Version 4 SHEET 1 2884 3000 WIRE -1152 240 -1200 240 WIRE -912 240 -1072 240 WIRE -704 240 -912 240 WIRE -576 256 -864 256 WIRE -416 256 -576 256 WIRE -864 272 -864 256 WIRE -576 272 -576 256 WIRE -576 272 -608 272 WIRE -512 272 -576 272 WIRE -416 272 -416 256 WIRE -608 304 -608 272 WIRE -512 304 -512 272 WIRE -272 304 -368 304 WIRE -160 304 -272 304 WIRE -128 304 -160 304 WIRE -16 304 -48 304 WIRE 32 304 -16 304 WIRE 144 304 112 304 WIRE 192 304 144 304 WIRE 304 304 272 304 WIRE 352 304 304 304 WIRE 640 304 432 304 WIRE 864 304 640 304 WIRE -368 320 -368 304 WIRE -272 320 -272 304 WIRE -16 320 -16 304 WIRE 144 320 144 304 WIRE 304 320 304 304 WIRE -160 336 -160 304 WIRE -896 352 -896 320 WIRE -864 352 -896 352 WIRE -800 352 -800 320 WIRE -800 352 -864 352 WIRE -864 368 -864 352 WIRE -800 368 -864 368 WIRE -704 368 -704 240 WIRE -704 368 -720 368 WIRE -688 368 -704 368 WIRE -576 368 -576 352 WIRE -576 368 -608 368 WIRE -416 368 -416 352 WIRE -416 368 -448 368 WIRE 672 368 560 368 WIRE 864 368 864 304 WIRE 864 368 832 368 WIRE -864 384 -864 368 WIRE -576 384 -576 368 WIRE -576 384 -608 384 WIRE -512 384 -576 384 WIRE -416 384 -416 368 WIRE -16 400 -16 384 WIRE 144 400 144 384 WIRE 304 400 304 384 WIRE -608 416 -608 384 WIRE -512 416 -512 384 WIRE -368 416 -368 400 WIRE -272 416 -272 400 WIRE -160 416 -160 400 WIRE 640 416 640 304 WIRE 656 416 640 416 WIRE 992 416 832 416 WIRE 1088 416 1072 416 WIRE -752 432 -768 432 WIRE -656 432 -672 432 WIRE -896 464 -896 432 WIRE -864 464 -896 464 WIRE -800 464 -800 432 WIRE -800 464 -864 464 WIRE -864 480 -864 464 WIRE -576 480 -576 464 WIRE -576 480 -864 480 WIRE -416 480 -416 464 WIRE -416 480 -576 480 WIRE 832 480 832 464 WIRE -512 512 -608 512 WIRE -272 512 -512 512 WIRE -160 512 -272 512 WIRE -16 512 -160 512 WIRE -160 528 -160 512 WIRE -912 544 -912 240 WIRE -896 544 -912 544 WIRE -816 544 -832 544 WIRE -272 560 -272 512 WIRE -608 592 -608 512 WIRE 256 592 256 576 WIRE 352 592 352 576 WIRE 944 624 864 624 WIRE 1024 624 1024 608 WIRE 1024 624 1008 624 WIRE 1040 624 1040 608 WIRE 1072 624 1040 624 WIRE -160 640 -160 608 WIRE -128 640 -160 640 WIRE -48 640 -64 640 WIRE -160 656 -160 640 WIRE 256 688 256 672 WIRE 352 688 352 672 WIRE -272 704 -272 640 WIRE -224 704 -272 704 WIRE -512 720 -512 512 WIRE -16 720 -16 512 WIRE 864 720 864 624 WIRE 880 720 864 720 WIRE 1024 720 1024 704 WIRE 1024 720 944 720 WIRE 1040 720 1040 704 WIRE 1072 720 1072 624 WIRE 1072 720 1040 720 WIRE -768 768 -768 432 WIRE -720 768 -768 768 WIRE -608 768 -608 672 WIRE -608 768 -624 768 WIRE -576 768 -608 768 WIRE -160 768 -160 752 WIRE -80 768 -160 768 WIRE -768 784 -768 768 WIRE -272 816 -272 704 WIRE 864 816 864 720 WIRE 944 816 864 816 WIRE 1024 816 1024 800 WIRE 1024 816 1008 816 WIRE 1040 816 1040 800 WIRE 1072 816 1072 720 WIRE 1072 816 