1. Active Filters
ENGI 242
ELEC 222

2. January 2004 ENGI 242/ELEC 222 2
First Order Low Pass Filter

3. January 2004 ENGI 242/ELEC 222 3
Second Order Low Pass Filter

4. January 2004 ENGI 242/ELEC 222 4
Low Pass Filter
Determine fr and AV

5. January 2004 ENGI 242/ELEC 222 5
High Pass Filter

6. January 2004 ENGI 242/ELEC 222 6
High Pass Filter
Determine fr and AV

7. January 2004 ENGI 242/ELEC 222 7
Bandpass Filter

8. January 2004 ENGI 242/ELEC 222 8
Bandpass Filter Output

9. January 2004 ENGI 242/ELEC 222 9
Bandpass Filter

10. January 2004 ENGI 242/ELEC 222 10
Bandpass Filter

11. January 2004 ENGI 242/ELEC 222 11
Notch Filter
fCH < fCL

12. January 2004 ENGI 242/ELEC 222 12
Butterworth Low Pass Filter Schematic

13. January 2004 ENGI 242/ELEC 222 13
Properties for VPRINT/Special1
Click on VPRINT1 (the printer symbol on the schematic)
Edit Properties
Place a Y in every column entry you want entered in netlist

14. January 2004 ENGI 242/ELEC 222 14
Butterworth Low Pass Netlist of VDB(OUT)
FREQ VM(OUT) VP(OUT) VDB(OUT)
1.000E+00 2.000E+00 -5.736E-02 6.020E+00
5.179E+00 2.000E+00 -2.971E-01 6.020E+00
1.000E+01 2.000E+00 -5.736E-01 6.020E+00
5.179E+01 1.997E+00 -2.968E+00 6.009E+00
1.000E+02 1.990E+00 -5.717E+00 5.977E+00
3.340E+02 1.897E+00 -1.849E+01 5.562E+00
5.179E+02 1.776E+00 -2.742E+01 4.990E+00
7.197E+02 1.624E+00 -3.580E+01 4.210E+00
8.031E+02 1.560E+00 -3.883E+01 3.862E+00
1.000E+03 1.415E+00 -4.509E+01 3.014E+00
1.116E+03 1.335E+00 -4.824E+01 2.512E+00
1.245E+03 1.253E+00 -5.135E+01 1.959E+00
1.390E+03 1.169E+00 -5.439E+01 1.356E+00
1.551E+03 1.085E+00 -5.734E+01 7.060E-01
1.730E+03 1.001E+00 -6.015E+01 1.272E-02
Look for frequency where VDB(OUT) has declined by -3dB
And where VM(OUT) has declined to .707 VM(OUT)max

15. January 2004 ENGI 242/ELEC 222 15
Butterworth Low Pass Filter Probe Output
Look for the frequency where output has declined 3dB from the maximally flat value

16. January 2004 ENGI 242/ELEC 222 16
Second Order Low Pass Filter Schematic

17. January 2004 ENGI 242/ELEC 222 17
Second Order Netlist Output
FREQ VM(OUT) VP(OUT) VDB(OUT)
1.000E+01 2.000E+00 -5.737E-01 6.021E+00
3.020E+01 2.001E+00 -1.733E+00 6.024E+00
5.248E+01 2.003E+00 -3.016E+00 6.032E+00
1.000E+02 2.010E+00 -5.775E+00 6.064E+00
1.905E+02 2.036E+00 -1.120E+01 6.176E+00
3.020E+02 2.089E+00 -1.841E+01 6.398E+00
5.248E+02 2.237E+00 -3.598E+01 6.994E+00
6.918E+02 2.311E+00 -5.311E+01 7.278E+00
7.586E+02 2.304E+00 -6.090E+01 7.248E+00
1.000E+03 2.002E+00 -9.024E+01 6.027E+00
1.096E+03 1.794E+00 -1.007E+02 5.078E+00
1.202E+03 1.560E+00 -1.106E+02 3.861E+00
1.272E+03 1.414E+00 -1.162E+02 3.007E+00
1.445E+03 1.104E+00 -1.273E+02 8.586E-01
1.585E+03 9.119E-01 -1.340E+02 -8.011E-01
1.738E+03 7.494E-01 -1.396E+02 -2.505E+00
2.291E+03 4.136E-01 -1.520E+02 -7.669E+00
3.020E+03 2.304E-01 -1.600E+02 -1.275E+01
5.248E+03 7.375E-02 -1.695E+02 -2.264E+01
6.310E+03 5.075E-02 -1.716E+02 -2.589E+01
8.318E+03 2.905E-02 -1.741E+02 -3.074E+01
1.000E+04 2.005E-02 -1.756E+02 -3.396E+01

