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MacOS 8.1

Win98

DOS

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+--------+-------------------------+-------------------------+--------+--------+
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|00000200| 44 42 20 39 30 44 53 4c | 54 31 31 39 41 2f 4c 54 |DB 90DSL|T119A/LT|
|00000210| 33 31 39 41 2f 4c 4d 31 | 31 39 2f 4c 4d 33 31 39 |319A/LM1|19/LM319|
|00000220| 44 75 61 6c 20 43 6f 6d | 70 61 72 61 74 6f 72 5c |Dual Com|parator\|
|00000230| 44 41 54 41 5c 44 41 54 | 41 42 4f 4f 4b 5c 31 39 |DATA\DAT|ABOOK\19|
|00000240| 39 30 5f 44 42 30 31 31 | 39 61 5f 5f 78 2e 70 64 |90_DB011|9a__x.pd|
|00000250| 66 4c 54 31 31 39 41 2f | 4c 54 33 31 39 41 20 4c |fLT119A/|LT319A L|
|00000260| 4d 31 31 39 2f 4c 4d 33 | 31 39 20 44 75 61 6c 20 |M119/LM3|19 Dual |
|00000270| 43 6f 6d 70 61 72 61 74 | 6f 72 20 0d 0a 46 45 41 |Comparat|or ..FEA|
|00000280| 54 55 52 45 53 0d 0a 20 | 47 75 61 72 61 6e 74 65 |TURES.. |Guarante|
|00000290| 65 64 20 4d 61 78 69 6d | 75 6d 20 30 2e 35 6d 56 |ed Maxim|um 0.5mV|
|000002a0| 20 49 6e 70 75 74 20 4f | 66 66 73 65 74 20 56 6f | Input O|ffset Vo|
|000002b0| 6c 74 61 67 65 0d 0a 20 | 49 6e 70 75 74 20 50 72 |ltage.. |Input Pr|
|000002c0| 6f 74 65 63 74 69 6f 6e | 20 44 69 6f 64 65 73 0d |otection| Diodes.|
|000002d0| 0a 20 4f 70 65 72 61 74 | 65 73 20 46 72 6f 6d 20 |. Operat|es From |
|000002e0| 53 69 6e 67 6c 65 20 35 | 56 20 53 75 70 70 6c 79 |Single 5|V Supply|
|000002f0| 0d 0a 20 32 35 6d 41 20 | 44 72 69 76 65 20 43 61 |.. 25mA |Drive Ca|
|00000300| 70 61 62 69 6c 69 74 79 | 0d 0a 20 38 30 6e 73 20 |pability|.. 80ns |
|00000310| 52 65 73 70 6f 6e 73 65 | 20 54 69 6d 65 0d 0a 46 |Response| Time..F|
|00000320| 45 41 54 55 52 45 53 20 | 0d 0a 20 57 69 6e 64 6f |EATURES |.. Windo|
|00000330| 77 20 44 65 74 65 63 74 | 6f 72 73 0d 0a 20 48 69 |w Detect|ors.. Hi|
|00000340| 67 68 20 53 70 65 65 64 | 20 4f 6e 65 20 53 68 6f |gh Speed| One Sho|
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|00000360| 72 69 76 65 72 73 0d 0a | 20 56 6f 6c 74 61 67 65 |rivers..| Voltage|
|00000370| 20 43 6f 6e 74 72 6f 6c | 6c 65 64 20 4f 73 63 69 | Control|led Osci|
|00000380| 6c 6c 61 74 6f 72 73 0d | 0a 44 45 53 43 52 49 50 |llators.|.DESCRIP|
|00000390| 54 49 4f 4e 0d 0a 54 68 | 65 20 4c 54 31 31 39 41 |TION..Th|e LT119A|
|000003a0| 20 69 73 20 61 6e 20 69 | 6d 70 72 6f 76 65 64 20 | is an i|mproved |
|000003b0| 76 65 72 73 69 6f 6e 20 | 6f 66 20 74 68 65 20 4c |version |of the L|
|000003c0| 4d 31 31 39 20 64 75 61 | 6c 20 63 6f 6d 70 61 72 |M119 dua|l compar|
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|000003e0| 73 20 6c 6f 77 65 72 20 | 69 6e 70 75 74 20 6f 66 |s lower |input of|
|000003f0| 66 73 65 74 20 76 6f 6c | 74 61 67 65 20 61 6e 64 |fset vol|tage and|
|00000400| 20 6f 66 66 73 65 74 20 | 63 75 72 72 65 6e 74 2c | offset |current,|
|00000410| 20 68 69 67 68 65 72 20 | 76 6f 6c 74 61 67 65 20 | higher |voltage |
|00000420| 67 61 69 6e 2c 20 67 75 | 61 72 61 6e 74 65 65 64 |gain, gu|aranteed|
|00000430| 20 63 6f 6d 6d 6f 6e 20 | 6d 6f 64 65 20 72 65 6a | common |mode rej|
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|00000450| 74 20 70 72 6f 74 65 63 | 74 69 6f 6e 20 64 69 6f |t protec|tion dio|
|00000460| 64 65 73 2e 0d 0a 54 68 | 65 20 4c 54 31 31 39 41 |des...Th|e LT119A|
|00000470| 20 69 73 20 63 61 70 61 | 62 6c 65 20 6f 66 20 6f | is capa|ble of o|
|00000480| 70 65 72 61 74 69 6f 6e | 20 6f 76 65 72 20 61 20 |peration| over a |
|00000490| 73 75 70 70 6c 79 20 72 | 61 6e 67 65 20 66 72 6f |supply r|ange fro|
|000004a0| 6d 20 35 56 20 74 6f 20 | 2b 2d 31 35 56 20 61 6e |m 5V to |+-15V an|
|000004b0| 64 20 63 61 6e 20 64 72 | 69 76 65 20 32 35 6d 41 |d can dr|ive 25mA|
|000004c0| 20 6c 6f 61 64 73 20 66 | 72 6f 6d 20 65 61 63 68 | loads f|rom each|
|000004d0| 20 6f 70 65 6e 20 63 6f | 6c 6c 65 63 74 6f 72 20 | open co|llector |
|000004e0| 6f 75 74 70 75 74 2e 20 | 41 20 73 65 70 61 72 61 |output. |A separa|
|000004f0| 74 65 20 67 72 6f 75 6e | 64 20 70 69 6e 20 61 6c |te groun|d pin al|
|00000500| 6c 6f 77 73 20 74 68 65 | 20 4c 54 31 31 39 41 20 |lows the| LT119A |
|00000510| 74 6f 20 69 73 6f 6c 61 | 74 65 20 73 79 73 74 65 |to isola|te syste|
|00000520| 6d 20 67 72 6f 75 6e 64 | 73 2e 0d 0a 4c 69 6e 65 |m ground|s...Line|
|00000530| 61 72 20 54 65 63 68 6e | 6f 6c 6f 67 79 20 43 6f |ar Techn|ology Co|
|00000540| 72 70 6f 72 61 74 69 6f | 6e 27 73 20 61 64 76 61 |rporatio|n's adva|
|00000550| 6e 63 65 64 20 70 72 6f | 63 65 73 73 69 6e 67 2c |nced pro|cessing,|
|00000560| 20 64 65 73 69 67 6e 20 | 74 65 63 68 6e 69 71 75 | design |techniqu|
|00000570| 65 73 20 61 6e 64 20 72 | 65 6c 69 61 62 69 6c 69 |es and r|eliabili|
|00000580| 74 79 20 6d 61 6b 65 20 | 74 68 65 20 4c 54 31 31 |ty make |the LT11|
|00000590| 39 41 2f 4c 54 33 31 39 | 41 20 61 6e 20 69 64 65 |9A/LT319|A an ide|
|000005a0| 61 6c 20 63 68 6f 69 63 | 65 20 6f 76 65 72 20 70 |al choic|e over p|
|000005b0| 72 65 76 69 6f 75 73 20 | 64 65 76 69 63 65 73 20 |revious |devices |
|000005c0| 69 6e 20 6d 6f 73 74 20 | 63 6f 6d 70 61 72 61 74 |in most |comparat|
|000005d0| 6f 72 20 61 70 70 6c 69 | 63 61 74 69 6f 6e 73 2e |or appli|cations.|
|000005e0| 07 00 00 00 00 00 e0 03 | 01 00 db 03 02 00 d9 03 |........|........|
|000005f0| 03 00 c0 03 04 00 b1 03 | 05 00 9b 03 06 00 8f 03 |........|........|
|00000600| 44 42 20 39 30 44 53 4c | 4d 31 38 35 2d 32 2e 35 |DB 90DSL|M185-2.5|
|00000610| 2f 4c 4d 33 38 35 2d 32 | 2e 35 4d 69 63 72 6f 70 |/LM385-2|.5Microp|
|00000620| 6f 77 65 72 20 56 6f 6c | 74 61 67 65 20 52 65 66 |ower Vol|tage Ref|
|00000630| 65 72 65 6e 63 65 5c 44 | 41 54 41 5c 44 41 54 41 |erence\D|ATA\DATA|
|00000640| 42 4f 4f 4b 5c 31 39 39 | 30 5f 44 42 30 31 38 35 |BOOK\199|0_DB0185|
|00000650| 32 35 5f 78 2e 70 64 66 | 4c 4d 31 38 35 2d 32 2e |25_x.pdf|LM185-2.|
|00000660| 35 2f 20 4c 4d 32 38 35 | 2d 32 2e 35 2f 4c 4d 33 |5/ LM285|-2.5/LM3|
|00000670| 38 35 2d 32 2e 35 20 4d | 69 63 72 6f 70 6f 77 65 |85-2.5 M|icropowe|
|00000680| 72 20 56 6f 6c 74 61 67 | 65 20 52 65 66 65 72 65 |r Voltag|e Refere|
|00000690| 6e 63 65 0d 0a 46 45 41 | 54 55 52 45 53 0d 0a 20 |nce..FEA|TURES.. |
|000006a0| 32 30 75 41 20 74 6f 20 | 32 30 6d 41 20 4f 70 65 |20uA to |20mA Ope|
|000006b0| 72 61 74 69 6e 67 20 52 | 61 6e 67 65 0d 0a 20 47 |rating R|ange.. G|
|000006c0| 75 61 72 61 6e 74 65 65 | 64 20 31 25 20 49 6e 69 |uarantee|d 1% Ini|
|000006d0| 74 69 61 6c 20 56 6f 6c | 74 61 67 65 20 54 6f 6c |tial Vol|tage Tol|
|000006e0| 65 72 61 6e 63 65 0d 0a | 20 47 75 61 72 61 6e 74 |erance..| Guarant|
|000006f0| 65 65 64 20 31 6f 68 6d | 73 20 44 79 6e 61 6d 69 |eed 1ohm|s Dynami|
|00000700| 63 20 49 6d 70 65 64 61 | 6e 63 65 0d 0a 20 56 65 |c Impeda|nce.. Ve|