1040 816 WIRE -688 832 -688 816 WIRE -160 832 -160 768 WIRE -16 832 -16 816 WIRE -768 864 -768 848 WIRE -512 864 -512 816 WIRE -496 864 -512 864 WIRE -400 864 -432 864 WIRE -336 864 -400 864 WIRE 480 864 384 864 WIRE 720 864 480 864 WIRE -400 880 -400 864 WIRE 384 880 384 864 WIRE 480 880 480 864 WIRE 720 880 720 864 WIRE 864 896 864 816 WIRE 880 896 864 896 WIRE 1072 896 1072 816 WIRE 1072 896 944 896 WIRE -16 928 -16 912 WIRE 48 928 -16 928 WIRE 224 928 192 928 WIRE 336 928 224 928 WIRE -16 944 -16 928 WIRE 224 944 224 928 WIRE 336 944 336 928 WIRE 560 944 560 368 WIRE 560 944 528 944 WIRE 576 944 560 944 WIRE 640 944 640 416 WIRE 640 944 624 944 WIRE 672 944 640 944 WIRE -160 960 -160 896 WIRE -400 976 -400 960 WIRE 992 976 992 960 WIRE 384 992 384 960 WIRE 400 992 384 992 WIRE 480 992 480 976 WIRE 480 992 464 992 WIRE 720 992 720 976 WIRE 768 992 720 992 WIRE 864 992 864 896 WIRE 864 992 848 992 WIRE 960 992 864 992 WIRE 480 1008 480 992 WIRE 720 1008 720 992 WIRE 864 1008 864 992 WIRE 1072 1008 1072 896 WIRE 1072 1008 1024 1008 WIRE 1280 1008 1072 1008 WIRE -512 1024 -512 864 WIRE 384 1024 384 992 WIRE 960 1024 944 1024 WIRE -272 1040 -272 912 WIRE -272 1040 -352 1040 WIRE -16 1040 -16 1024 WIRE 224 1040 224 1008 WIRE 336 1040 336 1024 WIRE 576 1040 624 944 WIRE 576 1040 528 1040 WIRE 624 1040 576 944 WIRE 672 1040 624 1040 WIRE -352 1056 -352 1040 WIRE 992 1056 992 1040 WIRE -272 1088 -272 1040 WIRE -160 1088 -160 1024 WIRE -80 1088 -160 1088 WIRE 864 1088 864 1072 WIRE -160 1104 -160 1088 WIRE 384 1120 384 1104 WIRE 480 1120 480 1104 WIRE 480 1120 384 1120 WIRE 720 1120 720 1104 WIRE 720 1120 480 1120 WIRE -800 1136 -880 1136 WIRE -672 1136 -736 1136 WIRE -352 1136 -352 1120 WIRE -512 1200 -512 1104 WIRE -272 1200 -272 1168 WIRE -272 1200 -512 1200 WIRE -160 1200 -160 1184 WIRE -160 1200 -272 1200 WIRE -16 1200 -16 1136 WIRE -16 1200 -160 1200 WIRE -912 1248 -912 544 WIRE -880 1248 -880 1136 WIRE -880 1248 -912 1248 WIRE -816 1248 -880 1248 WIRE -672 1248 -672 1136 WIRE -672 1248 -736 1248 WIRE -384 1248 -384 1232 WIRE -384 1248 -672 1248 WIRE -352 1248 -352 1232 WIRE -304 1248 -352 1248 WIRE 1072 1248 1072 1008 WIRE 1072 1248 -304 1248 WIRE -352 1296 -384 1296 WIRE -912 1312 -912 1248 WIRE -640 1312 -912 1312 WIRE -576 1312 -640 1312 WIRE -432 1312 -496 1312 WIRE -384 1312 -384 1296 WIRE -384 1312 -432 1312 WIRE -352 1312 -352 1296 WIRE -304 1312 -304 1248 WIRE -304 1312 -352 1312 WIRE -800 1360 -880 1360 WIRE -672 1360 -736 1360 WIRE -640 1424 -640 1312 WIRE -560 1424 -640 1424 WIRE -432 1424 -432 1312 WIRE -432 1424 -496 1424 WIRE -912 1472 -912 1312 WIRE -880 1472 -880 1360 WIRE -880 1472 -912 1472 WIRE -816 1472 -880 1472 WIRE -672 1472 -672 1360 WIRE -672 1472 -736 1472 WIRE -384 1472 -384 1456 WIRE -384 1472 -672 1472 WIRE -352 1472 -352 1456 