5

510 - 78 - 06

680p

V

CC

2k2

2n2

3µ3

PINK

NOISE

GENERATOR

1n5

2n2

10µ

LIN/LOG

CONVERTER

R

2R

HP

FILTER

+

-

PREAMP

+

-

40K

R

IN14

10K

VOLTAGE

REGULATOR

R

R

14

13

918

15

19

22

24

26

5

7

11

21

20

GND

D

OUT

IN

BUFFER

OUT

BUFFER

IN

+

-

LP

FILTER

LPFB

HP

HPFB

A

OUT

V

CC

P GND

12

LIN/LOG

CONVERTER

0.6 V

0.6V

6

27

OUT

B

68n

TP

B

10K

68n

10n

10n

1

31

30

I

HP

= 1.875 x

I

R

Fig. 6 Low Pass Filter Corner Frequency vs

I

LP

Current

(Note 1) (Fig.4 Test Circuit)

NOTES: 1. Corner frequency calculated in reference to signal at 3 kHz

10k

1k

100

80

0

0.25

0.5

0.75

1

1.25

1.5

1.75

2

NORMALIZED

I

Fig. 5 High Pass Filter Corner Frequency vs

I

(Note 1) (Fig.4 Test Circuit)

10k

1k

700

0

0.25

0.5

0.75

1

1.25

1.5

1.75

2

NORMALIZED

I

Fig. 4 AC Test Circuit for High & Low Pass Filters

All resistors in ohms, all capacitors in

farads, unless otherwise stated.