|00000710| 72 79 20 4c 6f 77 20 50 | 6f 77 65 72 20 43 6f 6e |ry Low P|ower Con|
|00000720| 73 75 6d 70 74 69 6f 6e | 0d 0a 41 50 50 4c 49 43 |sumption|..APPLIC|
|00000730| 41 54 49 4f 4e 53 0d 0a | 20 50 6f 72 74 61 62 6c |ATIONS..| Portabl|
|00000740| 65 20 4d 65 74 65 72 20 | 52 65 66 65 72 65 6e 63 |e Meter |Referenc|
|00000750| 65 73 0d 0a 20 50 6f 72 | 74 61 62 6c 65 20 54 65 |es.. Por|table Te|
|00000760| 73 74 20 49 6e 73 74 72 | 75 6d 65 6e 74 73 0d 0a |st Instr|uments..|
|00000770| 20 42 61 74 74 65 72 79 | 2d 4f 70 65 72 61 74 65 | Battery|-Operate|
|00000780| 64 20 53 79 73 74 65 6d | 73 0d 0a 20 50 61 6e 65 |d System|s.. Pane|
|00000790| 6c 20 4d 65 74 65 72 73 | 0d 0a 20 43 75 72 72 65 |l Meters|.. Curre|
|000007a0| 6e 74 20 4c 6f 6f 70 20 | 49 6e 73 74 72 75 6d 65 |nt Loop |Instrume|
|000007b0| 6e 74 61 74 69 6f 6e 0d | 0a 44 45 53 43 52 49 50 |ntation.|.DESCRIP|
|000007c0| 54 49 4f 4e 0d 0a 54 68 | 65 20 4c 4d 31 38 35 2d |TION..Th|e LM185-|
|000007d0| 32 2e 35 20 69 73 20 61 | 20 74 77 6f 2d 74 65 72 |2.5 is a| two-ter|
|000007e0| 6d 69 6e 61 6c 20 62 61 | 6e 64 20 67 61 70 20 72 |minal ba|nd gap r|
|000007f0| 65 66 65 72 65 6e 63 65 | 20 64 69 6f 64 65 20 74 |eference| diode t|
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|00000820| 61 74 69 6f 6e 73 20 77 | 68 69 63 68 20 72 65 71 |ations w|hich req|
|00000830| 75 69 72 65 20 70 72 65 | 63 69 73 69 6f 6e 20 70 |uire pre|cision p|
|00000840| 65 72 66 6f 72 6d 61 6e | 63 65 20 77 69 74 68 20 |erforman|ce with |
|00000850| 6d 69 63 72 6f 70 6f 77 | 65 72 20 6f 70 65 72 61 |micropow|er opera|
|00000860| 74 69 6f 6e 2e 20 54 68 | 65 20 64 65 76 69 63 65 |tion. Th|e device|
|00000870| 20 70 72 6f 76 69 64 65 | 73 20 67 75 61 72 61 6e | provide|s guaran|
|00000880| 74 65 65 64 20 6f 70 65 | 72 61 74 69 6f 6e 20 73 |teed ope|ration s|
|00000890| 70 65 63 69 66 69 63 61 | 20 74 69 6f 6e 73 20 61 |pecifica| tions a|
|000008a0| 74 20 63 75 72 72 65 6e | 74 73 20 61 73 20 6c 6f |t curren|ts as lo|
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|000008c0| 6f 6d 69 6e 61 6c 20 76 | 6f 6c 74 61 67 65 20 69 |ominal v|oltage i|
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|000008f0| 61 6e 63 65 73 20 61 76 | 61 69 6c 61 62 6c 65 2e |ances av|ailable.|
|00000900| 20 53 6f 6d 65 20 61 64 | 64 69 74 69 6f 6e 61 6c | Some ad|ditional|
|00000910| 20 66 65 61 74 75 72 65 | 73 20 61 72 65 3a 20 6d | feature|s are: m|
|00000920| 61 78 69 6d 75 6d 20 64 | 79 6e 61 6d 69 63 20 69 |aximum d|ynamic i|
|00000930| 6d 70 65 64 61 6e 63 65 | 20 6f 66 20 31 6f 68 6d |mpedance| of 1ohm|
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|00000950| 20 65 78 63 65 6c 6c 65 | 6e 74 20 73 74 61 62 69 | excelle|nt stabi|
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|00000980| 54 68 65 20 61 64 76 61 | 6e 63 65 64 20 64 65 73 |The adva|nced des|
|00000990| 69 67 6e 2c 20 70 72 6f | 63 65 73 73 69 6e 67 20 |ign, pro|cessing |
|000009a0| 61 6e 64 20 74 65 73 74 | 69 6e 67 20 74 65 63 68 |and test|ing tech|
|000009b0| 6e 69 71 75 65 73 20 6d | 61 6b 65 20 4c 69 6e 65 |niques m|ake Line|
|000009c0| 61 72 27 73 20 4c 4d 31 | 38 35 2d 32 2e 35 20 61 |ar's LM1|85-2.5 a|
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|00000a60| 75 61 72 61 6e 74 65 65 | 64 20 74 65 6d 70 65 72 |uarantee|d temper|
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|00000ab0| 00 4b 04 06 00 3f 04 44 | 42 20 39 32 44 53 4c 54 |.K...?.D|B 92DSLT|
|00000ac0| 43 34 38 35 4c 6f 77 20 | 50 6f 77 65 72 20 52 53 |C485Low |Power RS|
|00000ad0| 34 38 35 20 49 6e 74 65 | 72 66 61 63 65 20 54 72 |485 Inte|rface Tr|
|00000ae0| 61 6e 73 63 65 69 76 65 | 72 5c 44 41 54 41 5c 44 |ansceive|r\DATA\D|
|00000af0| 41 54 41 42 4f 4f 4b 5c | 31 39 39 32 5f 44 42 30 |ATABOOK\|1992_DB0|
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|00000b10| 35 0d 0a 4c 6f 77 20 50 | 6f 77 65 72 20 52 53 34 |5..Low P|ower RS4|
|00000b20| 38 35 20 49 6e 74 65 72 | 66 61 63 65 20 54 72 61 |85 Inter|face Tra|
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|00000b40| 50 54 49 4f 4e 0d 0a 54 | 68 65 20 4c 54 43 34 38 |PTION..T|he LTC48|
|00000b50| 35 20 69 73 20 61 20 6c | 6f 77 20 70 6f 77 65 72 |5 is a l|ow power|
|00000b60| 20 64 69 66 66 65 72 65 | 6e 74 69 61 6c 20 62 75 | differe|ntial bu|
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|00000b90| 6d 75 6c 74 69 70 6f 69 | 6e 74 20 64 61 74 61 20 |multipoi|nt data |
|00000ba0| 74 72 61 6e 73 6d 69 73 | 73 69 6f 6e 20 73 74 61 |transmis|sion sta|
|00000bb0| 6e 64 61 72 64 20 52 53 | 34 38 35 20 61 70 70 6c |ndard RS|485 appl|
|00000bc0| 69 63 61 74 69 6f 6e 73 | 20 77 69 74 68 20 65 78 |ications| with ex|
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|00000be0| 64 65 20 72 61 6e 67 65 | 20 28 31 32 56 20 74 6f |de range| (12V to|
|00000bf0| 20 2d 20 37 56 29 2e 20 | 49 74 20 61 6c 73 6f 20 | - 7V). |It also |
|00000c00| 6d 65 65 74 73 20 74 68 | 65 20 72 65 71 75 69 72 |meets th|e requir|
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|00000c20| 0d 0a 54 68 65 20 43 4d | 4f 53 20 64 65 73 69 67 |..The CM|OS desig|
|00000c30| 6e 20 6f 66 66 65 72 73 | 20 73 69 67 6e 69 66 69 |n offers| signifi|
|00000c40| 63 61 6e 74 20 70 6f 77 | 65 72 20 73 61 76 69 6e |cant pow|er savin|
|00000c50| 67 73 20 6f 76 65 72 20 | 69 74 73 20 62 69 70 6f |gs over |its bipo|
|00000c60| 6c 61 72 20 63 6f 75 6e | 74 65 72 70 61 72 74 20 |lar coun|terpart |
|00000c70| 77 69 74 68 6f 75 74 20 | 73 61 63 72 69 66 69 63 |without |sacrific|
|00000c80| 69 6e 67 20 72 75 67 67 | 65 64 6e 65 73 73 20 61 |ing rugg|edness a|
|00000c90| 67 61 69 6e 73 74 20 6f | 76 65 72 6c 6f 61 64 20 |gainst o|verload |
|00000ca0| 6f 66 20 45 53 44 20 64 | 61 6d 61 67 65 2e 0d 0a |of ESD d|amage...|
|00000cb0| 54 68 65 20 64 72 69 76 | 65 72 20 61 6e 64 20 72 |The driv|er and r|
|00000cc0| 65 63 65 69 76 65 72 20 | 66 65 61 74 75 72 65 20 |eceiver |feature |
|00000cd0| 74 68 72 65 65 2d 73 74 | 61 74 65 20 6f 75 74 70 |three-st|ate outp|
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|00000cf0| 69 76 65 72 20 6f 75 74 | 70 75 74 73 20 6d 61 69 |iver out|puts mai|
|00000d00| 6e 74 61 69 6e 69 6e 67 | 20 68 69 67 68 20 69 6d |ntaining| high im|
|00000d10| 70 65 64 61 6e 63 65 20 | 6f 76 65 72 20 74 68 65 |pedance |over the|
|00000d20| 20 65 6e 74 69 72 65 20 | 63 6f 6d 6d 6f 6e 2d 6d | entire |common-m|
|00000d30| 6f 64 65 20 72 61 6e 67 | 65 2e 20 45 78 63 65 73 |ode rang|e. Exces|
|00000d40| 73 69 76 65 20 70 6f 77 | 65 72 20 64 69 73 73 69 |sive pow|er dissi|
|00000d50| 70 61 74 69 6f 6e 20 63 | 61 75 73 65 64 20 62 79 |pation c|aused by|
|00000d60| 20 62 75 73 20 63 6f 6e | 74 65 6e 74 69 6f 6e 20 | bus con|tention |
|00000d70| 6f 72 20 66 61 75 6c 74 | 73 20 69 73 20 70 72 65 |or fault|s is pre|
