Continuous-Time State-Variable Filter

Component table with nominal values

 

Operational amplifiers:3 (Opamp1)

OA1-OA3

Resistors

R1-R5=10K, R6=3K , R7=7K 

Capacitors

C1-C2=20nF


Continuous-time state variable lowpass, bandpass and high pass filter responses with nominal values.

Component variation table

Nominal value

Variation at 1s

R1-R5

10KW

300 W

R6

3 KW

90 W

R7

7 KW

210 W

C1

20nF

1.0nF

C2

20nF

0.6nF

 


Continuous-time state-variable bandpass filter response with component variation.

 

Hard fault table

Faults

No. of faults

OA1-3

Opamp faults

3x22=66

R1-R7

Stuck-open/stuck-short

2x7=14

C1-C2

Stuck-open/stuck-short

2x2=4

Total no. of faults

 

84

 

Soft fault table

Nominal value

-6s

+6s

R1-R5

10KW

8.2KW

11.8KW

R6

3KW

2.46KW

3.54KW

R7

7 KW

5.74KW

8.26KW

C1

20nF

14.0nF

26.0nF

C2

20nF

16.4nF

23.6nF

 

*Continuous-time state-variable filter
.subckt OpAmp 9 11 12 13 14
R1 1 14 110k
M1 1 1 99 99 PMOS L=4U W=150U
R2 99 13 1
R3 1 13 1meg
M2 3 1 98 98 PMOS L=4U W=35U
R4 98 13 1
R5 3 13 1meg
M3 9 1 97 97 PMOS L=4U W=100U
R6 97 13 1
R7 9 13 1meg
M4 4 12 96 96 PMOS L=4U W=60U
R8 3 96 1
R9 4 96 1meg
M5 5 11 95 95 PMOS L=4U W=60U
R10 95 3 1
R11 5 95 1meg
cl 5 16 1.27pf
R12 5 16 1meg
R13 16 6 1
rl 6 9 8.75k
M6 4 4 94 94 NMOS L=4U W=27.5U
R14 94 14 1
R15 4 94 1meg
M7 5 4 93 93 NMOS L=4U W=27.5U
R16 93 14 1
R17 5 93 1meg
M8 9 5 92 92 NMOS L=4U W=100U
R18 92 14 1
R19 9 92 1meg
.MODEL NMOS NMOS LEVEL=3
+VTO=.79 GAMMA=.38 PHI=.53 RD=63 IS=1E-16 PB=.8 CGSO=1.973E-10
+CGDO=1.973E-10 RSH=45 CJ=0.00029 MJ=.486 CJSW=3.3E-10 MJSW=.33 JS=0.0001
+TOX=2.5E-08 NSUB=8.7E+15 NFS=8.2E+11 TPG=1 XJ=1E-07 LD=7E-08 UO=577
+VMAX=150000 FC=.5 DELTA=.3551 THETA=0.046 ETA=.16 KAPPA=0.05
.MODEL PMOS PMOS LEVEL=3
+VTO=-8.40000000E-01 GAMMA=.53 PHI=.58 RD=94 RS=94 IS=1E-16 PB=.8
+CGSO=3.284E-10 CGDO=3.284E-10 RSH=100 CJ=0.00041 MJ=.54 CJSW=3.4E-10 MJSW=.3
+JS=0.0001 TOX=2.5E-08 NSUB=1.75E+16 NFS=8.4E+11 TPG=1 XJ=0 LD=6E-08 UO=205
+VMAX=500000 FC=.5 DELTA=.4598 THETA=.14 ETA=.17 KAPPA=10
.ends OpAmp

Vss 0 18 5.0
Vdd 19 0 5.0
Xopamp1 11 2 1 19 18 OpAmp
Xopamp2 12 0 3 19 18 OpAmp
Xopamp3 13 0 4 19 18 OpAmp
R1 14 1 10k
R2 1 11 10k
R3 11 3 10k
R4 12 4 10k
R5 1 13 10k
R6 2 0 3k
R7 12 2 7k
C1 3 12 20n
C2 4 13 20n
Vin 14 0 AC 1.0 SIN(0 1 1E3)
.AC DEC 20 10 1e5
.plot v(13) v(12) v(11)
.options list node post=2
.end