I'm trying to use digital potentiometers, controlled by an arduino, as drop-in replacements for a number of 10k pots in a circuit in a piece of audio equipment.
I've been looking at datasheets for digital potentiometers, and all the ones I've found will not allow you to control resistance in a circuit with greater voltage than the supply voltage sent to the chip. For instance, the MCP4131 (datasheet here) states maximum voltage at P0A, P0B and P0W (pot terminal 1 2 and wiper) not exceed Vdd + .3v
I had assumed that, digital control aside, a digital potentiometer would operate like a plain one; with a maximum voltage and current that would probably be much higher than what I'd have to worry about (I'll be working with up to 12.5v). I didn't realize the control voltage would be a limiting factor for the voltage going through the potentiometer.
Are there digital potentiometers that allow control of circuits with higher voltage than the control/supply voltages?
If not, what would be the simplest solution for my application? (ie fewest components and connections), find a digital potentiometer allowing Vdd up to 12.5v, and then boost the control signal from the arduino? Something to do with a transistor added to the potentiometer side of the circuit? something that doesn't involve a digital potentiometer at all?