Version 4
SHEET 1 880 1444
WIRE -288 144 -640 144
WIRE -224 144 -288 144
WIRE -640 160 -640 144
WIRE -288 240 -288 144
WIRE -816 256 -864 256
WIRE -768 256 -816 256
WIRE -640 256 -640 224
WIRE -640 256 -688 256
WIRE -576 256 -640 256
WIRE -464 256 -496 256
WIRE -336 256 -464 256
WIRE -464 288 -464 256
WIRE -336 352 -336 304
WIRE -288 352 -288 320
WIRE -464 384 -464 352
WIRE -288 464 -640 464
WIRE -224 464 -288 464
WIRE -640 480 -640 464
WIRE -288 560 -288 464
WIRE -864 576 -864 256
WIRE -816 576 -864 576
WIRE -768 576 -816 576
WIRE -640 576 -640 544
WIRE -640 576 -688 576
WIRE -576 576 -640 576
WIRE -464 576 -496 576
WIRE -336 576 -464 576
WIRE -464 608 -464 576
WIRE -336 672 -336 624
WIRE -288 672 -288 640
WIRE -464 704 -464 672
WIRE -864 736 -864 576
WIRE -752 736 -864 736
WIRE -656 736 -704 736
WIRE -864 768 -864 736
WIRE -704 768 -704 736
WIRE -752 784 -752 736
WIRE -864 880 -864 848
WIRE -752 880 -752 832
WIRE -704 880 -704 848
WIRE -272 1024 -672 1024
WIRE -672 1072 -672 1024
WIRE -336 1120 -336 1104
WIRE -368 1136 -400 1136
WIRE -272 1152 -272 1024
WIRE -272 1152 -304 1152
WIRE -208 1152 -272 1152
WIRE -848 1168 -896 1168
WIRE -800 1168 -848 1168
WIRE -672 1168 -672 1136
WIRE -672 1168 -720 1168
WIRE -608 1168 -672 1168
WIRE -496 1168 -528 1168
WIRE -368 1168 -496 1168
WIRE -272 1184 -272 1152
WIRE -496 1200 -496 1168
WIRE -336 1200 -336 1184
WIRE -400 1280 -400 1136
WIRE -272 1280 -272 1264
WIRE -272 1280 -400 1280
WIRE -784 1296 -784 1280
WIRE -672 1296 -672 1280
WIRE -496 1296 -496 1264
WIRE -272 1296 -272 1280
WIRE -784 1392 -784 1376
WIRE -672 1392 -672 1376
WIRE -272 1392 -272 1376
FLAG -752 880 0
FLAG -704 880 0
FLAG -864 880 0
FLAG -656 736 test
FLAG -288 352 0
FLAG -336 352 0
FLAG -464 384 0
FLAG -816 256 in
FLAG -224 144 outb
FLAG -288 672 0
FLAG -336 672 0
FLAG -464 704 0
FLAG -816 576 in
FLAG -224 464 outa
FLAG -496 1296 0
FLAG -848 1168 in
FLAG -208 1152 out
FLAG -336 1104 V+
FLAG -336 1200 V-
FLAG -272 1392 0
FLAG -784 1280 V+
FLAG -672 1280 V-
FLAG -784 1392 0
FLAG -672 1392 0
SYMBOL voltage -864 752 R0
SYMATTR InstName V1
SYMATTR Value ac 1
SYMBOL e -704 752 R0
WINDOW 3 -66 169 Left 2
SYMATTR Value Laplace=4/(1+s*sqrt(2)/(10k*2*pi)+s*s/(10k*2*pi)**2)
SYMATTR InstName E1
SYMBOL e -288 224 R0
SYMATTR InstName E4
SYMATTR Value 4
SYMBOL res -784 272 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R1b
SYMATTR Value 13.787762k
SYMBOL res -592 272 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R2b
SYMATTR Value 5.567145k
SYMBOL cap -480 288 R0
SYMATTR InstName C2
SYMATTR Value 3.3n
SYMBOL cap -656 160 R0
SYMATTR InstName C1
SYMATTR Value 1n
SYMBOL e -288 544 R0
SYMATTR InstName E2
SYMATTR Value 4
SYMBOL res -784 592 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R1a
SYMATTR Value 61.238598k
SYMBOL res -592 592 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R2a
SYMATTR Value 1.253433k
SYMBOL cap -480 608 R0
SYMATTR InstName C2_
SYMATTR Value 3.3n
SYMBOL cap -656 480 R0
SYMATTR InstName C1_
SYMATTR Value 1n
SYMBOL cap -512 1200 R0
SYMATTR InstName C2o
SYMATTR Value 3.3n
SYMBOL cap -688 1072 R0
SYMATTR InstName C1o
SYMATTR Value 1n
SYMBOL Opamps\\UniversalOpamp2 -336 1152 R0
SYMATTR InstName U1
SYMBOL Misc\\EuropeanResistor -288 1168 R0
SYMATTR InstName R4
SYMATTR Value 3k
SYMBOL Misc\\EuropeanResistor -288 1392 M180
WINDOW 0 31 76 Left 2
WINDOW 3 31 40 Left 2
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL Misc\\EuropeanResistor -816 1184 R270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R1o
SYMATTR Value 13.787762k
SYMBOL Misc\\EuropeanResistor -624 1184 R270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R2o
SYMATTR Value 5.567145k
SYMBOL voltage -784 1280 R0
SYMATTR InstName V2
SYMATTR Value 5
SYMBOL voltage -672 1280 R0
SYMATTR InstName V3
SYMATTR Value -5
TEXT -864 40 Left 2 !.ac dec 100 10 100k
TEXT -136 152 Left 2 ;F(s)=1/(1+s/(wp*Qp)+s^2/(wp)^2\n \nButterworth: Qp=1/sqrt(2)\n \nEquation for R1: \nR1^2+a*R1+b = 0\na=-1/((C2-(v-1)*C1)*wp*Qp) \nb=1/(wp*wp*C1*(C2-(v-1)*C1))\n \n \nExample: fg=wp=1Hz\nScilab code:\nC1=0.1; C2=0.33; Qp=1/sqrt(2), v=4; wp=2*%pi*1;\na=-1/((C2-(v-1)*C1)*wp*Qp);\nb=1/(wp*wp*C1*(C2-(v-1)*C1));\nR1a=-a/2+sqrt((a/2)^2-b)\nR1b=-a/2-sqrt((a/2)^2-b)\nR2a=1/(wp*wp*R1a*C1*C2)\nR2b=1/(wp*wp*R1b*C1*C2)
TEXT -848 112 Left 2 ;fg=10kHz
TEXT -560 56 Left 4 ;Butterworth Filter 10kHz
TEXT -880 1024 Left 2 ;fg=10kHz