣌ʹग़ྗ͕ Low ݻʹఆ͞Ε·͢ɻ
νϟωϧɾϦϯΫ͸͍Ζ͍Ζͳσʔλૹड৴γεςϜͰͷ࢖༻Λ໨త
ʹ։ൃ͞Ε·ͨ͠ɻγεςϜʹΑΓ઀ଓ͢Δ෦ࡐ͸ҟͳΓ·͢ɻྫ͑
͹௿଎Ͱ͔ͭέʔϒϧ௕΋୹͍ ( ʻ 2m) ৔߹ʹ͸ɺ෦ࡐͷిؾ
తੑೳ͸͞΄Ͳॏཁͱ͸ͳΓ·ͤΜ͕ɺߴ଎͔ͭ௕཭ڑͷΞϓϦ
έʔγϣϯͰ͸෦ࡐͷੑೳ͕ॏཁͱͳΓ·͢ɻ࣮ࡍɺέʔϒϧͷߏ
੒ʹΑΓεΩϡʔ( ϖΞؒʹ͓͚Δ઀ଓ఺ؒͷిؾతͳઢ௕ࠩ )Λ
௿͢ݮΔࣄ͕Ͱ͖·͢ɻΑΓৄ͍͠಺༰ʹ͍ͭͯ͸ҎԼͷΞϓϦ
έʔγϣϯɾϊʔτΛࢀর͍ͩ͘͞ɻ
AN ʹ ####
AN-1041
AN-1108
AN-806
AN-905
AN-916
Topic
Introduction to Channel Link
Channel Link PCB and Interconnect
Design-In Guidelines
Transmission Line Theory
Transmission Line Calculations and
Differential Impedance
Cable Information
έʔϒϧ :τϥϯεϛολͱϨγʔόͷΠϯλϑΣʔεʹ༻͍ΒΕ͍ͯ
Δࠩಈͷ LVDS ৴߸͸έʔϒϧʹΑΓ఻ૹ͞Ε·͢ɻ21 Ϗοτɾ
νϟωϧɾϦϯΫɾνοϓηοτ (DS90CR217/218A) Ͱ͸ 4 ϖΞͷ
৴߸ઢ͕ɺ28 ϏοτɾνϟωϧɾϦϯΫɾνοϓηοτ(DS90CR287/
288A) Ͱ͸ 5 ϖΞͷ৴߸ઢ͕ඞཁͱͳΓ·͢ɻཧ૝తͳέʔϒϧ
/ ίωΫλͷΠϯλϑΣʔε͸఻ૹ࿏͢΂ͯʹΘͨΓ 100Њ Ұఆͷ
ࠩಈΠϯϐʔμϯεʹอͭ͜ͱͰ͢ɻ·ͨɺϨγʔόͰे෼ͳσʔ
λͷαϯϓϧɾ΢Οϯυ΢Λ֬อ͢ΔͨΊʹ 140ps (85MHz ࣌ ) Ҏ
ԼʹεΩϡʔΛ཈͍͑ͯͩ͘͞ɻ
͞ΒʹɺσʔλͱΫϩοΫΛ఻ૹ͢Δ 4 ·ͨ͸ 5 ϖΞͷέʔϒϧʹ࠷
௿ 1 ຊ (·ͨ͸ 1 ϖΞ ) ͷάϥ΢ϯυΛ༻ҙ͢Δ͜ͱΛਪ঑͠·͢ɻ
͜ͷάϥ΢ϯυʹΑΓίϞϯɾϞʔυͷϦλʔϯɾύεΛߏ੒Ͱ͖·͢ɻ
ҰରҰͷΞϓϦέʔγϣϯͰҰൠతʹ࢖༻͞Ε͍ͯΔέʔϒϧʹ
͸ϑϥοτɺϑϨοΫεɺπΠετϖΞɺTWIN-COAX ͕͋Γ·͢ɻ
ߏ੒΍ΦϓγϣϯʹΑΓ͞·͟·ͳέʔϒϧ͕༻ҙ͞Ε͍ͯ·͢ɻϑ
ϥοτɺϑϨοΫεɺπΠετɾϖΞ͸୹͍ҰରҰͷΞϓϦέʔγϣϯ
ʹ͸े෼Ͱ͢ɻTWIN-COAX ͸௕୹ͲͪΒͰ΋ߴ͍ੑೳΛࣔ͠
