If you want to replace your mechanical potentiometer, matching line impedance, programming voltage to current conversion in case you need of 4-/6-Channel Digital Potentiometers, maybe AD5204/AD5206 Analog to Digital Converter is device that you are looking for.
These device perform the same function as potentiometer or variable resistor. Its features are 256-position digitally controlled VR device, AD5204 has 4 channel of multiple independently programmable channels and AD5206 has 6 channel and other detailed featured can be found in complete datasheet below. In addition to the detailed features and descriptions, in this datasheet article describes also the operation of these device so that it contains a power shutdown pin (SHDN) that places the RDAC in a zero power consumption state, resulting in only leakage currents being consumed in the VR structure.
You can find section about how to programming variable resistor (rheostat operation), programming potentiometer divider, timing diagrams, sections of digital interfacing, and circuts testing. Download Analog Devices Inc AD5204/AD5206 Analog to Digital Converter Datasheet in 20 pages/399 Kb pdf format (source: analog.com).