|00000d80| 76 65 6e 74 65 64 20 62 | 79 20 61 20 74 68 65 72 |vented b|y a ther|
|00000d90| 6d 61 6c 20 73 68 75 74 | 64 6f 77 6e 20 63 69 72 |mal shut|down cir|
|00000da0| 63 75 69 74 20 77 68 69 | 63 68 20 66 6f 72 63 65 |cuit whi|ch force|
|00000db0| 73 20 74 68 65 20 64 72 | 69 76 65 72 20 6f 75 74 |s the dr|iver out|
|00000dc0| 70 75 74 73 20 69 6e 74 | 6f 20 61 20 68 69 67 68 |puts int|o a high|
|00000dd0| 20 69 6d 70 65 64 61 6e | 63 65 20 73 74 61 74 65 | impedan|ce state|
|00000de0| 2e 0d 0a 54 68 65 20 72 | 65 63 65 69 76 65 72 20 |...The r|eceiver |
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|00000ed0| 70 0d 0a 20 44 65 73 69 | 67 6e 65 64 20 66 6f 72 |p.. Desi|gned for|
|00000ee0| 20 52 53 34 38 35 20 49 | 6e 74 65 72 66 61 63 65 | RS485 I|nterface|
|00000ef0| 20 41 70 70 6c 69 63 61 | 74 69 6f 6e 73 0d 0a 20 | Applica|tions.. |
|00000f00| 53 69 6e 67 6c 65 20 35 | 56 20 73 75 70 70 6c 79 |Single 5|V supply|
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|00000f70| 20 54 68 65 72 6d 61 6c | 20 53 68 75 74 64 6f 77 | Thermal| Shutdow|
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|00000ff0| 20 4d 61 69 6e 74 61 69 | 6e 73 20 48 69 67 68 20 | Maintai|ns High |
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|00001120| 4c 49 43 41 54 49 4f 4e | 53 0d 0a 20 4c 6f 77 20 |LICATION|S.. Low |
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|00001140| 32 20 54 72 61 6e 73 63 | 65 69 76 65 72 0d 0a 20 |2 Transc|eiver.. |
|00001150| 4c 65 76 65 6c 20 54 72 | 61 6e 73 6c 61 74 6f 72 |Level Tr|anslator|
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|00001bc0| 4d 4f 53 20 67 61 74 65 | 73 20 66 72 6f 6d 20 45 |MOS gate|s from E|
|00001bd0| 53 44 20 76 6f 6c 74 61 | 67 65 73 20 77 65 6c 6c |SD volta|ges well|
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|00001c00| 65 63 74 65 64 20 63 75 | 72 72 65 6e 74 20 69 6e |ected cu|rrent in|
|00001c10| 20 74 68 65 20 4e 2d 77 | 65 6c 6c 20 6f 72 20 73 | the N-w|ell or s|
|00001c20| 75 62 73 74 72 61 74 65 | 20 63 6f 6e 73 69 73 74 |ubstrate| consist|
|00001c30| 73 20 6f 66 20 6d 61 6a | 6f 72 69 74 79 20 63 61 |s of maj|ority ca|
|00001c40| 72 72 69 65 72 73 2c 20 | 6c 61 74 63 68 75 70 20 |rriers, |latchup |
|00001c50| 69 73 20 70 72 65 76 65 | 6e 74 65 64 20 62 79 20 |is preve|nted by |
|00001c60| 63 61 72 65 66 75 6c 20 | 6c 61 79 6f 75 74 20 74 |careful |layout t|
|00001c70| 65 63 68 6e 69 71 75 65 | 73 2e 0d 0a 50 72 6f 70 |echnique|s...Prop|
|00001c80| 61 67 61 74 69 6f 6e 20 | 44 65 6c 61 79 0d 0a 4d |agation |Delay..M|
|00001c90| 61 6e 79 20 64 69 67 69 | 74 61 6c 20 65 6e 63 6f |any digi|tal enco|
|00001ca0| 64 69 6e 67 20 73 63 68 | 65 6d 65 73 20 61 72 65 |ding sch|emes are|
|00001cb0| 20 64 65 70 65 6e 64 65 | 6e 74 20 75 70 6f 6e 20 | depende|nt upon |
|00001cc0| 74 68 65 20 64 69 66 66 | 65 72 65 6e 63 65 20 69 |the diff|erence i|
|00001cd0| 6e 20 74 68 65 20 70 72 | 6f 70 61 67 61 74 69 6f |n the pr|opagatio|
|00001ce0| 6e 20 64 65 6c 61 79 20 | 74 69 6d 65 73 20 6f 66 |n delay |times of|
|00001cf0| 20 74 68 65 20 64 72 69 | 76 65 72 20 61 6e 64 20 | the dri|ver and |
|00001d00| 74 68 65 20 72 65 63 65 | 69 76 65 72 2e 20 55 73 |the rece|iver. Us|
|00001d10| 69 6e 67 20 74 68 65 20 | 74 65 73 74 20 63 69 72 |ing the |test cir|
|00001d20| 63 75 69 74 20 6f 66 20 | 46 69 67 75 72 65 20 31 |cuit of |Figure 1|
|00001d30| 33 2c 20 46 69 67 75 72 | 65 73 20 31 31 20 61 6e |3, Figur|es 11 an|
|00001d40| 64 20 31 32 20 73 68 6f | 77 20 74 68 65 20 74 79 |d 12 sho|w the ty|
|00001d50| 70 69 63 61 6c 20 4c 54 | 43 34 38 35 20 72 65 63 |pical LT|C485 rec|
|00001d60| 65 69 76 65 72 20 70 72 | 6f 70 61 67 61 74 69 6f |eiver pr|opagatio|
|00001d70| 6e 20 64 65 6c 61 79 2e | 0d 0a 54 68 65 20 72 65 |n delay.|..The re|
|00001d80| 63 65 69 76 65 72 20 64 | 65 6c 61 79 20 74 69 6d |ceiver d|elay tim|
|00001d90| 65 73 20 61 72 65 3a 0d | 0a 5b 74 20 50 4c 48 20 |es are:.|.[t PLH |
|00001da0| 2d 20 74 20 50 48 4c 20 | 5d 20 3d 20 39 6e 73 20 |- t PHL |] = 9ns |
|00001db0| 54 79 70 2c 20 56 20 43 | 43 20 3d 20 35 56 0d 0a |Typ, V C|C = 5V..|
|00001dc0| 54 68 65 20 64 72 69 76 | 65 72 20 73 6b 65 77 20 |The driv|er skew |
|00001dd0| 74 69 6d 65 73 20 61 72 | 65 3a 0d 0a 53 6b 65 77 |times ar|e:..Skew|
|00001de0| 20 3d 20 35 6e 73 20 54 | 79 70 2c 20 56 20 43 43 | = 5ns T|yp, V CC|
|00001df0| 20 3d 20 35 56 20 31 30 | 6e 73 20 4d 61 78 2c 20 | = 5V 10|ns Max, |
|00001e00| 56 20 43 43 20 3d 20 35 | 56 2c 20 54 20 41 20 3d |V CC = 5|V, T A =|
|00001e10| 20 2d 20 34 30 64 65 67 | 72 65 65 43 20 74 6f 20 | - 40deg|reeC to |
|00001e20| 38 35 64 65 67 72 65 65 | 43 0d 0a 0d 0a 41 50 50 |85degree|C....APP|
|00001e30| 4c 49 43 41 54 49 4f 4e | 53 20 49 4e 46 4f 52 4d |LICATION|S INFORM|
|00001e40| 41 54 49 4f 4e 0d 0a 4c | 54 43 34 38 35 20 4c 69 |ATION..L|TC485 Li|
|00001e50| 6e 65 20 4c 65 6e 67 74 | 68 20 76 73 20 44 61 74 |ne Lengt|h vs Dat|
|00001e60| 61 20 52 61 74 65 0d 0a | 54 68 65 20 6d 61 78 69 |a Rate..|The maxi|
|00001e70| 6d 75 6d 20 6c 69 6e 65 | 20 6c 65 6e 67 74 68 20 |mum line| length |
|00001e80| 61 6c 6c 6f 77 61 62 6c | 65 20 66 6f 72 20 74 68 |allowabl|e for th|
|00001e90| 65 20 52 53 34 32 32 2f | 52 53 34 38 35 20 73 74 |e RS422/|RS485 st|
|00001ea0| 61 6e 64 61 72 64 20 69 | 73 20 34 30 30 30 20 66 |andard i|s 4000 f|
|00001eb0| 65 65 74 2e 0d 0a 55 73 | 69 6e 67 20 74 68 65 20 |eet...Us|ing the |
|00001ec0| 74 65 73 74 20 63 69 72 | 63 75 69 74 20 69 6e 20 |test cir|cuit in |
|00001ed0| 46 69 67 75 72 65 20 31 | 34 2c 20 46 69 67 75 72 |Figure 1|4, Figur|
|00001ee0| 65 73 20 31 35 20 61 6e | 64 20 31 36 20 73 68 6f |es 15 an|d 16 sho|
|00001ef0| 77 20 74 68 61 74 20 77 | 69 74 68 20 7e 20 32 30 |w that w|ith ~ 20|
|00001f00| 56 20 50 2d 50 20 63 6f | 6d 6d 6f 6e 2d 6d 6f 64 |V P-P co|mmon-mod|
|00001f10| 65 20 6e 6f 69 73 65 20 | 69 6e 6a 65 63 74 65 64 |e noise |injected|
|00001f20| 20 6f 6e 20 74 68 65 20 | 6c 69 6e 65 2c 20 54 68 | on the |line, Th|
|00001f30| 65 20 4c 54 43 34 38 35 | 20 69 73 20 61 62 6c 65 |e LTC485| is able|
|00001f40| 20 74 6f 20 72 65 63 6f | 6e 73 74 72 75 63 74 20 | to reco|nstruct |
|00001f50| 74 68 65 20 64 61 74 61 | 20 73 74 72 65 61 6d 20 |the data| stream |
|00001f60| 61 74 20 74 68 65 20 65 | 6e 64 20 6f 66 20 34 30 |at the e|nd of 40|
|00001f70| 30 30 20 66 65 65 74 20 | 6f 66 20 74 77 69 73 74 |00 feet |of twist|
|00001f80| 65 64 20 70 61 69 72 20 | 77 69 72 65 2e 0d 0a 66 |ed pair |wire...f|
|00001f90| 49 47 55 52 45 53 20 31 | 37 20 41 4e 44 20 31 38 |IGURES 1|7 AND 18|
|00001fa0| 20 53 48 4f 57 20 54 48 | 41 54 20 54 48 45 20 6c | SHOW TH|AT THE l|
|00001fb0| 74 63 34 38 35 20 49 53 | 20 61 62 6c 65 20 74 6f |tc485 IS| able to|
|00001fc0| 20 63 6f 6e 66 6f 72 74 | 61 62 6c 79 20 64 72 69 | confort|ably dri|