WIRE -304 1472 -304 1312 WIRE -304 1472 -352 1472 WIRE -912 1536 -912 1472 WIRE -640 1536 -912 1536 WIRE -576 1536 -640 1536 WIRE -432 1536 -496 1536 WIRE -384 1536 -384 1520 WIRE -384 1536 -432 1536 WIRE -352 1536 -352 1520 WIRE -304 1536 -304 1472 WIRE -304 1536 -352 1536 WIRE -800 1584 -880 1584 WIRE -672 1584 -736 1584 WIRE -640 1648 -640 1536 WIRE -560 1648 -640 1648 WIRE -432 1648 -432 1536 WIRE -432 1648 -496 1648 WIRE -912 1696 -912 1536 WIRE -880 1696 -880 1584 WIRE -880 1696 -912 1696 WIRE -816 1696 -880 1696 WIRE -672 1696 -672 1584 WIRE -672 1696 -736 1696 WIRE -384 1696 -384 1680 WIRE -384 1696 -672 1696 WIRE -352 1696 -352 1680 WIRE -304 1696 -304 1536 WIRE -304 1696 -352 1696 WIRE -912 1760 -912 1696 WIRE -640 1760 -912 1760 WIRE -576 1760 -640 1760 WIRE -432 1760 -496 1760 WIRE -384 1760 -384 1744 WIRE -384 1760 -432 1760 WIRE -352 1760 -352 1744 WIRE -304 1760 -304 1696 WIRE -304 1760 -352 1760 WIRE -800 1808 -880 1808 WIRE -672 1808 -736 1808 WIRE -640 1872 -640 1760 WIRE -560 1872 -640 1872 WIRE -432 1872 -432 1760 WIRE -432 1872 -496 1872 WIRE -912 1920 -912 1760 WIRE -880 1920 -880 1808 WIRE -880 1920 -912 1920 WIRE -816 1920 -880 1920 WIRE -672 1920 -672 1808 WIRE -672 1920 -736 1920 WIRE -384 1920 -384 1904 WIRE -384 1920 -672 1920 WIRE -352 1920 -352 1904 WIRE -304 1920 -304 1760 WIRE -304 1920 -352 1920 WIRE -912 1984 -912 1920 WIRE -640 1984 -912 1984 WIRE -576 1984 -640 1984 WIRE -432 1984 -496 1984 WIRE -384 1984 -384 1968 WIRE -384 1984 -432 1984 WIRE -352 1984 -352 1968 WIRE -304 1984 -304 1920 WIRE -304 1984 -352 1984 WIRE -640 2096 -640 1984 WIRE -560 2096 -640 2096 WIRE -432 2096 -432 1984 WIRE -432 2096 -496 2096 FLAG 256 688 0 FLAG -272 416 0 FLAG -368 416 0 FLAG 336 1040 0 FLAG 400 992 0 FLAG 464 992 0 FLAG 352 688 0 FLAG 256 576 +V FLAG 352 576 -V FLAG 992 960 +V FLAG 992 1056 -V FLAG 944 1024 0 FLAG -1200 240 0 FLAG 1280 1008 OUT FLAG -656 432 0 FLAG -448 368 0 FLAG -160 416 0 FLAG -688 832 0 FLAG -400 976 0 FLAG -352 1136 0 FLAG -48 640 0 FLAG -16 1200 -V FLAG -16 512 +V FLAG -768 864 0 FLAG -816 544 0 FLAG -912 240 IN FLAG 224 1040 0 FLAG 1088 416 0 FLAG 832 480 0 FLAG 864 1088 0 FLAG 304 400 0 FLAG 144 400 0 FLAG -16 400 0 SYMBOL voltage 256 576 R0 SYMATTR InstName V1 SYMATTR Value 15 SYMBOL ind2 -432 256 R0 WINDOW 0 1 37 Right 2 WINDOW 3 -2 74 Right 2 SYMATTR InstName T3a SYMATTR Value 25µ SYMATTR Type ind SYMBOL ind2 -432 368 R0 WINDOW 0 -2 42 Right 2 WINDOW 3 -7 76 Right 2 SYMATTR InstName T3b SYMATTR Value 25µ SYMATTR Type ind SYMBOL ind2 -352 304 M0 WINDOW 0 2 39 Right 2 WINDOW 3 2 74 Right 2 SYMATTR InstName T3c SYMATTR Value 25µ SYMATTR Type ind SYMBOL res -288 304 R0 SYMATTR InstName R1 SYMATTR Value 500 SYMBOL res -32 288 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R2 SYMATTR Value 25K SYMBOL ind2 400 