Electronic Volume Controller IC

PT2256

Princeton Technology Corp.

Tel : 886-2-29162151

Fax: 886-2-29174598

URL: http://www.princeton.com.tw

PT2256 v1.3

4

Updated Sept. 2000

APPLICATION CIRCUIT

(Including Loudness but No Backup Circuit)

L-C h O utput

R-Ch O utpu t

R -Ch Input

L-C h Inp ut

Rx

Cx

8.2nF

8.2nF

820 O h m s

820 O h m s

820 O h m s

820 O h m s

820 O h m s

100

Note: Modifying the values of Rx and Cx affects the Oscillator Frequency of the IC. If the Fosc value is

big, then the volume control change is fast. Likewise, if the Fosc value is small, the volume control

change is slow. It is suggested that Rx= 33K, Cx = 2.2uF. The table for the Rx, Cx and Fosc values are

given below.

x

Rx

Cc

s

o

Fx

Rx

Cc

s

o

F

K

3

3F

u

0

.

1z

H

1

.

4

3K

3

3F

u

0

.

1z

H

1

.

4

3

K

3

3F

u

2

.

2z

H

8

.

7

1K

1

5F

u

0

.

1z

H

7

.

2

2

K

3

3F

u

0

1z

H

4

.

3K

0

0

1F

u

0

.

1z

H

8

.

1

1