|00001fd0| 76 65 20 34 30 30 30 20 | 66 65 65 74 20 6f 66 20 |ve 4000 |feet of |
|00001fe0| 77 69 72 65 20 61 74 20 | 31 31 30 6b 48 7a 2e 07 |wire at |110kHz..|
|00001ff0| 00 00 00 00 00 38 15 01 | 00 33 15 02 00 31 15 00 |.....8..|.3...1..|
|00002000| 03 00 2b 15 04 00 06 15 | 05 00 f0 14 06 00 e4 14 |..+.....|........|
|00002010| 44 42 20 39 32 44 53 4c | 54 43 34 38 36 51 75 61 |DB 92DSL|TC486Qua|
|00002020| 64 20 4c 6f 77 20 50 6f | 77 65 72 20 52 53 34 38 |d Low Po|wer RS48|
|00002030| 35 20 44 72 69 76 65 72 | 5c 44 41 54 41 5c 44 41 |5 Driver|\DATA\DA|
|00002040| 54 41 42 4f 4f 4b 5c 31 | 39 39 32 5f 44 42 30 34 |TABOOK\1|992_DB04|
|00002050| 38 36 5f 5f 5f 78 2e 70 | 64 66 4c 54 43 34 38 36 |86___x.p|dfLTC486|
|00002060| 20 51 75 61 64 20 4c 6f | 77 20 50 6f 77 65 72 20 | Quad Lo|w Power |
|00002070| 52 53 34 38 35 20 44 72 | 69 76 65 72 0d 0a 46 45 |RS485 Dr|iver..FE|
|00002080| 41 54 55 52 45 53 0d 0a | 20 56 65 72 79 20 4c 6f |ATURES..| Very Lo|
|00002090| 77 20 50 6f 77 65 72 3a | 20 49 20 43 43 20 3d 20 |w Power:| I CC = |
|000020a0| 31 31 30 75 41 20 54 79 | 70 0d 0a 20 44 65 73 69 |110uA Ty|p.. Desi|
|000020b0| 67 6e 65 64 20 66 6f 72 | 20 52 53 34 38 35 20 6f |gned for| RS485 o|
|000020c0| 72 20 52 53 34 32 32 20 | 41 70 70 6c 69 63 61 74 |r RS422 |Applicat|
|000020d0| 69 6f 6e 73 0d 0a 20 53 | 69 6e 67 6c 65 20 35 56 |ions.. S|ingle 5V|
|000020e0| 20 53 75 70 70 6c 79 0d | 0a 20 2d 20 37 56 20 74 | Supply.|. - 7V t|
|000020f0| 6f 20 31 32 56 20 42 75 | 73 20 43 6f 6d 6d 6f 6e |o 12V Bu|s Common|
|00002100| 2d 4d 6f 64 65 20 52 61 | 6e 67 65 20 50 65 72 6d |-Mode Ra|nge Perm|
|00002110| 69 74 73 20 2b 2d 20 37 | 56 20 47 4e 44 20 44 69 |its +- 7|V GND Di|
|00002120| 66 66 65 72 65 6e 63 65 | 20 42 65 74 77 65 65 6e |fference| Between|
|00002130| 20 44 65 76 69 63 65 73 | 20 6f 6e 20 74 68 65 20 | Devices| on the |
|00002140| 42 75 73 0d 0a 20 54 68 | 65 72 6d 61 6c 20 53 68 |Bus.. Th|ermal Sh|
|00002150| 75 74 64 6f 77 6e 20 50 | 72 6f 74 65 63 74 69 6f |utdown P|rotectio|
|00002160| 6e 0d 0a 20 50 6f 77 65 | 72 2d 55 70 2f 44 6f 77 |n.. Powe|r-Up/Dow|
|00002170| 6e 20 47 6c 69 74 63 68 | 2d 46 72 65 65 20 44 72 |n Glitch|-Free Dr|
|00002180| 69 76 65 72 20 4f 75 74 | 70 75 74 73 20 50 65 72 |iver Out|puts Per|
|00002190| 6d 69 74 20 4c 69 76 65 | 20 49 6e 73 65 72 74 69 |mit Live| Inserti|
|000021a0| 6f 6e 2f 52 65 6d 6f 76 | 61 6c 20 6f 66 20 50 61 |on/Remov|al of Pa|
|000021b0| 63 6b 61 67 65 0d 0a 20 | 44 72 69 76 65 72 20 4d |ckage.. |Driver M|
|000021c0| 61 69 6e 74 61 69 6e 73 | 20 48 69 67 68 20 49 6d |aintains| High Im|
|000021d0| 70 65 64 61 6e 63 65 20 | 69 6e 20 54 68 72 65 65 |pedance |in Three|
|000021e0| 2d 53 74 61 74 65 20 6f | 72 20 77 69 74 68 20 74 |-State o|r with t|
|000021f0| 68 65 20 50 6f 77 65 72 | 20 4f 66 66 0d 0a 20 32 |he Power| Off.. 2|
|00002200| 38 6e 73 20 54 79 70 69 | 63 61 6c 20 44 72 69 76 |8ns Typi|cal Driv|
|00002210| 65 72 20 50 72 6f 70 61 | 67 61 74 69 6f 6e 20 44 |er Propa|gation D|
|00002220| 65 6c 61 79 73 20 77 69 | 74 68 20 35 6e 73 20 53 |elays wi|th 5ns S|
|00002230| 6b 65 77 0d 0a 20 50 69 | 6e 20 43 6f 6d 70 61 74 |kew.. Pi|n Compat|
|00002240| 69 62 6c 65 20 77 69 74 | 68 20 74 68 65 20 53 4e |ible wit|h the SN|
|00002250| 37 35 31 37 32 2c 20 44 | 53 39 36 31 37 32 2c 20 |75172, D|S96172, |
|00002260| 75 41 39 36 31 37 32 2c | 20 61 6e 64 20 44 53 39 |uA96172,| and DS9|
|00002270| 36 46 31 37 32 0d 0a 41 | 50 50 4c 49 43 41 54 49 |6F172..A|PPLICATI|
|00002280| 4f 4e 53 0d 0a 20 4c 6f | 77 20 50 6f 77 65 72 20 |ONS.. Lo|w Power |
|00002290| 52 53 34 38 35 2f 52 53 | 34 32 32 20 44 72 69 76 |RS485/RS|422 Driv|
|000022a0| 65 72 73 0d 0a 20 4c 65 | 76 65 6c 20 54 72 61 6e |ers.. Le|vel Tran|
|000022b0| 73 6c 61 74 6f 72 0d 0a | 44 45 53 43 52 49 50 54 |slator..|DESCRIPT|
|000022c0| 49 4f 4e 0d 0a 54 68 65 | 20 4c 54 43 34 38 36 20 |ION..The| LTC486 |
|000022d0| 69 73 20 61 20 6c 6f 77 | 20 70 6f 77 65 72 20 64 |is a low| power d|
|000022e0| 69 66 66 65 72 65 6e 74 | 69 61 6c 20 62 75 73 2f |ifferent|ial bus/|
|000022f0| 6c 69 6e 65 20 64 72 69 | 76 65 72 20 64 65 73 69 |line dri|ver desi|
|00002300| 67 6e 65 64 20 66 6f 72 | 20 6d 75 6c 74 69 70 6f |gned for| multipo|
|00002310| 69 6e 74 20 64 61 74 61 | 20 74 72 61 6e 73 6d 69 |int data| transmi|
|00002320| 73 73 69 6f 6e 20 73 74 | 61 6e 64 61 72 64 20 52 |ssion st|andard R|
|00002330| 53 34 38 35 20 61 70 70 | 6c 69 63 61 74 69 6f 6e |S485 app|lication|
|00002340| 73 20 77 69 74 68 20 65 | 78 74 65 6e 64 65 64 20 |s with e|xtended |
|00002350| 63 6f 6d 6d 6f 6e 2d 6d | 6f 64 65 20 72 61 6e 67 |common-m|ode rang|
|00002360| 65 20 28 31 32 56 20 74 | 6f 20 2d 37 56 29 2e 20 |e (12V t|o -7V). |
|00002370| 49 74 20 61 6c 73 6f 20 | 6d 65 65 74 73 20 52 53 |It also |meets RS|
|00002380| 34 32 32 20 72 65 71 75 | 69 72 65 6d 65 6e 74 73 |422 requ|irements|
|00002390| 2e 0d 0a 54 68 65 20 43 | 4d 4f 53 20 64 65 73 69 |...The C|MOS desi|
|000023a0| 67 6e 20 6f 66 66 65 72 | 73 20 73 69 67 6e 69 66 |gn offer|s signif|
|000023b0| 69 63 61 6e 74 20 70 6f | 77 65 72 20 73 61 76 69 |icant po|wer savi|
|000023c0| 6e 67 73 20 6f 76 65 72 | 20 69 74 73 20 62 69 70 |ngs over| its bip|
|000023d0| 6f 6c 61 72 20 63 6f 75 | 6e 74 65 72 70 61 72 74 |olar cou|nterpart|
|000023e0| 20 77 69 74 68 6f 75 74 | 20 73 61 63 72 69 66 69 | without| sacrifi|
|000023f0| 63 69 6e 67 20 72 75 67 | 67 65 64 6e 65 73 73 20 |cing rug|gedness |
|00002400| 61 67 61 69 6e 73 74 20 | 6f 76 65 72 6c 6f 61 64 |against |overload|
|00002410| 20 6f 72 20 45 53 44 20 | 64 61 6d 61 67 65 2e 0d | or ESD |damage..|
|00002420| 0a 54 68 65 20 64 72 69 | 76 65 72 20 66 65 61 74 |.The dri|ver feat|
|00002430| 75 72 65 73 20 74 68 72 | 65 65 2d 73 74 61 74 65 |ures thr|ee-state|
|00002440| 20 6f 75 74 70 75 74 73 | 2c 20 77 69 74 68 20 74 | outputs|, with t|
|00002450| 68 65 20 64 72 69 76 65 | 72 20 6f 75 74 70 75 74 |he drive|r output|
|00002460| 73 20 6d 61 69 6e 74 61 | 69 6e 69 6e 67 20 68 69 |s mainta|ining hi|
|00002470| 67 68 20 69 6d 70 65 64 | 61 6e 63 65 20 6f 76 65 |gh imped|ance ove|
|00002480| 72 20 74 68 65 20 65 6e | 74 69 72 65 20 63 6f 6d |r the en|tire com|
|00002490| 6d 6f 6e 2d 6d 6f 64 65 | 20 72 61 6e 67 65 2e 20 |mon-mode| range. |
|000024a0| 45 78 63 65 73 73 69 76 | 65 20 70 6f 77 65 72 20 |Excessiv|e power |
|000024b0| 64 69 73 73 69 70 61 74 | 69 6f 6e 20 63 61 75 73 |dissipat|ion caus|
|000024c0| 65 64 20 62 79 20 62 75 | 73 20 63 6f 6e 74 65 6e |ed by bu|s conten|
|000024d0| 74 69 6f 6e 20 6f 72 20 | 66 61 75 6c 74 73 20 69 |tion or |faults i|
|000024e0| 73 20 70 72 65 76 65 6e | 74 65 64 20 62 79 20 61 |s preven|ted by a|
|000024f0| 20 74 68 65 72 6d 61 6c | 20 73 68 75 74 64 6f 77 | thermal| shutdow|
|00002500| 6e 20 63 69 72 63 75 69 | 74 20 77 68 69 63 68 20 |n circui|t which |
