The DS1802 is a dual audio taper-potentiometer manufactured by Dallas Semiconductor . The DS1802 digital potentiometer can be used for replacement of normally resistive mechanical potentiometer .
Each potentiometer provides 65 wiper positions with a 1 dB increment per step and device
mute. The DS1802 digital potentiometer has two methods of device control : pushbutton control and a 3-wire serial interface control for wiper positioning.
Using the pushbutton control inputs is not need a CPU to work while using of the 3-wire serial interface require using a CPU and provides the user the ability of reading or writing exact wiper positions of the two potentiometers.
Using a pushbutton control the DS1802 can also be configured to operate in either independent or “stereo” modes . Independent mode of operation allows for independent wiper control on each potentiometer while the stereo mode operation provides single input control over both potentiometer wiper positions.
This Ds1802 digitally controlled potentiometer circuit will provides only the volume up, volume down, and mute control for the audio signal.
The MAX4167 operational amplifiers connected on each channel output are required in this circuit because the DS1802 has a relatively high wiper (output) resistance and without buffering, the DS1802 can only drive a 1mA load. If the load is capacitive, the high output resistance will cause the attenuator to filter out high frequencies.
For this DS1802 schematic circuit you need to use a DC power supply with an output voltage between 3 and 5 volts (2.7 minimum 5.5 maximum accepted ) .