976 R180 WINDOW 0 1 71 Right 2 WINDOW 3 2 37 Right 2 SYMATTR InstName T1b SYMATTR Value 100µ SYMATTR Type ind SYMBOL ind2 400 1120 R180 WINDOW 0 1 70 Right 2 WINDOW 3 2 37 Right 2 SYMATTR InstName T1c SYMATTR Value 100µ SYMATTR Type ind SYMBOL ind2 320 1040 M180 WINDOW 0 0 72 Right 2 WINDOW 3 2 38 Right 2 SYMATTR InstName T1a SYMATTR Value 100µ SYMATTR Type ind SYMBOL njf 672 880 R0 WINDOW 3 56 54 Left 2 WINDOW 0 56 24 Left 2 SYMATTR Value 2N4416 SYMATTR InstName Q1 SYMBOL njf 672 1104 M180 WINDOW 0 56 73 Left 2 WINDOW 3 58 23 Left 2 SYMATTR InstName Q2 SYMATTR Value 2N4416 SYMBOL njf 528 880 M0 WINDOW 0 39 2 Right 2 WINDOW 3 36 101 Right 2 SYMATTR InstName Q3 SYMATTR Value 2N4416 SYMBOL njf 528 1104 R180 WINDOW 0 39 90 Right 2 WINDOW 3 35 7 Right 2 SYMATTR InstName Q4 SYMATTR Value 2N4416 SYMBOL voltage 352 576 R0 SYMATTR InstName V2 SYMATTR Value -15 SYMBOL current -1152 240 M90 WINDOW 0 -32 40 VBottom 2 WINDOW 3 32 40 VTop 2 WINDOW 123 74 40 VTop 2 WINDOW 39 53 40 VTop 2 SYMATTR InstName I1 SYMATTR Value PULSE(0 1000p 1m 1u 1u 5m 10m) SYMBOL res -720 1232 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value 100G SYMBOL cap -736 1120 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value .015p SYMBOL ind2 -816 352 M90 WINDOW 0 4 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName T2a SYMATTR Value 50µ SYMATTR Type ind SYMBOL ind2 -704 352 M90 WINDOW 0 4 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName T2b SYMATTR Value 50µ SYMATTR Type ind SYMBOL ind2 -656 448 M270 WINDOW 0 32 56 VTop 2 WINDOW 3 10 55 VBottom 2 SYMATTR InstName T2c SYMATTR Value 50µ SYMATTR Type ind SYMBOL cap -176 400 M180 WINDOW 0 24 56 Left 2 WINDOW 3 24 8 Left 2 SYMATTR InstName C2 SYMATTR Value 4n SYMBOL cap 1008 800 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 WINDOW 123 60 32 VTop 2 SYMATTR InstName C3 SYMATTR Value 1000p SYMATTR Value2 IC=0 SYMBOL Opamps\\LT1001 992 944 R0 WINDOW 3 -40 153 Left 2 SYMATTR InstName U1 SYMBOL njf -624 816 M270 WINDOW 0 51 48 VTop 2 WINDOW 3 -3 44 VLeft 2 SYMATTR InstName Q5 SYMATTR Value 2N4416 SYMBOL npn -576 720 R0 SYMATTR InstName Q6 SYMATTR Value 2N3904 SYMBOL res -528 1008 R0 SYMATTR InstName R4 SYMATTR Value 4.99K SYMBOL cap -432 848 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C4 SYMATTR Value .01µ SYMBOL res -416 864 R0 SYMATTR InstName R5 SYMATTR Value 1K SYMBOL npn -336 816 R0 SYMATTR InstName Q7 SYMATTR Value 2N3904 SYMBOL res -288 1072 R0 SYMATTR InstName R6 SYMATTR Value 4.75K SYMBOL cap -368 1056 R0 SYMATTR InstName C5 SYMATTR Value .01µ SYMBOL res -288 544 R0 SYMATTR InstName R7 SYMATTR Value 2.5K SYMBOL pnp -224 752 M180 WINDOW 0 59 68 Left 2 WINDOW 3 61 34 Left 2 SYMATTR InstName Q8 SYMATTR Value 2N3906 SYMBOL res -176 512 R0 SYMATTR InstName R8 SYMATTR Value 1.98K SYMBOL cap -128 624 