|00002510| 66 6f 72 63 65 73 20 74 | 68 65 20 64 72 69 76 65 |forces t|he drive|
|00002520| 72 20 6f 75 74 70 75 74 | 73 20 69 6e 74 6f 20 61 |r output|s into a|
|00002530| 20 68 69 67 68 20 69 6d | 70 65 64 61 6e 63 65 20 | high im|pedance |
|00002540| 73 74 61 74 65 2e 0d 0a | 42 6f 74 68 20 41 43 20 |state...|Both AC |
|00002550| 61 6e 64 20 44 43 20 73 | 70 65 63 69 66 69 63 61 |and DC s|pecifica|
|00002560| 74 69 6f 6e 73 20 61 72 | 65 20 67 75 61 72 61 6e |tions ar|e guaran|
|00002570| 74 65 65 64 20 66 72 6f | 6d 20 30 64 65 67 72 65 |teed fro|m 0degre|
|00002580| 65 43 20 74 6f 20 37 30 | 64 65 67 72 65 65 43 20 |eC to 70|degreeC |
|00002590| 28 43 6f 6d 6d 65 72 63 | 69 61 6c 29 2c 20 2d 20 |(Commerc|ial), - |
|000025a0| 34 30 64 65 67 72 65 65 | 43 20 74 6f 20 38 35 64 |40degree|C to 85d|
|000025b0| 65 67 72 65 65 43 20 28 | 49 6e 64 75 73 74 72 69 |egreeC (|Industri|
|000025c0| 61 6c 29 2c 20 6f 76 65 | 72 20 74 68 65 20 34 2e |al), ove|r the 4.|
|000025d0| 37 35 56 20 74 6f 20 35 | 2e 32 35 56 20 73 75 70 |75V to 5|.25V sup|
|000025e0| 70 6c 79 20 76 6f 6c 74 | 61 67 65 20 72 61 6e 67 |ply volt|age rang|
|000025f0| 65 2e 0d 0a 41 50 50 4c | 49 43 41 54 49 4f 4e 53 |e...APPL|ICATIONS|
|00002600| 20 49 4e 46 4f 52 4d 41 | 54 49 4f 4e 0d 0a 54 79 | INFORMA|TION..Ty|
|00002610| 70 69 63 61 6c 20 41 70 | 70 6c 69 63 61 74 69 6f |pical Ap|plicatio|
|00002620| 6e 0d 0a 41 20 74 79 70 | 69 63 61 6c 20 63 6f 6e |n..A typ|ical con|
|00002630| 6e 65 63 74 69 6f 6e 20 | 6f 66 20 74 68 65 20 4c |nection |of the L|
|00002640| 54 43 34 38 36 20 69 73 | 20 73 68 6f 77 6e 20 69 |TC486 is| shown i|
|00002650| 6e 20 46 69 67 75 72 65 | 20 36 2e 20 41 20 74 77 |n Figure| 6. A tw|
|00002660| 69 73 74 65 64 20 70 61 | 69 72 20 6f 66 20 77 69 |isted pa|ir of wi|
|00002670| 72 65 73 20 63 6f 6e 6e | 65 63 74 20 75 70 20 74 |res conn|ect up t|
|00002680| 6f 20 33 32 20 64 72 69 | 76 65 72 73 20 61 6e 64 |o 32 dri|vers and|
|00002690| 20 72 65 63 65 69 76 65 | 72 73 20 66 6f 72 20 68 | receive|rs for h|
|000026a0| 61 6c 66 20 64 75 70 6c | 65 78 20 64 61 74 61 20 |alf dupl|ex data |
|000026b0| 74 72 61 6e 73 6d 69 73 | 73 69 6f 6e 2e 20 54 68 |transmis|sion. Th|
|000026c0| 65 72 65 20 61 72 65 20 | 6e 6f 20 72 65 73 74 72 |ere are |no restr|
|000026d0| 69 63 74 69 6f 6e 73 20 | 6f 6e 20 77 68 65 72 65 |ictions |on where|
|000026e0| 20 74 68 65 20 63 68 69 | 70 73 20 61 72 65 20 63 | the chi|ps are c|
|000026f0| 6f 6e 6e 65 63 74 65 64 | 20 74 6f 20 74 68 65 20 |onnected| to the |
|00002700| 77 69 72 65 73 2c 20 61 | 6e 64 20 69 74 20 69 73 |wires, a|nd it is|
|00002710| 6e 27 74 20 6e 65 63 65 | 73 73 61 72 79 20 74 6f |n't nece|ssary to|
|00002720| 20 68 61 76 65 20 74 68 | 65 20 63 68 69 70 73 20 | have th|e chips |
|00002730| 63 6f 6e 6e 65 63 74 65 | 64 20 61 74 20 74 68 65 |connecte|d at the|
|00002740| 20 65 6e 64 73 2e 20 48 | 6f 77 65 76 65 72 2c 20 | ends. H|owever, |
|00002750| 74 68 65 20 77 69 72 65 | 73 20 6d 75 73 74 20 62 |the wire|s must b|
|00002760| 65 20 74 65 72 6d 69 6e | 61 74 65 64 20 6f 6e 6c |e termin|ated onl|
|00002770| 79 20 61 74 20 74 68 65 | 20 65 6e 64 73 20 77 69 |y at the| ends wi|
|00002780| 74 68 20 61 20 72 65 73 | 69 73 74 6f 72 20 65 71 |th a res|istor eq|
|00002790| 75 61 6c 20 74 6f 20 74 | 68 65 69 72 20 63 68 61 |ual to t|heir cha|
|000027a0| 72 61 63 74 65 72 69 73 | 74 69 63 20 69 6d 70 65 |racteris|tic impe|
|000027b0| 64 61 6e 63 65 2c 20 74 | 79 70 69 63 61 6c 6c 79 |dance, t|ypically|
|000027c0| 20 31 32 30 6f 68 6d 73 | 2e 20 54 68 65 20 6f 70 | 120ohms|. The op|
|000027d0| 74 69 6f 6e 61 6c 20 73 | 68 69 65 6c 64 73 20 61 |tional s|hields a|
|000027e0| 72 6f 75 6e 64 20 74 68 | 65 20 74 77 69 73 74 65 |round th|e twiste|
|000027f0| 64 20 70 61 69 72 20 68 | 65 6c 70 20 72 65 64 75 |d pair h|elp redu|
|00002800| 63 65 20 75 6e 77 61 6e | 74 65 64 20 6e 6f 69 73 |ce unwan|ted nois|
|00002810| 65 2c 20 61 6e 64 20 61 | 72 65 20 63 6f 6e 6e 65 |e, and a|re conne|
|00002820| 63 74 65 64 20 74 6f 20 | 47 4e 44 20 61 74 20 6f |cted to |GND at o|
|00002830| 6e 65 20 65 6e 64 2e 0d | 0a 54 68 65 72 6d 61 6c |ne end..|.Thermal|
|00002840| 20 53 68 75 74 64 6f 77 | 6e 0d 0a 54 68 65 20 4c | Shutdow|n..The L|
|00002850| 54 43 34 38 36 20 68 61 | 73 20 61 20 74 68 65 72 |TC486 ha|s a ther|
|00002860| 6d 61 6c 20 73 68 75 74 | 64 6f 77 6e 20 66 65 61 |mal shut|down fea|
|00002870| 74 75 72 65 20 77 68 69 | 63 68 20 70 72 6f 74 65 |ture whi|ch prote|
|00002880| 63 74 73 20 74 68 65 20 | 70 61 72 74 20 66 72 6f |cts the |part fro|
|00002890| 6d 20 65 78 63 65 73 73 | 69 76 65 20 70 6f 77 65 |m excess|ive powe|
|000028a0| 72 20 64 69 73 73 69 70 | 61 74 69 6f 6e 2e 20 49 |r dissip|ation. I|
|000028b0| 66 20 74 68 65 20 6f 75 | 74 70 75 74 73 20 6f 66 |f the ou|tputs of|
|000028c0| 20 74 68 65 20 64 72 69 | 76 65 72 20 61 72 65 20 | the dri|ver are |
|000028d0| 61 63 63 69 64 65 6e 74 | 6c 79 20 73 68 6f 72 74 |accident|ly short|
|000028e0| 65 64 20 74 6f 20 61 20 | 70 6f 77 65 72 0d 0a 73 |ed to a |power..s|
|000028f0| 75 70 70 6c 79 20 6f 72 | 20 6c 6f 77 20 69 6d 70 |upply or| low imp|
|00002900| 65 64 61 6e 63 65 20 73 | 6f 75 72 63 65 2c 20 75 |edance s|ource, u|
|00002910| 70 20 74 6f 20 32 35 30 | 6d 41 20 63 61 6e 20 66 |p to 250|mA can f|
|00002920| 6c 6f 77 20 74 68 72 6f | 75 67 68 20 74 68 65 20 |low thro|ugh the |
|00002930| 70 61 72 74 2e 20 54 68 | 65 20 74 68 65 72 6d 61 |part. Th|e therma|
|00002940| 6c 20 73 68 75 74 64 6f | 77 6e 20 63 69 72 63 75 |l shutdo|wn circu|
|00002950| 69 74 20 64 69 73 61 62 | 6c 65 73 20 74 68 65 20 |it disab|les the |
|00002960| 64 72 69 76 65 72 20 6f | 75 74 70 75 74 73 20 77 |driver o|utputs w|
|00002970| 68 65 6e 20 74 68 65 20 | 69 6e 74 65 72 6e 61 6c |hen the |internal|
|00002980| 20 74 65 6d 70 65 72 61 | 74 75 72 65 20 72 65 61 | tempera|ture rea|
|00002990| 63 68 65 73 20 31 35 30 | 64 65 67 72 65 65 43 20 |ches 150|degreeC |
|000029a0| 61 6e 64 20 74 75 72 6e | 73 20 74 68 65 6d 20 62 |and turn|s them b|
|000029b0| 61 63 6b 20 6f 6e 20 77 | 68 65 6e 20 74 68 65 20 |ack on w|hen the |
|000029c0| 74 65 6d 70 65 72 61 74 | 75 72 65 20 63 6f 6f 6c |temperat|ure cool|
|000029d0| 73 20 74 6f 20 31 33 30 | 64 65 67 72 65 65 43 2e |s to 130|degreeC.|
|000029e0| 20 49 66 20 74 68 65 20 | 6f 75 74 70 75 74 73 20 | If the |outputs |
|000029f0| 6f 66 20 74 77 6f 20 6f | 72 20 6d 6f 72 65 20 4c |of two o|r more L|
|00002a00| 54 43 34 38 36 20 64 72 | 69 76 65 72 73 20 61 72 |TC486 dr|ivers ar|
|00002a10| 65 20 73 68 6f 72 74 65 | 64 20 64 69 72 65 63 74 |e shorte|d direct|
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|00004640| 64 72 69 76 65 72 20 6f | 75 74 70 75 74 73 20 65 |driver o|utputs e|
|00004650| 6e 61 62 6c 65 64 20 77 | 69 6c 6c 20 66 6f 72 63 |nabled w|ill forc|
