The DS1868B has two 256-position potentiometers, with wiper positions each set as 8-bit values. The potentiometers can be used independently or stacked for increased total resistance and number of taps. Communication takes place through a 3-wire serial port interface that drives an internal control logic unit. Multiple DS1868s can be linked or daisy-chained for control by a single processor.The DS1868B dual digital potentiometer replaces DS1868, which has been discontinued. The device is designed for flexibility, operating from a single +5V or dual ±3V supply. Maximum standby current is only 2µA.Digital potentiometers improve upon mechanical devices with processor control and programmability, greater reliability and accuracy, and packaging options that facilitate automatic assembly. They are used for signal control in modems and phones, battery charging and control circuitry, tuning and calibration, offset trimming of operational amplifiers, gain control, and power-supply regulation.ApplicationsImpedance MatchingMechanical Potentiometer ReplacementOffset and Gain ControlProgrammable Filters, Delays, Time Constant