Version 4
SHEET 1 1656 984
WIRE 320 0 304 0
WIRE 432 0 368 0
WIRE 368 32 368 0
WIRE 320 48 320 0
WIRE -16 80 -80 80
WIRE 48 80 -16 80
WIRE 160 80 96 80
WIRE -80 112 -80 80
WIRE 96 128 96 80
WIRE 320 128 320 96
WIRE 368 128 368 112
WIRE 48 144 48 80
WIRE -80 224 -80 192
WIRE 48 224 48 192
WIRE 96 224 96 208
WIRE 272 320 80 320
WIRE 448 320 272 320
WIRE 80 352 80 320
WIRE 272 352 272 320
WIRE -48 464 -80 464
WIRE 80 464 80 432
WIRE 80 464 32 464
WIRE 112 464 80 464
WIRE 144 464 112 464
WIRE 272 464 272 416
WIRE 272 464 224 464
WIRE 304 464 272 464
WIRE 352 464 304 464
WIRE 448 480 448 320
WIRE 448 480 416 480
WIRE 496 480 448 480
WIRE 80 496 80 464
WIRE 352 496 320 496
WIRE 320 528 320 496
WIRE 80 576 80 560
FLAG -80 224 0
FLAG 48 224 0
FLAG 96 224 0
FLAG -16 80 in
FLAG 160 80 test
FLAG -80 464 in
FLAG 496 480 LP
FLAG 320 528 0
FLAG 112 464 1
FLAG 304 464 2
FLAG 80 576 0
FLAG 320 128 0
FLAG 368 128 0
FLAG 432 0 testab
FLAG 304 0 in
SYMBOL voltage -80 96 R0
SYMATTR InstName V1
SYMATTR Value AC 1
SYMBOL e 96 112 R0
SYMATTR InstName E1
SYMATTR Value Laplace=-(R2/R1)/(1+s*(R2+R3+R2*R3/R1)*C1+s*s*R2*R3*C1*C2)
SYMBOL Opamps\\opamp 384 416 R0
SYMATTR InstName U1
SYMBOL Misc\\EuropeanResistor -64 480 R270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R1
SYMATTR Value {R1}
SYMBOL Misc\\EuropeanResistor 64 336 R0
SYMATTR InstName R2
SYMATTR Value {R2}
SYMBOL cap 256 352 R0
SYMATTR InstName C1
SYMATTR Value {C1}
SYMBOL cap 64 496 R0
SYMATTR InstName C2
SYMATTR Value {C2}
SYMBOL Misc\\EuropeanResistor 128 480 R270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R3
SYMATTR Value {R3}
SYMBOL e 368 16 R0
SYMATTR InstName E2
SYMATTR Value Laplace=-(R2/R1)/(1+a*s/wg+b*s*s/(wg*wg))
TEXT -80 -48 Left 2 !.lib opamp.sub
TEXT -80 -8 Left 2 !.ac dec 100 100 10k
TEXT -80 -320 Left 2 !.param fg=1000\n.param wg=2*pi*fg\n.param a=1.3617 b=0.618 G0=-1\n.param C=10n\n.param C1=C \n.param C2=3*C\n.param R2=(a*C2+sqrt(a*a*C2*C2-4*C1*C2*b*(1-G0)))/(2*wg*C1*C2)\n.param R1=-R2/G0\n.param R3 = b/(wg*wg*C1*C2*R2)
TEXT 32 -1008 Left 4 ;Lowpass F(s) = 1/(1+a*P + b*P^2)
TEXT -64 -768 Left 2 ;Bessel\n \nOrdnung i ai bi\n \n1 1 1,0000 0,0000\n \n2 1 1,3617 0,6180\n \n3 1 0,7560 0,0000 \n- 2 0,9996 0,4772\n \n4 1 1,3397 0,4889\n- 2 0,7743 0,3890
TEXT 200 -768 Left 2 ;Butterworth\n \nOrdnung i ai bi\n \n1 1 1,0000 0,0000\n \n2 1 1,4142 1,0000\n \n3 1 1,0000 0,0000\n- 2 1,0000 1,0000\n \n4 1 1,8478 1,0000\n- 2 0,7654 1,0000
TEXT 448 -792 Left 2 ;Tschebyscheff\n(0,5 dB Welligkeit)\n \nOrdnung i ai bi\n \n1 1 1,0000 0,0000\n \n2 1 1,3614 1,3827\n \n3 1 1,8626 0,0000\n- 2 0,6402 1,1931\n \n4 1 2,6282 3,4341\n- 2 0,3648 1,1509
TEXT 704 -792 Left 2 ;Tschebyscheff\n(3 dB Welligkeit)\n \nOrdnung i ai bi\n \n1 1 1,0000 0,0000\n \n2 1 1,0650 1,9305\n \n3 1 3,3496 0,0000\n- 2 0,3559 1,1923\n \n4 1 2,1853 5,5339\n- 2 0,1964 1,2009
TEXT -56 -944 Left 2 ;Literatur: http://www.fbeit.htwk-leipzig.de/~reinhold/Elektronik_Uni_Lpz/EL2_Kap_3.pdf\nProf. Dr. Wolfgang Reinhold 24/24\nHTWK Leipzig\nFakultät Elektrotechnik und Informationstechnik Kap_3_Filter.docx, 20.05.2011
TEXT 584 392 Left 2 ;View -> SPICE Error Log\nr1 in 1 14449.8532221736 \nr2 lp 1 14449.8532221736 \nc1 lp 2 1e-008 \nc2 1 0 3e-008 \nr3 1 2 3611.13768932491
TEXT 288 -216 Left 4 ;C2 > C1*4*b*(1-G0)/a^2