|00004660| 65 20 44 4f 31 41 20 68 | 69 67 68 20 61 6e 64 20 |e DO1A h|igh and |
|00004670| 44 4f 31 42 20 6c 6f 77 | 2e 0d 0a 44 4f 31 41 20 |DO1B low|...DO1A |
|00004680| 28 50 69 6e 20 32 29 3a | 20 44 72 69 76 65 72 20 |(Pin 2):| Driver |
|00004690| 31 20 6f 75 74 70 75 74 | 2e 0d 0a 44 4f 31 42 20 |1 output|...DO1B |
|000046a0| 28 50 69 6e 20 33 29 3a | 20 44 72 69 76 65 72 20 |(Pin 3):| Driver |
|000046b0| 31 20 6f 75 74 70 75 74 | 2e 0d 0a 45 4e 31 32 20 |1 output|...EN12 |
|000046c0| 28 50 69 6e 20 34 29 3a | 20 44 72 69 76 65 72 20 |(Pin 4):| Driver |
|000046d0| 31 20 61 6e 64 20 32 20 | 6f 75 74 70 75 74 73 20 |1 and 2 |outputs |
|000046e0| 65 6e 61 62 6c 65 64 2e | 20 20 53 65 65 20 46 75 |enabled.|  See Fu|
|000046f0| 6e 63 74 69 6f 6e 20 54 | 61 62 6c 65 2e 0d 0a 44 |nction T|able...D|
|00004700| 4f 32 42 20 28 50 69 6e | 20 35 29 3a 20 44 72 69 |O2B (Pin| 5): Dri|
|00004710| 76 65 72 20 32 20 6f 75 | 74 70 75 74 2e 0d 0a 44 |ver 2 ou|tput...D|
|00004720| 4f 32 41 20 28 50 69 6e | 20 36 29 3a 20 44 72 69 |O2A (Pin| 6): Dri|
|00004730| 76 65 72 20 32 20 6f 75 | 74 70 75 74 2e 0d 0a 44 |ver 2 ou|tput...D|
|00004740| 49 32 20 20 28 50 69 6e | 20 37 29 3a 20 44 72 69 |I2  (Pin| 7): Dri|
|00004750| 76 65 72 20 32 20 69 6e | 70 75 74 2e 20 20 52 65 |ver 2 in|put.  Re|
|00004760| 66 65 72 20 74 6f 20 44 | 49 31 2e 0d 0a 47 4e 44 |fer to D|I1...GND|
|00004770| 20 28 50 69 6e 20 38 29 | 3a 20 47 4e 44 20 63 6f | (Pin 8)|: GND co|
|00004780| 6e 6e 65 63 74 69 6f 6e | 0d 0a 44 49 33 20 28 50 |nnection|..DI3 (P|
|00004790| 69 6e 20 39 29 3a 20 44 | 72 69 76 65 72 20 33 20 |in 9): D|river 3 |
|000047a0| 69 6e 70 75 74 2e 20 20 | 52 65 66 65 72 20 74 6f |input.  |Refer to|
|000047b0| 20 64 49 31 2e 0d 0a 44 | 4f 33 41 20 28 50 69 6e | dI1...D|O3A (Pin|
|000047c0| 20 31 30 29 3a 20 44 72 | 69 76 65 72 20 33 20 6f | 10): Dr|iver 3 o|
|000047d0| 75 74 70 75 74 2e 0d 0a | 44 4f 33 42 20 28 50 69 |utput...|DO3B (Pi|
|000047e0| 6e 20 31 31 29 3a 20 44 | 72 69 76 65 72 20 33 20 |n 11): D|river 3 |
|000047f0| 6f 75 74 70 75 74 2e 0d | 0a 45 4e 33 34 20 28 50 |output..|.EN34 (P|
|00004800| 69 6e 20 31 32 29 3a 20 | 44 72 69 76 65 72 20 33 |in 12): |Driver 3|
|00004810| 20 61 6e 64 20 34 20 6f | 75 74 70 75 74 73 20 65 | and 4 o|utputs e|
|00004820| 6e 61 62 6c 65 64 2e 20 | 20 53 65 65 20 46 75 6e |nabled. | See Fun|
|00004830| 63 74 69 6f 6e 20 54 61 | 62 6c 65 73 20 66 6f 72 |ction Ta|bles for|
|00004840| 20 64 65 74 61 69 6c 73 | 2e 0d 0a 44 4f 34 42 20 | details|...DO4B |
|00004850| 28 50 69 6e 20 31 33 29 | 3a 20 44 72 69 76 65 72 |(Pin 13)|: Driver|
|00004860| 20 34 20 6f 75 74 70 75 | 74 2e 0d 0a 44 4f 34 41 | 4 outpu|t...DO4A|
|00004870| 20 28 50 69 6e 20 31 34 | 29 3a 20 44 72 69 76 65 | (Pin 14|): Drive|
|00004880| 72 20 34 20 6f 75 74 70 | 75 74 2e 0d 0a 44 49 34 |r 4 outp|ut...DI4|
|00004890| 20 28 50 69 6e 20 31 35 | 29 3a 20 44 72 69 76 65 | (Pin 15|): Drive|
|000048a0| 72 20 34 20 69 6e 70 75 | 74 2e 20 20 52 65 66 65 |r 4 inpu|t.  Refe|
|000048b0| 72 20 44 49 31 2e 0d 0a | 56 63 63 20 28 50 69 6e |r DI1...|Vcc (Pin|
|000048c0| 20 31 36 29 3a 20 50 6f | 73 69 74 69 76 65 20 73 | 16): Po|sitive s|
|000048d0| 75 70 70 6c 79 3b 20 34 | 2e 37 35 20 3d 20 56 63 |upply; 4|.75 = Vc|
|000048e0| 63 20 3c 20 35 2e 32 35 | 2e 0d 0a 41 50 50 4c 49 |c < 5.25|...APPLI|
|000048f0| 43 41 54 49 4f 4e 53 20 | 49 4e 46 4f 52 4d 41 54 |CATIONS |INFORMAT|
|00004900| 49 4f 4e 0d 0a 54 79 70 | 69 63 61 6c 20 41 70 70 |ION..Typ|ical App|
|00004910| 6c 69 63 61 74 69 6f 6e | 20 0d 0a 41 20 74 79 70 |lication| ..A typ|
|00004920| 69 63 61 6c 20 63 6f 6e | 6e 65 63 74 69 6f 6e 20 |ical con|nection |
|00004930| 6f 66 20 74 68 65 20 4c | 54 43 34 38 37 20 69 73 |of the L|TC487 is|
|00004940| 20 73 68 6f 77 6e 20 69 | 6e 20 46 69 67 75 72 65 | shown i|n Figure|
|00004950| 20 36 2e 20 20 41 20 74 | 77 69 73 74 65 64 20 70 | 6.  A t|wisted p|
|00004960| 61 69 72 20 6f 66 20 77 | 69 72 65 73 20 63 6f 6e |air of w|ires con|
|00004970| 6e 65 63 74 20 75 70 20 | 74 6f 20 33 32 20 64 72 |nect up |to 32 dr|
|00004980| 69 76 65 72 73 20 61 6e | 64 20 72 65 63 65 69 76 |ivers an|d receiv|
|00004990| 65 72 73 20 66 6f 72 20 | 68 61 6c 66 20 64 75 70 |ers for |half dup|
|000049a0| 6c 65 78 20 64 61 74 61 | 20 74 72 61 6e 73 6d 69 |lex data| transmi|
|000049b0| 73 73 69 6f 6e 2e 20 20 | 54 68 65 72 65 20 61 72 |ssion.  |There ar|
|000049c0| 65 20 6e 6f 20 72 65 73 | 74 72 69 63 74 69 6f 6e |e no res|triction|
|000049d0| 73 20 6f 6e 20 77 68 65 | 72 65 20 74 68 65 20 63 |s on whe|re the c|
|000049e0| 68 69 70 73 20 61 72 65 | 20 63 6f 6e 6e 65 63 74 |hips are| connect|
|000049f0| 65 64 20 74 6f 20 74 68 | 65 20 77 69 72 65 73 2c |ed to th|e wires,|
|00004a00| 20 61 6e 64 20 69 74 20 | 69 73 6e 27 74 20 6e 65 | and it |isn't ne|
|00004a10| 63 61 73 73 61 72 79 20 | 74 6f 20 68 61 76 65 20 |cassary |to have |
|00004a20| 74 68 65 20 63 68 69 70 | 73 20 63 6f 6e 6e 65 63 |the chip|s connec|
|00004a30| 74 65 64 20 61 74 20 74 | 68 65 20 65 6e 64 73 2e |ted at t|he ends.|
|00004a40| 20 20 48 6f 77 65 76 65 | 72 2c 20 74 68 65 20 77 |  Howeve|r, the w|
|00004a50| 69 72 65 73 20 6d 75 73 | 74 20 62 65 20 74 65 72 |ires mus|t be ter|
|00004a60| 6d 69 6e 61 74 65 64 20 | 6f 6e 6c 79 20 61 74 20 |minated |only at |
|00004a70| 74 68 65 20 65 6e 64 73 | 20 77 69 74 68 20 61 20 |the ends| with a |
|00004a80| 72 65 73 69 73 74 6f 72 | 20 65 71 75 61 6c 20 74 |resistor| equal t|
|00004a90| 6f 20 74 68 65 69 72 20 | 63 68 61 72 61 63 74 65 |o their |characte|
|00004aa0| 72 69 73 74 69 63 20 69 | 6d 70 65 64 61 6e 63 65 |ristic i|mpedance|
|00004ab0| 2c 20 74 79 70 69 63 61 | 6c 6c 79 20 31 32 30 20 |, typica|lly 120 |
|00004ac0| 6f 68 6d 73 2e 20 20 54 | 68 65 20 6f 70 74 69 6f |ohms.  T|he optio|
|00004ad0| 6e 61 6c 20 73 68 69 65 | 6c 64 73 20 61 72 6f 75 |nal shie|lds arou|
|00004ae0| 6e 64 20 74 68 65 20 74 | 77 69 73 74 65 64 20 70 |nd the t|wisted p|
|00004af0| 61 69 72 20 68 65 6c 70 | 20 72 65 64 75 63 65 20 |air help| reduce |
|00004b00| 75 6e 77 61 6e 74 65 64 | 20 6e 6f 69 73 65 2c 20 |unwanted| noise, |
|00004b10| 61 6e 64 20 61 72 65 20 | 63 6f 6e 6e 65 63 74 65 |and are |connecte|
|00004b20| 64 20 74 6f 20 47 4e 44 | 20 61 74 20 6f 6e 65 20 |d to GND| at one |
|00004b30| 65 6e 64 2e 0d 0a 54 68 | 65 72 6d 61 6c 20 53 68 |end...Th|ermal Sh|
|00004b40| 75 74 64 6f 77 6e 0d 0a | 54 68 65 20 4c 54 43 34 |utdown..|The LTC4|
|00004b50| 38 37 20 68 61 73 20 61 | 20 74 68 65 72 6d 61 6c |87 has a| thermal|
|00004b60| 20 73 68 75 74 64 6f 77 | 6e 20 66 65 61 74 75 72 | shutdow|n featur|
|00004b70| 65 20 77 68 69 63 68 20 | 70 72 6f 74 65 63 74 73 |e which |protects|
|00004b80| 20 74 68 65 20 61 70 72 | 74 20 66 72 6f 6d 20 65 | the apr|t from e|
