Version 4 SHEET 1 2036 1860 WIRE -32 32 -80 32 WIRE 80 32 32 32 WIRE 864 32 832 32 WIRE 976 32 944 32 WIRE -752 96 -1072 96 WIRE -464 96 -672 96 WIRE -336 96 -464 96 WIRE -80 96 -80 32 WIRE -80 96 -336 96 WIRE 80 96 80 32 WIRE 128 96 80 96 WIRE 304 96 208 96 WIRE 528 96 304 96 WIRE 832 96 832 32 WIRE 832 96 624 96 WIRE 1136 96 832 96 WIRE 1280 96 1136 96 WIRE 1408 96 1280 96 WIRE -464 128 -464 96 WIRE 1280 128 1280 96 WIRE 1408 128 1408 96 WIRE -1072 144 -1072 96 WIRE 976 144 976 32 WIRE -80 160 -80 96 WIRE -32 160 -80 160 WIRE 80 160 80 96 WIRE 80 160 48 160 WIRE 528 160 528 128 WIRE 528 160 432 160 WIRE 624 160 624 128 WIRE 720 160 624 160 WIRE -464 240 -464 208 WIRE 432 240 432 160 WIRE 720 240 720 160 WIRE 976 240 976 208 WIRE 1280 240 1280 208 WIRE 1408 240 1408 192 WIRE -1072 272 -1072 224 WIRE -32 672 -80 672 WIRE 80 672 32 672 WIRE 832 672 800 672 WIRE 944 672 912 672 WIRE -784 736 -1072 736 WIRE -464 736 -704 736 WIRE -320 736 -464 736 WIRE -80 736 -80 672 WIRE -80 736 -320 736 WIRE 80 736 80 672 WIRE 224 736 80 736 WIRE 448 736 224 736 WIRE 800 736 800 672 WIRE 800 736 544 736 WIRE 1136 736 800 736 WIRE 1280 736 1136 736 WIRE 1408 736 1280 736 WIRE -464 768 -464 736 WIRE 944 768 944 672 WIRE 1280 768 1280 736 WIRE 1408 768 1408 736 WIRE -1072 784 -1072 736 WIRE -80 800 -80 736 WIRE -32 800 -80 800 WIRE 80 800 80 736 WIRE 80 800 48 800 WIRE 448 800 448 768 WIRE 448 800 352 800 WIRE 544 800 544 768 WIRE 640 800 544 800 WIRE -464 880 -464 848 WIRE 352 880 352 800 WIRE 640 880 640 800 WIRE 944 880 944 832 WIRE 1280 880 1280 848 WIRE 1408 880 1408 832 WIRE -1072 912 -1072 864 WIRE 832 1312 800 1312 WIRE 944 1312 912 1312 WIRE -32 1328 -80 1328 WIRE 80 1328 32 1328 WIRE -784 1392 -1072 1392 WIRE -464 1392 -704 1392 WIRE -320 1392 -464 1392 WIRE -80 1392 -80 1328 WIRE -80 1392 -320 1392 WIRE 80 1392 80 1328 WIRE 208 1392 80 1392 WIRE 448 1392 208 1392 WIRE 800 1392 800 1312 WIRE 800 1392 544 1392 WIRE 1136 1392 800 1392 WIRE 1264 1392 1136 1392 WIRE 1392 1392 1264 1392 WIRE -464 1424 -464 1392 WIRE 944 1424 944 1312 WIRE 1264 1424 1264 1392 WIRE 1392 1424 1392 1392 WIRE -1072 1440 -1072 1392 WIRE -80 1456 -80 1392 WIRE -32 1456 -80 1456 WIRE 80 1456 80 1392 WIRE 80 1456 48 1456 WIRE 448 1456 448 1424 WIRE 448 1456 352 1456 WIRE 544 1456 544 1424 WIRE 640 1456 544 1456 WIRE -464 1536 -464 1504 WIRE 352 1536 352 1456 WIRE 640 1536 640 1456 WIRE 944 1536 944 1488 WIRE 1264 1536 1264 1504 WIRE 1392 1536 1392 1488 WIRE -1072 1568 -1072 1520 FLAG 432 240 0 FLAG 720 240 0 FLAG -1072 272 0 FLAG 976 240 0 FLAG 1280 240 0 FLAG 1408 240 0 FLAG 1136 96 out_a FLAG -336 96 in_a FLAG 304 96 int_a FLAG -1072 912 0 FLAG 944 880 0 FLAG 1280 880 0 FLAG 1408 880 0 FLAG 1136 736 out_b FLAG -320 736 in_b FLAG 224 736 int_b FLAG -464 240 0 FLAG -464 880 0 FLAG -1072 1568 0 FLAG 944 1536 0 FLAG 1264 1536 0 FLAG 1392 1536 0 FLAG 1136 1392 out_c FLAG -320 1392 in_c FLAG 208 1392 int_c FLAG -464 1536 0 FLAG 352 