900CT Datasheet, PDF (13/19 Pages) Frequency Devices, Inc. – Tunable Active Filter Instrument

8-Pole, 6-Zero
Appendix A
Constant Delay
Low-Pass (80 dB)
Theoretical Transfer Characteristics
Frequency Response
f/fc
Amp Phase Delay1
0
(Hz) (dB) (deg) (sec)
0.00 0.00
0.00 .852
-20
0.10 0.017 -30.7 .852
0.20 0.058 -61.3 .852
-40
0.30 0.099 -92.0 .852
0.40 0.105 -123
.852
-60
0.50 0.034 -153
.852
0.60 -0.157 -184
.852
0.70 -0.510 -215
.852
0.80 -1.07 -245
.851
0.85 -1.44 -261
.850
0.90 -1.89 -276
.849
0.95 -2.41 -291
.846
1.00 -3.01 -306
.841
1.10 -4.50 -336
.821
1.20 -6.39 -365
.783
1.40 -11.3 -417
.656
1.60 -17.1 -459
.512
1.80 -23.2 -492
.396
2.00 -29.1 -517
.312
2.25 -36.3 -542
.239
2.50 -43.4 -561
.189
2.75 -50.3 -576
.153
3.00 -57.6 -589
.127
3.25 -62.5 -599
.107
3.50 -75.4 -608
.092
3.75 -98.3 -616
.079
4.00 -86.3 -442
.069
4.25 -84.1 -448
.061
4.50 -85.1 -454
.054
4.75 -87.9 -458
.049
5.00 -92.8 -462
.044
5.25 -104
-466
.040
5.50 -101
-289
.036
5.75 -93.3 -293
.033
6.00 -89.9 -295
.030
-80
-100
0.1
2 3 4 5 6 78 _1.0 2 3 4 5 6 7 _10.0
Normalized Frequency(f/fc)
Delay (Normalized)
1.0
0.5
0.0
0.1 ^{0.15 2}
3 4 5 6 7 8 9 _1.0 1.5
Normalized Time (1/f sec)
Step Response
1.2
1.0
0.8
6.50 -86.6 -300
.026
0.6
7.00 -85.1 -305
.022
8.00 -84.1 -312
.017
0.4
9.00 -84.3 -317
.013
10.0 -84.9 -321
.011
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
0.2
-0.0
-0.2
0
1
2
3
4
5
Normalized Time (1/f sec)
21
1784 Chessie Lane, Ottawa, IL 61350 • Tel: [phone] • FAX: [phone]
e-mail: [e-mail] ∑Web Address: http://www.freqdev.com ∑