|00004b90| 78 63 65 73 73 69 76 65 | 20 70 6f 77 65 72 20 64 |xcessive| power d|
|00004ba0| 69 73 73 69 70 61 74 69 | 6f 6e 2e 20 20 49 66 20 |issipati|on.  If |
|00004bb0| 74 68 65 20 6f 75 74 70 | 75 74 73 20 6f 66 20 74 |the outp|uts of t|
|00004bc0| 68 65 20 64 72 69 76 65 | 72 20 61 72 65 20 61 63 |he drive|r are ac|
|00004bd0| 63 69 64 65 6e 74 6c 79 | 20 73 68 6f 72 74 65 64 |cidently| shorted|
|00004be0| 20 74 6f 20 61 20 70 6f | 77 65 72 20 73 75 70 70 | to a po|wer supp|
|00004bf0| 6c 79 20 6f 72 20 6c 6f | 77 20 69 6d 70 65 64 61 |ly or lo|w impeda|
|00004c00| 6e 63 65 20 73 6f 75 72 | 63 65 2c 20 75 70 20 74 |nce sour|ce, up t|
|00004c10| 6f 20 32 35 30 6d 41 20 | 63 61 6e 20 66 6c 6f 77 |o 250mA |can flow|
|00004c20| 0d 0a 74 68 72 6f 75 67 | 68 20 74 68 65 20 70 61 |..throug|h the pa|
|00004c30| 72 74 2e 20 20 54 68 65 | 20 74 68 65 72 6d 61 6c |rt.  The| thermal|
|00004c40| 20 73 68 75 74 64 6f 77 | 6e 20 63 69 72 63 75 69 | shutdow|n circui|
|00004c50| 74 20 64 69 73 61 62 6c | 65 73 20 74 68 65 20 64 |t disabl|es the d|
|00004c60| 72 69 76 65 72 20 6f 75 | 74 70 75 74 73 20 77 68 |river ou|tputs wh|
|00004c70| 65 6e 20 74 68 65 20 69 | 6e 74 65 72 6e 61 6c 20 |en the i|nternal |
|00004c80| 74 65 6d 70 65 72 61 74 | 75 72 65 20 72 65 61 63 |temperat|ure reac|
|00004c90| 68 65 73 20 31 35 30 20 | 43 20 61 6e 64 20 74 75 |hes 150 |C and tu|
|00004ca0| 72 6e 73 20 74 68 65 6d | 20 62 61 63 6b 20 6f 6e |rns them| back on|
|00004cb0| 20 77 68 65 6e 20 74 68 | 65 20 74 65 6d 70 65 72 | when th|e temper|
|00004cc0| 61 74 75 72 65 20 63 6f | 6f 6c 73 20 74 6f 20 31 |ature co|ols to 1|
|00004cd0| 33 30 43 2e 20 20 49 66 | 20 74 68 65 20 6f 75 74 |30C.  If| the out|
|00004ce0| 70 75 74 73 20 6f 66 20 | 74 77 6f 20 6f 72 20 6d |puts of |two or m|
|00004cf0| 6f 72 65 20 4c 54 43 34 | 38 37 20 64 72 69 76 65 |ore LTC4|87 drive|
|00004d00| 72 73 20 61 72 65 20 73 | 68 6f 72 74 65 64 20 64 |rs are s|horted d|
|00004d10| 69 72 65 63 74 6c 79 2c | 20 74 68 65 20 64 72 69 |irectly,| the dri|
|00004d20| 76 65 72 20 6f 75 74 70 | 75 74 73 20 63 61 6e 6e |ver outp|uts cann|
|00004d30| 6f 74 20 73 75 70 70 6c | 79 20 65 6e 6f 75 67 68 |ot suppl|y enough|
|00004d40| 20 63 75 72 72 65 6e 74 | 20 74 6f 20 61 63 74 69 | current| to acti|
|00004d50| 76 61 74 65 20 74 68 65 | 20 74 68 65 72 6d 61 6c |vate the| thermal|
|00004d60| 20 73 68 75 74 64 6f 77 | 6e 2e 20 20 54 68 75 73 | shutdow|n.  Thus|
|00004d70| 2c 20 74 68 65 20 74 68 | 65 72 6d 61 6c 20 73 68 |, the th|ermal sh|
|00004d80| 75 74 64 6f 77 6e 20 63 | 69 72 63 75 69 74 20 77 |utdown c|ircuit w|
|00004d90| 69 6c 6c 20 6e 6f 74 20 | 70 72 65 76 65 6e 74 20 |ill not |prevent |
|00004da0| 63 6f 6e 74 65 6e 74 69 | 6f 6e 20 66 61 75 6c 74 |contenti|on fault|
|00004db0| 73 20 77 68 65 6e 20 74 | 77 6f 20 64 72 69 76 65 |s when t|wo drive|
|00004dc0| 72 73 20 61 72 65 20 61 | 63 74 69 76 65 20 6f 6e |rs are a|ctive on|
|00004dd0| 20 74 68 65 20 62 75 73 | 20 61 74 20 74 68 65 20 | the bus| at the |
|00004de0| 73 61 6d 65 20 74 69 6d | 65 2e 20 0d 0a 43 61 62 |same tim|e. ..Cab|
|00004df0| 6c 65 20 61 6e 64 20 44 | 61 74 65 20 52 61 74 65 |le and D|ate Rate|
|00004e00| 20 0d 0a 54 68 65 20 74 | 72 61 6e 73 6d 69 73 73 | ..The t|ransmiss|
|00004e10| 69 6f 6e 20 6c 69 6e 65 | 20 6f 66 20 63 68 6f 69 |ion line| of choi|
|00004e20| 63 65 20 66 6f 72 20 52 | 53 34 38 35 20 61 70 70 |ce for R|S485 app|
|00004e30| 6c 69 63 61 74 69 6f 6e | 73 20 69 73 20 61 20 74 |lication|s is a t|
|00004e40| 77 69 73 74 65 64 20 70 | 61 69 72 2e 20 20 54 68 |wisted p|air.  Th|
|00004e50| 65 72 65 20 61 72 65 20 | 63 6f 61 78 69 61 6c 20 |ere are |coaxial |
|00004e60| 63 61 62 6c 65 73 20 6d | 61 64 65 20 66 6f 72 20 |cables m|ade for |
|00004e70| 74 68 69 73 20 70 75 72 | 70 6f 73 65 20 74 68 61 |this pur|pose tha|
|00004e80| 74 20 63 6f 6e 74 61 69 | 6e 73 20 73 74 72 61 69 |t contai|ns strai|
|00004e90| 67 68 74 20 70 61 69 72 | 73 2c 20 62 75 74 20 74 |ght pair|s, but t|
|00004ea0| 68 65 73 65 20 61 72 65 | 20 6c 65 73 73 20 66 6c |hese are| less fl|
|00004eb0| 65 78 69 62 6c 65 2c 20 | 6d 6f 72 65 20 62 75 6c |exible, |more bul|
|00004ec0| 6b 79 2c 20 61 6e 64 20 | 6d 6f 72 65 20 63 6f 73 |ky, and |more cos|
|00004ed0| 74 6c 79 20 74 68 61 6e | 20 74 77 69 73 74 65 64 |tly than| twisted|
|00004ee0| 20 70 61 69 72 73 2e 20 | 20 4d 61 6e 79 20 63 61 | pairs. | Many ca|
|00004ef0| 62 6c 65 20 6d 61 6e 75 | 66 61 63 74 75 72 65 72 |ble manu|facturer|
|00004f00| 73 20 6f 66 66 65 72 20 | 61 20 62 72 6f 61 64 20 |s offer |a broad |
|00004f10| 72 61 6e 67 65 20 6f 66 | 20 31 32 30 20 63 61 62 |range of| 120 cab|
|00004f20| 6c 65 73 20 64 65 73 69 | 67 6e 65 64 20 66 6f 72 |les desi|gned for|
|00004f30| 20 52 53 34 38 35 20 61 | 70 70 6c 69 63 61 74 69 | RS485 a|pplicati|
|00004f40| 6f 6e 73 2e 0d 0a 4c 6f | 73 73 65 73 20 69 6e 20 |ons...Lo|sses in |
|00004f50| 61 20 74 72 61 6e 73 6d | 69 73 73 69 6f 6e 20 6c |a transm|ission l|
|00004f60| 69 6e 65 20 61 72 65 20 | 61 20 63 6f 6d 70 6c 65 |ine are |a comple|
|00004f70| 78 20 63 6f 6d 62 69 6e | 61 74 69 6f 6e 20 6f 66 |x combin|ation of|
|00004f80| 20 44 43 20 63 6f 6e 64 | 75 63 74 6f 72 20 6c 6f | DC cond|uctor lo|
|00004f90| 73 73 2c 20 41 43 20 6c | 6f 73 73 65 73 20 28 73 |ss, AC l|osses (s|
|00004fa0| 6b 69 6e 20 65 66 66 65 | 63 74 29 2c 20 6c 65 61 |kin effe|ct), lea|
|00004fb0| 6b 61 67 65 2c 20 61 6e | 64 20 41 43 20 6c 6f 73 |kage, an|d AC los|
|00004fc0| 73 65 73 20 69 6e 20 74 | 68 65 20 64 69 65 6c 65 |ses in t|he diele|
|00004fd0| 63 74 72 69 63 2e 20 20 | 49 6e 20 67 6f 6f 64 20 |ctric.  |In good |
|00004fe0| 70 6f 6c 79 65 74 68 79 | 6c 65 6e 65 20 63 61 62 |polyethy|lene cab|
|00004ff0| 6c 65 73 20 73 75 63 68 | 20 61 73 20 74 68 65 20 |les such| as the |
|00005000| 42 65 6c 64 65 6e 20 39 | 38 34 31 2c 20 74 68 65 |Belden 9|841, the|
|00005010| 20 63 6f 6e 64 75 63 74 | 6f 72 20 6c 6f 73 73 65 | conduct|or losse|
|00005020| 73 20 61 6e 64 20 64 69 | 65 6c 65 63 74 72 69 63 |s and di|electric|
|00005030| 20 6c 6f 73 73 65 73 20 | 61 72 65 20 6f 66 20 74 | losses |are of t|
|00005040| 68 65 20 73 61 6d 65 20 | 6f 72 64 65 72 20 6f 66 |he same |order of|
|00005050| 20 6d 61 67 6e 69 74 75 | 64 65 2c 20 6c 65 61 64 | magnitu|de, lead|
|00005060| 69 6e 67 20 74 6f 20 72 | 65 6c 61 74 69 76 65 6c |ing to r|elativel|
|00005070| 79 20 6c 6f 77 20 6f 76 | 65 72 61 6c 6c 20 6c 6f |y low ov|erall lo|
|00005080| 73 73 2e 0d 0a 57 68 65 | 6e 20 75 73 69 6e 67 20 |ss...Whe|n using |
|00005090| 6c 6f 77 20 6c 6f 73 73 | 20 63 61 62 6c 65 73 2c |low loss| cables,|
|000050a0| 20 46 69 67 75 72 65 20 | 38 20 63 61 6e 20 62 65 | Figure |8 can be|
|000050b0| 20 75 73 65 64 20 61 73 | 20 61 20 67 75 69 64 65 | used as| a guide|
|000050c0| 6c 69 6e 65 20 66 6f 72 | 20 63 68 6f 6f 73 69 6e |line for| choosin|
