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Electronic Volume Controller IC
PT2256V
APPLICATION CIRCUIT
SINGLE POWER SUPPLY (NO LOUDNESS AND NO BACKUP CIRCUIT)
VDD (4.5 to 11V)
0.1µF
VDD
OUT1 OUT2
VSS
+
+
+
+
10
10
µ
µ
F
F
10
10
µ
µ
F
F
L-Ch Output
L-Ch Input
R-Ch Output
R-Ch Input
IN1
LT1
IN2
LT3
3.9K
3.9K
AGND
DCO
/INH
AGND
/UP
UP Key
Down Key
10K
100K
/DN
Rx
/RST
OSC
+
0.1µF
+
100µF
PT2256V
Cx
10K
Notes:
1. 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=2.2µF.
2. The table for the Rx, Cx and Fosc values are given below:
Rx
Cx
Fosc
34.1Hz
17.8Hz
3.4Hz
Rx
33K
51K
100K
Cx
Fosc
33K
33K
33K
1.0µF
2.2µF
10µF
1.0µF
1.0µF
1.0µF
34.1Hz
22.7Hz
11.8Hz
PT2256V V1.2
- 10 -
August, 2006
PTC [ PRINCETON TECHNOLOGY CORP ]