·͢ɻϑϥοτɾέʔϒϧ࢖༻࣌ʹ͸֤ࠩಈ৴߸ؒʹάϥ΢ϯυઢ
ΛೖΕΔ͜ͱΛਪ঑͠·͢ɻ͜ͷάϥ΢ϯυʹΑΓɺۙ઀͢ΔϖΞؒ
ͷϊΠζʹΑΔׯবΛ๷͙͜ͱ͕Ͱ͖·͢ɻTWIN-COAX έʔϒϧ
Ͱ͸֤έʔϒϧϖΞΛγʔϧυ͢Δ͜ͱΛਪ঑͠·͢ɻҰରҰͰ
཭ڑΛ৳͹͢৔߹ʹ͸έʔϒϧͷλΠϓʹΑΒͣશέʔϒϧɾϖΞ
Λγʔϧυ͍ͯͩ͘͠͞ɻશମΛγʔϧυ͢Δ͜ͱͰɺEMS ΍ EMI
ىʹҼ͢Δ໰୊Λղܾ͠ɺ௕཭ڑԽɺߴ଎Խͱ͍ͬͨ఻ૹύϥ
ϝʔλͷ޲্ʹͳΓ·͢ɻ
͍Ζ͍ΖͳέʔϒϧɾλΠϓͰ LVDS ৴߸͸͢͹Β͍͠ੑೳΛࣔ
͍ͯ͠·͢ɻ͔͠͠ɺ૯߹తʹ࠷ߴͷੑೳͱͳͬͨͷ͸ TWIN-
COAX έʔϒϧΛ࢖༻ͨ͠ͱ͖Ͱͨ͠ɻTWIN-COAX έʔϒϧ͸
ͦͷߏ଄ͱγʔϧυͷೋॏԽʹΑΓɺ༏ΕͨεΩϡʔͱ EMI ੑೳ
Λ΋͍ͬͯ·͢ɻຊ߲ͱؔ࿈ͷΞϓϦέʔγϣϯɾϊʔτʹ͸ઃऀܭ
ʹ༗༻ͳ਺ଟ͘ͷΨΠυϥΠϯ͕͞ࡌهΕ͍ͯ·͢ɻઃऀܭ͸֤
ΞϓϦέʔγϣϯͰ҆શ͔ͭࡁܦతͳέʔϒϧͷͨΊʹ༷ʑͳτ
ϨʔυΦϑΛࠪఆ͢ΔΑ͏ਪ঑͠·͢ɻ
ϨγʔόɾϑΣΠϧηʔϑػೳ : ຊϨγʔό͸ɺϨγʔόೖྗ͕
Φʔϓϯ΋͘͠͸ऴ୺͞Εͨঢ়ଶͰ΋҆ఆͨ͠Ϩγʔόग़ྗΛಘΔ
ͨΊʹɺೖྗஈʹϑΣΠϧηʔϑͷόΠΞεճ࿏Λඋ͍͑ͯ·͢ɻ
͜ΕʹΑΓɺલهͷΑ͏ʹΦʔϓϯ΋͘͠͸ऴ୺͞Εͨঢ়ଶͰ΋ɺϨ
γʔόೖྗ͸ HIGH ʹͳΓ·͢ɻ͕ͨͬͯ͠ɺ΋͠ΫϩοΫ৴߸͕
༗ޮͰ͋Ε͹͢΂ͯͷσʔλग़ྗ΋ HIGH ʹͳΓ·͢ɻ΋͠Ϋϩο
Ϋ৴߸͕Φʔϓϯ΋͘͠͸ऴ୺͞Ε͍ͯͨͱ͢ΔͱɺϨγʔόग़ྗ
͸࠷ޙͷ༗ޮͳঢ়ଶΛอ࣋͠·͢ɻͳ͓ΫϩοΫೖྗ͕Φʔϓϯ
΋͘͠͸ऴ୺͞Ε͍ͯΔͱɺΫϩοΫग़ྗ͸ HIGH ʹͳΓ·͢ɻ
ϘʔυɾϨΠΞ΢τ : LVDS ͷ EMIɺϊΠζɾϚʔδϯΛ࠷େ׆ݶ
༻͢Δʹ͸ࠩಈ৴߸ͷϨΠΞ΢τʹ஫ҙΛ෷͏ඞཁ͕͋Γ·͢ɻ
ଞͷ৴߸͔ΒͷϊΠζʹΑΔׯবΛ཈͑ɺࠩಈ৴߸ͷϊΠζɾΩϟ
ϯηϧੑೳΛ༗ޮʹར༻͢ΔͨΊʹɺࠩಈ৴߸ϥΠϯ͸ৗʹۙ઀
͍ͯ͠ͳ͚Ε͹ͳΓ·ͤΜɻ·ͨɺࠩಈ৴߸ઢ௕΋౳௕ʹͳΔΑ͏
τϨʔεΛௐ੔͍ͯͩ͘͠͞ɻ͋ΒΏΔߴ଎ઃ͍͓ͯʹܭɺΠϯϐʔ
μϯεͷෆ੔߹͸ආ͚ͳ͚Ε͹͍͚·ͤΜ ( ϰΟΞΛݮΒ͢ɺ90
͕ۂʹ౓ΔτϨʔεΛආ͚ΔͳͲ )ɻࠩಈ৴߸ͷҰํͷϥΠϯʹΠ
ϯϐʔμϯεͷෆ੔߹͕͋Δͱଞํͷ৴߸ϥΠϯʹ΋Өݱ͕ڹΕ
