dual audio taper-potentiometer ds1802 used as stereo digital volume control

The DS1802 is a dual audio taper-potentiometer having logarithmic resistive characteristics over the device range. Each potentiometer provides 65 wiper positions with a 1 dB increment per step and device mute. The DS1802 has two methods of device control, which include contact closure (pushbutton) inputs and a 3-wire serial interface for wiper positioning. The pushbutton control inputs provide a simple interface for device control without the need for a CPU. While the 3-wire serial interface, using a CPU, provides the user the ability of reading or writing exact wiper positions of the two potentiometers. The DS1802 can also be configured to operate in either independent or “stereo” modes when using pushbutton control. Independent mode of operation allows for independent wiper control, and stereo mode of operation provides single input control over both potentiometer wiper positions. The DS1802 is offered in commercial temperature versions. Packages for the part include a 20-pin DIP, 20-pin SOIC, and 20-pin TSSOP.

PIN DESCRIPTION
L0, L1 - Low End of Resistor
H0, H1 - High End of Resistor
W1,W2 - Wiper End of Resistor
VCC - 3V/5V Power Supply Input
RST - Serial Port Reset Input
D - Serial Port Data Input
CLK - Serial Port Clock Input
MODE - Mode Select Input
UC0, UC1 - Up Control Pushbutton Inputs
DC0, DC1 - Down Control Pushbutton
Inputs
VU, VD - Volume-Up/Volume-Down
Inputs
B0, B1 - Balance Pot-0, Pot-1 Inputs
GND - Digital Ground
MUTE - Mute
AGND - Analog Ground
ZCEN - Zero-Crossing Detect Input
COUT - Cascade Output


FEATURES

• Ultra-low power consumption
• Operates from 3V or 5V supplies
• Two digitally controlled, 65-position potentiometers including mute
• Logarithmic resistive characteristics (1 dB per step)
• Zero-crossing detection eliminates noise caused by wiper movement
• Digital or mechanical pushbutton wiper control
• Serial port provides means for setting and reading both potentiometers wipers
• 20-pin SOIC and 20-pin TSSOP for surface mount applications
• Operating Temperature Range: -40°C to +85°C
• Software and hardware mute
• Resistance Available: 45