880 0 FLAG 640 880 0 FLAG 352 1536 0 FLAG 640 1536 0 SYMBOL voltage -1072 128 R0 WINDOW 3 24 160 Left 0 WINDOW 123 24 132 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 20 100n 1n 1n 499n 1000n) SYMATTR Value2 AC 20 SYMATTR InstName V1 SYMBOL res -48 176 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName Rtip_a SYMATTR Value 9MEG SYMBOL res 1264 112 R0 SYMATTR InstName Ri_a SYMATTR Value 1MEG SYMBOL tline 576 112 R0 WINDOW 3 4 -36 Left 0 SYMATTR Value Td=10n Z0=50 SYMATTR InstName T1 SYMBOL cap 960 144 R0 SYMATTR InstName Cadj_a SYMATTR Value 30p SYMBOL cap -32 48 R270 WINDOW 0 32 32 VTop 0 WINDOW 3 0 32 VBottom 0 SYMATTR InstName Ctip_a SYMATTR Value 28p SYMBOL res -768 112 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName Rg_a SYMATTR Value 50 SYMBOL cap 1392 128 R0 SYMATTR InstName Ci_a SYMATTR Value 20p SYMBOL res 848 48 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName Rser_a SYMATTR Value 100 SYMBOL voltage -1072 768 R0 WINDOW 3 24 160 Left 0 WINDOW 123 24 132 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 20 100n 1n 1n 499n 1000n) SYMATTR Value2 AC 20 SYMATTR InstName V2 SYMBOL res -48 816 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName Rtip_b SYMATTR Value 9MEG SYMBOL res 1264 752 R0 SYMATTR InstName Ri_b SYMATTR Value 1MEG SYMBOL cap 928 768 R0 SYMATTR InstName Cadj_b SYMATTR Value 30p SYMBOL cap -32 688 R270 WINDOW 0 32 32 VTop 0 WINDOW 3 0 32 VBottom 0 SYMATTR InstName Ctip_b SYMATTR Value 28p SYMBOL res -800 752 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName Rg_b SYMATTR Value 50 SYMBOL cap 1392 768 R0 SYMATTR InstName Ci_b SYMATTR Value 20p SYMBOL res 816 688 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName Rser_b SYMATTR Value 500 SYMBOL ltline 496 752 R0 SYMATTR InstName O1 SYMATTR Value LTRA1 SYMBOL res -480 112 R0 SYMATTR InstName Rt_a SYMATTR Value 50 SYMBOL res -480 752 R0 SYMATTR InstName Rt_b SYMATTR Value 50 SYMBOL voltage -1072 1424 R0 WINDOW 3 24 160 Left 0 WINDOW 123 24 132 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 20 100n 1n 1n 499n 1000n) SYMATTR Value2 AC 20 SYMATTR InstName V3 SYMBOL res -48 1472 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName Rtip_c SYMATTR Value 9MEG SYMBOL res 1248 1408 R0 SYMATTR InstName Ri_c SYMATTR Value 1MEG SYMBOL cap 928 1424 R0 SYMATTR InstName Cadj_c SYMATTR Value 30p SYMBOL cap -32 1344 R270 WINDOW 0 32 32 VTop 0 WINDOW 3 0 32 VBottom 0 SYMATTR InstName Ctip_c SYMATTR Value 17p SYMBOL res -800 1408 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName Rg_c SYMATTR Value 50 SYMBOL cap 1376 1424 R0 SYMATTR InstName Ci_c SYMATTR Value 20p SYMBOL res 816 1328 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName Rser_c SYMATTR Value 500 SYMBOL ltline 496 1408 R0 SYMATTR InstName O2 SYMATTR Value LTRA2 SYMBOL res -480 1408 R0 SYMATTR InstName Rt_c SYMATTR Value 50 SYMBOL res 112 112 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 0 56 