Low-Pass

4-Pole

Appendix A

Butterworth

7

1784 Chessie Lane, Ottawa, IL 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176

e-mail: sales@freqdev.com

(sec)

Normalized Frequency(f/fc)

Normalized Time (1/f sec)

Theoretical Transfer Characteristics

1

Frequency Response

Delay (Normalized)

Step Response

0.1

1.0

10.0

2

3 4 5 6 78

2

3 4 5 6 7

-100

-80

-60

-40

-20

0

0

1

2

3

4

5

-0.0

0.2

0.4

0.6

0.8

1.0

1.2

0.1

1.0

2

3

4

5 6 7 8 9

0.0

1.0

2.0

1.5

0.15

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.85

0.90

0.95

1.00

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

2.25

2.50

2.75

3.00

3.25

3.50

4.00

5.00

6.00

7.00

8.00

9.00

10.0

-62.3

-67.6

-72.2

-76.3

-80.0

-38.2

-41.0

-43.5

-48.2

-55.9

-22.3

-24.1

-28.2

-31.8

-35.1

-12.0

-14.3

-16.4

-18.5

-20.5

-2.21

-3.01

-4.97

-7.24

-9.62

-0.072

-0.243

-0.674

-1.047

-1.555

0.00

0.00

0.00

-0.00

-0.003

-0.017

0.00

-15.0

-30.1

-45.5

-61.4

-78.0

-95.7

-115

-136

-147

-158

-169

-180

-200

-217

-231

-242

-252

-260

-266

-272

-277

-282

-291

-299

-304

-309

-313

-317

-322

-330

-335

-339

-341

-343

-345

.012

.009

.007

.005

.004

.049

.041

.035

.027

.017

.134

.119

.091

.072

.059

.289

.241

.204

.175

.152

.612

.588

.513

.427

.350

.511

.558

.604

.619

.622

.416

.418

.423

.433

.449

.474

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).

Actual Delay =

Normalized Delay

Actual Corner Frequency (fc) in Hz

f/fc

(Hz)

Amp

(dB)

Phase

(deg)

Delay

Normalized Frequency(f/fc)