M90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C6 SYMATTR Value .01µ SYMBOL res -176 1088 R0 SYMATTR InstName R9 SYMATTR Value 4.22K SYMBOL npn -80 720 R0 SYMATTR InstName Q9 SYMATTR Value 2N3904 SYMBOL cap -784 848 M180 WINDOW 0 24 56 Left 2 WINDOW 3 24 8 Left 2 SYMATTR InstName C7 SYMATTR Value 2n SYMBOL res -624 576 R0 SYMATTR InstName R10 SYMATTR Value 1.2K SYMBOL pnp -80 1136 M180 WINDOW 0 59 68 Left 2 WINDOW 3 61 34 Left 2 SYMATTR InstName Q10 SYMATTR Value 2N3906 SYMBOL diode -176 832 R0 SYMATTR InstName D1 SYMATTR Value 1N4148 SYMBOL diode -176 960 R0 SYMATTR InstName D2 SYMATTR Value 1N4148 SYMBOL res -32 816 R0 SYMATTR InstName R11 SYMATTR Value 49.9 SYMBOL res -32 928 R0 SYMATTR InstName R12 SYMATTR Value 49.9 SYMBOL cap 192 912 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 WINDOW 39 60 32 VTop 2 SYMATTR InstName C8 SYMATTR Value .1µ SYMBOL res -720 1680 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R13 SYMATTR Value 10Meg SYMBOL cap -736 1568 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C9 SYMATTR Value 2.5p SYMBOL res -480 1744 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R14 SYMATTR Value 1Meg SYMBOL res -720 1904 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R15 SYMATTR Value 100K SYMBOL cap -496 1856 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C10 SYMATTR Value 75p SYMBOL cap -736 1792 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C11 SYMATTR Value 100p SYMBOL cap 944 704 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 WINDOW 123 60 32 VTop 2 SYMATTR InstName C12 SYMATTR Value .05µ SYMATTR Value2 IC=0 SYMBOL cap 1008 608 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 WINDOW 123 60 32 VTop 2 SYMATTR InstName C13 SYMATTR Value .1µ SYMATTR Value2 IC=0 SYMBOL njf -800 384 R90 WINDOW 0 34 48 VCenter 2 WINDOW 3 61 46 VCenter 2 SYMATTR InstName J3 SYMATTR Value 2N5432 SYMBOL njf -800 272 R90 WINDOW 0 34 48 VCenter 2 WINDOW 3 61 46 VCenter 2 SYMATTR InstName J1 SYMATTR Value 2N5432 SYMBOL njf -512 464 M270 WINDOW 0 34 48 VCenter 2 WINDOW 3 61 46 VCenter 2 SYMATTR InstName J4 SYMATTR Value 2N5432 SYMBOL njf -512 352 M270 WINDOW 0 34 48 VCenter 2 WINDOW 3 61 46 VCenter 2 SYMATTR InstName J2 SYMATTR Value 2N5432 SYMBOL res -480 1296 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R16 SYMATTR Value 10G SYMBOL cap -496 1408 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C14 SYMATTR Value .04p SYMBOL cap 944 880 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 WINDOW 123 60 32 VTop 2 SYMATTR InstName C15 SYMATTR Value 25p SYMATTR Value2 IC=0 SYMBOL cap -896 528 M90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C16 SYMATTR Value 100p SYMBOL res -720 1456 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R17 SYMATTR Value 1G SYMBOL cap -736 1344 