VBottom 0 SYMATTR InstName R1_a SYMATTR Value 270 TEXT -1080 -672 Left 0 ;.ac dec 500 0.1k 200MEG TEXT -1072 -712 Left 0 !.tran 0 1u 0 1n TEXT 184 624 Left 0 !.MODEL LTRA1 LTRA(R=100 C=100p L=250n LEN=2) TEXT 0 496 Left 0 ;PROBE-B, 10:1, WITH LOSSY TRANSMISSION LINE Z=50 Ohm, R=100 Ohm/m TEXT 8 -144 Left 0 ;PROBE-A, 10:1, WITH LOSSLESS TRANSMISSION LINE Z=50 Ohm TEXT 160 1280 Left 0 !.MODEL LTRA2 LTRA(R=190 C=50p L=500n LEN=2) TEXT 0 1152 Left 0 ;PROBE-C, 10:1, WITH LOSSY TRANSMISSION LINE Z=100 Ohm, R=190 Ohm/m TEXT -240 -784 Left 0 ;10:1 HIGH IMPEDANCE OSCILLOSCOPE PROBE NEEDS LOSSY CABLE TEXT -232 -496 Left 0 ;Probe-a(selfmade): probe with 50 Ohm cable, l=2m, R'=0 (lossless, standard coax) TEXT -232 -464 Left 0 ;Probe-b(selfmade): probe with 50 Ohm cable, l=2m, R'=100 Ohm/m, special cable TEXT -232 -432 Left 0 ;Probe-c(HP/Ag, Tek): their probes have typ. 100 Ohm cable, l=2m, R'=190 Ohm/m, special cable TEXT -232 -384 Left 0 ;R' is the ohmic resistance per 1m length of the inner conductor. TEXT -1080 -632 Left 0 ;.AC analysis can be used also to see the "flat" frequency response. TEXT -232 -592 Left 0 ;Characteristic Impedance Z: Z=sqrt(L/C) TEXT 1320 1040 Left 0 ;not used TEXT 1224 -96 Left 0 ;OSCILLOSCOPE TEXT 584 -72 Left 0 ;length = 2m TEXT -1048 -72 Left 0 ;PULSE GENERATOR\n \nf=1MHz, Trise=1ns, Tfall=1ns TEXT -520 -72 Left 0 ;FEEDTROUGH\n50 Ohm TEXT -528 568 Left 0 ;FEEDTROUGH\n50 Ohm TEXT -528 1232 Left 0 ;FEEDTROUGH\n50 Ohm TEXT 1224 1200 Left 0 ;OSCILLOSCOPE TEXT 1224 544 Left 0 ;OSCILLOSCOPE TEXT 192 584 Left 0 ;Inner conductor with ohmic resistance of 100 Ohm/m TEXT 160 1240 Left 0 ;Inner conductor with ohmic resistance of 190 Ohm/m TEXT 296 -72 Left 0 ;Standard 50 Ohm cable TEXT 296 -40 Left 0 ;Resistance of inner conductor omitted TEXT -1040 576 Left 0 ;PULSE GENERATOR\n \nf=1MHz, Trise=1ns, Tfall=1ns TEXT -1048 1224 Left 0 ;PULSE GENERATOR\n \nf=1MHz, Trise=1ns, Tfall=1ns TEXT -232 -736 Left 0 ;We learn how useless a standard coaxial cable is for this purpose. TEXT -232 -704 Left 0 ;Probe cables need adapted high ohmic resistance of inner conductor. TEXT -232 -560 Left 0 ;Delay: Tpd/m = sqrt(L*C) = 5ns/m or v=1/sqrt(L*C) = 2/3*c0 choosen TEXT 616 -784 Left 0 ;Helmut Sennewald, 4/25/2004 TEXT -232 -672 Left 0 ;Typical values are 100 Ohm/m to 200 Ohm/m depending on the cable's Z-impedance. TEXT -232 -640 Left 0 ;Z from dimensions: Z = 60/sqrt(Er)*log(D/d) [Ohm] , D/d = outer/inner diameter TEXT -256 1096 Left 0 ;HP/Ag or Tek 10:1 PROBE, LENGTH 2M TEXT -1080 -376 Left 0 ;http://www.tek.com/site/ps/0,,60-15265-INTRO_EN,00.html TEXT -1080 -344 Left 0 ;http://www.probemaster.com/helpful.htm TEXT -1080 -408 Left 0 ;Some links: TEXT -1080 -776 Left 0 ;Plot V(out_a), V(out:b) and V(out_c) LINE Normal 736 32 400 32 2 LINE Normal 752 32 736 32 2 LINE Normal 752 32 752 32 2 LINE Normal 752 160 400 160 2 LINE Normal -32 -32 240 -32 2 LINE Normal -288 96 -32 -32 2 LINE Normal -32 224 -288 96 