·͢ɻࠩಈ৴߸ͷτϨʔεͷΠϯϐʔμϯε͸બ୒͞Εͨέʔϒϧ
ͷΠϯϐʔμϯεͱ੔߹͍ͯ͠ͳ͚Ε͹͍͚·ͤΜ (͜ͷΠϯϐʔμ
ϯε͸Ϩγʔόೖྗ୺Ͱࠩಈ৴߸ؒʹೖΕΔऴ୺఍߅ͱ΋Ұக
͍ͯ͠ͳ͚Ε͹ͳΓ·ͤΜ )ɻ࠷ʹޙɺνϟωϧɾϦϯΫͷ TxOUT/
RxIN ϐϯ͸ɺPCB ্Ͱͷ༨෼ͳτϨʔεΛආ͚ΔͨΊʹϘʔυͷ
୺ʹͰ͖Δ͚͚͍ͩۙͮͯͩ͘͞ɻ͜ΕΒ͸͢΂ͯߴ଎ੑ΍ EMI
ʹӨڹΛ༩͑Δ൓ࣹ΍ΫϩετʔΫΛ཈੍͢Δ΋ͷͰ͢ɻ
ೖྗ : TxIN ୺ࢠ͓Αͼ੍ޚೖྗ୺ࢠ͸ɺLVCMOS Ϩϕϧ΋͠
͘͸ LVTTL Ϩϕϧʹ͢Ͱ׵ޓɻͨͩ͜͠ΕΒೖྗ͸ 5V ଱ѹͰ
͸͋Γ·ͤΜɻ
ະ࢖༻ೖྗ : TxIN ͷະ࢖༻ೖྗ͸͢΂ͯάϥ΢ϯυʹ઀ଓ͢Δ
͔ະ઀ଓঢ়ଶͷ··ʹ͍ͯͩ͘͠͞ɻϨγʔόͷະ࢖༻ೖྗ͸
Φʔϓϯͷ··Ͱ͔·͍·ͤΜɻ
ऴ୺ : ిྲྀϞʔυͷυϥΠόͰ͸Ϩγʔόͷೖྗʹऴ୺఍߅͕ඞ
ཁͰ͢ɻνϟωϧɾϦϯΫɾνοϓηοτͰ͸ϨγʔόࠩಈೖྗϖΞ
ͷʴͱʵ͝ͱʹ 100Њ ͷऴ୺఍߅͕ඞཁͰ͢ɻ࣮ࡍͷऴ୺఍߅
஋͸έʔϒϧͷࠩಈಛੑΠϯϐʔμϯε (90 ʙ 120Њ) ͱಉ͡ʹͳ
ΔΑ͏ʹબ୒͠·͢ɻFigure 17 ͷྫΛࢀর͍ͩ͘͞ɻPECL ͷΑ͏
ͳଞͷࠩಈ৴߸ͱҟͳΓϓϧΞοϓ΍ϓϧμ΢ϯͷ఍߅΋ඞཁ͋Γ
·ͤΜɻϦʔυͷΠϯμΫλϯεΛݮΒͨ͢Ίʹද໘࣮૷λΠϓͷ
఍߅Λਪ঑͠·͢ɻऴ୺఍߅͸ࠩಈ৴߸ΛޮՌతʹऴ୺͠ɺε
λϒΛ୹͘͢ΔͨΊʹϨγʔόೖྗϐϯͷͰ͖Δ͚ͩۙ͘ʹ഑ஔ͠
͍ͯͩ͘͞ɻ
σΧοϓϦϯάɾίϯσϯα : ੑೳΛ੍͢ݶΔεΠονϯάɾϊΠζ
Λ௿͢ݮΔͨΊʹɺόΠύεɾίϯσϯαΛೖΕ͍ͯͩ͘͞ɻ֤
VCCͱ GND ʹ 3 ݸฒྻʹσΧοϓϦϯάɾίϯσϯα ( ଟ૚ηϥ
ϛοΫͷද໘࣮૷λΠϓ )Λૠೖ͢Δ͜ͱΛਪ঑͠·͢ (Figure 18)ɻ
3 ݸͷίϯσϯαͷ஋͸ 0.1ЖFɺ0.01ЖFɺ0.001ЖF Ͱ͢ɻిͱݯ
άϥ΢ϯυ͸Ͱ͖Δ͚ͩ෯޿ͷτϨʔεΛ࢖༻֤͠ίϯσϯα͸ͦ
ΕͧΕݸผʹάϥ΢ϯυ઀ଓ͍ͯͩ͘͠͞ɻϘʔυ্ʹे෼ͳε
ϖʔε͕ͳ͍৔߹ɺPLL VCCɺLVDS VCCɺϩδοΫ VCC ͷॱ
ʹ༏ઌ͍ͯͩ͘͠͞ɻ
http://www.national.com/JPN/
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