* circuit e145 * Check NonLinear Capacitor .tran 100n 3.0m 0 Rs 4 1 2k *Rf 1 2 2M X1 0 1 2 opamp00 X2 3 0 4 opamp00 R1 3 2 1k R2 3 4 15k Cf 1 10 1u Vf 10 2 dc 0 ac 0 Fx 20 0 Vf 1 Rx 20 0 1k Bf 1 2 I=0 *Bf 1 2 I= I(Vf)*V(1,2)*V(1,2)/10 ; Cf' ... nonlinear *Bf 1 2 I= 1.0 * I(Vf) ; Cf' = 2.0 * Cf *Bf 1 2 I= 0.5 * I(Vf) ; Cf' = (3/2)* Cf *Bf 1 2 I= 0.0 * I(Vf) ; Cf' = 1.0 * Cf *Bf 1 2 I= -0.5 * I(Vf) ; Cf' = 0.5 * Cf *Bf 1 2 I= -0.75 * I(Vf) ; Cf' = (1/4)* Cf .probe *------------------------------------------------ * copy form * http://www.madlabo.com/mad/edat/spice/index.htm *------------------------------------------------ * HItachi Si EP High speed switch .model d1s2075 D(IS=1.387E-9 N=1.702 RS=1.53 + CJO=1.92pf VJ=0.4996 M=0.0605 TT=5ns BV=75 IBV=100E-15) * *Low Noise Amp PC=0.4W Ic=0.15A Vcbo=60V .model Q2SC1815 NPN(Is=2.04f Xti=3 Eg=1.11 Vaf=6 Bf=400 Ne=1.5 + Ise=0 Ikf=20m Xtb=1.5 Br=3.377 Nc=2 Isc=0 Ikr=0 Rc=1 Cjc=2p + Mjc=.3333 + Vjc=.75 Fc=.5 Cje=5p Mje=.3333 Vje=.75 Tr=10n Tf=311.1p + Itf=0 Vtf=0 Xtf=0) * TOSHIBA 90-01-29 creation * *Low Noise Amp PC=0.4W Ic=0.15A Vcbo=50V .model Q2SA1015 PNP(Is=295.1E-18 Xti=3 Eg=1.11 Vaf=100 Bf=110 Ne=1.5 + Ise=0 Ikf=0 Xtb=1.5 Br=10.45 Nc=2 Isc=0 Ikr=0 Rc=15 Cjc=66.2p + Mjc=1.054 Vjc=.75 Fc=.5 Cje=5p Mje=.3333 Vje=.75 Tr=10n + Tf=1.661n Itf=0 Vtf=0 Xtf=0) * TOSHIBA 90-01-23 creation * * Ideal Operational Amplifier . . . K. Mochizuki 2002.3.15 * + - out .subckt opamp00 50 51 55 rin 50 51 1G cin 50 51 5p e1st 52 0 50 51 100000 r53 0 52 1g r51 52 53 100k c51 0 53 53n d51 56 53 d1s2075 d52 53 57 d1s2075 v51 56 0 -13.7V v52 57 0 13.7V r52 53 54 1k c52 0 54 53p d53 58 54 d1s2075 d54 54 59 d1s2075 v53 58 0 -13V v54 59 0 13V eout 55 0 54 0 1 rpow 55 0 1G .ends *----------------------------------------------------- .END