2 LINE Normal 240 224 -32 224 2 LINE Normal 240 224 240 224 2 LINE Normal 1504 32 1488 32 LINE Normal 1520 -64 1504 32 LINE Normal 1536 -16 1520 -64 LINE Normal 1552 -32 1536 -16 LINE Normal 1568 -16 1552 -32 LINE Normal 1600 -16 1568 -16 LINE Normal 1600 64 1600 -16 LINE Normal 1616 32 1600 64 LINE Normal 1648 32 1616 32 LINE Normal 656 672 320 672 2 LINE Normal 672 672 656 672 2 LINE Normal 672 672 672 672 2 LINE Normal 656 1328 320 1328 2 LINE Normal 672 1328 656 1328 2 LINE Normal 672 1328 672 1328 2 LINE Normal 672 1456 320 1456 2 LINE Normal 1504 672 1488 672 LINE Normal 1520 576 1504 672 LINE Normal 1536 624 1520 576 LINE Normal 1552 608 1536 624 LINE Normal 1568 624 1552 608 LINE Normal 1600 624 1568 624 LINE Normal 1600 704 1600 624 LINE Normal 1616 672 1600 704 LINE Normal 1648 672 1616 672 LINE Normal 1504 1328 1488 1328 LINE Normal 1520 1232 1504 1328 LINE Normal 1536 1280 1520 1232 LINE Normal 1552 1264 1536 1280 LINE Normal 1568 1280 1552 1264 LINE Normal 1600 1280 1568 1280 LINE Normal 1600 1360 1600 1280 LINE Normal 1616 1328 1600 1360 LINE Normal 1648 1328 1616 1328 LINE Normal 672 624 672 624 2 LINE Normal 672 800 320 800 2 LINE Normal 720 1568 720 1568 2 LINE Normal 240 16 240 -32 2 LINE Normal 240 32 240 16 2 LINE Normal 240 224 240 160 2 LINE Normal 240 160 240 32 2 LINE Normal -64 608 128 608 2 LINE Normal -272 736 -64 608 2 LINE Normal -64 864 -272 736 2 LINE Normal 128 864 -64 864 2 LINE Normal 128 864 128 864 2 LINE Normal 128 656 128 608 2 LINE Normal 128 672 128 656 2 LINE Normal 128 864 128 800 2 LINE Normal 128 800 128 672 2 LINE Normal -48 1264 128 1264 2 LINE Normal -256 1392 -48 1264 2 LINE Normal -48 1520 -256 1392 2 LINE Normal 128 1520 -48 1520 2 LINE Normal 128 1520 128 1520 2 LINE Normal 128 1312 128 1264 2 LINE Normal 128 1328 128 1312 2 LINE Normal 128 1520 128 1456 2 LINE Normal 128 1456 128 1328 2 LINE Normal 1008 192 944 144 2 LINE Normal 960 144 944 144 2 LINE Normal 944 160 944 144 2 LINE Normal 976 816 912 768 2 LINE Normal 928 768 912 768 2 LINE Normal 912 784 912 768 2 LINE Normal 976 1472 912 1424 2 LINE Normal 928 1424 912 1424 2 LINE Normal 912 1440 912 1424 2 RECTANGLE Normal 1728 320 1184 -144 2 RECTANGLE Normal 1680 80 1456 -96 RECTANGLE Normal -608 352 -1136 -112 2 RECTANGLE Normal -384 288 -528 0 2 RECTANGLE Normal -608 992 -1136 528 2 RECTANGLE Normal -608 1632 -1136 1168 2 RECTANGLE Normal -384 928 -528 640 2 RECTANGLE Normal -384 1584 -528 1296 2 RECTANGLE Normal 1728 960 1184 496 2 RECTANGLE Normal 1728 1616 1184 1152 2 RECTANGLE Normal 1680 720 1456 544 RECTANGLE Normal 1680 1376 1456 1200 RECTANGLE Normal 1072 320 -288 -112 1 RECTANGLE Normal 1072 960 -272 528 1 RECTANGLE Normal 1072 1616 -256 1184 1 CIRCLE Normal 432 160 352 32 2 CIRCLE Normal 352 800 272 672 2 CIRCLE Normal 352 1456 272 1328 2 ARC Normal 704 32 800 160 758 133 765 16 2 ARC Normal 624 672 720 800 678 773 685 656 2 ARC Normal 624 1328 720 1456 678 1429 685 1312 2