|000050d0| 67 20 74 68 65 20 6d 61 | 78 69 6d 75 6d 20 6c 69 |g the ma|ximum li|
|000050e0| 6e 65 20 6c 65 6e 67 74 | 68 20 66 6f 72 20 61 20 |ne lengt|h for a |
|000050f0| 67 69 76 65 6e 20 64 61 | 74 61 20 72 61 74 65 2e |given da|ta rate.|
|00005100| 20 20 57 69 74 68 20 6c | 6f 77 65 72 20 71 75 61 |  With l|ower qua|
|00005110| 6c 69 74 79 20 50 56 43 | 20 63 61 62 6c 65 73 2c |lity PVC| cables,|
|00005120| 20 74 68 65 20 64 69 65 | 6c 65 63 74 72 69 63 20 | the die|lectric |
|00005130| 6c 6f 73 73 20 66 61 63 | 74 6f 72 20 63 61 6e 20 |loss fac|tor can |
|00005140| 62 65 20 31 30 30 30 20 | 74 69 6d 65 73 20 77 6f |be 1000 |times wo|
|00005150| 72 73 65 2e 20 20 50 56 | 43 20 74 77 69 73 74 65 |rse.  PV|C twiste|
|00005160| 64 20 70 61 69 72 73 20 | 68 61 76 65 20 74 65 72 |d pairs |have ter|
|00005170| 72 69 62 6c 65 20 6c 6f | 73 73 65 73 20 61 74 20 |rible lo|sses at |
|00005180| 68 69 67 68 20 64 61 74 | 61 20 72 61 74 65 73 20 |high dat|a rates |
|00005190| 61 6e 64 20 67 72 65 61 | 74 6c 79 20 72 65 64 75 |and grea|tly redu|
|000051a0| 63 65 20 74 68 65 20 6d | 61 78 69 6d 75 6d 20 63 |ce the m|aximum c|
|000051b0| 61 62 6c 65 20 6c 65 6e | 67 74 68 2e 20 20 41 74 |able len|gth.  At|
|000051c0| 20 6c 6f 77 20 64 61 74 | 61 20 72 61 74 65 73 20 | low dat|a rates |
|000051d0| 68 6f 77 65 76 65 72 2c | 20 74 68 65 79 20 61 72 |however,| they ar|
|000051e0| 65 20 61 63 63 65 70 74 | 61 62 6c 65 20 61 6e 64 |e accept|able and|
|000051f0| 20 6d 75 63 68 20 6d 6f | 72 65 20 65 63 6f 6e 6f | much mo|re econo|
|00005200| 6d 69 63 61 6c 2e 0d 0a | 43 61 62 6c 65 20 54 65 |mical...|Cable Te|
|00005210| 72 6d 69 6e 61 74 69 6f | 6e 0d 0a 54 68 65 20 70 |rminatio|n..The p|
|00005220| 72 6f 70 65 72 20 74 65 | 72 6d 69 6e 61 74 69 6f |roper te|rminatio|
|00005230| 6e 20 6f 66 20 74 68 65 | 20 63 61 62 6c 65 20 69 |n of the| cable i|
|00005240| 73 20 76 65 72 79 20 69 | 6d 70 6f 72 74 61 6e 74 |s very i|mportant|
|00005250| 2e 20 20 49 66 20 74 68 | 65 20 63 61 62 6c 65 20 |.  If th|e cable |
|00005260| 69 73 20 6e 6f 74 20 74 | 65 72 6d 69 6e 61 74 65 |is not t|erminate|
|00005270| 64 20 77 69 74 68 20 69 | 74 73 20 63 68 61 72 61 |d with i|ts chara|
|00005280| 63 74 65 72 69 73 74 69 | 63 20 69 6d 70 65 64 61 |cteristi|c impeda|
|00005290| 6e 63 65 2c 20 64 69 73 | 74 6f 72 74 65 64 20 77 |nce, dis|torted w|
|000052a0| 61 76 65 66 6f 72 6d 73 | 20 77 69 6c 6c 20 72 65 |aveforms| will re|
|000052b0| 73 75 6c 74 2e 20 20 49 | 6e 20 73 65 76 65 72 65 |sult.  I|n severe|
|000052c0| 20 63 61 73 65 73 2c 20 | 64 69 73 74 6f 72 74 65 | cases, |distorte|
|000052d0| 64 20 28 66 61 6c 73 65 | 29 20 64 61 74 61 20 61 |d (false|) data a|
|000052e0| 6e 64 20 6e 75 6c 6c 73 | 20 77 69 6c 6c 20 6f 63 |nd nulls| will oc|
|000052f0| 63 75 72 2e 20 20 41 20 | 71 75 69 63 6b 20 6c 6f |cur.  A |quick lo|
|00005300| 6f 6b 20 61 74 20 74 68 | 65 20 6f 75 74 70 75 74 |ok at th|e output|
|00005310| 20 6f 66 20 74 68 65 20 | 64 72 69 76 65 72 20 77 | of the |driver w|
|00005320| 69 6c 6c 20 74 65 6c 6c | 20 68 6f 77 20 77 65 6c |ill tell| how wel|
|00005330| 6c 20 74 68 65 20 63 61 | 62 6c 65 20 69 73 20 74 |l the ca|ble is t|
|00005340| 65 72 6d 69 6e 61 74 65 | 64 2e 20 20 49 74 20 69 |erminate|d.  It i|
|00005350| 73 20 62 65 73 74 20 74 | 6f 20 6c 6f 6f 6b 20 61 |s best t|o look a|
|00005360| 74 20 61 20 64 72 69 76 | 65 72 20 63 6f 6e 6e 65 |t a driv|er conne|
|00005370| 63 74 65 64 20 74 6f 20 | 74 68 65 20 65 6e 64 20 |cted to |the end |
|00005380| 6f 66 20 74 68 65 20 63 | 61 62 6c 65 2c 20 73 69 |of the c|able, si|
|00005390| 6e 63 65 20 74 68 69 73 | 20 65 6c 69 6d 69 6e 61 |nce this| elimina|
|000053a0| 74 65 73 20 74 68 65 20 | 70 6f 73 73 69 62 69 6c |tes the |possibil|
|000053b0| 69 74 79 20 6f 66 20 67 | 65 74 74 69 6e 67 20 72 |ity of g|etting r|
|000053c0| 65 66 6c 65 63 74 69 6f | 6e 73 20 66 72 6f 6d 20 |eflectio|ns from |
|000053d0| 74 77 6f 20 64 69 72 65 | 63 74 69 6f 6e 73 2e 20 |two dire|ctions. |
|000053e0| 20 53 69 6d 70 6c 79 20 | 6c 6f 6f 6b 20 61 74 20 | Simply |look at |
|000053f0| 74 68 65 20 64 72 69 76 | 65 72 20 6f 75 74 70 75 |the driv|er outpu|
|00005400| 74 20 77 68 69 6c 65 20 | 74 72 61 6e 73 6d 69 74 |t while |transmit|
|00005410| 74 69 6e 67 20 73 71 75 | 61 72 65 20 77 61 76 65 |ting squ|are wave|
|00005420| 20 64 61 74 61 2e 20 20 | 49 66 20 74 68 65 20 63 | data.  |If the c|
|00005430| 61 62 6c 65 20 69 73 20 | 74 65 72 6d 69 6e 61 74 |able is |terminat|
|00005440| 65 64 20 70 72 6f 70 65 | 72 6c 79 2c 20 74 68 65 |ed prope|rly, the|
|00005450| 20 77 61 76 65 66 6f 72 | 6d 20 77 69 6c 6c 20 6c | wavefor|m will l|
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|00006270| 72 61 73 69 74 69 63 20 | 63 61 70 61 63 69 74 61 |rasitic |capacita|
|00006280| 6e 63 65 20 77 69 6c 6c | 20 6c 6f 61 64 20 64 6f |nce will| load do|
|00006290| 77 6e 20 74 68 65 20 62 | 75 73 2e 07 00 00 00 00 |wn the b|us......|
|000062a0| 00 8b 22 01 00 86 22 02 | 00 84 22 03 00 7e 22 04 |.."...".|.."..~".|
|000062b0| 00 63 22 05 00 4d 22 06 | 00 41 22 44 42 20 39 34 |.c"..M".|.A"DB 94|
|000062c0| 44 53 4c 54 43 34 38 38 | 2f 4c 54 43 34 38 39 51 |DSLTC488|/LTC489Q|
|000062d0| 75 61 64 20 52 53 34 38 | 35 20 4c 69 6e 65 20 52 |uad RS48|5 Line R|
|000062e0| 65 63 65 69 76 65 72 5c | 44 41 54 41 5c 44 41 54 |eceiver\|DATA\DAT|
|000062f0| 41 42 4f 4f 4b 5c 31 39 | 39 34 5f 44 42 30 34 38 |ABOOK\19|94_DB048|
|00006300| 38 5f 5f 5f 78 2e 70 64 | 66 4c 54 43 34 38 38 2f |8___x.pd|fLTC488/|
|00006310| 4c 54 43 34 38 39 20 51 | 75 61 64 20 52 53 34 38 |LTC489 Q|uad RS48|
|00006320| 35 20 4c 69 6e 65 20 52 | 65 63 65 69 76 65 72 0d |5 Line R|eceiver.|
|00006330| 0a 46 45 41 54 55 52 45 | 53 0d 0a 20 4c 6f 77 20 |.FEATURE|S.. Low |
|00006340| 50 6f 77 65 72 3a 20 49 | 20 43 43 20 3d 20 37 6d |Power: I| CC = 7m|
|00006350| 41 20 54 79 70 2e 0d 0a | 20 44 65 73 69 67 6e 65 |A Typ...| Designe|
|00006360| 64 20 66 6f 72 20 52 53 | 34 38 35 20 6f 72 20 52 |d for RS|485 or R|
|00006370| 53 34 32 32 20 41 70 70 | 6c 69 63 61 74 69 6f 6e |S422 App|lication|
|00006380| 73 0d 0a 20 53 69 6e 67 | 6c 65 20 35 56 20 53 75 |s.. Sing|le 5V Su|
|00006390| 70 70 6c 79 0d 0a 20 2d | 20 37 56 20 74 6f 20 31 |pply.. -| 7V to 1|
|000063a0| 32 56 20 42 75 73 20 43 | 6f 6d 6d 6f 6e 20 4d 6f |2V Bus C|ommon Mo|
|000063b0| 64 65 20 52 61 6e 67 65 | 20 50 65 72 6d 69 74 73 |de Range| Permits|
|000063c0| 20 2b 2d 37 56 20 47 72 | 6f 75 6e 64 20 44 69 66 | +-7V Gr|ound Dif|
|000063d0| 66 65 72 65 6e 63 65 20 | 42 65 74 77 65 65 6e 20 |ference |Between |
|000063e0| 44 65 76 69 63 65 73 20 | 6f 6e 20 74 68 65 20 42 |Devices |on the B|
|000063f0| 75 73 0d 0a 20 36 30 6d | 56 20 54 79 70 69 63 61 |us.. 60m|V Typica|
+--------+-------------------------+-------------------------+--------+--------+