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C17 SYMATTR Value .2p SYMBOL res -480 1520 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R18 SYMATTR Value 100Meg SYMBOL cap -496 1632 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C18 SYMATTR Value .4p SYMBOL res -480 1968 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R19 SYMATTR Value 10K SYMBOL cap -496 2080 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C19 SYMATTR Value 50p SYMBOL cap 208 1008 M180 WINDOW 0 24 56 Left 2 WINDOW 3 24 8 Left 2 SYMATTR InstName C20 SYMATTR Value 1n SYMBOL Digital\\dflop 752 320 M0 WINDOW 0 -10 75 Center 2 WINDOW 3 -97 197 Left 2 WINDOW 123 -56 165 Left 2 SYMATTR InstName A1 SYMATTR Value Vhigh=0 Vlow=-5 SYMATTR Value2 Trise=10n SYMBOL voltage 976 416 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 -32 56 VBottom 2 SYMATTR InstName V3 SYMATTR Value pulse(-5 0 0 10n 10n .5u 1u) SYMBOL cap 848 1008 R0 SYMATTR InstName C21 SYMATTR Value .01µ SYMBOL res 864 976 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R20 SYMATTR Value 100 SYMBOL res 144 912 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R21 SYMATTR Value 500 SYMBOL cap 288 320 R0 SYMATTR InstName C22 SYMATTR Value 1n SYMBOL res 448 288 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R22 SYMATTR Value 100 SYMBOL cap 128 320 R0 SYMATTR InstName C23 SYMATTR Value 500p SYMBOL res 288 288 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R23 SYMATTR Value 200 SYMBOL cap -32 320 R0 SYMATTR InstName C24 SYMATTR Value 250p SYMBOL res 128 288 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R24 SYMATTR Value 400 TEXT 792 1392 Left 2 !.tran 15m TEXT -384 256 Bottom 2 !K3 T3a T3b T3c 1. TEXT 392 864 Bottom 2 !K1 T1a T1b T1c 1. TEXT -704 232 Bottom 2 !K2 T2a T2b T2c 1. TEXT -24 216 Bottom 2 ;Old Fashioned Electrometer Using Parametric up Conversion\nThese days you should just use a AD549 TEXT -536 1368 Center 2 ;±1nA full scale TEXT -768 1640 Center 2 ;±1µA full scale TEXT -776 1864 Center 2 ;±100µA full scale TEXT 1088 816 Left 2 ;Add for ±1µA full scale TEXT -536 1816 Center 2 ;±10µA full scale TEXT 1088 624 Left 2 ;Add for ±100µA, ±1mA full scale TEXT -776 1192 Center 2 ;±100pA full scale TEXT 1088 896 Left 2 ;±100pA, ±1nA, ±10nA, ±100nA full scale TEXT -768 1416 Center 2 ;±10nA full scale TEXT -536 1592 Center 2 ;±100nA full scale TEXT 1088 720 Left 2 ;Add for ±10µA full scale TEXT -536 2040 Center 2 ;±1mA full scale TEXT -216 1544 Left 2 ;A 1% mismatch in J1, J2, J3, J4 capacitiances give a 6mV input offset and a 425mV output offset(4.25pA readout error) at ±100pA full scale range.\nQ1, Q2, Q3, Q4 require a low drive impedance lest the gain of the loop inverts at high input currents. TEXT 1184 1008 Bottom 2 ;±10V full scale TEXT 976 1120 Top 2 ;Trim to reduce\nerror to a\nfraction of 1pA