Low-Pass
4-Pole
Appendix A
Theoretical Transfer Characteristics
1
f/fc
Amp
Phase
Delay
(Hz)
(dB)
(deg)
(sec)
0.00
0.00
0.00
.416
0.10
0.00
-15.0
.418
0.20
0.00
-30.1
.423
0.30
-0.00
-45.5
.433
0.40
-0.003
-61.4
.449
0.50
-0.017
-78.0
.474
0.60
-0.072
-95.7
.511
0.70
-0.243
-115
.558
0.80
-0.674
-136
.604
0.85
-1.047
-147
.619
0.90
-1.555
-158
.622
0.95
-2.21
-169
.612
1.00
-3.01
-180
.588
1.10
-4.97
-200
.513
1.20
-7.24
-217
.427
1.30
-9.62
-231
.350
1.40
-12.0
-242
.289
1.50
-14.3
-252
.241
1.60
-16.4
-260
.204
1.70
-18.5
-266
.175
1.80
-20.5
-272
.152
1.90
-22.3
-277
.134
2.00
-24.1
-282
.119
2.25
-28.2
-291
.091
2.50
-31.8
-299
.072
2.75
-35.1
-304
.059
3.00
-38.2
-309
.049
3.25
-41.0
-313
.041
3.50
-43.5
-317
.035
4.00
-48.2
-322
.027
5.00
-55.9
-330
.017
6.00
-62.3
-335
.012
7.00
-67.6
-339
.009
8.00
-72.2
-341
.007
9.00
-76.3
-343
.005
-80.0
10.0
-345
.004
Butterworth
Frequency Response
0
Amp (dB)
-20
-40
-60
-80
-100
0.1
2
1.0
2 3 4 5 6 7
10.0
Normalized Frequency(f/fc)
3 4 5 6 78
Delay
(Normalized)
2.0
Delay (sec)
1.0
0.0
0.1
0.15 2
1.0
1.5
Normalized Frequency(f/fc)
3
4
5 6 7 89
Step Response
Step Response (V/V)
1.2
1.0
0.8
0.6
0.4
0.2
-0.0
0
1
2
3
4
Normalized Time (1/f sec)
5
1.Normalized
Group Delay:
The above delay data is normalized to a corner frequency
of 1.0Hz.The actual delay is the normalized delay divided
by the actual corner frequency (fc).
Normalized Delay
Actual Delay =
Actual Corner Frequency (fc) in Hz
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7
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