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Electronic Volume Controller IC
PT2256V
DC OUTPUT FOR VOLUME LEVEL
The DC Output for the Volume Level Meter is internally connected to the D/A Converter. PT2256V has
8 stages of output voltage with each stage corresponding to a particular volume level. Please refer to
the table below:
Step
0-3
4-7
Attenuation (dB)
0-6
Output Voltage (V)
7/8 VDD
6/8 VDD
5/8 VDD
4/8 VDD
3/8 VDD
2/8 VDD
1/8 VDD
0
8-14
16-22
24-30
32-38
40-50
54-66
70-∞
8-11
12-15
16-19
20-23
24-27
28-31
UP/DOWN VOLUME CONTROL
PT2256V features two Volume Control Pins, namely: UP and DN. UP is the control pin used to
increase volume level while the DN is the control pin used to decrease the volume level. Thus, volume
level may regulated using the Up or Down Keys. These keys are operated on a 1 step/1 push volume
level control when UP or DN keys are set to “L” Level. If the keys are continuously pressed (input
“Low”), then the volume level continuously steps up or down as the case maybe. Please refer to the
diagram below for the timing of the key input.
/UP, /DN Input
Volume Level
Control
t
T
Notes:
1. t= Preventive Time for Chattering (2.2 x 1/fosc )
2. T= Switching Time to Automatic Mode (10 x 1/fosc)
3. a=Up, Down Speed (2x1/fosc)
PT2256V V1.2
- 5 -
August, 2006
PTC [ PRINCETON TECHNOLOGY CORP ]