18. January 2004 ENGI 242/ELEC 222 18
Second Order Low Pass Probe Output

19. January 2004 ENGI 242/ELEC 222 19
Third Order Low Pass Filter Schematic

20. January 2004 ENGI 242/ELEC 222 20
Third Order Low Pass Probe Output

21. January 2004 ENGI 242/ELEC 222 21
Fourth Order Low Pass Filter Schematic

22. January 2004 ENGI 242/ELEC 222 22
Fourth Order Low Pass Probe Output

23. January 2004 ENGI 242/ELEC 222 23
Butterworth High Pass Filter Schematic

24. January 2004 ENGI 242/ELEC 222 24
Netlist Output for Butterworth High Pass
FREQ VM(OUT) VP(OUT) VDB(OUT)
1.000E+02 1.988E-01 8.428E+01 -1.403E+01
1.562E+02 3.083E-01 8.111E+01 -1.022E+01
5.125E+02 9.114E-01 6.283E+01 -8.058E-01
6.404E+02 1.078E+00 5.731E+01 6.506E-01
8.003E+02 1.249E+00 5.127E+01 1.930E+00
9.284E+02 1.360E+00 4.705E+01 2.671E+00
1.000E+03 1.413E+00 4.491E+01 3.006E+00
1.250E+03 1.561E+00 3.855E+01 3.867E+00
1.682E+03 1.719E+00 3.056E+01 4.703E+00
3.047E+03 1.900E+00 1.783E+01 5.575E+00
5.946E+03 1.972E+00 8.865E+00 5.898E+00
8.003E+03 1.984E+00 6.199E+00 5.952E+00
1.000E+04 1.990E+00 4.554E+00 5.976E+00
2.102E+04 1.997E+00 2.836E-01 6.007E+00
3.047E+04 1.997E+00 -1.660E+00 6.008E+00
5.125E+04 1.995E+00 -4.835E+00 5.998E+00
8.003E+04 1.988E+00 -8.574E+00 5.970E+00
1.000E+05 1.982E+00 -1.103E+01 5.943E+00

25. January 2004 ENGI 242/ELEC 222 25
High Pass Probe Output

26. January 2004 ENGI 242/ELEC 222 26
Second Order High Pass Schematic

27. January 2004 ENGI 242/ELEC 222 27
Second High Pass Probe Output

28. January 2004 ENGI 242/ELEC 222 28
Butterworth Bandpass Filter Schematic

29. January 2004 ENGI 242/ELEC 222 29
Netlist Output for Bandpass
FREQ VM(OUT) VDB(OUT)
3.511E+01 1.608E+00 4.125E+00
5.337E+01 2.220E+00 6.927E+00
6.579E+01 2.541E+00 8.100E+00
8.111E+01 2.848E+00 9.091E+00
1.000E+02 3.124E+00 9.893E+00
3.511E+02 3.900E+00 1.182E+01
8.111E+02 3.980E+00 1.200E+01
1.000E+03 3.986E+00 1.201E+01
1.520E+03 3.992E+00 1.202E+01
2.310E+03 3.991E+00 1.202E+01
3.511E+03 3.985E+00 1.201E+01
4.329E+03 3.978E+00 1.199E+01
8.111E+03 3.928E+00 1.188E+01
1.000E+04 3.893E+00 1.181E+01
2.310E+04 3.512E+00 1.091E+01
3.511E+04 3.079E+00 9.769E+00
4.329E+04 2.796E+00 8.930E+00
5.337E+04 2.482E+00 7.897E+00
6.579E+04 2.157E+00 6.676E+00
8.111E+04 1.838E+00 5.285E+00

30. January 2004 ENGI 242/ELEC 222 30
Bandpass Probe Output

31. January 2004 ENGI 242/ELEC 222 31
Narrow Bandpass Filter Schematic

32. January 2004 ENGI 242/ELEC 222 32
Netlist Output for Narrow Bandpass
FREQ VM(OUT) VP(OUT) VDB(OUT)
1.000E+03 3.210E+00 -1.142E+02 1.013E+01
1.079E+03 3.967E+00 -1.204E+02 1.197E+01
1.107E+03 4.285E+00 -1.231E+02 1.264E+01
1.135E+03 4.642E+00 -1.263E+02 1.333E+01
1.164E+03 5.043E+00 -1.300E+02 1.405E+01
1.194E+03 5.488E+00 -1.344E+02 1.479E+01
1.224E+03 5.971E+00 -1.395E+02 1.552E+01
1.256E+03 6.477E+00 -1.456E+02 1.623E+01
1.321E+03 7.416E+00 -1.608E+02 1.740E+01
1.355E+03 7.731E+00 -1.697E+02 1.776E+01
1.390E+03 7.858E+00 -1.792E+02 1.791E+01
1.425E+03 7.769E+00 1.712E+02 1.781E+01
1.462E+03 7.484E+00 1.621E+02 1.748E+01
1.499E+03 7.062E+00 1.539E+02 1.698E+01
1.537E+03 6.570E+00 1.466E+02 1.635E+01
1.577E+03 6.061E+00 1.404E+02 1.565E+01
1.617E+03 5.572E+00 1.351E+02 1.492E+01
1.659E+03 5.120E+00 1.306E+02 1.419E+01
1.790E+03 4.022E+00 1.207E+02 1.209E+01
1.931E+03 3.248E+00 1.143E+02 1.023E+01

33. January 2004 ENGI 242/ELEC 222 33
Narrow Bandpass Probe Output